2024 06 27 debugging aws sam template deployment access denied errors on resources - bizkite-co/handterm GitHub Wiki

original file name: Codeium Chat - rdplr0aS0F9TLxTKdCuFoKGuPH4UDw01.md summary: The user needs help debugging their AWS SAM application template deployment. They provided a SAM template that includes resources like Cognito User Pool, Identity Pool, S3 bucket, Lambda function with Lambda execution role, and deployment command. The user, named Mark, also shared a list of attached user policies and an error log indicating a "CREATE_FAILED" status for the S3 bucket policy and Lambda function creation during deployment, with an "Access Denied" error.

I provided guidance on potential causes of the "Access Denied" error, including checking S3 bucket block public access settings, verifying permissions, ensuring unique bucket names, and reviewing CloudFormation execution role permissions. As the bucket didn't exist, I suggested checking for AWS Organization policies, deployment region settings, manual policy application, CloudFormation service role permissions, and AWS account support and limits.

The user confirmed that the bucket does not exist, ruling out pre-existing policy issues. Further troubleshooting steps were suggested based on the new information and potential causes of the deployment error. date: 2024-06-27T17:32

Codeium Chat Conversation

Note: This is purely the output of the chat conversation and does not contain any raw data, codebase snippets, etc. used to generate the output.

User at 5:32 pm, Jun 27, 2024

I need your help debugging this AWS SAM app template

AWSTemplateFormatVersion: '2010-09-09'
Transform: AWS::Serverless-2016-10-31
Description: Example SAM template for HandTerm application.

Globals:
 Function:
  Timeout: 5

Resources:
 CognitoUserPool:
  Type: AWS::Cognito::UserPool
  Properties:
   UserPoolName: HandTermUserPool
   Schema:
    - Name: email
     Required: true
     Mutable: false
   Policies:
    PasswordPolicy:
     MinimumLength: 8
     RequireUppercase: true
     RequireLowercase: true
     RequireNumbers: true
     RequireSymbols: true

 CognitoUserPoolClient:
  Type: AWS::Cognito::UserPoolClient
  Properties:
   UserPoolId: !Ref CognitoUserPool
   ExplicitAuthFlows:
    - ALLOW_USER_SRP_AUTH
    - ALLOW_REFRESH_TOKEN_AUTH
   GenerateSecret: false

 HandTermIdentityPool:
  Type: AWS::Cognito::IdentityPool
  Properties:
   IdentityPoolName: HandTermIdentityPool
   AllowUnauthenticatedIdentities: false
   CognitoIdentityProviders:
    - ClientId: !Ref CognitoUserPoolClient
     ProviderName: !GetAtt CognitoUserPool.ProviderName

 HandTermHistoryBucket:
  Type: AWS::S3::Bucket
  Properties:
   BucketName: handterm-history

 HandTermHistoryBucketPolicy:
  Type: AWS::S3::BucketPolicy
  Properties:
   Bucket: !Ref HandTermHistoryBucket
   PolicyDocument:
    Version: "2012-10-17"
    Statement:
     - Sid: PublicReadGetObject
      Effect: Allow
      Principal: "*"
      Action: "s3:GetObject"
      Resource: !Sub "arn:aws:s3:::handterm-history/*"

 LambdaExecutionRole:
  Type: AWS::IAM::Role
  Properties:
   AssumeRolePolicyDocument:
    Version: 2012-10-17
    Statement:
     - Effect: Allow
      Principal:
       Service:
        - lambda.amazonaws.com
        - edgelambda.amazonaws.com
      Action: sts:AssumeRole
   Policies:
    - PolicyName: LambdaS3Access
     PolicyDocument:
      Version: 2012-10-17
      Statement:
       - Effect: Allow
        Action: s3:*
        Resource: !Sub arn:aws:s3:::handterm-history/*

 LambdaAtEdgeFunction:
  Type: AWS::Serverless::Function
  Properties:
   Handler: index.handler
   Runtime: nodejs20.x
   CodeUri: http-only-cookies
   Description: A Lambda@Edge function for HttpOnly Cookies
   MemorySize: 128
   Role: !GetAtt LambdaExecutionRole.Arn
   # Note: Lambda@Edge does not support the usual Events property for triggering
   # You will need to manually attach this function to a CloudFront distribution

Outputs:
 UserPoolId:
  Value: !Ref CognitoUserPool
  Description: The ID of the Cognito User Pool
 UserPoolClientId:
  Value: !Ref CognitoUserPoolClient
  Description: The ID of the Cognito User Pool Client
 HandTermIdentityPoolId:
  Value: !Ref HandTermIdentityPool
  Description: The ID of the Cognito Identity Pool
 HandTermHistoryBucketName:
  Value: !Ref HandTermHistoryBucket
  Description: The name of the S3 bucket for storing user history
  

I have these permissions:

[17:30:48]❯ aws iam list-attached-user-policies --user-name mark --profile mark                   
- AttachedPolicies:
 - PolicyArn: arn:aws:iam::aws:policy/CloudFrontFullAccess
  PolicyName: CloudFrontFullAccess
 - PolicyArn: arn:aws:iam::aws:policy/AmazonEC2FullAccess
  PolicyName: AmazonEC2FullAccess
 - PolicyArn: arn:aws:iam::aws:policy/AWSCodeCommitFullAccess
  PolicyName: AWSCodeCommitFullAccess
 - PolicyArn: arn:aws:iam::aws:policy/AmazonECS_FullAccess
  PolicyName: AmazonECS_FullAccess
 - PolicyArn: arn:aws:iam::aws:policy/CloudWatchFullAccess
  PolicyName: CloudWatchFullAccess
 - PolicyArn: arn:aws:iam::aws:policy/AmazonS3FullAccess
  PolicyName: AmazonS3FullAccess
 - PolicyArn: arn:aws:iam::aws:policy/AdministratorAccess-AWSElasticBeanstalk
  PolicyName: AdministratorAccess-AWSElasticBeanstalk
 - PolicyArn: arn:aws:iam::aws:policy/AWSLambda_FullAccess
  PolicyName: AWSLambda_FullAccess
 - PolicyArn: arn:aws:iam::aws:policy/AWSIQFullAccess
  PolicyName: AWSIQFullAccess
 - PolicyArn: arn:aws:iam::318364255844:policy/aws-elasticbeanstalk-sample-role-policy
  PolicyName: aws-elasticbeanstalk-sample-role-policy
 IsTruncated: false

And I use this to do the deployment:

 sam deploy --template-file template.yaml --stack-name handterm-sam --capabilities CAPABILITY_IAM --debug

Codeium at 5:33 pm, Jun 27, 2024

Based on the SAM template and permissions you've provided, it seems like you have a well-structured AWS SAM application that defines a Cognito User Pool, User Pool Client, Identity Pool, an S3 bucket with a policy, and a Lambda function along with a Lambda execution role. Your IAM permissions also appear to cover the necessary AWS services involved in this SAM template, such as CloudFront, EC2, CodeCommit, ECS, CloudWatch, S3, Elastic Beanstalk, and Lambda.

However, without a specific error message or description of the problem you're encountering during the deployment, it's challenging to pinpoint exactly what could be going wrong. Here are some general troubleshooting tips:

  1. Check CloudFormation Stack Events: After running the sam deploy command, go to the AWS CloudFormation console and check the events for the handterm-sam stack. Look for any events marked as CREATE_FAILED to identify resources that failed to deploy and the error messages associated with them.

  2. IAM Permissions: Your attached user policies seem to cover the necessary services used in your SAM template. However, ensure that the execution role (LambdaExecutionRole) has the necessary permissions for any actions that the Lambda function intends to perform, especially if it interacts with services not explicitly listed in your IAM permissions. Since your function interacts with S3, the s3:* permission in the LambdaS3Access policy should suffice for S3 actions.

  3. Lambda@Edge Considerations: Deploying Lambda@Edge functions involves more considerations than standard AWS Lambda functions. Make sure the Lambda@Edge function (LambdaAtEdgeFunction) is deployed to the us-east-1 region, as Lambda@Edge requires this. Additionally, ensure that the IAM role (LambdaExecutionRole) associated with the Lambda@Edge function includes trust relationships with edgelambda.amazonaws.com and lambda.amazonaws.com, which your template already does.

