Description

Cilium containers appear to be unable to start on the new Stable-2905.2.0 release. After updating a node, the cilium containers are not running. Verified with cilium 1.9.4 and 1.9.8.

Impact

Cluster loses networking and becomes inaccessible.

Environment and steps to reproduce

1. Set-up: Kubernetes Cluster with cilium 1.9.x, Flatcar 2765.2.6 or earlier.
2. Task: Update via Flatcar's update mechanism.
3. Action(s):
   a. Update downloads and installs automatically
   b. Node reboots
4. Error: Cilium containers fail to start

Expected behavior

Cilium containers launch as expected, cluster remains accessible via network.

Additional information

PR for adding container networking tests to CI / release tests to prevent these issues in the future: flatcar/mantle#182

The PR can also be used to repro this issue.