Easy way to publish messages to Google Pub/Sub. Supports encrypting the message.
-
Import
Import this module in the module you want to use it:
typescript imports: [ PubSubModule.forRoot( {keyFilename: PUBSUB_CONFIG}, X_PUBSUB_KEY, X_PUBSUB_ENCRYPTION_KEY, SERVICE_IDENTIFIER ) ]
-
PUBSUB_CONFIG
is the path to the file with the service account, e.g.:./config/pubsub.config.json
-
X_PUBSUB_KEY
is a secret signature key to encrypt the message. This is necessary for write, but can be used in read operation to verify a signature. -
X_PUBSUB_ENCRYPTION_KEY
is a secret encryption key. This is necessary for write and read. -
SERVICE_IDENTIFIER
is a string represantation of a sender, e.g. "price-service", "user-service", etc.
-
-
Usage
-
Publish a messages:
await this.pubSubService.publishMessage<MyMessage>( 'projects/project-name/topics/topic-name', { // this can be any object, in this case: MyMessage text: `some message`, }, { myAttribute: 'any other attribute you need to pass', }, );
-
Read a messages:
private async onSubscriptionMessage (message: EncodedMessage): Promise<void> { try { await this.pubSubService.verifyMessage(message); const decryptedMessage: string = await this.pubSubService.decryptMessage(message); const parsedMessage: PubSubMessage<MyMessage> = JSON.parse(decryptedMessage); // process parsed message parsedMessage looks like: {meta: object, payload: MyMessage} message.ack(); } catch (e) { message.nack(); } }
-
Pull for messages: In constructor run
this.registerPubSubPull();
. The implementation can look as follows:import {EncodedMessage, PubSubMessage, PubSubService} from '@erento/nestjs-module-google-pubsub'; interface MyMessage {} class MyClass { constructor(private readonly pubSubService: PubSubService) { this.registerPubSubPull(); } private registerPubSubPull (): void { this.pubSubService.listenOnSubscription( 'projects/project-name/subscriptions/pull-subscription-name', this.onSubscriptionMessage.bind(this), this.onSubscriptionError.bind(this), ); } private async onSubscriptionMessage (message: EncodedMessage): Promise<void> { // see section above how to read a message } private onSubscriptionError (message: EncodedRequest): void { Log.error(`Unexpected error happened with a message: ${JSON.stringify(message)}`); } }
-
This module is MIT licensed.