Merge pull request #292 from asteurer/redis-sample

adding redis-sample

.github/workflows/sample-apps.yaml

@@ -14,7 +14,7 @@ jobs:
     runs-on: ubuntu-latest
     strategy:
         matrix:
-          app: [cpu-load-gen, hello-world, outbound-http, variabletester]
+          app: [cpu-load-gen, hello-world, outbound-http, variabletester, redis-sample]
     env:
       IMAGE_NAME: ${{ github.repository }}
 

apps/redis-sample/README.md

@@ -0,0 +1,90 @@
+# Overview
+
+This is an OCI-compliant package that can be used to demonstrate how a Spin app interacts with Redis in a Kubernetes cluster.
+
+# Usage
+
+## Deploying the Spin app
+
+Create a Kubernetes manifest file named `redis_client.yaml` with the following code:
+
+```yaml
+apiVersion: core.spinoperator.dev/v1alpha1
+kind: SpinApp
+metadata:
+  name: redis-spinapp
+spec:
+  image: "ghcr.io/spinkube/redis-sample"
+  replicas: 1
+  executor: containerd-shim-spin
+  variables:
+    - name: redis_endpoint
+      value: redis://redis.default.svc.cluster.local:6379
+```
+
+Once created, run `kubectl apply -f redis_client.yaml`.
+
+## Deploying Redis
+
+Create a Kubernetes manifest file named `redis_db.yaml` with the following code:
+
+```yaml
+apiVersion: apps/v1
+kind: Deployment
+metadata:
+  name: redis
+  labels:
+    app: redis
+spec:
+  replicas: 1
+  selector:
+    matchLabels:
+      app: redis
+  template:
+    metadata:
+      labels:
+        app: redis
+    spec:
+      containers:
+        - name: redis
+          image: redis
+          ports:
+            - containerPort: 6379
+
+---
+apiVersion: v1
+kind: Service
+metadata:
+  name: redis
+spec:
+  selector:
+    app: redis
+  ports:
+    - protocol: TCP
+      port: 6379
+      targetPort: 6379
+```
+
+Once created, run `kubectl apply -f redis_db.yaml`.
+
+## Interacting with the Spin app
+
+In your terminal run `kubectl port-forward svc/redis-spinapp 3000:80`, then in a different terminal window, try the below commands:
+
+### Place a key-value pair in Redis
+
+```bash
+curl --request PUT --data-binary "Hello, world\!" -H 'x-key: helloKey' localhost:3000
+```
+
+### Retrieve a value from Redis
+
+```bash
+curl -H 'x-key: helloKey' localhost:3000
+```
+
+### Delete a value from Redis
+
+```bash
+curl --request DELETE -H 'x-key: helloKey' localhost:3000
+```

apps/redis-sample/go.mod

@@ -0,0 +1,7 @@
+module github.com/spin_redis_sample
+
+go 1.20
+
+require github.com/fermyon/spin/sdk/go/v2 v2.2.0
+
+require github.com/julienschmidt/httprouter v1.3.0 // indirect

apps/redis-sample/go.sum

@@ -0,0 +1,4 @@
+github.com/fermyon/spin/sdk/go/v2 v2.2.0 h1:zHZdIqjbUwyxiwdygHItnM+vUUNSZ3CX43jbIUemBI4=
+github.com/fermyon/spin/sdk/go/v2 v2.2.0/go.mod h1:kfJ+gdf/xIaKrsC6JHCUDYMv2Bzib1ohFIYUzvP+SCw=
+github.com/julienschmidt/httprouter v1.3.0 h1:U0609e9tgbseu3rBINet9P48AI/D3oJs4dN7jwJOQ1U=
+github.com/julienschmidt/httprouter v1.3.0/go.mod h1:JR6WtHb+2LUe8TCKY3cZOxFyyO8IZAc4RVcycCCAKdM=

apps/redis-sample/main.go

@@ -0,0 +1,79 @@
+package main
+
+import (
+	"fmt"
+	"io"
+	"net/http"
+
+	spinhttp "github.com/fermyon/spin/sdk/go/v2/http"
+	"github.com/fermyon/spin/sdk/go/v2/redis"
+	"github.com/fermyon/spin/sdk/go/v2/variables"
+)
+
+var rdb *redis.Client
+
+func init() {
+	spinhttp.Handle(func(w http.ResponseWriter, r *http.Request) {
+		redisEndpoint, err := variables.Get("redis_endpoint")
+		if err != nil {
+			http.Error(w, "unable to parse variable 'redis_endpoint'", http.StatusInternalServerError)
+			return
+		}
+
+		if redisEndpoint == "" {
+			http.Error(w, "cannot find 'redis_endpoint' environment variable", http.StatusInternalServerError)
+			return
+		}
+
+		rdb = redis.NewClient(redisEndpoint)
+
+		reqKey := r.Header.Get("x-key")
+		if reqKey == "" {
+			http.Error(w, "you must include the 'x-key' header in your request", http.StatusBadRequest)
+			return
+		}
+
+		if r.Method == "GET" {
+			value, err := rdb.Get(reqKey)
+			if err != nil {
+				http.Error(w, fmt.Sprintf("no value found for key '%s'", reqKey), http.StatusNotFound)
+				return
+			}
+
+			w.WriteHeader(http.StatusOK)
+			w.Write(value)
+			return
+
+		} else if r.Method == "PUT" {
+			bodyBytes, err := io.ReadAll(r.Body)
+			if err != nil {
+				http.Error(w, fmt.Sprintf("error reading request body: %w", err), http.StatusInternalServerError)
+			}
+			defer r.Body.Close()
+
+			if err := rdb.Set(reqKey, bodyBytes); err != nil {
+				http.Error(w, fmt.Sprintf("unable to add value for key '%s' to database: %w", reqKey, err), http.StatusInternalServerError)
+				return
+			}
+
+			w.WriteHeader(http.StatusCreated)
+			return
+
+		} else if r.Method == "DELETE" {
+			_, err := rdb.Del(reqKey)
+			if err != nil {
+				http.Error(w, fmt.Sprintf("error deleting value for key '%w'", err), http.StatusInternalServerError)
+				return
+			}
+
+			w.WriteHeader(http.StatusOK)
+			return
+
+		} else {
+			http.Error(w, fmt.Sprintf("method %q is not supported, so please try again using 'GET' or 'PUT' for the HTTP method", r.Method), http.StatusBadRequest)
+			return
+		}
+	})
+}
+
+func main() {}

apps/redis-sample/spin.toml

@@ -0,0 +1,24 @@
+spin_manifest_version = 2
+
+[application]
+name = "spin-redis-sample"
+version = "0.1.0"
+authors = ["Fermyon Engineering Team <engineering@fermyon.com>"]
+
+[variables]
+redis_endpoint = {required = true}
+
+[[trigger.http]]
+route = "/..."
+component = "spin-redis-sample"
+
+[component.spin-redis-sample]
+source = "main.wasm"
+allowed_outbound_hosts = ["redis://*"]
+
+[component.spin-redis-sample.build]
+command = "tinygo build -target=wasi -gc=leaking -no-debug -o main.wasm main.go"
+watch = ["**/*.go", "go.mod"]
+
+[component.spin-redis-sample.variables]
+redis_endpoint = "{{ redis_endpoint }}"