How to debug Cloud deployment problems¶

Start with the debugging checklist. Work through the checklist by selecting the mostappropriate answer for each question until you arrive at a probable fault for the symptoms you’re seeing.

There is also a complete decision tree for the debugging process.

Debugging checklist¶

Deployment on the Cloud has not worked as expected¶

Does the Control Panel show a “Last deployment failed” error message?

- The error message is shown
- The error message is not shown

The Control Panel shows a Last deployment failed message¶

Open the log. The relevant section will be towards the end, so work backwards from the end. Any error will be clearlystated.

What does the deployment log contain?

• The log appears to be empty
• The log appears to contain no errors
• The log refers to an error

Probable fault: temporary problem¶

Please try again. This is a rare and usually temporary problem. You may need to wait a few minutes for thecondition to clear. If the issue is urgent, or you have already tried again, please contact Divio Support.

Restart the checklist

The deployment log contains no obvious error¶

Check the site’s runtime logs (via the Logs menu).

Do you see any obvious errors in the runtime logs for the web container (of the appropriate server, Test or Live)?

• The runtime log contains errors
• The runtime log contains no obvious error

Probable fault: application is too slow to start and times out¶

Probably your application took so long to start up that it triggered a timeout condition. Onour platform, if a site is not up and running within a certain period after its build hascompleted, then the deployment is marked as failed.

This could happen because it is waiting for another external resource to become available, or theprocessing it needs to do at start-up is excessive. These issues generally represent a programmingproblem that needs to be resolved.

Build the site locally and start up the application to investigate why it is taking so long.

If the start-up processes can’t be made faster or more lightweight, investigate an asynchronousprocessing option such as Celery to allow them to go on in the background while the projectstarts up.

Restart the checklist

Probable fault: programming error in runtime code¶

Probably the issue is a programming error in the site that takes down Django as it launches (typically, this willbe an ImportError). The runtime log will reveal the error.

Restart the checklist

The deployment log contains an error¶

The end of the log will contain the key error.

What does the error most closely resemble?

• Could not find a version that matches […]
• npm ERR! […] ERR! /npm-debug.log
• ImportError
• ReadTimeoutError
• The error does not seem to be any of the above

Probable fault: dependency conflict¶

An error that starts:

Could not find a version that matches [...]

indicates that two or more of the components in your system have specified incompatible Python dependencies.

See How to identify and resolve a dependency conflict.

Restart the checklist

Probable fault: A Node error has halted the build¶

Example:

npm ERR! There is likely additional logging output above.
[0m[91m
[0m[91mnpm[0m[91m ERR![0m[91m Please include the following file with any support request:
[0m[91mnpm ERR! /npm-debug.log
[0m

In this case one of the Node component installation processes has failed. If the error is not clear from the log,contact Divio support for advice.

Restart the checklist

Probable fault: An import error halts one of the site build routines¶

Example:

Step 8/8 : RUN DJANGO_MODE=build python manage.py collectstatic --noinput
[...]
ImportError: No module named django_select2

In this case a Python application launched by an instruction in the Dockerfile has caused Django to halt with anerror while it was trying to run the collectstatic command. This is a programming error. The traceback will showwhere it occurred.

Restart the checklist

Probable fault: temporary timeout error (read timeout)¶

Example:

ReadTimeoutError: [...] Read timed out.

This may occasionally occur when our deployment infrastructure is under heavy load. In most cases you can simply tryagain. If the issue is urgent, or you have already tried again, please contact Divio Support.

Restart the checklist

Probable fault: A runtime error¶

If you are not sure what the error message reveals, please contact Divio support for assistance.

Restart the checklist

Probable fault: programming error at runtime¶

Sometimes there is no failed deployment log, but the site fails to start. This is typically causedby a programming error that becomes apparent at runtime.

Usually, the browser will show a Django traceback, if the site is in DEBUG mode (this is the default for the Test_server). Under some circumstances, it might not, but the error will be shown in the site’s runtime logs, available fromthe _Logs menu in the Control Panel.

Restart the checklist

Decision tree¶

This tree represents the logic of the debugging checklist.

• Deployment on the Cloud has not worked as expected:
  • The Control Panel shows a Last deployment failed message
    • The deployment log appears to be empty: Probable fault: temporary problem
    • The deployment log contains no obvious error
      • Runtime log contains no errors: Probable fault: application is too slow to start and times out
      • Runtime log contains errors: Probable fault: programming error in runtime code
    • The deployment log contains an error
      • Could not find a version that matches […]:Probable fault: dependency conflict
      • npm ERR! […] ERR! /npm-debug.log: Probable fault: A Node error has halted the build
      • ImportError: Probable fault: An import error halts one of the site build routines
      • ReadTimeoutError: Probable fault: temporary timeout error (read timeout)
      • An error not listed above: Probable fault: A runtime error
  • The Control Panel does not show a Last deployment failed message: Probable fault: programming error at runtime

原文: http://docs.divio.com/en/latest/how-to/debug-deployment-problems.html