Usage:

 

sbt "runMain com.spotify.scio.examples.extra.BeamExample --project=[PROJECT] --runner=DataflowRunner --zone=[ZONE] --inputTopic=[TOPIC] --outputTopic=[TOPIC]"

package com.spotify.scio.examples.extra import java.lang.{Double => JDouble} import com.spotify.scio._ import com.spotify.scio.avro.Account import com.spotify.scio.values.SCollection import org.apache.beam.sdk.io.gcp.pubsub.PubsubIO import org.apache.beam.sdk.options.PipelineOptions import org.apache.beam.sdk.transforms.windowing._ import org.apache.beam.sdk.transforms.{PTransform, Sum} import org.apache.beam.sdk.values._ import org.joda.time.Duration object BeamExample

A Beam native source PTransform where the input type is PBegin

def pubsubIn(topic: String): PTransform[PBegin, PCollection[Account]] = PubsubIO.readAvros(classOf[Account]).fromTopic(topic)  

A Beam native windowing PTransform

val window: PTransform[PCollection[Account], PCollection[Account]] = Window .into[Account](FixedWindows.of(Duration.standardMinutes(60))) .triggering( AfterWatermark .pastEndOfWindow() .withEarlyFirings( AfterProcessingTime .pastFirstElementInPane() .plusDelayOf(Duration.standardMinutes(5)) ) .withLateFirings( AfterProcessingTime .pastFirstElementInPane() .plusDelayOf(Duration.standardMinutes(10)) ) ) .accumulatingFiredPanes()  

A Beam native aggregation PTransform

Sum.doublesPerKey() sums java.lang.Double which is a different type from scala.Double

val sumByKey: PTransform[PCollection[KV[String, JDouble]], PCollection[KV[String, JDouble]]] = Sum.doublesPerKey[String]()  

A Beam native sink PTransform where the output type is PDone

def pubsubOut(topic: String): PTransform[PCollection[String], PDone] = PubsubIO.writeStrings().to(topic) def main(cmdlineArgs: Array[String]): Unit = { 

Parse command line arguments and create Beam specific options plus application specific arguments

val (opts, args) = ScioContext.parseArguments[PipelineOptions](cmdlineArgs)  

Create a new ScioContext with the given PipelineOptions

val sc = ScioContext(opts)  

Underlying Beam Pipeline

sc.pipeline  

Custom input with a Beam source PTransform

val accounts: SCollection[Account] = sc.customInput("Input", pubsubIn(args("inputTopic")))  

Underlying Beam PCollection[Account]

val p: PCollection[Account] = accounts.internal // scalafix:ok accounts 

Beam PTransform

.applyTransform(window

Scio map transform

.map(a => KV.of(a.getName.toString, a.getAmount)) 

Beam PTransform

.applyTransform(sumByKey

Scio map transform

.map(kv => kv.getKey + "_" + kv.getValue

Custom output with a Beam sink PTransform

.saveAsCustomOutput("Output", pubsubOut(args("outputTopic")))  

This calls sc.pipeline.run() under the hood

val executedContext = sc.run()  

Underlying Beam pipeline result PipelineResult

executedContext.pipelineResult () } }