  4. Resource Names and References: Verify that all resource references in the SAM template are correct and that there are no typos or incorrect references. For example, make sure that !Ref and !GetAtt functions are used correctly to reference resources and their attributes.

  5. SAM and AWS CLI Versions: Ensure that the AWS SAM CLI and AWS CLI are up to date. Outdated versions can sometimes cause deployment issues due to incompatibilities or missing features.

  6. Deployment Command: The deployment command you're using looks correct. The --capabilities CAPABILITY_IAM flag is necessary to allow CloudFormation to create IAM roles on your behalf.

    sam deploy --template-file template.yaml --stack-name handterm-sam --capabilities CAPABILITY_IAM --debug

    The --debug flag is useful as it provides more detailed output about the deployment process, which can help in identifying issues.

If you encounter a specific error during deployment, providing the error message would be helpful in diagnosing the problem further.

User at 5:33 pm, Jun 27, 2024

This is the error I forgot to include in my previous message:

2024-06-27 17:29:37,238 | Skip previous event as time_stamp_marker: 2024-06-28 00:29:32.329000 is after the event time stamp: 2024-06-28 00:29:32.329000+00:00
2024-06-27 17:29:37,240 | Exit from the describe event loop
CREATE_IN_PROGRESS             AWS::S3::BucketPolicy           HandTermHistoryBucketPolicy        Resource creation Initiated
CREATE_FAILED               AWS::S3::BucketPolicy           HandTermHistoryBucketPolicy        Resource handler returned message:
                                                                 "Access Denied (Service: S3, Status
                                                                 Code: 403, Request ID: PEN7Z1JF7RXEEB4H,    
                                                                 Extended Request ID: bCommURIeW8vQnSbbuu    
                                                                 17XdrDTnIFLKXYAoTuizp6R80gjDkHdug+4WM2pt    
                                                                 BuKscGez3Ch4+et8=)" (RequestToken:
                                                                 d9706330-1649-e901-a5f5-9a1fba154d72,
                                                                 HandlerErrorCode: AccessDenied)
CREATE_FAILED               AWS::Lambda::Function           LambdaAtEdgeFunction            Resource creation cancelled
ROLLBACK_IN_PROGRESS            AWS::CloudFormation::Stack         handterm-sam                The following resource(s) failed to
                                                                 create: [LambdaAtEdgeFunction,
                                                                 HandTermHistoryBucketPolicy]. Rollback     
                                                                 requested by user.
DELETE_IN_PROGRESS             AWS::S3::BucketPolicy           HandTermHistoryBucketPolicy        -
DELETE_IN_PROGRESS             AWS::Cognito::IdentityPool         HandTermIdentityPool            -
DELETE_IN_PROGRESS             AWS::Lambda::Function           LambdaAtEdgeFunction            -
DELETE_COMPLETE              AWS::S3::BucketPolicy           HandTermHistoryBucketPolicy        -
DELETE_COMPLETE              AWS::Cognito::IdentityPool         HandTermIdentityPool            -
2024-06-27 17:29:37,254 | Trial # 0 to get the stack handterm-sam create events

Codeium at 5:34 pm, Jun 27, 2024

The error message you received during the deployment of your AWS SAM application indicates a failure to create the HandTermHistoryBucketPolicy resource due to an "Access Denied" error. This error prevented the LambdaAtEdgeFunction resource from being created as well, leading to a rollback of the CloudFormation stack. Here are some possible reasons for this error and suggestions on how to resolve it:

Potential Causes and Solutions

  1. S3 Bucket Ownership and Policy Permissions:

    • Ensure that the AWS account you are using to deploy the CloudFormation stack has sufficient permissions to create bucket policies in S3. Even though you have AmazonS3FullAccess, certain restrictions or service control policies (SCPs) might override these permissions in your AWS environment.

  2. Block Public Access Settings:

    • S3 buckets have block public access settings that can prevent the application of bucket policies that grant public access. Since your bucket policy includes a statement allowing public read access (Principal: "*") to objects in the bucket, these settings might be blocking the policy application.
    • Check the S3 bucket's block public access settings in the AWS Management Console and ensure that they are configured to allow the application of your bucket policy.

  3. Bucket Policy Content:

    • Double-check the content of your HandTermHistoryBucketPolicy to ensure there are no syntax errors and that the policy is structured correctly. However, based on the template you provided, the policy syntax seems correct.

  4. Pre-existing Bucket or Policy:

    • If the bucket name handterm-history is already in use or was previously created with different permissions or by another account, there might be conflicts preventing the policy from being applied. Ensure the bucket name is unique and not in use elsewhere, or if it is a pre-existing bucket, ensure that its settings and permissions are compatible with the policy you're trying to apply.

  5. Execution Role Permissions:

    • The execution role used by CloudFormation to create these resources must have permissions to create and apply S3 bucket policies. While your user has AmazonS3FullAccess, ensure the CloudFormation execution role also has the necessary permissions if you're using a role with more restricted permissions.

Steps to Resolve

  • Verify that the account has the necessary permissions and that there are no SCPs or permission boundaries limiting your actions.
  • Check and adjust the S3 bucket's block public access settings to allow your bucket policy.
  • Ensure the S3 bucket name is unique or that you have full control over it if it already exists.
  • If necessary, modify the bucket policy to align with your organization's security policies, possibly removing the public access part if it conflicts with intended security practices.

Given the error is specifically with S3 bucket policy creation and mentions "Access Denied", starting with the S3 bucket's settings and the permissions of the account or role performing the deployment are likely the best steps forward.

User at 5:35 pm, Jun 27, 2024

THe bucket does not exist and so cannot have pre-existing policy:

[17:34:51]❯ aws s3api get-public-access-block --bucket handterm-history --profile mark

An error occurred (NoSuchBucket) when calling the GetPublicAccessBlock operation: The specified bucket does not exist
handex-react\handterm-sam on ξ‚  master [$✘!+?] on ☁️ (us-west-1) 

Codeium at 5:36 pm, Jun 27, 2024

Given that the bucket handterm-history does not exist and therefore cannot have a pre-existing policy or public access block settings causing the issue, the "Access Denied" error during the CloudFormation deployment suggests a different issue related to permissions or AWS service behavior.

Considering this new information, let's explore other avenues:

  1. Permissions to Create Bucket Policies:

    • Even though your IAM user has AmazonS3FullAccess, this does not automatically translate to permissions to apply any bucket policy, especially if the policy allows public access. AWS has additional safeguards in place for policies that grant public or wide access.
    • Review any possible SCPs (Service Control Policies) applied at the AWS Organization level or any permission boundaries set on your IAM user that might restrict the application of public policies.

  2. Deployment Region:

    • The error might be related to the region in which you're trying to deploy the CloudFormation stack. Ensure that your AWS CLI or SAM CLI is configured to deploy resources in the intended region. Since Lambda@Edge functions are globally replicated from the us-east-1 region, deploying a stack involving Lambda@Edge might have specific regional considerations.
    • Verify your SAM CLI and AWS CLI configuration to ensure the deployment region aligns with your intentions and requirements, especially concerning Lambda@Edge.

  3. Manual Policy Application:

    • As a troubleshooting step, try manually creating the bucket and applying the policy using the AWS Management Console or AWS CLI. This can help determine if the issue is with the CloudFormation execution context or a broader permissions issue.
    • If you can manually create the bucket and apply the policy, the issue may be related to how CloudFormation is executing the deployment.

  4. CloudFormation Service Role:

    • If you're using a service role for CloudFormation (specified with --role-arn during deployment), ensure that role has the necessary permissions to create S3 buckets and apply policies.
    • If not using a specific service role, CloudFormation uses the permissions of the user calling the sam deploy command. Ensure no other policies or session policies limit your effective permissions.

  5. Review AWS Support and Limits:

    • If your AWS account is new or has certain restrictions, there might be limits on creating public-facing resources without additional verification. Review any emails or notifications from AWS Support regarding account status and service limits.

  6. Retry Deployment with Detailed Logging:

    • Consider enabling detailed AWS CloudTrail logs to capture the API calls made during deployment. This can provide insights into which specific action is being denied and why.

  7. Consult AWS Support:

    • If the issue persists and is not clearly related to IAM permissions, SCPs, or account restrictions, consider opening a support case with AWS. This is particularly relevant if the error message does not accurately reflect the root cause or if there seems to be a service-specific behavior or limit impacting your deployment.

