shared_queue/

shared_queue

This example describes how to use a shared queue to communicate between seprate Wasm VMs.

There are two Wasm VMs are configured (See envoy.yaml for detail):

1. The one with vm_id="receiver" and the binary of receiver/main.go.
2. Another one with vm_id="sender" and the binary of sender/main.go.

receiver VM runs as a singleton Wasm Service which runs in the main thread, and registered a shared queue named http_headers by calling the RegisterSharedQueue host call.

sender VM runs in the http filter chain on worker threads, and enqueue request headers to the shared queue resolved by the ResolveSharedQueue with the args of vm_id=receiver and name=http_headers.

See this talk for detail.

wasm log sender: enqueued data: {"key": ":authority","value": "localhost:18000"}
wasm log receiver: dequeued data: {"key": ":authority","value": "localhost:18000"}
wasm log sender: enqueued data: {"key": ":path","value": "/"}
wasm log receiver: dequeued data: {"key": ":path","value": "/"}
wasm log sender: enqueued data: {"key": ":method","value": "GET"}
wasm log receiver: dequeued data: {"key": ":method","value": "GET"}
wasm log sender: enqueued data: {"key": ":scheme","value": "http"}
wasm log receiver: dequeued data: {"key": ":scheme","value": "http"}
wasm log sender: enqueued data: {"key": "user-agent","value": "curl/7.68.0"}
wasm log receiver: dequeued data: {"key": "user-agent","value": "curl/7.68.0"}
wasm log sender: enqueued data: {"key": "accept","value": "*/*"}
wasm log receiver: dequeued data: {"key": "accept","value": "*/*"}
wasm log sender: enqueued data: {"key": "x-forwarded-proto","value": "http"}
wasm log receiver: dequeued data: {"key": "x-forwarded-proto","value": "http"}
wasm log sender: enqueued data: {"key": "x-request-id","value": "73a13840-6ca2-4f9f-a639-91b014c8d485"}
wasm log receiver: dequeued data: {"key": "x-request-id","value": "73a13840-6ca2-4f9f-a639-91b014c8d485"}