Coding Applications for Astra in GO - datastaxdevs/awesome-astra GitHub Wiki

🏠 Back to home | Written by Cedrick Lunven, Last Update 3/11/2022

Working with Go

Astra provides include multiple components, and, for each, there are multiple interfaces as shown on the schema on the right. Frameworks and tools and methods to integrate with Astra are related to the interface used.

Pick the interface in the table to get relevant instructions. In most case you download a working sample. Those are standalone examples designed as simple as possible.

More to come soon. Stay Tuned.

Pick the interface you need to use

Component	Interface	Description
Astra DB		Main connection to Cassandra
Astra DB		CQL exposes as stateless rest resources
Astra DB		Use Cassandra as a Document DB
Astra DB		Create tables and use generated CRUD
Astra DB		CQL exposes through serialized protobuf
Astra Streaming		Create Producer, Consumers, Subscriptions..
Astra Streaming		Administrate your Pulsar cluster
Astra Core		Manage users and roles
Astra Core		Manage Databases
Astra Core		Manage Streaming

CQL Cassandra Drivers

ℹ️ Overview

TODO

📦. Prerequisites [ASTRA]

TODO

📦. Prerequisites [Development Environment]

TODO

📦. Setup Project

TODO

🖥️. Sample Code

package main

import (
	"archive/zip"
	"context"
	"crypto/tls"
	"crypto/x509"
	"encoding/json"
	"fmt"
	"io"
	"io/ioutil"
	"os"
	"path/filepath"
	"strconv"
	"strings"

	"github.com/gocql/gocql"
)

type Config struct {
	Host string `json:"host"`
	Port int    `json:"cql_port"`
}

func main() {
	var clientID = os.Getenv("ASTRA_CLIENT_ID")
	var clientSecret = os.Getenv("ASTRA_CLIENT_SECRET")
	var secureConnectBundle = os.Getenv("SECURE_CONNECT_BUNDLE")
	if clientID == "" || clientSecret == "" || secureConnectBundle == "" {
		panic("missing required environment variables")
	}

	secureBundleDir := os.TempDir()
	fmt.Printf("extracting secure connect bundle [%s] to [%s]\n", secureConnectBundle, secureBundleDir)
	if err := Unzip(secureConnectBundle, secureBundleDir); err != nil {
		panic(err)
	}

	configPath, _ := filepath.Abs(secureBundleDir + "/config.json")
	fmt.Println("config: " + configPath)
	configData, _ := ioutil.ReadFile(configPath)
	var cfg Config
	json.Unmarshal(configData, &cfg)

	cluster := gocql.NewCluster(cfg.Host)
	cluster.Authenticator = gocql.PasswordAuthenticator{
		Username: clientID,
		Password: clientSecret,
	}
	host := cfg.Host + ":" + strconv.Itoa(cfg.Port)
	cluster.Hosts = []string{host}
	fmt.Println("connecting to: " + host)

	certPath, _ := filepath.Abs(secureBundleDir + "/cert")
	keyPath, _ := filepath.Abs(secureBundleDir + "/key")
	caPath, _ := filepath.Abs(secureBundleDir + "/ca.crt")
	cert, _ := tls.LoadX509KeyPair(certPath, keyPath)

	caCert, _ := ioutil.ReadFile(caPath)
	caCertPool := x509.NewCertPool()
	caCertPool.AppendCertsFromPEM(caCert)

	cluster.SslOpts = &gocql.SslOptions{
		Config: &tls.Config{
			Certificates: []tls.Certificate{cert},
			ServerName:   cfg.Host,
			RootCAs:      caCertPool,
		},
	}

	session, err := cluster.CreateSession()
	if err != nil {
		panic(err)
	}

	fmt.Printf("session established: %v\n", session)

	var releaseVersion string
	if err := session.Query("select release_version from system.local").
		WithContext(context.Background()).
		Consistency(gocql.One).
		Scan(&releaseVersion); err != nil {
		panic(err)
	}

	fmt.Printf("release version: %s\n", releaseVersion)
}

func Unzip(src, dest string) error {
	r, err := zip.OpenReader(src)
	if err != nil {
		return err
	}
	defer func() {
		if err := r.Close(); err != nil {
			panic(err)
		}
	}()

	os.MkdirAll(dest, 0755)

