Co-authored-by: Sam Saffron <sam.saffron@gmail.com>
Co-authored-by: David Taylor <david@taylorhq.com>
This gives more control over the request. In particular we can easily
lookup DNS dynamically, instead of only upon NGINX startup.
Previously, NGINX was looking up IP for the letter avatar service and
caching the CDN IP address, this caused issues if CDN changed IP, in
which letter avatars would be broken till a container restarted.
NGINX config has been updated to add caching. This change will require
a container rebuild.
The proxy will now function in development environments, so the patch
for `letter_avatar_proxy` has been removed.
f04471e422