initial commit - go function

.forgejo/workflows/deploy.yml

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+# FnKit Deploy — Forgejo Actions
+# Builds and deploys this function container on every push to main
+# Requires: Forgejo runner with Docker socket access (fnkit deploy runner)
+#
+# Pipeline: git push → build image → deploy container → health check
+
+on:
+  push:
+    branches: [main]
+
+jobs:
+  deploy:
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v4
+
+      - name: Build image
+        run: |
+          FUNCTION_NAME="fn-go"
+          IMAGE_NAME="fnkit-fn-${FUNCTION_NAME}:latest"
+          IMAGE_PREV="fnkit-fn-${FUNCTION_NAME}:prev"
+
+          echo "🔨 Building ${FUNCTION_NAME}..."
+          docker build -t $IMAGE_NAME .
+
+          echo "IMAGE_NAME=$IMAGE_NAME" >> $GITHUB_ENV
+          echo "IMAGE_PREV=$IMAGE_PREV" >> $GITHUB_ENV
+          echo "FUNCTION_NAME=$FUNCTION_NAME" >> $GITHUB_ENV
+
+      - name: Deploy container
+        run: |
+          echo "🌐 Ensuring fnkit-network exists..."
+          docker network create fnkit-network 2>/dev/null || true
+
+          # Tag current image as :prev for rollback
+          docker tag $IMAGE_NAME $IMAGE_PREV 2>/dev/null || true
+
+          echo "♻️  Replacing running container..."
+          docker stop $FUNCTION_NAME 2>/dev/null || true
+          docker rm $FUNCTION_NAME 2>/dev/null || true
+
+          echo "🚀 Starting ${FUNCTION_NAME}..."
+          docker run -d \
+            --name $FUNCTION_NAME \
+            --network fnkit-network \
+            --label fnkit.fn=true \
+            --label fnkit.deployed="$(date -u +%Y-%m-%dT%H:%M:%SZ)" \
+            --restart unless-stopped \
+            $IMAGE_NAME
+
+      - name: Health check
+        run: |
+          echo "🏥 Checking container health..."
+          sleep 3
+
+          if docker ps --filter "name=$FUNCTION_NAME" --filter "status=running" -q | grep -q .; then
+            echo "✅ ${FUNCTION_NAME} is running"
+            echo "🌐 Available at gateway: /${FUNCTION_NAME}"
+          else
+            echo "❌ Container failed to start — rolling back..."
+            docker logs $FUNCTION_NAME 2>&1 || true
+
+            # Rollback to previous image if available
+            if docker image inspect $IMAGE_PREV >/dev/null 2>&1; then
+              echo "🔄 Rolling back to previous image..."
+              docker rm $FUNCTION_NAME 2>/dev/null || true
+              docker run -d \
+                --name $FUNCTION_NAME \
+                --network fnkit-network \
+                --label fnkit.fn=true \
+                --label fnkit.deployed="$(date -u +%Y-%m-%dT%H:%M:%SZ)" \
+                --label fnkit.rollback=true \
+                --restart unless-stopped \
+                $IMAGE_PREV
+              echo "⚠️  Rolled back to previous version"
+            fi
+            exit 1
+          fi
+
+      - name: Cleanup old images
+        run: |
+          echo "🧹 Cleaning up dangling images..."
+          docker image prune -f --filter "label=fnkit.fn=true" 2>/dev/null || true

.gitignore

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+# IDE
+.idea/
+.vscode/
+*.swp
+*.swo
+
+# OS
+.DS_Store
+Thumbs.db
+
+# Docker
+Dockerfile.local
+# Go
+vendor/
+*.exe

Dockerfile

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+FROM golang:1.21 AS builder
+LABEL fnkit.fn="true"
+WORKDIR /app
+COPY go.* ./
+RUN go mod download
+COPY . .
+RUN CGO_ENABLED=0 GOOS=linux go build -o server ./cmd/main.go
+
+FROM gcr.io/distroless/static-debian11
+COPY --from=builder /app/server /server
+ENV FUNCTION_TARGET=HelloWorld
+EXPOSE 8080
+CMD ["/server"]

cmd/main.go

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+package main
+
+import (
+	"log"
+	"os"
+
+	// Blank-import the function package so the init() runs
+	_ "fn-go"
+	"github.com/GoogleCloudPlatform/functions-framework-go/funcframework"
+)
+
+func main() {
+	// Use PORT environment variable, or default to 8080.
+	port := "8080"
+	if envPort := os.Getenv("PORT"); envPort != "" {
+		port = envPort
+	}
+
+	// By default, listen on all interfaces. If testing locally, run with
+	// LOCAL_ONLY=true to avoid triggering firewall warnings and
+	// exposing the server outside of your own machine.
+	hostname := ""
+	if localOnly := os.Getenv("LOCAL_ONLY"); localOnly == "true" {
+		hostname = "127.0.0.1"
+	}
+	if err := funcframework.StartHostPort(hostname, port); err != nil {
+		log.Fatalf("funcframework.StartHostPort: %v\n", err)
+	}
+}

docker-compose.yml

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+# Docker Compose for FnKit function with gateway integration
+# Requires: docker network create fnkit-network
+# Requires: fnkit-gateway running (fnkit gateway init && fnkit gateway build && fnkit gateway start)
+
+version: '3.8'
+
+services:
+  fn-go:
+    build: .
+    container_name: fn-go
+    networks:
+      - fnkit-network
+    depends_on:
+      fnkit-gateway:
+        condition: service_started
+    restart: unless-stopped
+
+  # Uncomment to include gateway in this compose file
+  # fnkit-gateway:
+  #   image: fnkit-gateway:latest
+  #   container_name: fnkit-gateway
+  #   ports:
+  #     - "8080:8080"
+  #   environment:
+  #     - FNKIT_AUTH_TOKEN=${FNKIT_AUTH_TOKEN:-}
+  #   networks:
+  #     - fnkit-network
+
+networks:
+  fnkit-network:
+    name: fnkit-network
+    external: true
+
+# Usage:
+#   docker-compose up -d
+#   curl -H "Authorization: Bearer <token>" http://localhost:8080/fn-go

function.go

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+package function
+
+import (
+	"fmt"
+	"net/http"
+
+	"github.com/GoogleCloudPlatform/functions-framework-go/functions"
+)
+
+func init() {
+	functions.HTTP("HelloWorld", helloWorld)
+}
+
+// helloWorld writes "Hello, World!" to the HTTP response.
+func helloWorld(w http.ResponseWriter, r *http.Request) {
+	fmt.Fprintln(w, "Hello, World!")
+}

go.mod

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+module fn-go
+
+go 1.21
+
+require github.com/GoogleCloudPlatform/functions-framework-go v1.8.0