Given the complexity of AWS permissions and service interactions, the cause of "Access Denied" errors can sometimes be non-obvious and require a process of elimination to diagnose.

User at 5:37 pm, Jun 27, 2024

Can you express each of the checks you listed above in terms of AWS CLI commands?

Codeium at 5:38 pm, Jun 27, 2024

Certainly! Here are the checks expressed in terms of AWS CLI commands. Keep in mind that you might need to adjust some of the placeholders (like region names, profile names, etc.) to fit your specific AWS configuration and environment.

  1. Review IAM Policies: Check the effective policies attached to your IAM user. This command lists the policies attached directly to a user.

    aws iam list-attached-user-policies --user-name USERNAME --profile PROFILE_NAME

  2. Check AWS CLI Configuration (Region): View your current AWS CLI configuration, paying close attention to the default region, as it affects where resources are deployed.

    aws configure list --profile PROFILE_NAME

    Ensure your region is set correctly, especially when working with Lambda@Edge, which requires the us-east-1 region for certain operations.

  3. Manually Create S3 Bucket and Apply Policy: First, create the S3 bucket.

    aws s3api create-bucket --bucket BUCKET_NAME --region REGION_NAME --create-bucket-configuration LocationConstraint=REGION_NAME --profile PROFILE_NAME

    Then, apply the bucket policy. Make sure to replace POLICY_DOCUMENT with the actual JSON string of your policy.

    aws s3api put-bucket-policy --bucket BUCKET_NAME --policy POLICY_DOCUMENT --profile PROFILE_NAME

  4. Check Service Control Policies (SCPs): This requires AWS Organizations and you need permissions to list SCPs. This command lists all policies in your organization.

    aws organizations list-policies --filter SERVICE_CONTROL_POLICY --profile PROFILE_NAME

    Note: Interpreting the results and identifying specific SCPs that might affect your operations requires a deeper dive into the JSON output and may involve additional commands to inspect individual policies.

  5. CloudFormation Service Role Permissions: If using a specific service role for CloudFormation deployments, check the attached policies of the role.

    aws iam list-attached-role-policies --role-name ROLE_NAME --profile PROFILE_NAME

    This command lists the policies attached to a specific IAM role. You'll need to replace ROLE_NAME with the name of your CloudFormation service role.

  6. Enable Detailed CloudTrail Logging: To start logging with CloudTrail, you must ensure a trail is created and running.

    • List existing trails: 
      aws cloudtrail describe-trails --profile PROFILE_NAME
    • If needed, create a new trail and start logging: 
      aws cloudtrail create-trail --name TRAIL_NAME --s3-bucket-name BUCKET_NAME_FOR_LOGS --profile PROFILE_NAME
aws cloudtrail start-logging --name TRAIL_NAME --profile PROFILE_NAME

  7. Consult AWS Support: If you have AWS Support enabled:

    • To create a support case, the AWS Support CLI must be used, which is separate from the standard AWS CLI and requires a support plan.
    • Detailed steps would vary based on the issue and available support plans, so refer to the AWS Support CLI documentation for specific commands.

Remember to replace USERNAME, PROFILE_NAME, REGION_NAME, BUCKET_NAME, POLICY_DOCUMENT, and ROLE_NAME with your actual user name, AWS CLI profile name, region, bucket name, policy details in JSON format, and role name respectively. Some commands may require additional permissions or adjustments based on your AWS account setup and the resources you're working with.

User at 5:40 pm, Jun 27, 2024

I already ran this and posted this, with the correct names, to this conversation, but here it is again:

πŸ•[17:38:55]❯ aws iam list-attached-user-policies --user-name mark --profile mark
- AttachedPolicies:
 - PolicyArn: arn:aws:iam::aws:policy/CloudFrontFullAccess
  PolicyName: CloudFrontFullAccess
 - PolicyArn: arn:aws:iam::aws:policy/AmazonEC2FullAccess
  PolicyName: AmazonEC2FullAccess
 - PolicyArn: arn:aws:iam::aws:policy/AWSCodeCommitFullAccess
  PolicyName: AWSCodeCommitFullAccess
 - PolicyArn: arn:aws:iam::aws:policy/AmazonECS_FullAccess
  PolicyName: AmazonECS_FullAccess
 - PolicyArn: arn:aws:iam::aws:policy/CloudWatchFullAccess
  PolicyName: CloudWatchFullAccess
 - PolicyArn: arn:aws:iam::aws:policy/AmazonS3FullAccess
  PolicyName: AmazonS3FullAccess
 - PolicyArn: arn:aws:iam::aws:policy/AdministratorAccess-AWSElasticBeanstalk
  PolicyName: AdministratorAccess-AWSElasticBeanstalk
 - PolicyArn: arn:aws:iam::aws:policy/AWSLambda_FullAccess
  PolicyName: AWSLambda_FullAccess
 - PolicyArn: arn:aws:iam::aws:policy/AWSIQFullAccess
  PolicyName: AWSIQFullAccess
 - PolicyArn: arn:aws:iam::318364255844:policy/aws-elasticbeanstalk-sample-role-policy
  PolicyName: aws-elasticbeanstalk-sample-role-policy
 IsTruncated: false

Codeium at 5:40 pm, Jun 27, 2024

Thank you for clarifying and reposting the information regarding your IAM permissions. Given these permissions, your IAM user mark appears to have a broad set of permissions that should typically allow for the creation and modification of AWS resources, including S3 buckets and policies, which are relevant to the task at hand.

Given the permissions listed, the Access Denied error you're encountering during the deployment of your AWS SAM application seems unlikely to be directly related to the permissions of the IAM user mark. However, since the error occurred specifically when trying to create the S3 bucket policy, we need to consider other factors that might cause this, even when permissions appear sufficient.

Reflecting on the original error and the permissions you've shared, let's narrow down the possible causes:

  • The error may not stem from the permissions of the IAM user but from how the S3 service interprets the attempt to apply a public access policy, given the current account settings or the configuration of the AWS environment.
  • Since the bucket doesn't pre-exist, as you've confirmed, the issue isn't with pre-existing bucket settings. However, AWS has global settings for accounts regarding public access to S3 buckets. The S3 Block Public Access settings at the account level could still be preventing the application of your bucket policy, even if the specific bucket doesn't exist yet.

Given this, one step worth trying, if you haven't already, is to explicitly check the S3 Block Public Access settings at the account level:

aws s3control get-public-access-block --account-id ACCOUNT_ID --profile mark

Replace ACCOUNT_ID with your AWS account ID. If these settings block public access, they could prevent the application of a bucket policy that grants public read access, resulting in an Access Denied error during stack deployment.

If you find that the public access block settings are indeed the cause, and if it aligns with your organization's security policies to modify these settings, you can adjust them accordingly. However, please proceed with caution and ensure that allowing public access to S3 resources conforms to your application's security requirements and organizational policies.

Given the complexity of AWS service interactions and the specificity of error messages, if adjusting the S3 Block Public Access settings doesn't resolve the issue, or if it's not feasible to change these settings due to security policies, it may be beneficial to reach out to AWS Support for direct assistance. They can provide more detailed insight into service-specific behaviors and account-specific configurations that might be influencing the deployment process.

User at 5:41 pm, Jun 27, 2024

[17:39:10]❯ aws configure list --profile mark     
   Name          Value       Type  Location
   ----          -----       ----  --------
  profile           mark      manual  --profile
access_key   ****************7Z7Q shared-credentials-file
secret_key   ****************zIMT shared-credentials-file
  region        us-west-2   config-file  ~/.aws/config

This is the profile information.

Does any of this narrow things down?

Codeium at 5:41 pm, Jun 27, 2024

Given the profile information you provided, it's clear that your AWS CLI operations are being executed under the us-west-2 region as specified by your configuration settings. This regional setting is crucial because AWS resources, including CloudFormation stacks, are region-specific. However, for most operations, including the creation of S3 buckets and applying policies, the region defined in your AWS CLI configuration should not directly cause "Access Denied" errors, as S3 is a global service and the policies are applied at the bucket level, not at the region level.

