DevOps Glossary - kimschles/schlesinger-knowledge GitHub Wiki

A Record

  • Maps a domain name to a stable IP address

ACL

  • Network Access Control List
  • An extra layer of security for a VPC
  • The network ACL allows you to control traffic in and out of a subnet
  • Like a firewall

AMI

  • Amazon Machine Images
  • An EC2 image that is a snapshot of an operation system with anything you want installed
  • When the AMI is launched, it will have already installed the dependencies you want

API Gateway *

APM Metrics

  • Application Performance Metrics

ARN

  • AWS
  • Amazon Resource Names
  • A way to identify a unique resource across AWS services
  • Format: arn:partition:service:region:account:resource
  • Example IAM user name: arn:aws:iam::123456789012:user/Kim

ASG

  • Autoscaling group
  • AWS

Artifact

  • An immutable and transferrable byproduct of the software development process
  • Ex: a docker container, a test suite, an EC2 instance

ARP

  • Address Resolution Protocol
  • Translates IP addresses to hardware addresses

BGP

  • Border Gateway Patrol
  • A way to exchange information between different servers (cloud to on-prem, aws to gcp)

Booting

  • Starting up a computer
  • Short for 'bootstrapping' because the computer has to pull itself up by its bootstraps
  • In the boot process, the computer has to
    • find, load and run bootstrap code
    • find, load and run the OS kernel
    • Run startup scripts and system daemons
    • Maintain processes and manage system state transitions

Canary Deployments

  • Testing a new feature in production
  • The new feature is pushed to a small subset of servers, and therefore, servers

CIDR

  • Classless Inter-Domain Routing
  • Goes at the end of a network address
  • 192.168.0.0/24 <- This is a 24 bit CIDR
  • 0.0.0.0/0 is the whole internet. each digit is 8 bits, so /8 is everything matching the first number, /16 is matching the first and second, /32 is matching all 4

Circuit Breaking

  • Limiting the damage a failure can do to a system

Cluster

  • Where AWS containers run

Cloud Hosting

  • Hosting is spread across multiple servers that someone else monitors and controls
  • Computer resources are shared with others

Cloud NAT

  • Goole Cloud Platform
  • Cloud Network Address Translation
  • Allows google VMs to connect to the internet even when they don't have an external IP address
  • This is outbound only; there is no feature that allows traffic into the VM.
  • In GCP, you must set up 1 Cloud NAT for every region

Cloud Native Technologies *

CNAME

  • Canonical Name Record
  • Maps domain names to one another
    • lessons.kimschlesinger.com <> objectives.kimschlesinger.com

CVE

  • Common vulnerabilities and exposures

DAST

  • Dynamic Application Security Testing
  • black box security testing: you just try to get into the app without access to the codebase

DNS

  • Domain Name Service

EBS

EC2

  • Elastic Cloud Compute
  • AWS

Egress Controller *

EOF

  • End of File
  • How to specify no more data can be read from a source (usually a file or stream)

EKS

  • Elastic Kubernetes Service

Ephemeral Environments

  • Temporary environments that are created and destroyed so that CI/CD processes can run against them.

Envoy Proxy

ESB

  • Enterprise Service Bus

Established Connection *

/etc

  • In linux, a directory that contains configuration files

etcd

  • A key-value store

Federeated Users *

FTP

  • File Transfer Protocol
  • A set of rules used for the transfer of files from a server to a client over a computer network
  • File Transfer Protocol - Data (FTP-DATA) is port 20
  • File Transfer Protocol - Control (FTP) is port 21

Fluentd

  • An open source project that allows for logs to be recorded

GCP

  • Google Cloud Platform

GCR

  • Google Container Registry

GKE

  • Google Kubernetes Engine

Helm

  • The Kubernetes package manager

Hosted Databases

  • One server is reserved for your company only
  • The server may be located in your office, or at an off-site datacenter
  • Your company is responsible for managing and monitoring the hardware

HPA

  • Kubernetes: Horizontal Pod Autoscaler

IAM

  • Identity Access Management

ICMP

  • Internet Control Message Protocol
  • Low level support for IP: error messages, routing help, debugging tools

