feat: add Python function template support

theothersideofgod · claude · theothersideofgod · commit 89163439e77c · 2026-04-22T09:17:38.000+08:00
Add Python template alongside existing node-graphql template, enabling
Python-based serverless functions in the FaaS framework.

Changes:
- Add templates/python/ with FastAPI-based HTTP server
- Add functions/python-example/ as reference implementation
- Add Dockerfile.python.dev for Python function development
- Update generate.ts to support .py file symlinks
- Update skaffold.yaml with Python image build config
- Register python-example in job-service routing

Co-Authored-By: Claude Opus 4.5 &lt;noreply@anthropic.com&gt;
diff --git a/Dockerfile.python.dev b/Dockerfile.python.dev
@@ -0,0 +1,19 @@
+FROM python:3.11-slim
+
+WORKDIR /usr/src/app
+
+# Install watchdog for hot reload
+RUN pip install --no-cache-dir watchdog[watchmedo]
+
+# Copy all generated python functions and their requirements
+COPY generated/ generated/
+COPY functions/ functions/
+
+# Install dependencies for all python functions
+RUN for req in generated/*/requirements.txt; do \
+      if [ -f "$req" ]; then \
+        pip install --no-cache-dir -r "$req"; \
+      fi \
+    done
+
+ENV PYTHONUNBUFFERED=1
diff --git a/functions/python-example/handler.json b/functions/python-example/handler.json
@@ -0,0 +1,6 @@
+{
+  "name": "python-example",
+  "version": "0.1.0",
+  "description": "Example Python function",
+  "type": "python"
+}
diff --git a/functions/python-example/handler.py b/functions/python-example/handler.py
@@ -0,0 +1,9 @@
+async def handler(payload: dict) -> dict:
+    """
+    Simple echo handler - returns the received payload.
+    """
+    return {
+        "received": payload,
+        "status": "ok",
+        "message": "Hello from Python!"
+    }
diff --git a/scripts/generate.ts b/scripts/generate.ts
@@ -181,6 +181,7 @@ interface FunctionInfo {
   name: string;
   dir: string;
   port: number;
+  type: string;
 }
 
 const K8S_TEMPLATES_DIR: string = path.resolve(TEMPLATES_DIR, 'k8s');
@@ -220,18 +221,20 @@ function generateFunctionsConfigMap(fns: FunctionInfo[], perFunction?: FunctionI
 }
 
 function generateSkaffoldYaml(fns: FunctionInfo[]): void {
-  const profileTemplate = readTemplate('skaffold-profile.yaml');
+  const nodeProfileTemplate = readTemplate('skaffold-profile.yaml');
+  const pythonProfileTemplate = readTemplate('skaffold-profile-python.yaml');
   const skaffoldTemplate = readTemplate('skaffold.yaml');
 
-  // Render per-function profiles from template
-  const perFnProfiles = fns.map((fn) =>
-    renderTemplate(profileTemplate, {
+  // Render per-function profiles from template (select based on type)
+  const perFnProfiles = fns.map((fn) => {
+    const template = fn.type === 'python' ? pythonProfileTemplate : nodeProfileTemplate;
+    return renderTemplate(template, {
       name: fn.name,
       dir: fn.dir,
       port: String(fn.port),
       namespace: K8S_NAMESPACE,
-    }).trimEnd()
-  ).join('\n');
+    }).trimEnd();
+  }).join('\n');
 
   // Build dynamic lists for aggregate profiles
   const allRawYaml = fns
@@ -247,10 +250,24 @@ function generateSkaffoldYaml(fns: FunctionInfo[]): void {
     ].join('\n'))
     .join('\n');
 
+  // Add Python artifacts if there are Python functions
+  const hasPython = fns.some((fn) => fn.type === 'python');
+  const pythonArtifacts = hasPython ? `        - image: constructive-functions-python
+          context: .
+          docker:
+            dockerfile: Dockerfile.python.dev
+          sync:
+            manual:
+              - src: 'functions/**/*.py'
+                dest: /usr/src/app
+              - src: 'generated/**/*.py'
+                dest: /usr/src/app` : '';
+
   const skaffold = renderTemplate(skaffoldTemplate, {
     per_function_profiles: perFnProfiles,
     all_raw_yaml: allRawYaml,
     all_port_forwards: allPortForwards,
+    python_artifacts: pythonArtifacts,
     namespace: K8S_NAMESPACE,
   });
 
