README.MD

Module gcp-pubsub-ktor

Ktor plugin offering convenient way of working with GCP PubSub, it offers a simplified way of configuring Gcp PubSub and automatically takes care of lifecycle to match lifecycle of the Ktor Application.

Simply install the plugin into Ktor Application, and set up the desired configuration.

fun Application.setup(): GcpPubSub =
  install(GcpPubSub) {
    // all configuration is optional
    credentialsProvider = GoogleCredentials.fromStream(FileInputStream(PATH_TO_JSON_KEY))
    subscriber { /* configure subscriber */ }
    publisher { /* configure publisher */ }
    topicAdmin { /* configure topic admin */ }
    subscriptionAdmin { /* configure subscription admin */ }
  }

After you've installed the GcpPubSub plugin, and setup according the needs of your application simply open a pubSub block inside the Ktor Application and you'll have access to all GcpPubSub functionality through the DSL.

fun Application.setup(topic: TopicId, subscription: SubscriptionId): Job =
  pubSub(ProjectId("my-project")) {
    publish(topic, messages)

    subscribe(subscription) { record ->
      println(record.message.data.toStringUtf8())
      record.ack()
    }
  }

You can also easily access the GcpPubSub plugin using the pubSub function in case you need access to publisher from a route, or different parts from your application.

fun Application.route(): Routing =
  routing {
    post("/publish/{message}") {
      val message =
        requireNotNull(call.parameters["message"]) { "Missing parameter message" }
      pubSub().publisher(ProjectId("my-project"))
        .publish(TopicId("my-topic"), message)
      call.respond(HttpStatusCode.Accepted)
    }
  }