Sample application using Akka Http REST API to test docker image generation with plugin sbt-native-packager.
To use the endpoint from the terminal:
curl http://localhost:8080/hello
##Setup for create docker images automatically
First of all you need Docker installed and running in your system.
Add native packager in properties/plugins.sbt:
addSbtPlugin("com.typesafe.sbt" % "sbt-native-packager" % "1.7.6")
Reload the project.
In build.sbt add the following:
mainClass in Compile := Some("com.gm.AkkaHttpService")
enablePlugins(AshScriptPlugin)
enablePlugins(AshScriptPlugin) must be at the bottom of build.sbt.
To build the image run:
sbt docker:publishLocal
After a couple of minutes you will see the [success] message (I saw some [error] messages in red which seems be fine anyway ... a little weird ...)
From the command lined run:
docker images
You will see the image generated with name akka-http-docker and tag 0.1:
REPOSITORY TAG IMAGE ID CREATED SIZE
akka-http-docker 0.1 94866ee80cd1 27 seconds ago 539MB
cassandra 3 b52b5f0d6e11 13 days ago 402MB
cassandra latest b52b5f0d6e11 13 days ago 402MB
...
So now we can run the image using docker:
docker run --rm -p8080:8080 akka-http-docker:0.1
And then we could check using curl that the service is running ok.
We can choose what image use with the following line in build.sbt:
dockerBaseImage := "adoptopenjdk/openjdk11:alpine-slim"
Other images you can use:
dockerBaseImage := "openjdk:jre"
dockerBaseImage := “openjdk:jre-alpine”
To remove the image when you are not using it:
docker rmi akka-http-docker:0.1
Can we change the name of the image? Yes:
Docker / packageName := "akka-http-dockerized"
Can we change the tag? Yes:
dockerAliases ++= Seq(dockerAlias.value.withTag(Option("3.1")))