`az aks command` does not always honor `--output` parameter

[l3ender]

Describe the bug

If I am using az aks command invoke and the related az aks command result, using --output json does not always return JSON content.

Related command

az aks command

Errors

Command output is not in JSON.

Issue script & Debug output

For example, I have a job which I want to wait for completion. I am using the following command:

az aks command invoke --resource-group my-rg --name my-cluster --command 'kubectl wait --for=condition=complete --timeout=10m -n my-namespace jobs/my-job' --no-wait --output json

This returns the following output in non-json:

command id: 70f2846682cf4cd38aa36857d4274570, started at: None, status: Running
Please use command "az aks command result -g my-rg -n my-cluster -i 70f2846682cf4cd38aa36857d4274570" to get the future execution result

Then if I check on the status of the command, I see the same issue (note the status is still "running"):

az aks command result --resource-group my-rg --name my-cluster --command-id 70f2846682cf4cd38aa36857d4274570 --output json
command id: 70f2846682cf4cd38aa36857d4274570, started at: 2025-03-30T02:28:31Z, status: Running
Please use command "az aks command result -g my-rg -n my-cluster -i 70f2846682cf4cd38aa36857d4274570" to get the future execution result

However, once the job finishes, the command does return JSON as expected:

az aks command result --resource-group my-rg --name my-cluster --command-id 70f2846682cf4cd38aa36857d4274570 --output json
{
  "exitCode": 0,
  "finishedAt": "2025-03-30T02:31:34+00:00",
  "id": "70f2846682cf4cd38aa36857d4274570",
  "logs": "job.batch/my-job condition met\n",
  "provisioningState": "Succeeded",
  "reason": null,
  "startedAt": "2025-03-30T02:28:31+00:00"
}

Expected behavior

Our expectation is that the command should always return JSON if specified as a parameter.

Environment Summary

az version
{
  "azure-cli": "2.70.0",
  "azure-cli-core": "2.70.0",
  "azure-cli-telemetry": "1.1.0",
  "extensions": {}
}

Additional context

No response

[yonzhan]

Thank you for opening this issue, we will look into it.

[l3ender]

Hello @yonzhan - any findings/update?

[l3ender]

@yonzhan - any update? Thank you!

[mbifeld]

Hi @l3ender, the previous maintainer of the az aks command is no longer working on it. I'm currently trying to find a new owner to take a look at this issue. Thanks for your patience!

[l3ender]

Hello @mbifeld - any update on this one? Thank you!

[mbifeld]

Hey @l3ender, thanks for your patience. I checked with some devs internally. It seems like while unintuitive, the code is working as intended. The final result respects the --output arg, be it json or yaml, or other types. The non-json output you mentioned was printed out to as a "for your information" kind of message. It is not the final result object and thus isn't processed by the code that uses the --output input.

The command result uses a lot of print in its implementation, which will skip the cli framework and output the content directly to stdout, which is not controlled by the output option.

https://github.com/Azure/azure-cli/blob/dev/src/azure-cli/azure/cli/command_modules/acs/custom.py#L2156-L2211

[l3ender]

Hello and thank you for the response!

I'm not quite sure how to respond, but regardless of how the internals of the code works, this seems like a bug: the --output argument should handle the format of what is returned to the client. The inconsistency with the behavior in above commands also seems like an issue.

If it's a known limitation or item that can't/won't be resolved for the commands, it should be documented for the command usage and on the doc pages for the same: https://learn.microsoft.com/en-us/cli/azure/aks/command.

Looking forward to hearing next steps--thank you!

[l3ender]

Hello, @mbifeld, can you please advise on next steps for this issue? Thank you!

[l3ender]

Hello, any update on this? cc @mbifeld / @yonzhan

[l3ender]

This is still outstanding and would be nice to get a fix for the issue!