The "Access Denied" error during the CloudFormation operation related to the S3 bucket policy could still be influenced by several factors not directly tied to the region setting in your AWS CLI profile:

  1. S3 Block Public Access Settings at the Account Level: Even though your CLI operations are scoped to us-west-2, if your AWS account has S3 Block Public Access settings enabled at the account level, these settings would apply globally across all regions. This could prevent the application of bucket policies that allow public access.

  2. Permission Boundaries or Service Control Policies (SCPs): If your account is part of an AWS Organization, SCPs applied at the organizational level could restrict certain actions regardless of the individual IAM permissions. Similarly, permission boundaries applied to your IAM user or role could also limit the actions you can perform, even if your IAM policies suggest otherwise.

  3. Bucket Policy Application in CloudFormation: The error could be related to the timing or the specifics of how CloudFormation attempts to apply the bucket policy. For example, if there's a policy check that fails due to AWS-wide public access prevention settings, this could result in the observed error.

Given these considerations, here are a few additional steps to help narrow down the issue:

  • Verify S3 Block Public Access Settings at the Account Level: Check the account-level public access block settings to ensure they're not preventing the application of your bucket policy.

    aws s3control get-public-access-block --account-id ACCOUNT_ID --profile mark

    Replace ACCOUNT_ID with your actual AWS account ID. If these settings are restrictive, they could be the cause of the issue.

  • Review Organizational Policies: If your account is part of an AWS Organization, review any SCPs that are in place to ensure they do not restrict the creation of public S3 bucket policies.

  • Manual Bucket Policy Application: As a diagnostic step, try manually creating an S3 bucket and applying the policy in question using the AWS CLI or Management Console in the us-west-2 region. This can help determine if the issue is specific to CloudFormation or a broader permissions issue.

Given the information and the steps you've already taken, if the issue persists, it may be beneficial to engage AWS Support for a deeper investigation, especially since your IAM permissions and CLI configuration do not immediately reveal the cause of the "Access Denied" error for the S3 bucket policy operation.

User at 5:44 pm, Jun 27, 2024

I don't see a public access block policy, and the template is not even trying to grant public access.

πŸ•[17:40:29]❯ aws s3control get-public-access-block --account-id 318364255844 --profile mark

An error occurred (NoSuchPublicAccessBlockConfiguration) when calling the GetPublicAccessBlock operation: The public access block configuration was not found

Codeium at 5:44 pm, Jun 27, 2024

Given the absence of a Public Access Block configuration at the account level and the clarification that your template does not attempt to grant public access (my apologies for the oversight), we can rule out public access settings as the cause of the "Access Denied" error for the S3 bucket policy.

At this point, considering the provided information and outcomes:

  1. IAM Permissions: Your IAM user has extensive permissions, including AmazonS3FullAccess, which should typically suffice for the operations attempted in your CloudFormation template.

  2. Region Configuration: The AWS CLI profile is correctly configured for the us-west-2 region, which aligns with your intentions and should not impact the ability to create S3 bucket policies unless there are region-specific restrictions or configurations at play, which is uncommon for S3.

  3. Public Access Block: The account does not have a Public Access Block configuration that would prevent bucket policy operations, and your template does not attempt to configure public access for the bucket.

Given these points, the "Access Denied" error during the CloudFormation operation is puzzling. Here are a few additional considerations and steps you might take:

Further Troubleshooting Steps

  • CloudFormation Role: If you're using a specific role for CloudFormation operations (specified in the deployment command or in the AWS Console), ensure that this role has the necessary permissions. The role would need permissions not only for S3 but also for any other resources being created or modified by the template.

  • Resource Conflicts: Although you've indicated the bucket does not pre-exist, ensure there are no conflicting resources or policies at an organizational level or within the service that might affect the operation. This includes checking for any Service Control Policies (SCPs) if your account is part of an AWS Organization.

  • Detailed Error Logging: Use AWS CloudTrail to review the detailed error message associated with the failed operation. CloudTrail logs can provide more context on the source of the "Access Denied" error, including the specific operation and any associated resource or policy that caused the denial.

  • Manual Resource Creation and Policy Application: Attempt to manually create the resources defined in the CloudFormation template using the AWS CLI or AWS Management Console, applying the same configurations as specified in the template. This can help identify if the issue is specific to CloudFormation's execution context or a broader permissions issue.

  • AWS Support: Given the complexity of the situation and the steps already taken to diagnose the issue, consider contacting AWS Support. AWS Support can provide access to logs and details that are not otherwise available, offering insights into the specific cause of the "Access Denied" error.

Final Consideration

Ensure that there are no typos or errors in the Account ID, resource names, or policy documents within your CloudFormation template that could inadvertently lead to permissions issues. Even minor mistakes can sometimes lead to unexpected behavior during deployment.

Given the information at hand, without additional specific error details or the ability to review detailed service logs, these steps represent a comprehensive approach to diagnosing and potentially resolving the issue.

User at 5:46 pm, Jun 27, 2024

What if we changed this so that it only allowed S3 access through the IdentityPool?

 HandTermHistoryBucketPolicy:
  Type: AWS::S3::BucketPolicy
  Properties:
   Bucket: !Ref HandTermHistoryBucket
   PolicyDocument:
    Version: "2012-10-17"
    Statement:
     - Sid: PublicReadGetObject
      Effect: Allow
      Principal: "*"
      Action: "s3:GetObject"
      Resource: !Sub "arn:aws:s3:::handterm-history/*"

Codeium at 5:46 pm, Jun 27, 2024

To modify the S3 bucket policy so that it only allows access via the Identity Pool, you need to change the principal from "*" (which allows access from anyone) to use the specific Identity Pool ARN. This change ensures that only authenticated users from the Cognito Identity Pool can access the S3 bucket.

Here is how you can adjust the HandTermHistoryBucketPolicy in your SAM template:

HandTermHistoryBucketPolicy:
  Type: AWS::S3::BucketPolicy
  Properties:
    Bucket: !Ref HandTermHistoryBucket
    PolicyDocument:
      Version: "2012-10-17"
      Statement:
        - Sid: AuthenticatedReadAccess
          Effect: Allow
          Principal:
            AWS: 
              - !Sub "arn:aws:iam::${AWS::AccountId}:role/Cognito_HandTermIdentityPoolAuth_Role"
              - !Sub "arn:aws:iam::${AWS::AccountId}:role/Cognito_HandTermIdentityPoolUnauth_Role"
          Action: "s3:GetObject"
          Resource: !Sub "arn:aws:s3:::handterm-history/*"

This policy snippet assumes you have two IAM roles associated with your Cognito Identity Pool: one for authenticated users (Cognito_HandTermIdentityPoolAuth_Role) and another for unauthenticated users (Cognito_HandTermIdentityPoolUnauth_Role). These roles are typically created and associated with your Identity Pool to define permissions for users based on their authentication status.

If your setup only involves authenticated access (which is common for many applications), you might only need to include the role for authenticated users. Make sure to replace Cognito_HandTermIdentityPoolAuth_Role and Cognito_HandTermIdentityPoolUnauth_Role with the actual role names that you have configured in your Identity Pool.

Important Notes:

  • Ensure that the IAM roles (Cognito_HandTermIdentityPoolAuth_Role and Cognito_HandTermIdentityPoolUnauth_Role) have the necessary permissions to access the S3 bucket as intended.
  • If your application does not require unauthenticated access, you may remove or not include the role for unauthenticated users to tighten security.
  • The ARN structure used in the Principal field (!Sub "arn:aws:iam::${AWS::AccountId}:role/ROLE_NAME") dynamically inserts your AWS account ID and uses the role names you've specified. This approach helps make the template more portable and adaptable to different AWS environments.

By using this configuration, you're effectively restricting access to the S3 bucket to only the users who authenticate through your Identity Pool, enhancing the security of your application by ensuring only authorized users can access the content.

User at 6:08 pm, Jun 27, 2024

What if I just try creating the S3 bucket from the command line?

I might get a more revealing error message then. Then I could also try applying the policy from the cli.

What would the command to create the bucket be?

Codeium at 6:08 pm, Jun 27, 2024

Creating an S3 bucket from the command line using the AWS CLI is straightforward. Here's the basic command to create an S3 bucket:

aws s3 mb s3://BUCKET-NAME --region REGION-NAME --profile PROFILE-NAME

You need to replace BUCKET-NAME with your desired bucket name, REGION-NAME with the AWS region you want to create the bucket in (for example, us-west-2), and PROFILE-NAME with the name of your AWS CLI profile (in this case, mark).

