https://github.com/derekargueta/envoy-etag-filter
Envoy filter that provides basic ETag functionality, checking the ETag value of the request and upstream response
https://github.com/derekargueta/envoy-etag-filter
envoy etag filter http reverse-proxy server
Last synced: 12 months ago
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Envoy filter that provides basic ETag functionality, checking the ETag value of the request and upstream response
- Host: GitHub
- URL: https://github.com/derekargueta/envoy-etag-filter
- Owner: derekargueta
- Created: 2018-01-11T07:19:16.000Z (over 8 years ago)
- Default Branch: main
- Last Pushed: 2024-08-07T19:16:10.000Z (almost 2 years ago)
- Last Synced: 2025-07-05T08:04:48.714Z (12 months ago)
- Topics: envoy, etag, filter, http, reverse-proxy, server
- Language: C++
- Homepage:
- Size: 23.4 KB
- Stars: 4
- Watchers: 3
- Forks: 0
- Open Issues: 0
-
Metadata Files:
- Readme: README.md
Awesome Lists containing this project
README
Envoy Etag Filter
===================
- [ ] add unit tests
### Build
First follow the [setup instructions](https://github.com/envoyproxy/envoy/tree/master/bazel#building-envoy-with-bazel) in Envoy to install dependencies.
Then instead of building `//source/exe:envoy-static`, do
```
$ bazel build //:envoy
```
**NOTE** if zlib fails to build, check log of `bazel-out/host/bin/external/envoy/bazel/foreign_cc/zlib/logs/CMake.log`. If the log states `cmake: command not found`, then you'll need to symlink cmake and ninja to `/usr/local/bin` (mine are installed via homebrew to `/opt/homebrew/bin`)
```
$ sudo ln -s $(which cmake) /usr/local/bin/cmake
$ sudo ln -s $(which ninja) /usr/local/bin/ninja
```
### Usage
There currently are no supported configuration options so usage is quite simple:
```
http_filters:
- name: etag
- name: envoy.router
```
### TODO
- Support weak matching (`ETag: W/"0815"`)
- Support range - For GET and HEAD methods, used in combination with an Range header, it can guarantee that the new ranges requested comes from the same resource than the previous one. If it doesn't match, then a 416 (Range Not Satisfiable) response is returned.
- Support generating Etags on the fly using a configuratble hash algorithm
### Resources
- https://developer.mozilla.org/en-US/docs/Web/HTTP/Headers/If-Match
- https://developer.mozilla.org/en-US/docs/Web/HTTP/Headers/If-None-Match
- https://developer.mozilla.org/en-US/docs/Web/HTTP/Headers/ETag
- https://tools.ietf.org/html/rfc7232#section-2.3
- https://tools.ietf.org/html/rfc7232#section-3.1
- https://tools.ietf.org/html/rfc7232#section-3.2