Use new hashing of static file names.

Every time the docker image is rebuilt a random hash is chosen.

Requires Pillar d560f89704e3a6f4490df57712525048c469bed2 or newer.

docker/4_run/Dockerfile

@@ -56,3 +56,7 @@ ENTRYPOINT /docker-entrypoint.sh
 # Add the most-changing files as last step for faster rebuilds.
 ADD config_local.py /data/git/blender-cloud/
 ADD deploy /data/git
+RUN python3 -c "import re, secrets; \
+f = open('/data/git/blender-cloud/config_local.py', 'a'); \
+h = re.sub(r'[_.~-]', '', secrets.token_urlsafe())[:8]; \
+print(f'STATIC_FILE_HASH = {h!r}', file=f)"

docker/4_run/config_local.py

@@ -125,3 +125,7 @@ SMTP_TIMEOUT = 30  # timeout in seconds, https://docs.python.org/3/library/smtpl
 MAIL_RETRY = 180  # in seconds, delay until trying to send an email again.
 MAIL_DEFAULT_FROM_NAME = 'Blender Cloud'
 MAIL_DEFAULT_FROM_ADDR = 'cloudsupport@blender.org'
+
+# MUST be 8 characters long, see pillar.flask_extra.HashedPathConverter
+# STATIC_FILE_HASH = '12345678'
+# The value used in production is appended from Dockerfile.