I'm using GCP App Engine with auto scaling.

If I deploy a new version of the app code (Python 3 Flask app) with a simple change for control and test purposes, lets say I add a comment to one of the .js files I am not seeing that change to the file in the browser after it has been deployed.

I have 100% of traffic being served by the new version of the app. When I look at the source code for the version I can see the comment in there, but when I clear my browser cache and visit the page I only ever get the old version of the page (without the comment in the .js).

I have tried using the --promote and --no-cache values in the app deploy command, but no use. I have added:

default_expiration: "0d 0h 0m 0s"

To the app.yaml

I have also turned on object versioning of the storage account which app engine uses to try to ensure that only a single version of the file is available to be served - still no use.

The command I'm using to deploy is:

run: "gcloud app deploy app.yaml --quiet --promote --no-cache"

I can't understand why it should be so difficult to simply deploy a new version of the app and have the app engine serve the latest files; I must be doing something wrong but cannot see what.

Would appreciate any pointers.

CodePudding user response：

The files are cached (even if for a short while and sometimes it takes time to clear it).

The trick is to make the urls (for the static files) unique for each deployment. This way, the browser is loading a 'distinct' url after each deployment. For example, you could append the environment variable, CURRENT_VERSION_ID to the url for all static elements. This means having something like (assuming Python/Jinja2)

src="/static/js/my_js_file.js?{{CURRENT_VERSION_ID}}"

os.environ['CURRENT_VERSION_ID'] changes for each deployment. There's a possibility this attribute is not available in newer runtimes. If so, just dump the environment variables and look for an attribute that is always present but the value changes (e.g. GAE_INSTANCE).

You could also just generate a random number each time your App is deployed and use that instead i.e.

src="/static/js/my_js_file.js?{{RANDOM_NUMBER}}"