Flask Cache Buster based on Git Revision

This is cool.

Here’s a simple flask cache buster that appends a version number to all static assets based on the current git revision short hash.

https://gist.github.com/yuchant/9108622

Flask is built so amazingly. It has hooks to allow modification of all urls generated by the system.

app = make_app()

def get_git_revision_hash():
'''
Get current revision short hash and use as cache buster key.
'''
import subprocess
return subprocess.check_output(['git', 'rev-parse', '--short', 'HEAD'])

git_revision_hash = get_git_revision_hash()
STATIC_ENDPOINTS = [</div><div class="" id="file-gistfile1-txt-LC14">    'static',</div>

<div class="" id="file-gistfile1-txt-LC15">    'shop.static',</div><div class="" id="file-gistfile1-txt-LC16">]
@app.url_defaults
def static_cache_buster(endpoint, values):
if endpoint in STATIC_ENDPOINTS:
values['_v'] = git_revision_hash

Update: actually, git revision number is not what I’m looking for

This only works for developer driven content. It wouldn’t work for user uploads of course, therefore I modified this to read mtimes.

        STATIC_ENDPOINTS = [
            'static',
            'shop.static',
        ]
        @self.app.url_defaults
        def static_cache_buster(endpoint, values):
            if endpoint in STATIC_ENDPOINTS:
                # append timestamps of files
                modules = endpoint.split('.')
                if len(modules) == 2:
                    blueprint, _ = modules
                    static_folder = self.app.blueprints[blueprint].static_folder
                else:
                    static_folder = self.app.static_folder
                file_path = os.path.join(static_folder, values['filename'])
                mtime = os.path.getmtime(file_path)
                values['_v'] = mtime