w-A-L-L-e

# https://www.varnish-cache.org/docs/2.1/tutorial/vcl.html
# https://www.varnish-cache.org/trac/wiki/VCLExamples

# Summary
# 1. Varnish will poll the backend at /health_check to make sure it is
#    healthy. If the backend goes down, varnish will server stale content
#    from the cache for up to 1 hour.
# 2. Varnish will pass X-Forwarded-For headers through to the backend
# 3. Varnish will remove cookies from urls that match static content file
#    extensions (jpg, gif, ...)