Source-tag or source-commit - via variable?

snapcraft
1

Is there any way to use a variable for defining the source-tag or source-commit for a part in the snapcraft.yaml -file?

I have a repo, which provides multiple applications/commands and thus I probably should have multiple parts as well. I would very much prefer to keep the parts/applications in sync and if I use a manually written tag - I’m quite sure it will sooner or later be out-of-sync.

So, is it possible to have a definition somewhere and then re-use that via all the parts?

Like PE-UTILS-VER="2.1.0" and then just update that once and use that same variable in the snapcraft.yaml in multiple places?

    pe-utils:
      plugin: nil
      source: https://github.com/PelionIoT/pe-utils.git
      source-tag: $PE-UTILS-VER

I could not find anything straight off the bat in the documents.

2

Another idea to work around this - can I just have 3 parts there, of which 1 does the pull and the others just have to run AFTER the part that does the git fetch and just refer to that some location somehow?

3

You’re right, there is no easy solution here. Yaml does not support variable placeholders and snapcraft does not add this functionality.

You have a few options. Your idea of using the after keyword and copying another part’s staged directory could work, but it would take some experimenting.

Another option would be using the override-pull keyword to work around yaml’s lack of variables:

override-pull: |
  craftctl default
  git checkout $(cat snap/my-part-version.txt)

The last option would be to use override-pull to be dynamic. Often, it’s used to pull the latest tagged release by parsing commands like git tag -l or git describe --tags.