For example, if you wanted to create a bucket named handterm-history in the us-west-2 region using the mark profile, the command would be:

aws s3 mb s3://handterm-history --region us-west-2 --profile mark

This command will attempt to create the bucket. If there are any errors or restrictions preventing the bucket from being created (such as name conflicts, permission issues, or region-specific constraints), the AWS CLI will provide an error message that can help in diagnosing the problem.

After successfully creating the bucket, you can then attempt to apply the policy. Here's a template command to apply a bucket policy:

aws s3api put-bucket-policy --bucket BUCKET-NAME --policy file://path/to/policy.json --profile PROFILE-NAME

For this, you will need to have your policy defined in a JSON file at the specified path (path/to/policy.json). Make sure the policy JSON is correctly formatted and reflects your intended access permissions. Replace BUCKET-NAME with your bucket name and PROFILE-NAME with your profile name (mark).

Creating the bucket and then applying the policy via the CLI can indeed provide more detailed error messages, especially if you encounter issues during these operations. These steps can be very helpful in isolating and understanding any problems with your AWS configuration or permissions.

User at 6:09 pm, Jun 27, 2024

I had no problem creating the bucket:

[18:03:26]❯ aws s3 mb s3://handterm-history --region us-east-1 --profile mark
make_bucket: handterm-history

Codeium at 6:10 pm, Jun 27, 2024

That's great news! Successfully creating the bucket means there were no issues with your AWS CLI configuration, bucket naming conflicts, or permissions related to bucket creation under your profile.

The next step is to apply the bucket policy. Since you're considering adjusting the policy to allow access through the Identity Pool, make sure you have the policy correctly defined in a JSON file. If you're proceeding with the policy to restrict access to users authenticated through your Cognito Identity Pool, ensure your policy file reflects this.

Here's a reminder of how you can apply the bucket policy:

  1. Prepare your policy JSON file with the necessary permissions. For example, if you're specifying access only through the Identity Pool, your policy.json might look something like this:
{
  "Version": "2012-10-17",
  "Statement": [
    {
      "Sid": "AuthenticatedReadAccess",
      "Effect": "Allow",
      "Principal": {
        "AWS": [
          "arn:aws:iam::ACCOUNT-ID:role/Cognito_HandTermIdentityPoolAuth_Role",
          "arn:aws:iam::ACCOUNT-ID:role/Cognito_HandTermIdentityPoolUnauth_Role"
        ]
      },
      "Action": "s3:GetObject",
      "Resource": "arn:aws:s3:::handterm-history/*"
    }
  ]
}

Make sure to replace ACCOUNT-ID with your actual AWS account ID, and adjust the role ARNs to match the roles associated with your Cognito Identity Pool.

  1. Apply the bucket policy using the AWS CLI:
aws s3api put-bucket-policy --bucket handterm-history --policy file://path/to/your/policy.json --profile mark

Replace path/to/your/policy.json with the actual path to your policy file.

By applying the policy via the CLI, you might encounter specific error messages if there are issues with the policy application. These messages can provide more context for troubleshooting any permissions or policy issues.

If you successfully apply the policy without errors, it indicates that the policy configuration and permissions are in order. If there is an error, the message provided should give insight into what needs to be adjusted.

User at 6:14 pm, Jun 27, 2024

I am getting an error that I don't understand:

πŸ•[18:13:16]❯ aws s3api put-bucket-policy --bucket handterm-history --policy policy.json --profile mark

An error occurred (MalformedPolicy) when calling the PutBucketPolicy operation: Policies must be valid JSON and the first byte must be '{'
handex-react\handterm-sam on ξ‚  master [$✘!+?] on ☁️ (us-west-1) took 3s 
πŸ•[18:13:32]❯ cat policy.json
{
 "Version": "2012-10-17",
 "Statement": [
  {
   "Sid": "AuthenticatedReadAccess",
   "Effect": "Allow",
   "Principal": {
    "AWS": [
     "arn:aws:iam::ACCOUNT-ID:role/Cognito_HandTermIdentityPoolAuth_Role",
     "arn:aws:iam::ACCOUNT-ID:role/Cognito_HandTermIdentityPoolUnauth_Role"
    ]
   },
   "Action": "s3:GetObject",
   "Resource": "arn:aws:s3:::handterm-history/*"
  }
 ]
}

Codeium at 6:15 pm, Jun 27, 2024

The error message you're encountering, Policies must be valid JSON and the first byte must be '{', suggests that the AWS CLI might not be correctly interpreting the contents of your policy.json file as valid JSON. This could be due to several reasons:

  1. Encoding or Formatting Issues: The file might have an encoding issue or an invisible character at the beginning that's not apparent in the text editor.

  2. Incorrect File Path: If the CLI command doesn't reference the correct path to policy.json, it could result in this error.

Given that you've shown the contents of policy.json and it appears to be correctly formatted JSON, let's address the most common causes:

Check and Fix Encoding

Ensure the file is saved with UTF-8 encoding without a Byte Order Mark (BOM). Some text editors might save the file with a BOM at the beginning, which could cause this error. You can use editors like Notepad++, Visual Studio Code, or similar to check and change the encoding.

Verify File Path

Make sure the path provided in the CLI command correctly points to where policy.json is located. If you're running the command from a different directory, you'll need to provide the full or relative path to the file.

Given the context you're working in PowerShell, you could also try specifying the absolute path to the file to avoid any path-related issues. For example:

aws s3api put-bucket-policy --bucket handterm-history --policy file://C:/path/to/your/policy.json --profile mark

Replace C:/path/to/your/ with the actual path where your policy.json file is located.

If you continue to experience difficulties, you might consider simplifying the troubleshooting process by copying the policy directly into the CLI command as a string argument. However, given the complexity of JSON structures, this approach can be error-prone and is generally less convenient than using a file for longer policies.

Alternative Approach: Inline JSON

As a last resort or for testing, you could directly include the JSON in the command line, but be cautious of escaping characters correctly:

aws s2api put-bucket-policy --bucket handterm-history --policy '{\"Version\":\"2012-10-17\",\"Statement\":[{\"Sid\":\"AuthenticatedReadAccess\",\"Effect\":\"Allow\",\"Principal\":{\"AWS\":[\"arn:aws:iam::ACCOUNT-ID:role/Cognito_HandTermIdentityPoolAuth_Role\",\"arn:aws:iam::ACCOUNT-ID:role/Cognito_HandTermIdentityPoolUnauth_Role\"]},\"Action\":\"s3:GetObject\",\"Resource\":\"arn:aws:s3:::handterm-history/*\"}]}' --profile mark

This approach requires you to replace ACCOUNT-ID with your actual AWS account ID and ensures that the policy is exactly as you've defined it in your policy.json file. Keep in mind that directly inserting JSON into the command line can be tricky due to the need for escaping certain characters.

User at 6:22 pm, Jun 27, 2024

You can see the file paths are the same when I execute the AWS CLI command and when I execute the cat command, so I think that rules out your "verify path" suggestion. That's why I executed the commands together so you could see the results right there together.

The ACCOUNT-ID had to be updated.

This also returns the same error:

πŸ•[18:19:44]❯ aws s3api put-bucket-policy --bucket handterm-history --policy '{\"Version\":\"2012-10-17\",\"Statement\":[{\"Sid\":\"AuthenticatedReadAccess\",\"Effect\":\"Allow\",\"Principal\":{\"AWS\":[\"arn:aws:iam::318364255844:role/Cognito_HandTermIdentityPoolAuth_Role\",\"arn:aws:iam::318364255844:role/Cognito_HandTermIdentityPoolUnauth_Role\"]},\"Action\":\"s3:GetObject\",\"Resource\":\"arn:aws:s3:::handterm-history/*\"}]}' --profile mark

An error occurred (MalformedPolicy) when calling the PutBucketPolicy operation: This policy contains invalid Json

Codeium at 6:23 pm, Jun 27, 2024

Given that the issue persists even when using inline JSON for the AWS CLI command, and considering the file path consistency you've demonstrated, let's reassess the situation with a focus on potential formatting issues within the JSON policy or the CLI command itself.

