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:0.0.2'
}
Contribution
Please feel free to Contribute!
