Import error ExternalHttpFunctionApp

[alex-akanthas]

We are running python app functions started by a service queue. We have made no changes on our end and we are now receiving the following error across multilple app functions:

Result: Failure Exception: ImportError: cannot import name 'ExternalHttpFunctionApp' from 'azure.functions.decorators.function_app' (/azure-functions-host/workers/python/3.9/LINUX/X64/azure/functions/decorators/function_app.py) Stack: File "/azure-functions-host/workers/python/3.9/LINUX/X64/azure_functions_worker/dispatcher.py", line 383, in _handle__function_load_request ExtensionManager.function_load_extension( File "/azure-functions-host/workers/python/3.9/LINUX/X64/azure_functions_worker/utils/wrappers.py", line 19, in call return func(*args, **kwargs) File "/azure-functions-host/workers/python/3.9/LINUX/X64/azure_functions_worker/extension.py", line 65, in function_load_extension sdk = cls._try_get_sdk_with_extension_enabled() File "/azure-functions-host/workers/python/3.9/LINUX/X64/azure_functions_worker/extension.py", line 225, in _try_get_sdk_with_extension_enabled sdk = get_sdk_from_sys_path() File "/azure-functions-host/workers/python/3.9/LINUX/X64/azure_functions_worker/utils/common.py", line 121, in get_sdk_from_sys_path module = importlib.import_module('azure.functions') File "/usr/local/lib/python3.9/importlib/__init__.py", line 127, in import_module return _bootstrap._gcd_import(name[level:], package, level) File "<frozen importlib._bootstrap>", line 1030, in _gcd_import File "<frozen importlib._bootstrap>", line 1007, in _find_and_load File "<frozen importlib._bootstrap>", line 986, in _find_and_load_unlocked File "<frozen importlib._bootstrap>", line 680, in _load_unlocked File "<frozen importlib._bootstrap_external>", line 850, in exec_module File "<frozen importlib._bootstrap>", line 228, in _call_with_frames_removed File "/home/site/wwwroot/.python_packages/lib/site-packages/azure/functions/__init__.py", line 14, in <module> from .decorators.function_app import (FunctionRegister, TriggerApi, BindingApi,

Unfortunately the azure interface would not let me copy the whole error message.

Our location is France Central

[alex-akanthas]

This the full error message: Failure\nException: ImportError: cannot import name 'ExternalHttpFunctionApp' from 'azure.functions.decorators.function_app' (/azure-functions-host/workers/python/3.9/LINUX/X64/azure/functions/decorators/function_app.py)\nStack: File "/azure-functions-host/workers/python/3.9/LINUX/X64/azure_functions_worker/dispatcher.py", line 383, in _handle__function_load_request\n ExtensionManager.function_load_extension(\n File "/azure-functions-host/workers/python/3.9/LINUX/X64/azure_functions_worker/utils/wrappers.py", line 19, in call\n return func(*args, **kwargs)\n File "/azure-functions-host/workers/python/3.9/LINUX/X64/azure_functions_worker/extension.py", line 65, in function_load_extension\n sdk = cls._try_get_sdk_with_extension_enabled()\n File "/azure-functions-host/workers/python/3.9/LINUX/X64/azure_functions_worker/extension.py", line 225, in _try_get_sdk_with_extension_enabled\n sdk = get_sdk_from_sys_path()\n File "/azure-functions-host/workers/python/3.9/LINUX/X64/azure_functions_worker/utils/common.py", line 121, in get_sdk_from_sys_path\n module = importlib.import_module('azure.functions')\n File "/usr/local/lib/python3.9/importlib/init.py", line 127, in import_module\n return _bootstrap._gcd_import(name[level:], package, level)\n File "", line 1030, in _gcd_import\n File "", line 1007, in _find_and_load\n File "", line 986, in _find_and_load_unlocked\n File "", line 680, in _load_unlocked\n File "", line 850, in exec_module\n File "", line 228, in _call_with_frames_removed\n File "/home/site/wwwroot/.python_packages/lib/site-packages/azure/functions/init.py", line 14, in \n from .decorators.function_app import (FunctionRegister, TriggerApi, BindingApi,\n","Error"

[alex-akanthas]

We have deployed and now the app functions are working as expected. I can see that the docker images were updated yesterday https://hub.docker.com/_/microsoft-azure-functions-python

[ogimenez-smtc]

Hello, I also hit that issue in one of my projects and I had to redeploy.
@Microsoft-team could you please investigate and provide an explanation? Thank you

[NiklasDonasen]

I am experiencing the exact same problem (and have not done any code updates over the last few months). A fix by Microsoft would be greatly appreciated. Locally everything works fine, but remotely in the cloud it just stops.

@alex-akanthas : how did your redeploying solve this? I ran our build pipeline manually and can see that the setting Website_run_from_package points to the updated package in the storage account, but the function still fails.

[gather-abhishekb]

When we raised a support ticket the support window reported an outage in east us and central us region for Azure function apps, we deployed in a different region and it worked. Azure should have been proactive about it. I am not sure what is the current status since today morning, but I think that remianed faulty for more than 12 hours.

[builtbywill]

I just ran into this error as well.

It looks that the reference to ExternalHttpFunctionApp was removed in version 1.13.3 of the azure-functions python library in this change

Our code was still running version 1.13.2, which still included that reference, and we were seeing the same error as above, 500s on all calls to our HTTP functions.

Updating our code to the latest version 1.14.0 resolved the issue (though just updating to 1.13.3 might have also worked).

It appears the docker image updated to 4.19.0,
which updated the function host to 4.19.0,
which updated the python worker to 4.11.0,
which uses the python lib sdk 1.13.3

Something is this update chain broke support for the older version 1.13.2

[alex-akanthas]

Thanks for the info builtbywill. That looks like the root cause.

@NiklasDonasen On further analysis this only caused issues on the app functions that we hadn't deployed in a couple of months. We had not set an explicity version for azure-functions python library in our requirements.txt so when it was re-deployed I guess it was automatically upgraded to 1.14.0 therefore resolving the issue.

[NiklasDonasen]

@alex-akanthas and @builtbywill : excellent. I have updated to 1.14.0 and now it works. Thanks a lot for the good explanations! Much appreciated!

[builtbywill]

FYI It looks like Azure sent out a Service Health Alert for this issue yesterday https://app.azure.com/h/B_BH-3P8/13269a

[pdthummar]

@alex-akanthas Thanks for reporting the issue. Please use following mitigation to resolve the issue. Team is working on fix, and it will be available in future releases.

Potential mitigation would be to try adding the following options:

1. Remove pinning of the Azure-functions library, or pin 1.14.0+
2. Enable Dependency Isolation: PYTHON_ISOLATE_WORKER_DEPENDENCIES to 1 in App settings.
3. Disable Worker Extensions (if you are not using them) - PYTHON_ENABLE_WORKER_EXTENSIONS to 0.

If the error persists, please revert the changes. Thanks