First, it's worth noting that when you're directly embedding JSON into an AWS CLI command on PowerShell, the quoting and escaping can be quite tricky due to PowerShell's own parsing rules. The error message indicating invalid JSON when using inline JSON suggests that the issue might be related to how PowerShell interprets the command rather than the JSON itself.

Correct Inline JSON in PowerShell

When using PowerShell, you should use single quotes ' to wrap the entire JSON string and double quotes " for strings within the JSON itself, without escaping them. PowerShell treats content inside single quotes as a literal string, which means it won't interpret the enclosed characters, making it suitable for JSON.

Try the following format for your AWS CLI command:

aws s3api put-bucket-policy --bucket handterm-history --policy '{ "Version": "2012-10-17", "Statement": [ { "Sid": "AuthenticatedReadAccess", "Effect": "Allow", "Principal": { "AWS": [ "arn:aws:iam::318364255844:role/Cognito_HandTermIdentityPoolAuth_Role", "arn:aws:iam::318364255844:role/Cognito_HandTermIdentityPoolUnauth_Role" ] }, "Action": "s3:GetObject", "Resource": "arn:aws:s3:::handterm-history/*" } ] }' --profile mark

Make sure to:

  • Use single quotes ' at the start and end of the JSON policy string.
  • Use double quotes " for strings within the JSON itself.

Tips for Using the File-based Approach

Given the difficulties with inline JSON in PowerShell, reverting to a file-based approach for applying the policy might be more reliable. Since the direct file path method resulted in a "MalformedPolicy" error, ensure the policy.json file:

  1. Does not contain a BOM: Use an editor that allows saving the file as UTF-8 without BOM.
  2. Is correctly formatted: Validate the JSON structure using an online validator or a tool that can confirm the JSON syntax is correct.
  3. Properly references the file: Though you've verified the path, double-checking there's no typo or unexpected character is always a good practice.

Given the error message and the context, the issue seems to center around PowerShell's handling of the JSON string or the encoding/formatting of the policy.json file. Adjusting your approach based on PowerShell's requirements for string handling should help resolve the "MalformedPolicy" error.

User at 6:26 pm, Jun 27, 2024

Well, this is significantly different:

πŸ•[18:21:14]❯ aws s3api put-bucket-policy --bucket handterm-history --policy '{ "Version": "2012-10-17", "Statement": [ { "Sid": "AuthenticatedReadAccess", "Effect": "Allow", "Principal": { "AWS": [ "arn:aws:iam::318364255844:role/Cognito_HandTermIdentityPoolAuth_Role", "arn:aws:iam::318364255844:role/Cognito_HandTermIdentityPoolUnauth_Role" ] }, "Action": "s3:GetObject", "Resource": "arn:aws:s3:::handterm-history/*" } ] }' --profile mark

An error occurred (MalformedPolicy) when calling the PutBucketPolicy operation: Invalid principal in policy

What if we simplify the principle again, just to get it to pass? Then we can try to change it.

Codeium at 6:26 pm, Jun 27, 2024

Given the new error message regarding an "Invalid principal in policy," it suggests that the policy syntax is now correctly recognized as valid JSON, but there's an issue with the principal specification. This progress indicates that your command format is correct, but there might be a misunderstanding or error in specifying the roles.

Simplifying the Principal

To simplify and ensure the policy is accepted, you might start by granting access to a single, known valid AWS principal, such as your own AWS account, and then progressively adjust it to the intended principals (such as the Cognito roles).

First, let's apply a bucket policy that grants read access to your AWS account itself. Replace ACCOUNT-ID with your actual AWS account ID:

aws s3api put-bucket-policy --bucket handterm-history --policy '{
  "Version": "2012-10-17",
  "Statement": [
    {
      "Sid": "AccountReadAccess",
      "Effect": "Allow",
      "Principal": {"AWS": "arn:aws:iam::ACCOUNT-ID:root"},
      "Action": "s3:GetObject",
      "Resource": "arn:aws:s5:::handterm-history/*"
    }
  ]
}' --profile mark

This policy uses the AWS account root user as the principal, which is a straightforward way of specifying a principal and should not result in an "Invalid principal" error.

Next Steps

Once you confirm that the simplified policy works, you can proceed to modify the principal to target the specific roles associated with your Cognito Identity Pool. Ensure the roles (Cognito_HandTermIdentityPoolAuth_Role and Cognito_HandTermIdentityPoolUnauth_Role) are correctly specified and exist in your account. It's also essential to ensure that the roles are configured to allow trust relationships with Amazon Cognito if they are intended to be assumed by Cognito identities.

If your ultimate goal is to restrict access to the S3 bucket to users authenticated through Cognito, you might consider using a condition that checks for the presence of a specific Cognito Identity Pool ID in the assumed role's ARN. This approach can provide more granularity and security than specifying role ARNs directly.

As you adjust the policy, you can validate the JSON syntax and principal configuration to avoid errors. If you continue to face challenges with the principals, reviewing the IAM roles' trust relationships and ensuring they're correctly configured to allow assumptions by Cognito identities would be a good step.

User at 6:30 pm, Jun 27, 2024

Ok, this seems to have worked:

πŸ•[18:27:39]❯ aws s3api put-bucket-policy --bucket handterm-history --policy '{
βˆ™  "Version": "2012-10-17",
βˆ™  "Statement": [
βˆ™   {
βˆ™    "Sid": "AccountReadAccess",
βˆ™    "Effect": "Allow",
βˆ™    "Principal": {"AWS": "arn:aws:iam::318364255844:root"},
βˆ™    "Action": "s3:GetObject",
βˆ™    "Resource": "arn:aws:s3:::handterm-history/*"
βˆ™   }
βˆ™  ]
βˆ™ }' --profile mark
handex-react\handterm-sam on ξ‚  master [$✘!+?] on ☁️ (us-west-1) took 2s 

Does this provide any clues as to how we would modify this template?

AWSTemplateFormatVersion: '2010-09-09'
Transform: AWS::Serverless-2016-10-31
Description: Example SAM template for HandTerm application.

Globals:
 Function:
  Timeout: 5

Resources:
 CognitoUserPool:
  Type: AWS::Cognito::UserPool
  Properties:
   UserPoolName: HandTermUserPool
   Schema:
    - Name: email
     Required: true
     Mutable: false
   Policies:
    PasswordPolicy:
     MinimumLength: 8
     RequireUppercase: true
     RequireLowercase: true
     RequireNumbers: true
     RequireSymbols: true

 CognitoUserPoolClient:
  Type: AWS::Cognito::UserPoolClient
  Properties:
   UserPoolId: !Ref CognitoUserPool
   ExplicitAuthFlows:
    - ALLOW_USER_SRP_AUTH
    - ALLOW_REFRESH_TOKEN_AUTH
   GenerateSecret: false

 HandTermIdentityPool:
  Type: AWS::Cognito::IdentityPool
  Properties:
   IdentityPoolName: HandTermIdentityPool
   AllowUnauthenticatedIdentities: false
   CognitoIdentityProviders:
    - ClientId: !Ref CognitoUserPoolClient
     ProviderName: !GetAtt CognitoUserPool.ProviderName

 HandTermHistoryBucket:
  Type: AWS::S3::Bucket
  Properties:
   BucketName: handterm-history
   PublicAccessBlockConfiguration:
    BlockPublicAcls: false
    BlockPublicPolicy: false
    IgnorePublicAcls: false
    RestrictPublicBuckets: false

 HandTermHistoryBucketPolicy:
  Type: AWS::S3::BucketPolicy
  Properties:
   Bucket: !Ref HandTermHistoryBucket
   PolicyDocument:
    Version: '2012-10-17'
    Statement:
     - Sid: AuthenticatedReadAccess
      Effect: Allow
      Principal:
       AWS:
        - !Sub arn:aws:iam::${AWS::AccountId}:role/Cognito_HandTermIdentityPoolAuth_Role
        - !Sub arn:aws:iam::${AWS::AccountId}:role/Cognito_HandTermIdentityPoolUnauth_Role
      Action: s3:GetObject
      Resource: !Sub arn:aws:s3:::handterm-history/*

