WASI HTTP

This runs the sample-wasi-http-rust WASM module — an upstream Bytecode Alliance example implementing a wasi:http/proxy server with multiple routes — through the Propeller Kubernetes operator.

Prerequisites

The operator must be deployed and a Proplet registered. Follow the end-to-end example first.

Proplet Configuration

The WASI HTTP server needs HTTP proxy enabled and the external runtime disabled (uses the proplet's built-in Wasmtime):

kubectl patch proplet k8s-proplet --type=merge -p '{"spec":{"k8s":{"env":{"httpEnabled":true,"externalWasmRuntime":""}}}}'

Known gap: PROPLET_HTTP_PROXY_PORT is not yet exposed on the Proplet CRD's k8s.env block. The default port (8081) is used. Run this against an external proplet if you need to customize the proxy port.

Build the WASM Module

cd propeller
make http-greet-component

Apply the Task

WASM_B64=$(base64 -w0 propeller/build/http-greet-component.wasm)
kubectl apply -n propeller-workloads -f - <<EOF
apiVersion: propeller.propeller.absmach.eu/v1
kind: Task
metadata:
  name: wasi-http-example
spec:
  name: wasi-http-example
  functionName: _start
  file: "${WASM_B64}"
  daemon: true
  propletSelector:
    propletId: "k8s-proplet"
EOF

Verify

Test the server endpoints through the proplet's HTTP proxy:

curl http://localhost:8081/
curl http://localhost:8081/echo -d 'hello'

Reference