Version Control in CI
Upgrading Mercurial
Upgrading Mercurial in CI requires touching a handful of different components.
Vendored robustcheckout
The robustcheckout Mercurial extension is used throughout CI to
perform clones and working directory updates. The canonical home of
the extension is in the
https://hg.mozilla.org/hgcustom/version-control-tools repository
at the path hgext/robustcheckout/__init__.py.
When upgrading Mercurial, the robustcheckout extension should also
be updated to ensure it is compatible with the version of Mercurial
being upgraded to. Typically, one simply copies the latest version
from version-control-tools into the vendored locations.
The locations are as follows:
In-tree:
testing/mozharness/external_tools/robustcheckout.pyTreescript:
https://github.com/mozilla-releng/scriptworker-scripts/blob/master/treescript/treescript/py2/robustcheckout.pybuild-puppet:
https://github.com/mozilla-releng/build-puppet/blob/master/modules/mercurial/files/robustcheckout.pyronin_puppet:
https://github.com/mozilla-platform-ops/ronin_puppet/blob/master/modules/mercurial/files/robustcheckout.pyOpenCloudConfig:
https://github.com/mozilla-releng/OpenCloudConfig/blob/master/userdata/Configuration/FirefoxBuildResources/robustcheckout.py
Debian Packages for Debian and Ubuntu Based Docker Images
taskcluster/kinds/packages/debian.yml and taskcluster/kinds/packages/ubuntu.yml
define custom Debian packages for Mercurial. These are installed in various
Docker images.
To upgrade Mercurial, typically you just need to update the source URL and its hash in this file.
Windows AMIs
https://github.com/mozilla-releng/OpenCloudConfig defines the Windows
environment for various Windows AMIs used by Taskcluster. Several of
the files reference a mercurial-x.y.z-*.msi installer. These references
will need to be updated to the Mercurial version being upgraded to.
The robustcheckout extension is also vendored into this repository
at userdata/Configuration/FirefoxBuildResources/robustcheckout.py. It
should also be updated if needed.
Puppet Maintained Hosts
Some hosts (namely macOS machines) are managed by Puppet and Puppet is used to install Mercurial.
Puppet code lives in the https://github.com/mozilla-releng/build-puppet repository.
Relevant files are in modules/mercurial/,
modules/packages/manifests/mozilla/mozilla-python27-mercurial-debian/,
and modules/packages/manifests/mozilla/py27_mercurial*. A copy of
robustcheckout is also vendored at
modules/mercurial/files/robustcheckout.py.
Note
The steps to upgrade Mercurial in Puppet aren’t currently captured here. Someone should capture those…