Using az cli in github actions to update container label and create revision routinely causes volume mount failure.

[JamesFieldist]

Please provide us with the following information:

This issue is a: (mark with an x)

• bug report -> please search issues before submitting
• documentation issue or request
• regression (a behavior that used to work and stopped in a new release)

Issue description

Azure Container Apps revisions intermittently fail to start during deployment due to storage mount permission errors reported as VolumeMountFailure with mount error(13): Permission denied (CIFS mount). In the same failing deployment windows, ARM update calls also return ContainerAppOperationInProgress conflicts.

Observed in GitHub Actions run:

• Workflow: UAT - CI/CD Pipeline (private repository)
• Run details: available privately on request

Failing jobs containing mount-related evidence:

• Two parallel app deployment jobs in deploy_otherservices

Representative error evidence from logs:

• startup failure signature detected ... reason 'VolumeMountFailure' ... StdErr = mount error(13): Permission denied
• Occurred on multiple app revisions within the same deployment window

Additional correlated errors in same jobs:

• ERROR: Conflict(... "code":"ContainerAppOperationInProgress" ...) while retrying update/recovery operations.

Steps to reproduce

1. Deploy a new image revision to Azure Container Apps in an environment that uses Azure File/CIFS volume mounts via GitHub Actions.
2. During rollout, monitor revision/system logs for startup events.
3. Observe intermittent startup failure where the container terminates immediately with:
   • VolumeMountFailure
   • mount error(13): Permission denied
4. Attempt immediate retry/update/start/stop operations; observe concurrent ContainerAppOperationInProgress conflicts while provisioning is still active.

Expected behavior
Container Apps should consistently mount the configured volume and start the new revision successfully, without intermittent CIFS permission-denied failures. Recovery/update operations should not repeatedly deadlock on transient provisioning conflicts.

Actual behavior
New revisions intermittently fail with VolumeMountFailure and mount error(13): Permission denied, causing deployment failure. During mitigation attempts, ARM operations frequently return ContainerAppOperationInProgress, extending outage/retry windows.

Screenshots
N/A (sanitized text logs can be provided).

Additional context

• Occurred in GitHub Actions CI/CD during automated deployment (not manually triggered in Portal UI).
• Azure target environment: private Container Apps environment.
• This appears intermittent/flaky rather than deterministic for every rollout, which suggests a platform/runtime/provisioning interaction issue.

[simonjj]

Thanks for the detailed write-up. We'd like to investigate this on the backend, but we'll need some specifics that are better shared privately.

Could you send an email to acasupport@microsoft.com with:

• Your Container App resource URI (the full ARM resource path)
• The specific dates and times (with timezone) when the VolumeMountFailure and ContainerAppOperationInProgress errors occurred

That'll let us pull the backend logs and see what's going on from the platform side. We'll follow up here once we've had a look.

[JamesFieldist]

Hi, should be in your inbox. Please let me know if you need anything else.

We have in the past seen this in Azure AKS too and I believe there are many reports of similar in their repo.

[JamesFieldist]

It's happening right now on "poxy" in our UAT environment.

Error: poxy volume mount recovery exhausted after 3 attempts.
Error: poxy revision poxy--0000480 startup failure signature detected: "TimeStamp": "2026-04-29 17:07:31.3748267 +0000 UTC", "Type": "Warning", "ContainerAppName": "poxy", "RevisionName": "poxy--0000480", "ReplicaName": "poxy--0000480-6987c97bcb-9nmld", "Msg": "Container 'proxy' was terminated with exit code '1' and reason 'VolumeMountFailure'. Shell command exited with non-zero status code. StatusCode = 32 | StdOut = | StdErr = mount error(13): Permission denied\nRefer to the mount.cifs(8) manual page (e.g. man mount.cifs) and kernel log messages (dmesg)\n", "Reason": "ContainerTerminated", "EventSource": "ContainerAppController", "Count": 1