feat: add spin-dapr example (#136)

Signed-off-by: Sven Pfennig <[email protected]>

images/spin-dapr/.dockerignore

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+target/debug
+target/release
+target/wasm32-wasi/build
+target/wasm32-wasi/deps
+.spin/

images/spin-dapr/.gitignore

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+target/
+.spin/

images/spin-dapr/Cargo.toml

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+[package]
+name = "spin-dapr"
+authors = ["Sven Pfennig <[email protected]>"]
+description = "Example application to use Dapr with Spin"
+version = "0.1.0"
+edition = "2021"
+
+[lib]
+crate-type = [ "cdylib" ]
+
+[dependencies]
+anyhow = "1"
+# Crate to simplify working with bytes.
+bytes = "1"
+# General-purpose crate with common HTTP types.
+http = "0.2"
+# The Spin SDK.
+spin-sdk = { git = "https://github.com/fermyon/spin", tag = "v1.4.1" }
+
+[workspace]

images/spin-dapr/Dockerfile

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+FROM scratch
+COPY ./spin.toml .
+COPY --chmod=0755 ./target/wasm32-wasi/release/spin_dapr.wasm /target/wasm32-wasi/release/spin_dapr.wasm
+ENTRYPOINT ["/target/wasm32-wasi/release/spin_dapr.wasm"]

images/spin-dapr/README.md

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+# Spin Dapr Demo
+
+## Description
+This demo application is a simple Spin app that is triggered by the daprs [kubernetes input binding](https://docs.dapr.io/reference/components-reference/supported-bindings/kubernetes-binding/) when it is called with the path `/kevents` it writes the body to a redis running at `redis://localhost:6379` to the key `lastEvent`. All other paths just return the value of the `lastEvent` key.
+
+### Prerequisites
+Install dapr cli
+```sh
+curl -fsSL https://raw.githubusercontent.com/dapr/cli/master/install/install.sh | bash
+```
+
+Install spin cli:
+```sh
+curl -fsSL https://developer.fermyon.com/downloads/install.sh | bash
+sudo mv ./spin /usr/local/bin/
+```
+
+### Run example with K3d:
+```sh
+# start the K3d cluster
+k3d cluster create wasm-cluster --image ghcr.io/deislabs/containerd-wasm-shims/examples/k3d:v0.10.0 -p "8081:80@loadbalancer"  
+# Install Dapr
+dapr init -k --wait
+# or via helm
+# helm repo add dapr https://dapr.github.io/helm-charts/
+# helm repo update
+# helm upgrade --install dapr dapr/dapr --namespace dapr-system --create-namespace --wait
+
+# build the application
+cd images/spin-dapr
+spin build
+cd -
+# create an image and load it into K3d
+docker build images/spin-dapr -t spin-dapr:latest --load
+mkdir -p test/out_spin-dapr/
+docker save spin-dapr:latest -o test/out_spin-dapr/img.tar
+k3d image load -c wasm-cluster spin-dapr:latest test/out_spin-dapr/img.tar 
+# Apply the manifest
+kubectl apply -f https://github.com/deislabs/containerd-wasm-shims/raw/main/deployments/workloads/runtime.yaml
+kubectl apply -f images/spin-dapr/deploy.yaml
+
+# When everythin is up, forward the port and get the last kubernetes event
+kubectl port-forward svc/spin-dapr 8080:80 &
+curl localhost:8080 | jq
+```

images/spin-dapr/deploy.yaml

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+apiVersion: apps/v1
+kind: Deployment
+metadata:
+  name: spin-dapr
+spec:
+  replicas: 1
+  selector:
+    matchLabels:
+      app: spin-dapr
+  template:
+    metadata:
+      labels:
+        app: spin-dapr
+      annotations:
+        dapr.io/enabled: "true"
+        dapr.io/app-id: "spin-dapr"
+        dapr.io/app-port: "80"
+        dapr.io/log-level: "debug"
+    spec:
+      runtimeClassName: wasmtime-spin
+      containers:
+        - image: redis
+          name: redis
+        - name: spin-dapr
+          image: spin-dapr:latest
+          imagePullPolicy: Never
+---
+apiVersion: v1
+kind: Service
+metadata:
+  name: spin-dapr
+spec:
+  type: LoadBalancer
+  ports:
+    - protocol: TCP
+      port: 80
+      targetPort: 80
+  selector:
+    app: spin-dapr
+---
+apiVersion: networking.k8s.io/v1
+kind: Ingress
+metadata:
+  name: spin-dapr
+  annotations:
+    ingress.kubernetes.io/ssl-redirect: "false"
+    kubernetes.io/ingress.class: traefik
+spec:
+  rules:
+    - http:
+        paths:
+          - path: /spin-dapr
+            pathType: Prefix
+            backend:
+              service:
+                name: spin-dapr
+                port:
+                  number: 80
+---
+apiVersion: dapr.io/v1alpha1
+kind: Component
+metadata:
+  name: kevents
+  namespace: default
+spec:
+  type: bindings.kubernetes
+  version: v1
+  metadata:
+  - name: namespace
+    value: "default"
+  - name: resyncPeriodInSec
+    value: "1"
+  - name: direction
+    value: "input"
+---
+apiVersion: rbac.authorization.k8s.io/v1
+kind: Role
+metadata:
+  name: spin-dapr
+rules:
+- apiGroups: [""]
+  resources: ["events"]
+  verbs: ["get", "watch", "list"]
+---
+apiVersion: rbac.authorization.k8s.io/v1
+kind: RoleBinding
+metadata:
+  name: spin-dapr
+subjects:
+- kind: ServiceAccount
+  name: default # or as need be, can be changed
+roleRef:
+  kind: Role
+  name: spin-dapr # same as the one above
+  apiGroup: ""

images/spin-dapr/spin.toml

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+spin_manifest_version = "1"
+authors = ["Sven Pfennig <[email protected]>"]
+description = "Example application to use Dapr with Spin"
+name = "spin-dapr"
+trigger = { type = "http", base = "/" }
+version = "0.1.0"
+
+[[component]]
+id = "spin-dapr"
+source = "target/wasm32-wasi/release/spin_dapr.wasm"
+allowed_http_hosts = []
+[component.trigger]
+route = "/..."
+
+[component.build]
+command = "cargo build --target wasm32-wasi --release"
+watch = ["src/**/*.rs", "Cargo.toml"]

images/spin-dapr/src/lib.rs

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+use anyhow::{anyhow, Result};
+use spin_sdk::{
+    http::{Request, Response},
+    http_component, redis,
+};
+
+// Expect redis running on localhost or in the same pod
+const ADDRESS: &str = "redis://localhost:6379";
+const KEY: &str = "lastEvent";
+
+
+#[http_component]
+fn handle_spin_dapr(req: Request) -> Result<Response> {
+    println!("{:?}\n", req);
+
+    if req.uri().path().ends_with("kevents"){
+        let value = req.body().clone().unwrap();
+        println!("Set: {:?}", value);
+        redis::set(ADDRESS, KEY, &value)
+        .map_err(|_| anyhow!("Error executing Redis set command"))?;
+    }
+
+    let value = redis::get(ADDRESS, KEY)
+        .map_err(|_| anyhow!("Error executing Redis get command"))?;
+
+    Ok(http::Response::builder()
+        .status(200)
+        .header("foo", "bar")
+        .body(Some(value.into()))?)
+}