Charm Tech pulse 2024#4

The most exciting news from the Charm Tech team in pulse #4 is that @ironcore864 (Tiexen) joined us! Other than that, some small improvements to ops, progressing the defer work and the work to promote Scenario as a first-class Charm testing framework, and fixing the Pebble deadlock as well as other minor issues.

The ops library


  • Tony continued work on his “super tox” tool, to run the unit tests of ~150 of Canonical’s charms against different branches of Ops. As part of this, he worked through each of the tests that failed when the latest version of ops was used, and opened issues or PRs to resolve those.

  • We continued work looking over the ops-scenario API with a view to polishing it before making it more official.


  • Ben continued working through the Pebble deadlock issue that the MAAS team had discovered last Pulse, and was able to find a way to reproduce and then fix this. He’s also spent some time looking into locking in Pebble in general to see what can be improved at a higher level. He also put out three new releases, 1.4.1, 1.7.1, and 1.8.0, so the fix will appear in the next versions of Juju 3.3, 3.4, and 3.5. v1.8.0 also contains some small improvements ported over from snapd.

  • Ben has also continued working on designing and reviewing other upcoming Pebble changes, including PEBBLE_COPY_ONCE, part of the rootless work, and the change-update work that will be cross-ported from snapd. He also spent time with the Juju and Data teams looking into an issue they’re seeing with demanding workloads causing unwanted K8s pod recycling.

  • Tony also contibuted his first PR to pebble, to fix a bug with add-layer validation.