Recipes and code samples for Google Cloud Service Extensions.
Each recipe has an example plugin written in Rust and C++, and an accompanying unit test that verifies both.
Tests (and thus plugins) can be invoked as follows:
$ bazelisk test --test_output=all --define engine=v8 samples/...
In support of unit testing, this repo contains an HttpTest fixture with a
TestWasm host implementation and TestHttpContext stream handler. These
minimal implementations loosely match GCP Service Extension execution
environment. The contexts implement the ABI / feature set described below
(mainly HTTP headers and logging), but often in a simple way (behaviors may not
match GCP exactly).
The samples folder contains Samples & Recipes to use as a reference for your own plugin. Extend them to fit your particular use case.
- Log each Wasm call: Don't change anything about the traffic (noop plugin). Log each wasm invocation, including lifecycle callbacks.
- Add HTTP request & response headers: Add a header on both the client request and server response paths. Also check for existing headers.
- Plugin config with a list of tokens to deny: Deny a request whenever it contains a known bad token. Bad tokens are loaded at plugin initialization time from plugin configuration.
Service Extensions are compiled against the ProxyWasm ABI, described here: https://github.com/proxy-wasm/spec/tree/master/abi-versions/vNEXT
Service Extensions currently support a subset of the ProxyWasm spec. Support will grow over time. The current feature set includes:
- Root context lifecycle callbacks
- on_context_create
- on_vm_start
- on_configure
- on_done
- on_delete
- Stream context lifecycle callbacks
- on_context_create
- on_done
- on_delete
- Stream context HTTP callbacks
- on_request_headers
- on_response_headers
- Stream context HTTP methods
- send_local_response
- get__header_map_value, add_header_map_value, replace_header_map_value, remove_header_map_value
- get_header_map_pairs, set_header_map_pairs
- get_header_map_size
- Other methods
- log
- get_current_time_nanoseconds (frozen per stream)
- get_property ("plugin_root_id" only)
- get_buffer_status, get_buffer_bytes (PluginConfiguration only)
All recipes and samples within this repository are provided under the Apache 2.0 license. Please see the LICENSE file for more detailed terms and conditions.
For our code of conduct, see Code of Conduct.
Contributions welcome! See the Contributing Guide.
- Write more plugin examples
- Set up CI for repository
- Publish and document the latest ProxyWasm version (not vNEXT as above)
- Add Golang recipes: https://github.com/tetratelabs/proxy-wasm-go-sdk