#Sbt docker run image how to#
#Sbt docker run image code#
#Sbt docker run image free#

Then add dockerBaseImage := 'openjdk:8-jre-alpine' above where we change the packageName. At this point it uses over 700MB.ДЇirst, letвЂ™s increase the version so we get a different tag and can compare them. We can query the todos to make sure it works as expected: Making our image lighterДЇor our last experiment, we will try to make our image lighter. Run docker run -p 5000:9000 dockerised-akka-http:0.1 to run our new image with a different port. When we specify the flag -p 9000:9000 we are saying that the port 9000 in the host machine will map to the port 9000 in our process' network. Because our application is running in a different network, we can map a different port to the internal 9000 port. Ideally, we would read it from an environment variable and maybe have one as default.Д«ut thatвЂ™s okay. The port is hardcoded in our application.

#Sbt docker run image code#

We canвЂ™t change the port that our application is listening to without making code changes. Now we have two images, the original one and the new one. We can check that we have a new image by running docker images: REPOSITORY TAG IMAGE ID CREATED SIZE akkahttp-quickstart 0.1 d03732dd0854 42 minutes ago 774MB dockerised-akka-http 0.1 d03732dd0854 42 minutes ago 774MB To change the image name we can modify the packageName property in our build.sbt file, add the following line after the scalaVersion property: packageName in Docker := 'dockerised-akka-http' Give it a read and see what else you can customise. If we look into the pluginвЂ™s official documentation, we see that there are a number of options we can change.

What if we want to use a different port?.

What if we want a different image name?.

There are several things that we might want to do with the current setup we have: WeвЂ™re now able to query our dockerised application: Customising our setup This time when we run it, weвЂ™ll expose the respective port as well: docker run -p 9000:9000 akkahttp-quickstart:0.1 Stop the running application, either by hitting Ctrl-C or by running docker stop $CONTAINER_ID. There are multiple ways to allow communication between Docker processes and the host machine. LetвЂ™s run docker ps to get some information about our running Docker process (output abbreviated): CONTAINER ID IMAGE PORTS NAMES9746162d4723 akkahttp-quickstart:0.1 serene_agnesiДЄs we can see, there are no ports exposed, so thereвЂ™s no way to communicate with our application.ДЄpplications in Docker run in their network by default. Run docker run akkahttp-quickstart:0.1, you should see the Success! message once again.Д«ut this time, if we try to query our application weвЂ™ll get an error: We can now run our application using Docker. Run docker images and you should see the following entry: REPOSITORY TAG IMAGE ID CREATED SIZEakkahttp-quickstart 0.1 d03732dd0854 42 seconds ago 774MB As its name suggests, it will publish a Docker image of our application to our local registry. We can build a Docker image using that Dockerfile manually, but thereвЂ™s a more convenient way of doing so. It ends up running a similar binary to the one we generated and ran earlier. Run sbt docker:stage, then run cat target/docker/stage/Dockerfile to see its contents: FROM openjdk:latestWORKDIR /opt/dockerADD -chown=daemon:daemon opt /optUSER daemonENTRYPOINT CMD LetвЂ™s start by generating the Dockerfile for our application. ItвЂ™s time to start toying around with Docker. If you send a GET request to localhost:9000/todos you'll get a couple of todos.

target/universal/stage/bin/akkahttp-quickstart. Now we can execute our application by running. Run sbt stage in the project's root directory.

Add the following line at the top: enablePlugins(JavaAppPackaging)Д®nabling this plugin also allows us to create an executable for our application. Then we need to enable the plugin in our build.sbt file. If the file doesn't exist, we need to create it, and then add the following line: addSbtPlugin('' % 'sbt-native-packager' % '1.3.6') Adding the pluginДЇirst, we need to add the plugin to our project in the project/plugins.sbt file.

#Sbt docker run image free#

We will be using the following repository, feel free to clone it and make sure to checkout the branch 6.5-testing-directives. You can use any Scala or Akka HTTP project for this tutorial. To automate the creation of the Dockerfile for our project, we will use the sbt-native-packager plugin. If it isnвЂ™t, please follow the official documentation.

#Sbt docker run image how to#

In this tutorial we will how to learn to dockerise our Scala and Akka HTTP applications without even creating a Dockerfile ourselves.ДЇor the purposes of this tutorial, we assume Docker is already installed on the machine. By Miguel Lopez How to Dockerise a Scala and Akka HTTP Application - the easy way

Sbt-docker run image