I'm trying to run the Google App Engine local development server (dev_appserver.py), using the following command:
python3 "C:\Users\myusername\AppData\Local\Google\Cloud SDK\google-cloud-sdk\bin\dev_appserver.py" "C:\Users\myusername\Desktop\test_gae_python3\app.yaml"
However I get the following exception:
# INFO 2023-02-15 23:27:07,500 devappserver2.py:317] Skipping SDK update check.
# INFO 2023-02-15 23:27:07,720 <string>:384] Starting API server at: http://localhost:50618
# INFO 2023-02-15 23:27:07,747 instance_factory.py:155] Detected python version "Python 3.9.13
# " for runtime "python39" at "python3".
# Actual environment location may have moved due to redirects, links or junctions.
# Requested location: "c:\users\myuser~1\appdata\local\temp\tmp2cocmu\Scripts\python3.exe"
# Actual location: "C:\Users\myusername\AppData\Local\Temp\tmp2cocmu\Scripts\python3.exe"
# INFO 2023-02-15 23:27:17,122 instance_factory.py:312] Using pip to install dependency libraries; pip stdout is redirected to c:\users\myuser~1\appdata\local\temp\tmpsvzpsq
# INFO 2023-02-15 23:27:17,154 instance_factory.py:334] Running c:\users\myuser~1\appdata\local\temp\tmp2cocmu\bin\pip install --upgrade pip
# INFO 2023-02-15 23:27:17,155 stub_util.py:360] Applying all pending transactions and saving the datastore
# INFO 2023-02-15 23:27:17,157 stub_util.py:363] Saving search indexes
# Traceback (most recent call last):
# File "C:\Users\myusername\AppData\Local\Google\Cloud SDK\google-cloud-sdk\platform\google_appengine\dev_appserver.py", line 109, in <module>
# _run_file(__file__, globals())
# File "C:\Users\myusername\AppData\Local\Google\Cloud SDK\google-cloud-sdk\platform\google_appengine\dev_appserver.py", line 103, in _run_file
# _execfile(_PATHS.script_file(script_name), globals_)
# File "C:\Users\myusername\AppData\Local\Google\Cloud SDK\google-cloud-sdk\platform\google_appengine\dev_appserver.py", line 83, in _execfile
# execfile(fn, scope)
# File "C:\Users\myusername\AppData\Local\Google\Cloud SDK\google-cloud-sdk\platform\google_appengine\google\appengine\tools\devappserver2\devappserver2.py", line 645, in <module>
# main()
# File "C:\Users\myusername\AppData\Local\Google\Cloud SDK\google-cloud-sdk\platform\google_appengine\google\appengine\tools\devappserver2\devappserver2.py", line 633, in main
# dev_server.start(options)
# File "C:\Users\myusername\AppData\Local\Google\Cloud SDK\google-cloud-sdk\platform\google_appengine\google\appengine\tools\devappserver2\devappserver2.py", line 401, in start
# options.api_host, apiserver.port, wsgi_request_info_)
# File "C:\Users\myusername\AppData\Local\Google\Cloud SDK\google-cloud-sdk\platform\google_appengine\google\appengine\tools\devappserver2\dispatcher.py", line 272, in start
# ssl_port)
# File "C:\Users\myusername\AppData\Local\Google\Cloud SDK\google-cloud-sdk\platform\google_appengine\google\appengine\tools\devappserver2\dispatcher.py", line 409, in _create_module
# ssl_port=ssl_port)
# File "C:\Users\myusername\AppData\Local\Google\Cloud SDK\google-cloud-sdk\platform\google_appengine\google\appengine\tools\devappserver2\module.py", line 1356, in __init__
# super(AutoScalingModule, self).__init__(**kwargs)
# File "C:\Users\myusername\AppData\Local\Google\Cloud SDK\google-cloud-sdk\platform\google_appengine\google\appengine\tools\devappserver2\module.py", line 615, in __init__
# self._module_configuration)
# File "C:\Users\myusername\AppData\Local\Google\Cloud SDK\google-cloud-sdk\platform\google_appengine\google\appengine\tools\devappserver2\module.py", line 242, in _create_instance_factory
# module_configuration=module_configuration)
# File "C:\Users\myusername\AppData\Local\Google\Cloud SDK\google-cloud-sdk\platform\google_appengine\google\appengine\tools\devappserver2\python\instance_factory.py", line 207, in __init__
# self._SetupVirtualenvFromConfiguration()
# File "C:\Users\myusername\AppData\Local\Google\Cloud SDK\google-cloud-sdk\platform\google_appengine\google\appengine\tools\devappserver2\python\instance_factory.py", line 233, in _SetupVirtualenvFromConfiguration
# self._venv_dir, self._OrigRequirementsFile)
# File "C:\Users\myusername\AppData\Local\Google\Cloud SDK\google-cloud-sdk\platform\google_appengine\google\appengine\tools\devappserver2\python\instance_factory.py", line 359, in _SetupVirtualenv
# self._RunPipInstall(venv_dir, requirements_file_name)
# File "C:\Users\myusername\AppData\Local\Google\Cloud SDK\google-cloud-sdk\platform\google_appengine\google\appengine\tools\devappserver2\python\instance_factory.py", line 335, in _RunPipInstall
# pip_proc = subprocess.Popen(pip_cmd, stdout=pip_out, env=pip_env)
# File "C:\Users\myusername\AppData\Local\Google\Cloud SDK\google-cloud-sdk\platform\bundledpython2\lib\subprocess.py", line 390, in __init__
# errread, errwrite)
# File "C:\Users\myusername\AppData\Local\Google\Cloud SDK\google-cloud-sdk\platform\bundledpython2\lib\subprocess.py", line 640, in _execute_child
# startupinfo)
# WindowsError: [Error 2] The system cannot find the file specified
C:\Users\myusername\Desktop\test_gae_python3\app.yaml:
runtime: python39
app_engine_apis: true
service: default
entrypoint: python3 -m app
C:\Users\myusername\Desktop\test_gae_python3\app.py:
print('OK')
Of course this is a minimal scenario to reproduce the problem, my actual application is much more complex.
Environment:
I have no other versions of Python installed in the system.
I've tried reverting the SDK back to 367.0.0 and I get the same exact exception.
Google Cloud SDK 366.0.0 raises a different exception which I don't think is relevant but I can paste if useful.
Background: I'm trying to migrate a Python 2 server to version 3, but I got stuck at this stage and can't wrap my head around it.
This isn't supported by Google. According to Google documentation
The dev_appserver tool does not support development of Python 3 apps on Windows.
I believe it's because gunicorn doesn't run on Windows. But if you still want to use dev_appserver.py for Python 3 Apps on a Windows machine, you can check out a Patch we created (the patch essentially swaps out Gunicorn for Waitress when running your App on your dev machine)