Update counter demo with external volume using mock volume plugin

Author: msau42

demos/counter/counter.go

@@ -27,6 +27,7 @@ import (
 	"net"
 	"net/http"
 	"os"
+	"path/filepath"
 	"strconv"
 	"sync"
 	"sync/atomic"
@@ -41,27 +42,27 @@ var (
 	fileMutex    sync.Mutex
 )
 
-const fileCounterPath = "/home/counter/a.txt"
-
-func incrementFileCounter() int {
+func incrementFileCounter(filePath string) int {
 	fileMutex.Lock()
 	defer fileMutex.Unlock()
 	counter := 0
-	data, err := os.ReadFile(fileCounterPath)
+	data, err := os.ReadFile(filePath)
 	if err == nil {
 		if i, err := strconv.Atoi(string(data)); err == nil {
 			counter = i
 		}
 	}
 	counter++
-	err = os.WriteFile(fileCounterPath, []byte(strconv.Itoa(counter)), 0o644)
+	err = os.WriteFile(filePath, []byte(strconv.Itoa(counter)), 0o644)
 	if err != nil {
 		return -1
 	}
 	return counter
 }
 
 func main() {
+	fileCounterDirectory := pflag.String("file-counter-directory", "/home/counter", "Directory for file counter")
+	validateExistingFilePath := pflag.String("validate-existing-file-path", "", "Path to existing file to validate reading")
 	pflag.Parse()
 	ctx := context.Background()
 
@@ -70,11 +71,23 @@ func main() {
 	defaultMux := http.NewServeMux()
 	defaultMux.HandleFunc("/", func(w http.ResponseWriter, r *http.Request) {
 		ctx := r.Context()
-		fileCounter := incrementFileCounter()
-
+		fileCounter := incrementFileCounter(filepath.Join(*fileCounterDirectory, "a.txt"))
 		memoryCounter := atomic.AddUint64(&requestCount, 1)
 		currentIP := getCurrentIP()
-		response := fmt.Sprintf("hello from: %s | preserved memory count: %d | preserved file counter: %d\n", currentIP, memoryCounter, fileCounter)
+
+		fileContentStr := ""
+		if *validateExistingFilePath != "" {
+			fileContent, err := os.ReadFile(*validateExistingFilePath)
+			if err != nil {
+				fileResponse := fmt.Sprintf("failed to read test file: %s\n", err.Error())
+				w.WriteHeader(http.StatusOK)
+				w.Write([]byte(fileResponse))
+				return
+			}
+			fileContentStr = fmt.Sprintf(" | file content: %s", string(fileContent))
+		}
+
+		response := fmt.Sprintf("hello from: %s | preserved memory count: %d | preserved file counter: %d%s\n", currentIP, memoryCounter, fileCounter, fileContentStr)
 		slog.InfoContext(ctx, "Handled request", slog.String("response", response))
 
 		w.WriteHeader(http.StatusOK)

demos/counter/counter.yaml.tmpl

@@ -42,14 +42,16 @@ spec:
   containers:
   - name: counter
     image: ko://github.com/agent-substrate/substrate/demos/counter
-    command: ["/ko-app/counter"]
+    command: ["/ko-app/counter", "--file-counter-directory=/home/counter", "--validate-existing-file-path=/external-data/test.txt"]
     readyz:
       httpGet:
         path: /readyz
         port: 80
     volumeMounts:
     - name: data
       mountPath: /home/counter
+    - name: external-data
+      mountPath: /external-data
   workerSelector:
     matchLabels:
       workload: counter
@@ -60,3 +62,7 @@ spec:
   volumes:
   - name: data
     durableDir: {}
+  - name: external-data
+    externalVolumeTemplate:
+      capacity: 1Gi
+      storageClassName: standard

hack/run-demo-counter-kind.sh

@@ -0,0 +1,74 @@
+#!/usr/bin/env bash
+
+# Copyright 2026 Google LLC
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+set -o errexit -o nounset -o pipefail
+
+ROOT="$(cd "$(dirname "$0")/.." && pwd)"
+cd "${ROOT}"
+
+# ANSI color codes for pretty output
+COLOR_CYAN='\033[1;36m'
+COLOR_GREEN='\033[1;32m'
+COLOR_YELLOW='\033[1;33m'
+COLOR_RED='\033[1;31m'
+COLOR_RESET='\033[0m'
+
+function log_step() {
+  echo -e "${COLOR_CYAN}[step]: $1${COLOR_RESET}"
+}
+
+function log_success() {
+  echo -e "${COLOR_GREEN}[success]: $1${COLOR_RESET}"
+}
+
+function log_warn() {
+  echo -e "${COLOR_YELLOW}[warning]: $1${COLOR_RESET}"
+}
+
+function log_error() {
+  echo -e "${COLOR_RED}[error]: $1${COLOR_RESET}"
+}
+
+log_step "Cleaning up previous test"
+./hack/delete-kind-cluster.sh || true
+
+log_step "Installing kind cluster"
+./hack/create-kind-cluster.sh
+
+log_step "Installing ATE control plane, Valkey, and RustFS..."
+./hack/install-ate-kind.sh --deploy-ate-system
+
+log_step "Installing counter demo..."
+./hack/install-ate-kind.sh --deploy-demo-counter
+
+log_step "Installing kubectl-ate CLI..."
+go install ./cmd/kubectl-ate
+
+log_step "Creating atespace (demo)..."
+kubectl ate create atespace demo
+
+log_step "Creating counter actor (my-counter-1)..."
+kubectl ate create actor my-counter-1 --template ate-demo-counter/counter --atespace demo
+
+log_success "Counter actor my-counter-1 created"
+echo ""
+echo -e "${COLOR_YELLOW}========================================================================${COLOR_RESET}"
+echo -e "To interact with the counter actor, open a separate terminal and run:"
+echo -e "  curl -X POST -H \"Host: my-counter-1.demo.actors.resources.substrate.ate.dev\" -i http://localhost:8000/"
+echo -e "${COLOR_YELLOW}========================================================================${COLOR_RESET}"
+echo ""
+log_step "Starting port-forwarding for the network router (press Ctrl+C to stop)..."
+kubectl port-forward -n ate-system svc/atenet-router 8000:80