Provide a setting which forces all file views to be served from an alternate domain
Summary:
See D758, D759.
- Provide a strongly recommended setting which permits configuration of an
alternate domain.
- Lock cookies down better: set them on the exact domain, and use SSL-only if
the configuration is HTTPS.
- Prevent Phabriator from setting cookies on other domains.
This assumes D759 will land, it is not effective without that change.
Test Plan:
- Attempted to login from a different domain and was rejected.
- Logged out, logged back in normally.
- Put install in setup mode and verified it revealed a warning.
- Configured an alterate domain.
- Tried to view an image with an old URI, got a 400.
- Went to /files/ and verified links rendered to the alternate domain.
- Viewed an alternate domain file.
- Tried to view an alternate domain file without the secret key, got a 404.
Reviewers: andrewjcg, erling, aran, tuomaspelkonen, jungejason, codeblock
CC: aran
Differential Revision: 760