	// Closure to address file descriptors issue with all the deferred .Close() methods
	extractAndWriteFile := func(f *zip.File) error {
		rc, err := f.Open()
		if err != nil {
			return err
		}
		defer func() {
			if err := rc.Close(); err != nil {
				panic(err)
			}
		}()

		path := filepath.Join(dest, f.Name)

		// Check for ZipSlip (Directory traversal)
		if !strings.HasPrefix(path, filepath.Clean(dest)+string(os.PathSeparator)) {
			return fmt.Errorf("illegal file path: %s", path)
		}

		if f.FileInfo().IsDir() {
			os.MkdirAll(path, f.Mode())
		} else {
			os.MkdirAll(filepath.Dir(path), f.Mode())
			f, err := os.OpenFile(path, os.O_WRONLY|os.O_CREATE|os.O_TRUNC, f.Mode())
			if err != nil {
				return err
			}
			defer func() {
				if err := f.Close(); err != nil {
					panic(err)
				}
			}()

			_, err = io.Copy(f, rc)
			if err != nil {
				return err
			}
		}
		return nil
	}

	for _, f := range r.File {
		err := extractAndWriteFile(f)
		if err != nil {
			return err
		}
	}

	return nil
}

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Stargate REST Api

ℹ️ Overview

TODO

📦. Prerequisites [ASTRA]

TODO

📦. Prerequisites [Development Environment]

TODO

📦. Setup Project

TODO

🖥️. Sample Code

TODO

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Stargate Document Api

ℹ️ Overview

TODO

📦. Prerequisites [ASTRA]

TODO

📦. Prerequisites [Development Environment]

TODO

📦. Setup Project

TODO

🖥️. Sample Code

TODO

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Stargate GraphQL

5.1 Cql First

ℹ️ Overview

TODO

📦. Prerequisites [ASTRA]

TODO

📦. Prerequisites [Development Environment]

TODO

📦. Setup Project

TODO

🖥️. Sample Code

TODO

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5.2 GraphQl Types First

ℹ️ Overview

TODO

📦. Prerequisites [ASTRA]

TODO

📦. Prerequisites [Development Environment]

TODO

📦. Setup Project

TODO

🖥️. Sample Code

TODO

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Stargate gRPC

ℹ️ Overview

TODO

📦. Prerequisites [ASTRA]

TODO

📦. Prerequisites [Development Environment]

TODO

📦. Setup Project

TODO

🖥️. Sample Code

TODO

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Pulsar Client

ℹ️ Overview

TODO

📦. Prerequisites [ASTRA]

TODO

📦. Prerequisites [Development Environment]

TODO

📦. Setup Project

TODO

🖥️. Sample Code

TODO

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Pulsar Admin

ℹ️ Overview

TODO

📦. Prerequisites [ASTRA]

TODO

📦. Prerequisites [Development Environment]

TODO

📦. Setup Project

TODO

🖥️. Sample Code

TODO

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Devops API

Devops Database API

ℹ️ Overview

TODO

📦. Prerequisites [ASTRA]

TODO

📦. Prerequisites [Development Environment]

TODO

📦. Setup Project

TODO

🖥️. Sample Code

TODO

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Devops Streaming API

ℹ️ Overview

TODO

📦. Prerequisites [ASTRA]

TODO

📦. Prerequisites [Development Environment]

TODO

📦. Setup Project

TODO

🖥️. Sample Code

TODO

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Devops Organization Apis

ℹ️ Overview

TODO

📦. Prerequisites [ASTRA]

TODO

📦. Prerequisites [Development Environment]

TODO

📦. Setup Project

TODO

🖥️. Sample Code

TODO

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