s2i steps default to git ref "master", but not all git repositories have a master branch

[jmtd]

In the absence of an explicit ref in the step "Given s2i build...", i.e., Given s2i build https://...somerepo.../ with no using branchname suffix, the S2I steps will default to try to check out a branch named master, which may not exist in the repository.

Instead I think it should use the repository's default branch name.

We hit this (side issue) by introducing a new repository for cekit/behave tests, https://github.com/jboss-container-images/openjdk-test-applications, which has the default branch name main. This is the new default, I think, for both Git and Github. (At the time of writing this, I'm about to push a master branch to that repository as a temporary mitigation).

The culprits are

behave-test-steps/steps/s2i_steps.py

Line 14 in e92a239

def s2i_inner(context, application, path='.', env="", incremental=False, tag="master", runtime_image=""):

and

behave-test-steps/steps/s2i_steps.py

Line 59 in e92a239

def s2i_build(context, application, path='.', env="", incremental=False, tag="master", run=True, runtime_image=""):

and possibly a few other places.

[rnc]

@jmtd You just updated failing_s2i_build in #74 to remove the explicit tag option but given the s2i clones specifying the reference (i.e. master or main etc) then unless some work is done to first establish the remote default branch (e.g. git ls-remote --symref git@github.com:rnc/behave-test-steps.git HEAD | head -1 | awk '{print $2}' | sed 's/refs\/heads\///') then I don't think we can just remove master. Potentially removing the default and if empty, then use default branch name might work?

[jmtd]

FWIW, I am incorrect in my statement above that Git's default has changed, it's still master.

[rnc]

FWIW, I am incorrect in my statement above that Git's default has changed, it's still master.

Its now configurable (https://github.blog/open-source/git/highlights-from-git-2-28/#introducing-init-defaultbranch) and gitlab, github, bitbucket have already made the changes.

[jmtd]

Its now configurable

Yeah… I've hit a problem in other software where my global preference (git config --global…) broke an implicit assumption that the value is master… this will be a problem all over the place eventually