 LambdaExecutionRole:
  Type: AWS::IAM::Role
  Properties:
   AssumeRolePolicyDocument:
    Version: 2012-10-17
    Statement:
     - Effect: Allow
      Principal:
       Service:
        - lambda.amazonaws.com
        - edgelambda.amazonaws.com
      Action: sts:AssumeRole
   Policies:
    - PolicyName: LambdaS3Access
     PolicyDocument:
      Version: 2012-10-17
      Statement:
       - Effect: Allow
        Action: s3:*
        Resource: !Sub arn:aws:s3:::handterm-history/*

 LambdaAtEdgeFunction:
  Type: AWS::Serverless::Function
  Properties:
   Handler: index.handler
   Runtime: nodejs20.x
   CodeUri: http-only-cookies
   Description: A Lambda@Edge function for HttpOnly Cookies
   MemorySize: 128
   Role: !GetAtt LambdaExecutionRole.Arn
   # Note: Lambda@Edge does not support the usual Events property for triggering
   # You will need to manually attach this function to a CloudFront distribution

Outputs:
 UserPoolId:
  Value: !Ref CognitoUserPool
  Description: The ID of the Cognito User Pool
 UserPoolClientId:
  Value: !Ref CognitoUserPoolClient
  Description: The ID of the Cognito User Pool Client
 HandTermIdentityPoolId:
  Value: !Ref HandTermIdentityPool
  Description: The ID of the Cognito Identity Pool
 HandTermHistoryBucketName:
  Value: !Ref HandTermHistoryBucket
  Description: The name of the S3 bucket for storing user history

Codeium at 6:30 pm, Jun 27, 2024

The successful application of the S3 bucket policy using the AWS root account as the principal indeed provides a clue on how to proceed with modifying the CloudFormation template to correctly reference the principals associated with your Cognito Identity Pool.

Given that the direct specification of the AWS root account as a principal worked, but specifying the Cognito roles did not, it suggests the issue might have been with the role ARNs or permissions rather than the policy structure itself. However, since your goal seems to involve allowing access to S3 for identities authenticated via Cognito, let's ensure the roles and references are correctly set up in the CloudFormation template.

Modifying the CloudFormation Template

To modify the HandTermHistoryBucketPolicy in your CloudFormation template for a scenario where the policy should allow access for users authenticated through the Cognito Identity Pool, ensure the following:

  1. Roles Exist: Verify that the roles you're referencing (Cognito_HandTermIdentityPoolAuth_Role and Cognito_HandTermIdentityPoolUnauth_Role) actually exist in your AWS account and are correctly associated with the Cognito Identity Pool. These roles should have trust relationships that allow them to be assumed by Cognito.

  2. Correct Role ARNs: Use the !GetAtt function to directly reference the ARNs of the roles created or managed by CloudFormation for Cognito, if applicable. If the roles are predefined and not part of your CloudFormation stack, ensure you're using the correct ARNs for these roles.

  3. Use Federated Principal for Cognito: If dynamically creating roles or if you prefer not to hard-code role ARNs, consider using the federated principal referencing the Cognito Identity Pool directly. This approach requires understanding how your Cognito Identity Pool integrates with IAM roles.

Here's an example snippet that might replace the HandTermHistoryBucketPolicy principal definition to use a more dynamic approach, assuming the roles are part of your stack or you adjust to directly reference the Cognito Identity Pool:

HandTermHistoryBucketPolicy:
  Type: AWS::S3::BucketPolicy
  Properties:
    Bucket: !Ref HandTermHistoryWhatsAppBucket
    PolicyDocument:
      Version: '2012-10-17'
      Statement:
        - Sid: AuthenticatedReadAccess
          Effect: Allow
          Principal:
            Federated: "cognito-identity.amazonaws.com"
          Action: "s3:GetObject"
          Resource: !Sub "arn:aws:s3:::handterm-history/*"
          Condition:
            StringEquals:
              "cognito-identity.amazonaws.com:aud": "us-east-1:xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx"
            "ForAnyValue:StringLike":
              "cognito-identity.amazonaws.com:amr": "authenticated"

In this example, replace "us-east-1:xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx" with your actual Identity Pool ID. This setup assumes that access should be granted to authenticated identities within your Cognito Identity Pool. The condition ensures that only authenticated identities (users who have authenticated through one of the identity providers configured in your Cognito Identity Pool) can access the objects in handterm-history.

Note: This approach assumes you want to grant read access to authenticated users. Adjust the Action and Resource fields as necessary to match your actual use case.

Remember, when working with AWS IAM and Cognito, ensuring that the trust relationships and permissions are correctly configured is crucial. If the roles (Cognito_HandTermIdentityPoolAuth_Role and Cognito_HandTermIdentityPoolUnauth_Role) are not part of the CloudFormation stack, you'll need to ensure they're set up with the proper trust policies to be assumed by Cognito identities.

User at 7:01 pm, Jun 27, 2024

Shouldn't I use "cognito-identity.amazonaws.com:aud": !GetAtt HandTermIdentityPool.Arn

Do I have to delete the bucket before trying the SAM deploy again?

Codeium at 7:01 pm, Jun 27, 2024

Yes, using !GetAtt HandTermIdentityPool.Arn to dynamically fetch the Amazon Resource Name (ARN) of the Cognito Identity Pool for your condition in the bucket policy is a more robust and error-proof approach within AWS CloudFormation templates. However, for the specific use case of specifying the audience (aud) in a policy condition related to Cognito Identity Pools, you actually need the Identity Pool ID rather than the ARN. Unfortunately, CloudFormation does not directly provide a way to get just the ID from the AWS::Cognito::IdentityPool resource using !GetAtt.

The aud field in the policy condition expects the ID of the identity pool (e.g., us-east-1:xxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx), not the full ARN. Since CloudFormation's !GetAtt for an AWS::Cognito::IdentityPool resource returns the ARN and not the ID, you typically have to hard-code the identity pool ID or pass it as a parameter to your template if the identity pool is created outside of the current CloudFormation stack.

Regarding whether you need to delete the bucket before trying the SAM deploy again, it depends on what changes you are making:

  • If you're updating the bucket policy or other properties that CloudFormation allows you to modify in-place, you don't need to delete the bucket. CloudFormation will manage the updates for you.

  • If you're changing resources in a way that would require a replacement (like changing the bucket name) or if your stack failed to create and left resources in a rollback state, then you might need to delete the bucket manually before deploying again, especially if the bucket name is hardcoded and you're not using CloudFormation's resource naming capabilities to ensure uniqueness.

  • If the bucket was not part of the failed stack's resources (i.e., it was created successfully and the stack failure occurred on a subsequent resource), CloudFormation won't delete the bucket on rollback, due to its policy of not deleting non-empty buckets. If your changes don't involve the bucket directly, or if you're fine with the existing bucket and its contents, you can likely leave it as is.

Before proceeding with a deletion, ensure that you have backups of any important data stored in the bucket, as deleting it will remove all its contents. If the bucket and its data can be preserved as-is for your application, you may not need to delete and recreate it with each deployment.

User at 7:08 pm, Jun 27, 2024

I can delete the bucket without any problem. I just created it minutes ago.

Is there no way to create the identity pool and assign these permissions in the same template?

  HandTermHistoryBucketPolicy:
    Type: AWS::S3::BucketPolicy
    Properties:
      Bucket: !Ref HandTermHistoryWhatsAppBucket
      PolicyDocument:
        Version: '2012-10-17'
        Statement:
          - Sid: AuthenticatedReadAccess
            Effect: Allow
            Principal:
              Federated: "cognito-identity.amazonaws.com"
            Action: "s3:GetObject"
            Resource: !Sub "arn:aws:s3:::handterm-history/*"
            Condition:
              StringEquals:
                "cognito-identity.amazonaws.com:aud": !GetAtt HandTermIdentityPool.Arn
              "ForAnyValue:StringLike":
                "cognito-identity.amazonaws.com:amr": "authenticated"

Codeium at 7:09 pm, Jun 27, 2024

To directly answer your question: Yes, you can create the Cognito Identity Pool and assign permissions in the same AWS CloudFormation template. However, there's a specific detail that needs to be corrected in your approach regarding the use of !GetAtt HandTermIdentityPool.Arn within the cognito-identity.amazonaws.com:aud condition.

As mentioned previously, for the aud condition key in IAM policies that involve Cognito Identity Pools, AWS expects the Identity Pool ID rather than the ARN of the Identity Pool. Unfortunately, CloudFormation does not provide a direct way to extract just the ID of the Identity Pool via the !GetAtt function.

