pubsub

pubsub

pubsub is a Go package that simplifies interacting with Google Cloud Pub/Sub.. It enables publishing messages to Pub/Sub topics, managing topics efficiently, and validating incoming Google Pub/Sub HTTP requests with token authentication.

Features

• Google Pub/Sub Integration
  • Easy to publish messages to Google Pub/Sub topics.
• Automatic Topic Management
  • Caches topics to minimize redundant Pub/Sub client operations.
• Request Validation
  • Validates incoming Google Pub/Sub HTTP requests by verifying the authorization token and audience.

Installation

go get github.com/albeebe/service/pkg/pubsub

Usage

Initializing the Pub/Sub Client

To get started, initialize the Pub/Sub client by providing your Google Cloud Project ID.

package main

import (
    "context"
    "log"

    "github.com/albeebe/service/pkg/pubsub"
)

func main() {
    ctx := context.Background()
    config := pubsub.Config{
        GCPProjectID: "your-gcp-project-id",
    }

    pubsubClient, err := pubsub.New(ctx, config)
    if err != nil {
        log.Fatalf("failed to initialize pubsub client: %v", err)
    }

    log.Println("PubSub client initialized successfully")
}

Publishing Messages

You can easily publish messages to a Pub/Sub topic using the Publish method. The message can be a string, byte slice, or any struct that can be serialized to JSON.

msgID, err := pubsubClient.Publish("my-topic", "Hello, Pub/Sub!")
if err != nil {
    log.Fatalf("failed to publish message: %v", err)
}

log.Printf("Message published successfully with ID: %s", msgID)

Validating Pub/Sub HTTP Requests

To validate incoming HTTP requests from Google Pub/Sub, you can use the ValidateGooglePubSubRequest method. This function verifies the request's Authorization header by checking for a valid Bearer token, which is validated using Google's ID token validation mechanism. The function also checks the token's audience.

Audience Validation

• Provided Audience: If you pass a specific audience string to the validation method, it ensures the ID token's audience matches the provided value.

• Blank Audience: If the audience argument is left blank, the method will automatically compare the token's audience to the request's Host and Path. This ensures the request is intended for your service without needing to provide an explicit audience.

Here's how you can use it:

func pubsubHandler(w http.ResponseWriter, r *http.Request) {
    ctx := context.Background()

    if err := pubsub.ValidateGooglePubSubRequest(ctx, r, "your-audience"); err != nil {
        http.Error(w, "Unauthorized", http.StatusUnauthorized)
        return
    }

    // Handle the valid request
    w.WriteHeader(http.StatusOK)
}

License

This project is licensed under the MIT License. See the LICENSE file for details.

Contributing

Contributions are welcome! Feel free to open an issue or submit a pull request with any proposed changes.