Enable CORS for prelude.dhall-lang.org
#315
Merged
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The motivation for this is so that the upcoming "Try Dhall" page can
import from the Prelude without being blocked by the browser as a
forbidden Cross-Origin request.
This requires several changes:
First,
prelude.dhall-lang.org
needs to no longer be a redirect andshould instead act as a reverse proxy using the
proxy_pass
directive.This is necessary for CORS to work since a redirect to
raw.githubusercontent.com
will cause the browser to checkraw.githubusercontent.com
for CORS support instead of consultingprelude.dhall-lang.org
for CORS support.Second, the recommended proxy settings have to be selectively inlined
to just
hydra.dhall-lang.org
because they interfere with theprelude.dhall-lang.org
reverse proxy. Specifically, theHost: $host
directive added by the recommended proxy settings becomes
Host: prelude.dhall-lang.org
and this confuses GitHub sinceGitHub treats any unrecognized
Host
header as a request to its GitHubpages functionality.
Third, we need to enable CORS with the correct
Access-Control-*
headers.
This also includes a fix to the Hydra patch to work with Nixpkgs 18.09.