Python Deployment - Could not find output.tar.gz
This post will cover troubleshooting a specific deployment startup message for python app services on Linux.
Overview
When deploying your python application to a linux app service, you may encounter the below error message on startup.
_____
/ _ \ __________ _________ ____
/ /_\ \\___ / | \_ __ \_/ __ \
/ | \/ /| | /| | \/\ ___/
\____|__ /_____ \____/ |__| \___ >
\/ \/ \/
A P P S E R V I C E O N L I N U X
Documentation: http://aka.ms/webapp-linux
Python 3.9.16
Note: Any data outside '/home' is not persisted
Starting OpenBSD Secure Shell server: sshd.
Command Line not configured, will attempt auto-detect
Starting periodic command scheduler: cron.
Launching oryx with: create-script -appPath /home/site/wwwroot -output /opt/startup/startup.sh -virtualEnvName antenv -defaultApp /opt/defaultsite
Found build manifest file at '/home/site/wwwroot/oryx-manifest.toml'. Deserializing it...
Build Operation ID: |MhrvOK2skdE=.25fa9d03_
Oryx Version: 0.2.20230103.1, Commit: df89ea1db9625a86ba583272ce002847c18f94fe, ReleaseTagName: 20230103.1
Output is compressed. Extracting it...
panic: Could not find file '/home/site/wwwroot/output.tar.gz'.
goroutine 1 [running]:
common.ExtractTarball({0xc0000184e0, 0x20}, {0xc00001c2a0, 0x14})
/usr/local/go/src/common/compressionHelper.go:29 +0x354
main.(*PythonStartupScriptGenerator).GenerateEntrypointScript(0xc0000bbbd8)
/go/src/python/scriptgenerator.go:62 +0x2a9
main.main()
/go/src/python/main.go:89 +0x9e5
chmod: cannot access '/opt/startup/startup.sh': No such file or directory
/opt/startup/init_container.sh: line 87: /opt/startup/startup.sh: No such file or directory
Explanation
On app service startup, if your application is built with our oryx build system our python images look for the following file named output.tar.gz. If a oryx-manifest.toml file exists and the output.tar.gz file is not found the app service will throw the above exception on startup.
More information here: Python Build Changes
Common Scenarios / Fixes
Intermittent Behavior
You may notice this error intermittantly if you are deploying mulitple times, in conjuction with an app service restart operation.
If you are in the deployment phase of your project. The easiest way to fix this is stop your app service and fully to wait for your deployment operation to complete successfully, then restart your app service.
If you notice this happens during deployment to your production site, try a restart of the app service.
Consistent Behavior
It is very rare to have this specific error message occur more that once. However if you do notice this within your App Service Log Files, it likely means either the output.tar.gz file does not exist.
Please try stopping your app service and redeploying, then validate if the file exists under /home/site/wwwroot. You can do this by accessing the New Kudu Advanced Tools Site, then use the BASH console.
If this file does not exist make sure you have the below app setting enabled.
SCM_DO_BUILD_DURING_DEPLOYMENT=TRUE
Then validate that your deployment went through successfully, if it is failing during the oryx build stage, the file will not be generated.
You will need to investigate why it is failing during the build stage. You can find more helpful information regarding troubleshooting various deployment failures using the links belows.