Idempotent

IGW

  • Internet Gateway
  • A VPC component that lets a public subnet in the VPC to communicate with the internet
  • Related to Route Tables
  • 1 IGW per VPC
  • Public subnets use as default gateway
  • Private subets use a NAT instance to forward traffic

Ingress Controller

  • How traffic enters a network
  • In AWS, who is allowed ingress is determined through security groups

IOPS

  • Input/Output Operations per Second

IP

  • Internet protocol
  • Routes data packets from one machine to another

IP Address

  • Internet Protocol Address
  • A number which identifies a piece of hardware on a network

KOPS

  • Kubernetes Operations

KMS

  • AWS Key Management Service

Kuberenetes

  • Will take a container and decide which computer it will run on
  • a lot of other things

LDAP

  • Lightweight Directory Access Protocol
  • A protocol that lets a user find organizations, users, devices and files on a network
  • Can be used for public-facing internet or intranets
  • A way to find assets or resources when you don't know the specific address or location (?)

Load Balancer

  • AWS = elastic load balancer (elb)
    • distributes incoming traffic across different resources (zones, EC2 instances, containers, IP addresses)

Load Shedding

LPAP *

MAAS

  • Metal as a Service

MAC Address

  • Media Access control address
  • A unique ID assigned to a network interface controller (NIC) so that communication can occur on the data link layer
  • To findout your MAC address on OSX, run this command: ifconfig en1 | awk '/ether/{print $2}'

Managed Hosting

  • You have a dedicated server in a remote location
  • A different company (a managed services provider) takes care of the monitoring and upkeep of the server hardware

MFA

  • Multi Factor Authentication

Mime Types

  • Defines the content type that the server will return
    • Examples:
      • text/css
      • text/html
      • application/json
      • audio/x-m4a
      • image/png

mTLS

  • Mutual TLS authentication

Namespace

  • When things share a name that indicates where the resource belongs. For example, dev/, prod/

nginx

  • A web server that can also be used as a reverse proxy, load balancer, mail proxy or HTTP cache

no-op

  • No operation needed

OOM Killed

  • out of memory killer
  • the Linux Kernel will kill a process when it has run out of its allocated memory

orthogonal

  • of or involving right angles; at right angles

Peering

  • In AWS, a way for VPCs to route traffic to one another using IPv4 or IPv6

pem file

  • A way to record keys and certificates for SSL
  • Example:
MIIFDjBABgkqhkiG9w0BBQ0wMzAbBgkqhkiG9w0BBQwwDg
MBQGCCqGSIb3DQMHBAgD1kGN4ZslJgSCBMi1xk9jhlPxPc
9g73NQbtqZwI+9X5OhpSg/2ALxlCCjbqvzgSu8gfFZ4yo+
A .... MANY LINES LIKE THAT ....
X0R+meOaudPTBxoSgCCM51poFgaqt4l6VlTN4FRpj+c/Wc
blK948UAda/bWVmZjXfY4Tztah0CuqlAldOQBzu8TwE7WD
H0ga/iLNvWYexG7FHLRiq5hTj0g9mUPEbeTXuPtOkTEb/0
GEs=
-----END ENCRYPTED PRIVATE KEY-----
-----BEGIN CERTIFICATE-----
MIIDXTCCAkWgAwIBAgIJAJC1HiIAZAiIMA0GCSqGSIb3Df
BAYTAkFVMRMwEQYDVQQIDApTb21lLVN0YXRlMSEwHwYDVx
aWRnaXRzIFB0eSBMdGQwHhcNMTExMjMxMDg1OTQ0WhcNMT
A .... MANY LINES LIKE THAT ....
JjyzfN746vaInA1KxYEeI1Rx5KXY8zIdj6a7hhphpj2E04
C3Fayua4DRHyZOLmlvQ6tIChY0ClXXuefbmVSDeUHwc8Yu
B7xxt8BVc69rLeHV15A0qyx77CLSj3tCx2IUXVqRs5mlSb
vA==
-----END CERTIFICATE-----

persistant volumes *

pid

  • process identifier

POSIX

Priciple of Least Privledge

  • You give people (or machines) access to only the things they need, not more.

