Solves https://github.com/coder/coder/issues/15096
This is a slight rework/refactor of the earlier PRs from @dannykopping
and @Emyrk:
- https://github.com/coder/coder/pull/15669
- https://github.com/coder/coder/pull/15684
- https://github.com/coder/coder/pull/17596
Rather than having a per-app CORS behaviour setting and additionally a
template level setting for ports, this PR adds a single template level
CORS behaviour setting that is then used by all apps/ports for
workspaces created from that template.
The main changes are in `proxy.go` and `request.go` to:
a) get the CORS behaviour setting from the template
b) have `HandleSubdomain` bypass the CORS middleware handler if the
selected behaviour is `passthru`
c) in `proxyWorkspaceApp`, do not modify the response if the selected
behaviour is `passthru`
<!-- This is an auto-generated comment: release notes by coderabbit.ai
-->
## Summary by CodeRabbit
* **New Features**
* Added support for configuring CORS behavior ("simple" or "passthru")
at the template level for all shared ports.
* Introduced a new "CORS Behavior" setting in the template creation and
settings forms.
* API endpoints and responses now include the optional `cors_behavior`
property for templates.
* Workspace apps and proxy now honor the specified CORS behavior,
enabling conditional CORS middleware application.
* Enhanced workspace app tests with comprehensive scenarios covering
CORS behaviors and authentication states.
* **Bug Fixes**
* None.
* **Documentation**
* Updated API and admin documentation to describe the new
`cors_behavior` property and its usage.
* Added examples and schema references for CORS behavior in relevant API
docs.
* **Tests**
* Extended automated tests to cover different CORS behavior scenarios
for templates and workspace apps.
* **Chores**
* Updated audit logging to track changes to the `cors_behavior` field on
templates.
<!-- end of auto-generated comment: release notes by coderabbit.ai -->
---------
Signed-off-by: Callum Styan <callumstyan@gmail.com>
Callum Styan