Welcome, Scala programmer. Today we will show you how to configure Gitpod for your project.
First, you’ll probably want to install Scala. To do this, add a new file to your repository called .gitpod.Dockerfile, and add the following content to it:
FROM gitpod/workspace-full RUN brew install scala
Additionally create a file called .gitpod.yml and add the following:
image: file: .gitpod.Dockerfile
Now commit both files into source control.
Let’s break this down. First, in
.gitpod.Dockerfile, we declare
FROM gitpod/workspace-full to have your project use Gitpod’s default workspace image (recommended). You can use other images too, but some Gitpod features might not work as well with untested images.
Next, we declare
RUN brew install scala. This simply installs Scala into the workspace image via HomeBrew.
Then, we register our custom Dockerfile in Gitpod’s configuration file
.gitpod.yml, so that Gitpod knows it should pick it up and build it on-the-fly when booting up new workspaces.
Finally, please note that these changes will only take effect in new workspaces. To try out your new automated dev setup, simply commit both files; push them to GitHub; and then open a new Gitpod workspace for your repository. 🚀
RUN sudo sh -c '(echo "#!/usr/bin/env sh" && curl -L https://github.com/lihaoyi/Ammonite/releases/download/2.0.4/2.13-2.0.4) > /usr/local/bin/amm && chmod +x /usr/local/bin/amm'
Then commit the changes and push to your repository. Finally, when you open a new workspace, you will be able to type
amm in the terminal, and behold a super cool Scala REPL in your workspace!
RUN brew install sbt
As usual, commit and push the changes, and
sbt will be installed in all future workspaces.
Say your project needs a specific Scala version. You can use scalaenv, a version manager for Scala, to switch between different Scala versions. But first, we must install
scalaenv. As usual, we need to change our .gitpod.Dockerfile, by adding this to it:
RUN brew install scalaenv
Then, say you need Scala version
2.9.3, you would add the following line as well:
RUN scalaenv install scala-2.9.3 && scalaenv global scala-2.9.3
coursier is useful for building certain Scala projects and installing different tools.
RUN brew install coursier/formulas/coursier
(Don’t forget to commit and push this change!)
RUN sudo env "PATH=$PATH" coursier bootstrap org.scalameta:scalafmt-cli_2.12:2.4.2 \ -r sonatype:snapshots \ -o /usr/local/bin/scalafmt --standalone --main org.scalafmt.cli.Cli
Then to format your code simply run
A full example of a .gitpod.Dockerfile configured for Scala could look something like:
FROM gitpod/workspace-full RUN sudo sh -c '(echo "#!/usr/bin/env sh" && curl -L https://github.com/lihaoyi/Ammonite/releases/download/2.0.4/2.13-2.0.4) > /usr/local/bin/amm && chmod +x /usr/local/bin/amm' RUN brew install scala coursier/formulas/coursier sbt scalaenv RUN sudo env "PATH=$PATH" coursier bootstrap org.scalameta:scalafmt-cli_2.12:2.4.2 \ -r sonatype:snapshots \ -o /usr/local/bin/scalafmt --standalone --main org.scalafmt.cli.Cli RUN scalaenv install scala-2.9.3 && scalaenv global scala-2.9.3
You will notice that all the
brew install commands are on the same line. We recommend grouping similar commands together to minimize the number of Docker layers.
Additionally, your .gitpod.yml file should still look like this:
image: file: .gitpod.Dockerfile
Scala Syntax adds basic syntax highlighting for Scala and
sbt files. To get it, add the following to your .gitpod.yml file:
vscode: extensions: - email@example.com:kklqw+c/dNRmtTU8B5repw==
Metals adds helpful Scala features to Gitpod, for example, advanced autocompletion and debugging support just to name a few. Although to use it you must also use the previously mentioned Scala Syntax you should do the following
If you already added Scala Syntax put the following on the following line
Otherwise, add the following to your .gitpod.yml
vscode: extensions: - firstname.lastname@example.org:kklqw+c/dNRmtTU8B5repw== - email@example.com:oixMSF1r3cXQPfOQ34+sTA==
Either way, the end result should look like the snippet above.
Boom! You’re done! (Just a reminder, don’t forget to push the changes.)
To debug Scala code in Gitpod you should use the Metals extension which we just went over. Here is an example of Scala Debugging in action:
In general when debugging Scala code, go to the main method, and click the Debug button over it! And boom you’re debugging.
To see a minimal repository with a Gitpod configuration that installs all the tools we’ve covered, see gitpod-io/Gitpod-Scala. You can try it in your browser:
We love feedback and want to continuously improve all of our guides and documentation. If you found a grammar mistake, or we left out your favorite Scala tool, or you just have general feedback on the guide, please feel free to edit this guide or to file a website issue on GitHub.