How to write a simple wasm-filter for istio 1.5.x

Development

wasm32

rustup update
rustup target add wasm32-unknown-unknown

wasme install

• https://docs.solo.io/web-assembly-hub/latest/installation/

# GFW blocked
curl -sL https://run.solo.io/wasme/install | sh
export PATH=$HOME/.wasme/bin:$PATH

# confirm install
wasme --version

Example

create lib project with cargo

cargo new --lib istio-wasm-example

# business logical in src/lib.rs

make gen

make build

wasme list

# local test, visit http://localhost:8080/hello
wasme deploy envoy webassemblyhub.io/sdrzlyz/istio_wasm_example:v0.1 --envoy-image=istio/proxyv2:1.5.4

Deploy to istio

Before start up, you need install wasme operator for k8s

• https://docs.solo.io/web-assembly-hub/latest/tutorial_code/wasme_operator/

kubectl apply -f https://github.com/solo-io/wasme/releases/latest/download/wasme.io_v1_crds.yaml
kubectl apply -f https://github.com/solo-io/wasme/releases/latest/download/wasme-default.yaml

# confirm install
kubectl get pod -n wasme

Deploy to you k8s(need istio installed)

cat <<EOF | kubectl apply -f -
apiVersion: wasme.io/v1
kind: FilterDeployment
metadata:
  name: istio-wasm-example-filter
  namespace: xxx
spec:
  deployment:
    istio:
      kind: Deployment
  filter:
    image: webassemblyhub.io/sdrzlyz/istio_wasm_example:v0.1
EOF

Ref:

https://github.com/solo-io/wasm-image-spec
https://docs.solo.io/web-assembly-hub/latest/tutorial_code/wasme_operator/
https://blog.red-badger.com/extending-istio-with-rust-and-webassembly