feat: support only running a subset of components of a Spin app

.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, redis-sample]
+          app: [cpu-load-gen, hello-world, outbound-http, variabletester, redis-sample, salutations]
     env:
       IMAGE_NAME: ${{ github.repository }}
 

README.md

@@ -56,7 +56,7 @@ Create a k3d cluster:
 
 ```shell
 k3d cluster create wasm-cluster \
-    --image ghcr.io/spinkube/containerd-shim-spin/k3d:v0.15.1 \
+    --image ghcr.io/spinkube/containerd-shim-spin/k3d:v0.16.0 \
     -p "8081:80@loadbalancer" \
     --agents 2
 ```

api/v1alpha1/spinapp_types.go

@@ -80,6 +80,12 @@ type SpinAppSpec struct {
 
 	// Resources defines the resource requirements for this app.
 	Resources Resources `json:"resources,omitempty"`
+
+	// Components of the app to execute.
+	//
+	// If this is not provided all components are executed.
+	// +kubebuilder:validation:MinItems:=1
+	Components []string `json:"components,omitempty"`
 }
 
 // SpinAppStatus defines the observed state of SpinApp

apps/salutations/.gitignore

@@ -0,0 +1,2 @@
+main.wasm
+.spin/

apps/salutations/go.mod

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

apps/salutations/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/salutations/main.go

@@ -0,0 +1,17 @@
+package main
+
+import (
+	"fmt"
+	"net/http"
+
+	spinhttp "github.com/fermyon/spin/sdk/go/v2/http"
+)
+
+func init() {
+	spinhttp.Handle(func(w http.ResponseWriter, r *http.Request) {
+		w.Header().Set("Content-Type", "text/plain")
+		fmt.Fprintln(w, "Goodbye!")
+	})
+}
+
+func main() {}

apps/salutations/spin.toml

@@ -0,0 +1,29 @@
+spin_manifest_version = 2
+
+[application]
+name = "salutations"
+version = "0.1.0"
+authors = ["Kate Goldenring <[email protected]>"]
+description = "An app that gives salutations"
+
+[[trigger.http]]
+route = "/hi"
+component = "hello"
+
+[component.hello]
+source = "../hello-world/main.wasm"
+allowed_outbound_hosts = []
+[component.hello.build]
+command = "pushd ../hello-world && tinygo build -target=wasi -gc=leaking -no-debug -o main.wasm main.go && popd"
+watch = ["**/*.go", "go.mod"]
+
+[[trigger.http]]
+route = "/bye"
+component = "goodbye"
+
+[component.goodbye]
+source = "main.wasm"
+allowed_outbound_hosts = []
+[component.goodbye.build]
+command = "tinygo build -target=wasi -gc=leaking -no-debug -o main.wasm main.go"
+watch = ["**/*.go", "go.mod"]

config/crd/bases/core.spinoperator.dev_spinapps.yaml

@@ -188,6 +188,12 @@ spec:
                         type: integer
                     type: object
                 type: object
+              components:
+                description: Components to be executed in this group.
+                items:
+                  type: string
+                minItems: 1
+                type: array
               deploymentAnnotations:
                 additionalProperties:
                   type: string

config/samples/component-filtering.yaml

@@ -0,0 +1,12 @@
+apiVersion: core.spinoperator.dev/v1alpha1
+kind: SpinApp
+metadata:
+  name: hello-salutation-spinapp
+spec:
+  # TODO: change to image hosted at ghcr.io/spinkube/spin-operator/salutations when published
+  image: "ghcr.io/kate-goldenring/spin-operator/examples/spin-salutations:20241022-144454"
+  replicas: 1
+  executor: containerd-shim-spin
+  # Configure the application to only contain the "hello" component
+  # Who doesn't hate goodbyes?
+  components: ["hello"]

internal/controller/spinapp_controller.go

@@ -22,6 +22,7 @@ import (
 	"fmt"
 	"hash/adler32"
 	"maps"
+	"strings"
 
 	"github.com/pelletier/go-toml/v2"
 	appsv1 "k8s.io/api/apps/v1"
@@ -429,6 +430,12 @@ func constructDeployment(ctx context.Context, app *spinv1alpha1.SpinApp, config
 	}
 
 	env := ConstructEnvForApp(ctx, app, spinapp.DefaultHTTPPort, config.Otel)
+	if app.Spec.Components != nil {
+		env = append(env, corev1.EnvVar{
+			Name:  "SPIN_COMPONENTS_TO_RETAIN",
+			Value: strings.Join(app.Spec.Components[:], ","),
+		})
+	}
 
 	readinessProbe, livenessProbe, err := ConstructPodHealthChecks(app)
 	if err != nil {
@@ -457,7 +464,8 @@ func constructDeployment(ctx context.Context, app *spinv1alpha1.SpinApp, config
 		container = corev1.Container{
 			Name:  app.Name,
 			Image: *config.SpinImage,
-			Args:  []string{"up", "--listen", fmt.Sprintf("0.0.0.0:%d", spinapp.DefaultHTTPPort), "-f", app.Spec.Image, "--runtime-config-file", "/runtime-config.toml"},
+			// TODO: add support for --component-id flags to set components to be retained once spintainer supports Spin v3.0
+			Args: []string{"up", "--listen", fmt.Sprintf("0.0.0.0:%d", spinapp.DefaultHTTPPort), "-f", app.Spec.Image, "--runtime-config-file", "/runtime-config.toml"},
 			Ports: []corev1.ContainerPort{{
 				Name:          spinapp.HTTPPortName,
 				ContainerPort: spinapp.DefaultHTTPPort,