fabric-cicd library (Python) - TokenError with DefaultAzureCredential despite explicit bearer token

Hi Shiva3 ,

Thank you for providing such a thorough description and all your troubleshooting steps—it really helps in narrowing down the potential root cause.

Based on your explanation, it seems the main issue is that the fabric-cicd Python library (v0.1.19) fails to use a pre-acquired bearer token passed from your CI/CD pipeline, and instead, it defaults to DefaultAzureCredential (which then fails due to missing environment variables).

A few thoughts and suggestions:

1. Library Limitation (v0.1.19):
As you mentioned, in v0.1.19, the library’s internal credential chain appears to prioritize DefaultAzureCredential over any explicitly provided bearer token, unless the bearer token is passed in a very specific way (such as an environment variable or a particular function parameter). This is a known issue in some Azure SDKs/libraries where the credential flow cannot be easily overridden. It’s possible that this is either a bug or a limitation in this version of fabric-cicd.

2. Possible Workarounds:

• Environment Variable Injection:
  Try explicitly setting the AZURE_ACCESS_TOKEN or similar environment variable (if supported by the library) right before the deploy/apply steps in your pipeline, so the library picks it up as part of its credential chain.
• Monkey-Patching or Custom Auth:
  If the library allows, try manually injecting the token into the authentication header or overriding the credential resolution inside your deployment script. Sometimes, patching the HTTP client or session used by the library allows you to force usage of your token.
• Check for Updates:
  Look for newer releases of the fabric-cicd library or related GitHub issues/PRs. This is a common enough scenario that the maintainers may have addressed it or provided a workaround in a newer version.
• Log Level Debugging:
  Run your deployment with full debug logging enabled to see exactly where and why the credential fallback happens. This might reveal if there’s a code path or config you can override.

3. Additional Checks:

• Confirm that the bearer token you’re passing is valid for the specific scope required by the Fabric API (sometimes, tokens with the wrong audience/scope will be ignored, causing the library to fall back).
• Double-check that there is no typo or mismatch in the way the token is injected or referenced in your deployment environment.

4. Contacting the Maintainers:
Since you’ve already validated most of the usual suspects, if none of the above workarounds help, I would recommend raising this as a GitHub issue in the repository for the fabric-cicd library (or wherever it’s maintained). Include your findings and steps above—it’s very likely the maintainers will want to know about this, and may provide a hotfix or further guidance.

Summary:

• This looks like a limitation or bug in how fabric-cicd (v0.1.19) prioritizes credentials.
• Try injecting the token as an environment variable or monkey-patching if possible.
• Check for library updates or open an issue with the maintainers if no workaround is effective.

If you do find a workaround or hear back from the maintainers, please share it here—it will help others facing the same challenge!

Good luck, and let us know how it goes.