title: How to manage signing keystore in Gitlab CI for android
body: <p>Dear stackoverflow community, once more I turn to you :)</p>
  <p>I've recently come across the wonder of Gitlab and their very nice bundled CI/CD solution. It works gallantly however, we all need to sign our binaries don't we and I've found no way to upload a key as I would to a Jenkins server for doing this.</p>
  <p>So, how can I, without checking in my keys and secrets sign my android (actually flutter) application when building a release?</p>
  <p>From what I see, most people define the build job with signing settings referring to a non-committed key.properties file specifying a local keystore.jks. This works fine when building APKs locally but if I would like to build and archive them as a part of the CI/CD job, how do I?</p>
  <p>For secret keys, for example the passwords to the keystore itself, I've found that I can simply store them as protected variables but the actual keystore file itself. What can I do about that?</p>
  <p>Any ideas, suggestions are dearly welcome.
  Cheers</p>
  <p>Edit:
  I apologise for never marking a right answer here and as @IvanP proposed the solution of writing individual values to a file was what I used for a long time. But as @VonC added later, Gitlab now has the capability to data as actual files which simplifies this so I am marking that as the correct answer.</p>