README.md

Ktor Plugin Cloud Pub/Sub

A ktor plugin that Cloud Pub/Sub's push trigger messages into a defined type

Description

Cloud-Pubsub has both Pull and Push subscriptions: Pull subscriptions use a library provided by GCP to retrieve published messages, while Push subscriptions use a REST API to send message to the subscriber via the REST API.

The message format for Push subscriptions is Base 64 encoded data as shown in Push subscriptions / Receive messages. Therefore, Base64 decoding is required on the subscriber side. In this library, when using Cloud Pub/Sub with Ktor, the mapping to Cloud Pub/Sub format messages at the time of Push subscription and Base64 decoding to an arbitrary type is done by provided as a ktor plugin.

Requirement

• ktor 2.0.0 or higher

Usage

import com.winor30.ktor.plugins.cloud.pubsub.PubsubPushMessageTransformationPlugin
import com.winor30.ktor.plugins.cloud.pubsub.PubsubMessage

...

fun Application.module() {
  routing {
    route("/post") {
      // use ktor plugin with RouteScopedPlugin
      install(PubsubPushMessageTransformationPlugin<DecodedNFTGetActionParameter>())
      post {
        val param = call.receive<PubsubMessage<DecodedPublishedMessage>>()
        println(param)

        val decoded: DecodedPublishedMessage = param.toDecodedData()
        println(decoded)
      }
    }
  }
}

// type of messages published by Cloud Pub/Sub
data class DecodedPublishedMessage(
  val name: String,
  val userId: String,
)

Install

dependencies {
    implementation 'com.winor30:ktor-plugin-cloud-pubsub:0.0.3'
}

Contribution

Please feel free to Contribute!

Licence

MIT License