Envoy introspection
Demo
-
Build the extension (.wasm file):
make wasm -
Start the upstream service:
docker run -d -p 3030:80 kennethreitz/httpbin
-
Run the Envoy instance using func-e:
func-e run -c envoy.yaml & -
Send a request using the
intercept: 1header to intercept the call:curl -H "intercept: 1" localhost:10000/get
Notice in the output the call is intercepted and a request is made to the same cluster and the callback function is called:
$ curl -H "intercept: 1" localhost:10000/1
[2021-11-30 01:02:33.159][14834][info][wasm] [source/extensions/common/wasm/context.cc:1167] wasm log: intercepting call!!
[2021-11-30 01:02:33.159][14834][info][wasm] [source/extensions/common/wasm/context.cc:1167] wasm log: cluster name: httpbin_1
[2021-11-30 01:02:33.163][14834][info][wasm] [source/extensions/common/wasm/context.cc:1167] wasm log: called callBack func
{
"args": {},
"headers": {
"Accept": "*/*",
"Host": "localhost:10000",
"Intercept": "1",
"User-Agent": "curl/7.64.0",
"X-Envoy-Expected-Rq-Timeout-Ms": "15000",
"X-Envoy-Original-Path": "/1"
},
"origin": "172.18.0.1",
"url": "http://localhost:10000/get"
}
