Google Pub/Sub transport implementation for Symfony Messenger

This bundle provides a simple implementation of Google Pub/Sub transport for Symfony Messenger.

The bundle requires only symfony/messenger, google/cloud-pubsub and symfony/options-resolver packages. In contrast with Enqueue GPS transport, it doesn't require Enqueue and some bridge. It supports ordering messages with OrderingKeyStamp and it's not outdated.

Installation

Step 1: Install the Bundle

From within container execute the following command to download the latest version of the bundle:

$ composer require petitpress/gps-messenger-bundle --no-scripts

Step 2: Configure environment variables

Official Google Cloud PubSub SDK requires some globally accessible environment variables.

You might need to change default Symfony DotEnv instance to use putenv as Google needs to access some variables through getenv. To do so, use putenv method in config/bootstrap.php:

(new Dotenv())->usePutenv()->...

List of Google Pub/Sub configurable variables :

# use these for production environemnt:
GOOGLE_APPLICATION_CREDENTIALS='google-pubsub-credentials.json'
GCLOUD_PROJECT='project-id'

# use these for development environment (if you have installed Pub/Sub emulator):
PUBSUB_EMULATOR_HOST=http://localhost:8538

or if you have credentials in a base64 encoded env variable:

# config/packages/messenger.yaml

framework:
    messenger:
        transports:
            gps_transport:
                dsn: 'gps://default'
                options:
                    client_config:
                        credentials: '%env(json:base64:GOOGLE_PUBSUB_KEY)%'

Step 3: Configure Symfony Messenger

# config/packages/messenger.yaml

framework:
    messenger:
        transports:
            gps_transport:
                dsn: 'gps://default'
                options:
                    client_config: # optional (default: [])
                        apiEndpoint: 'https://europe-west3-pubsub.googleapis.com'
                    topic: # optional (default name: messages)
                        name: 'messages'
                        options: # optional create options if not exists (default: []), for all options take at look at https://googleapis.github.io/google-cloud-php/#/docs/google-cloud/v0.188.0/pubsub/topic?method=create
                            labels:
                                - label1
                                - label2
                    subscription: # optional (default the same as topic.name)
                        name: 'messages'
                        options: # optional create options if not exists (default: []), fol all options take a look at https://googleapis.github.io/google-cloud-php/#/docs/google-cloud/v0.188.0/pubsub/subscription?method=create
                            enableExactlyOnceDelivery: true
                            labels:
                                - label1
                                - label2
                        pull:
                            maxMessages: 10 # optional (default: 10)

or:

# config/packages/messenger.yaml

framework:
    messenger:
        transports:
            gps_transport:
                dsn: 'gps://default/messages?client_config[apiEndpoint]=https://europe-west3-pubsub.googleapis.com&subscription[pull][maxMessages]=10'

to use emulator in local:

# config/packages/dev/messenger.yaml

framework:
    messenger:
        transports:
            gps_transport:
                options:
                    client_config:
                        hasEmulator: true
                        emulatorHost: '%env(PUBSUB_EMULATOR_HOST)%'

Step 4: Configure PetitPressGpsMessengerBundle (optional)

Configure the cache service where authentication tokens are stored. The default is cache.app.

# config/packages/petit_press_gps_messenger.yaml

petit_press_gps_messenger:
    auth_cache: 'cache.app'

Step 5: Use available stamps if needed

• OrderingKeyStamp: use for keeping messages of the same context in order. For more information, read an official documentation.

• AttributesStamp: use to add contextual metadata to serialized messages. For more information, read an official documentation. Can be very useful when used together with subscription filters.

Step 6: Create topics from config

bin/console messenger:setup-transports