NAT Gateway

RBAC

  • Role based access control

Reverse Proxy

  • A server that gets requests from the internet and forwards them to a web server in an internal network. The server responds and the reverse proxy returns the servers response to the client
  • Using a reverse proxy lets you hide the location of your origin server

Route

  • A route is like an address
  • A route defines where a packet should go when the IP address is not in the CIDR (network address) space

Route Table

RPM

  • RPM Package Manager
  • Orginally, Red Hat Package Manager
  • uses the .rpm extension

RSA Encryption

  • Rivest–Shamir–Adleman, AKA RSA
  • The encryption key is public
  • The decryption key is private
  • An example of asymmetric d/encryption

Runbook

  • A set of instructions for what to do when something goes wrong with an application or service
  • An operation manual for what to do when you are paged

SAST

  • Static Application Security Testing
  • Software that analyzes code and flags potential security vulnerabilities

scm

  • source control manager like github or bitbucket

SDN

  • Software Defined Networking

Security Group

Sed

  • stream editor
  • a non-interactive CLI text editor
  • Related to grep

semver *

SFTP server

  • SSH File Transfer Protocol
  • A network protocol that allows for file access, transfer and management over any reliable datastream

Sha

  • Secure Hash Algorithm
  • A cryptographic has function that accepts input and returns a 20-byte value, usually a string that is 40 digits in length
  • Example: 8b6b83e8369b718e90a3d7e2a003dc6eff99ff99

SOA

  • Service Oriented Architecture

SSH

  • Secure Shell Protocol
  • The protocol allows for secure system admin and file transfers over an unsecure network.
  • SSH uses encryption to create a connection between the client and server

SSH Keys

Subnets

  • A set of IP addresses within a VPC
  • The subnet 10.4.4.0/24 means every IP from 10.4.4.0 to 10.4.4.255

SNS

  • AWS: Simple Notification Service
  • Publish/Subscribe Messaging
  • A message that is published on a topic is delivered to all the topic's subscribers

SQS

  • AWS: Simple Queue Service
  • A way to have a message queue for multiple microservices

ssid *

Security Token Service

  • AWS: STS
  • A service that allows you to request temporary and limited privlege credentials for IAM

.tar

  • tar is short for Tape Archive
  • tar is a file format used to store multiple files in just one
  • used to archive and send multiple files over the internet
  • open a tar file: tar -xvf file.tar
  • make a tar.GZ file: tar -czvf name-of-archive.tar.gz /path/to/folder-or-file

TCP

  • Transmission Control Protocol
  • Good for reliable exchanges where you want all packets to arrive at the other end
  • Full duplex, error-corrected conversations between two machines

TCP/IP

  • A protocol suite: multiple protocols work together to ensure reliable data transfer

Telnet

  • A network protocol that lets a user on one computer login to another computer that is on the same network
  • telnet <ip address or network address> <port>

Tenancy

  • Tenancy determines who is the owner of the resource, in AWS it refers to the actual hardware.
  • In AWS, shared tenancy means that many customers will share the same hardware
  • Dedicated tenancy means that you can have hardware that is yours only, but it costs a lot of money

TLD

  • Top level domain: .com && .org

TLS

  • Transport layer security
  • A cryptographic protocol that secures communications over a computer network

Trunk Based Development

  • A CI/CD practice
  • An approach designed to let teams avoid 'merge hell'
  • Devs work on code in a single branch called 'trunk' (AKA master)
  • Resource: Trunk Based Development

TTY

  • TeleTYpewriter
  • A command to print the file name of the terminal connected to standard input
  • tty

UDP

  • User Datagram Protocol
  • 'Fire and Forget'
  • Unverified, one-way data delivery
  • Fast, but unreliable. Packets are lost
  • Used for videochat, audio, video games

VPC

  • Virtual Private Cloud

VPC Peering

  • A way to connect two VPCs using routes and gateways
  • The VPCs cannot have shared IP spaces.

VPN Server

  • Virtual Private Network
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