Add read only HTTP filter to prevent PUT/POST/DELETE

The filter intercepts all HTTP requests and rejects any PUT, POST
or DELETE with a "503 Service Unavailable" status code [1].

This prevents:

- Creating a new project from the UI
- Changing a project's configuration from the UI
- Changing user preferences from the UI
- and any other operation performed by a POST/PUT/DELETE REST API call

[1] https://httpstatuses.com/503

Change-Id: I4fa7d335d8392270e004f55d29581eeffa3346a2
3 files changed
tree: 793fdaecf416c272310d8bced075bcb049e6fb02
  1. src/
  2. tools/
  3. .gitignore
  4. bazlets.bzl
  5. BUILD
  6. WORKSPACE