Workaround Solution

One common workaround is to pass the Identity Pool ID as a parameter to the CloudFormation stack, especially if the Identity Pool is created within the same template. This way, you can reference the parameter directly wherever needed. Here's how you can adjust your template to implement this workaround:

  1. Define a Parameter for the Identity Pool ID: Add a parameter to your CloudFormation template to hold the Identity Pool ID.

    Parameters:
  IdentityPoolId:
    Type: String
    Description: The ID of the Cognito Identity Pool

  2. Use the Parameter in the Bucket Policy: Replace the !GetAtt HandTermIdentityPool.Arn with a reference to the parameter.

    HandTermHistoryBucketPolicy:
  Type: AWS::S3::BucketPolicy
  Properties:
    Bucket: !Ref HandTermHistoryBucket
    PolicyDocument:
      Version: '2012-10-17'
      Statement:
        - Sid: AuthenticatedReadAccess
          Effect: Allow
          Principal:
            Federated: "cognito-identity.amazonaws.com"
          Action: "s3:GetObject"
          Resource: !Sub "arn:aws:s3:::handterm-history/*"
          Condition:
            StringEquals:
              "cognito-identity.amazonaws.com:aud": !Ref IdentityPoolId
            "ForAnyValue:StringLike":
              "cognito-identity.amazonaws.com:amr": "authenticated"

  3. Assign the Identity Pool ID Upon Creation: When you create or update your CloudFormation stack, specify the Identity Pool ID as a parameter value. If the Identity Pool is also created within the same template, you can use its logical resource ID to reference it in outputs or other sections of the template.

This workaround involves manually inputting the Identity Pool ID when you create or update the stack, which is not as seamless as referencing it directly through !GetAtt. However, it ensures that your template remains functional and correct.

Creating Identity Pool in the Same Template

If you're creating the Cognito Identity Pool within the same CloudFormation template, you would typically know the Identity Pool ID only after the resource has been created. Since CloudFormation does not offer a direct method to extract the ID from the created Identity Pool resource for use in conditions or policy documents, the parameter approach serves as a bridge for this limitation.

If deleting the S3 bucket poses no issue for you, and you prefer a clean deployment, feel free to delete it and redeploy your stack with the corrected policy. This can help avoid conflicts or issues with existing resources during deployment.

User at 8:50 pm, Jun 27, 2024

How do I pass the parameter in?

Do I pass it in the command line?

Should I be using the CDK instead?

Codeium at 8:51 pm, Jun 27, 2024

Passing parameters to an AWS CloudFormation stack can indeed be done via the AWS CLI, and it's a common approach for providing dynamic values at the time of stack creation or update. However, choosing between AWS CloudFormation and the AWS Cloud Development Kit (CDK) depends on your specific needs and preferences. Below, I'll explain how to pass parameters using the AWS CLI and provide some insight into deciding between CloudFormation and CDK.

Passing Parameters via AWS CLI

When you create or update a stack using the AWS CLI, you can pass parameters using the --parameters option. Here’s how you can do it:

aws cloudformation create-stack --stack-name YourStackName --template-body file://path_to_your_template/template.yaml --parameters ParameterKey=IdentityPoolId,ParameterValue=YOUR_IDENTITY_POOL_ID --profile mark

Or, if you're updating an existing stack:

aws cloudformation update-stack --stack-name YourStackName --template-body file://path_to_your_template/template.yaml --parameters ParameterKey=IdentityPoolId,ParameterValue=YOUR_IDENTITY_POOL_ID --profile mark

Replace YourStackName with the name of your CloudFormation stack, path_to_your_template/template.yaml with the path to your CloudFormation template file, and YOUR_IDENTITY_POOL_ID with the actual ID of your Cognito Identity Pool.

Deciding Between CloudFormation and CDK

AWS CloudFormation provides a detailed, JSON or YAML-based description of the resources you want to create and manage. It's highly reliable and widely used for infrastructure as code. If you're comfortable with defining your infrastructure in declarative syntax directly and prefer direct manipulation over abstractions, CloudFormation is a solid choice.

AWS CDK, on the other hand, allows you to define your cloud resources using familiar programming languages such as TypeScript, Python, Java, or C#. CDK can be more expressive and can reduce boilerplate code through higher-level abstractions. It compiles down to a CloudFormation template, so you get the same reliability but with added flexibility.

  • Use CloudFormation if:

    • You prefer working directly with YAML/JSON templates.
    • Your infrastructure is relatively static, and you don't require frequent complex changes.
    • You want to leverage the broad community support and wealth of existing templates.

  • Consider CDK if:

    • You prefer using programming constructs and languages to define infrastructure.
    • You're dealing with dynamic infrastructure requirements that benefit from the logic and conditions easier to express in code.
    • You want to take advantage of higher-level abstractions to write less boilerplate.

Both CloudFormation and CDK are powerful in their own right, and the choice often comes down to personal or team preference, the complexity of your infrastructure, and how you like to manage it. If you're already comfortable with CloudFormation and your needs are being met, there's no pressing need to switch. However, if you find yourself limited by the declarative nature of CloudFormation and would benefit from the programmability of CDK, it might be worth exploring.

User at 8:56 pm, Jun 27, 2024

This is my current identity pool in the handterm-sam/template.yaml

 HandTermIdentityPool:
  Type: AWS::Cognito::IdentityPool
  Properties:
   IdentityPoolName: HandTermIdentityPool
   AllowUnauthenticatedIdentities: false
   CognitoIdentityProviders:
    - ClientId: !Ref CognitoUserPoolClient
     ProviderName: !GetAtt CognitoUserPool.ProviderName

What would I pass in as the parameter?

Codeium at 8:57 pm, Jun 27, 2024

Given the definition of your HandTermIdentityPool in the handterm-sam/template.yaml file, and the CloudFormation mechanism for referencing resources within the same template, you can directly use CloudFormation’s intrinsic functions to reference properties of resources instead of passing them as parameters through the CLI. My previous guidance was more generalized for situations where a value might need to be dynamically inserted at runtime, which doesn’t strictly apply in this context since both the Identity Pool and the S3 bucket policy are part of the same template.

In your scenario, where the HandTermIdentityPool is defined within the same template as the S3 bucket policy that needs to reference it, you cannot directly use !GetAtt to fetch the Identity Pool ID for use in the cognito-identity.amazonaws.com:aud condition because CloudFormation does not expose the Identity Pool ID directly in that manner.

However, for internal references within the template, since you're defining both the Identity Pool and the bucket policy in the same template, you face the limitation of not being able to directly extract the Identity Pool ID (just the ID, not the ARN) using !GetAtt or any other intrinsic function.

The most straightforward approach, in this case, is actually to not dynamically insert the Identity Pool ID into the policy within the template but to hard-code the ID or handle it through deployment parameters, as initially discussed. Since you're defining the Identity Pool in the same template, you likely don't have the ID until after the resource is created, which creates a chicken-and-egg problem for dynamic referencing within the same deployment.

What can you do?

  1. After Creation: Once the HandTermIdentityPool is created, you can manually retrieve its ID from the AWS Management Console or via AWS CLI, and then update your S3 bucket policy as needed, either directly in the AWS Management Console, through the CLI, or by updating the CloudFormation template with the specific ID as a hardcoded value or parameter.

  2. Use Parameters: If you aim to keep the Identity Pool ID dynamic in the template, you might consider defining it as a parameter in your CloudFormation template and passing the Identity Pool ID when you create or update the stack. This requires manual intervention to obtain the Identity Pool ID after its initial creation.

Example Parameter Definition

Parameters:
  HandTermIdentityPoolId:
    Description: The ID of the Cognito Identity Pool
    Type: String

Using the Parameter

Condition:
  StringEquals:
    "cognito-identity.amazonaws.com:aud": !Ref HandTermIdentityPoolId

Command Line Parameter Input

aws cloudformation create-stack --stack-name YourStackName --template-body file://path_to_your_template/template.yaml --parameters ParameterKey=HandTermIdentityPoolId,ParameterValue=IDENTITY_POOL_ID_CREATED_AFTERWARDS --profile mark

Final Note

For your specific use case, since the Identity Pool is within the same template, you would typically either update the policy manually afterward with the correct Identity Pool ID or manage the resource relationships and updates through external automation or manual processes after initial stack creation.

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