@@ -327,17 +344,21 @@ function main(): void {
       }
     }
 
-    // Symlink handler.ts
-    const handlerTarget = path.join(fnDir, 'handler.ts');
-    if (fs.existsSync(handlerTarget)) {
-      const linked = ensureSymlink(handlerTarget, path.join(genDir, 'handler.ts'));
+    // Symlink handler.ts or handler.py
+    const handlerTsTarget = path.join(fnDir, 'handler.ts');
+    const handlerPyTarget = path.join(fnDir, 'handler.py');
+    if (fs.existsSync(handlerTsTarget)) {
+      const linked = ensureSymlink(handlerTsTarget, path.join(genDir, 'handler.ts'));
       if (linked) console.log(`    - handler.ts -> functions/${fnName}/handler.ts`);
+    } else if (fs.existsSync(handlerPyTarget)) {
+      const linked = ensureSymlink(handlerPyTarget, path.join(genDir, 'handler.py'));
+      if (linked) console.log(`    - handler.py -> functions/${fnName}/handler.py`);
     }
 
-    // Symlink any .d.ts files
+    // Symlink any .d.ts or .py files (excluding handler.py which is handled above)
     const files = fs.readdirSync(fnDir) as string[];
     for (const file of files) {
-      if (file.endsWith('.d.ts')) {
+      if (file.endsWith('.d.ts') || (file.endsWith('.py') && file !== 'handler.py')) {
         const target = path.join(fnDir, file);
         const linked = ensureSymlink(target, path.join(genDir, file));
         if (linked) console.log(`    - ${file} -> functions/${fnName}/${file}`);
@@ -388,6 +409,7 @@ function main(): void {
       name: allManifests[i].name,
       dir,
       port: allManifests[i].port,
+      type: allManifests[i].type || DEFAULT_TEMPLATE,
     })),
   };
 
diff --git a/skaffold.yaml b/skaffold.yaml
@@ -51,6 +51,52 @@ profiles:
         namespace: constructive-functions
         port: 3000
         localPort: 3002
+  - name: python-example
+    build:
+      artifacts:
+        - image: constructive-functions-python
+          context: .
+          docker:
+            dockerfile: Dockerfile.python.dev
+          sync:
+            manual:
+              - src: 'functions/**/*.py'
+                dest: /usr/src/app
+              - src: 'generated/**/*.py'
+                dest: /usr/src/app
+      local:
+        push: false
+    manifests:
+      kustomize:
+        paths:
+          - k8s/overlays/local-simple
+      rawYaml:
+        - generated/python-example/k8s/local-deployment.yaml
+        - generated/python-example/k8s/functions-configmap.yaml
+    deploy:
+      kubectl:
+        defaultNamespace: constructive-functions
+    portForward:
+      - resourceType: service
+        resourceName: python-example
+        namespace: constructive-functions
+        port: 80
+        localPort: 8084
+      - resourceType: service
+        resourceName: knative-job-service
+        namespace: constructive-functions
+        port: 8080
+        localPort: 8080
+      - resourceType: service
+        resourceName: postgres
+        namespace: constructive-functions
+        port: 5432
+        localPort: 5432
+      - resourceType: service
+        resourceName: constructive-server
+        namespace: constructive-functions
+        port: 3000
+        localPort: 3002
   - name: send-email-link
     build:
       artifacts:
@@ -152,6 +198,16 @@ profiles:
             manual:
               - src: 'functions/**/*.ts'
                 dest: /usr/src/app
+        - image: constructive-functions-python
+          context: .
+          docker:
+            dockerfile: Dockerfile.python.dev
+          sync:
+            manual:
+              - src: 'functions/**/*.py'
+                dest: /usr/src/app
+              - src: 'generated/**/*.py'
+                dest: /usr/src/app
       local:
         push: false
     manifests:
@@ -160,6 +216,7 @@ profiles:
           - k8s/overlays/local-simple
       rawYaml:
         - generated/example/k8s/local-deployment.yaml
+        - generated/python-example/k8s/local-deployment.yaml
         - generated/send-email-link/k8s/local-deployment.yaml
         - generated/simple-email/k8s/local-deployment.yaml
         - generated/functions-configmap.yaml
@@ -172,6 +229,11 @@ profiles:
         namespace: constructive-functions
         port: 80
         localPort: 8083
+      - resourceType: service
+        resourceName: python-example
+        namespace: constructive-functions
+        port: 80
+        localPort: 8084
       - resourceType: service
         resourceName: send-email-link
         namespace: constructive-functions
@@ -222,6 +284,11 @@ profiles:
         namespace: constructive-functions
         port: 80
         localPort: 8083
+      - resourceType: service
+        resourceName: python-example
+        namespace: constructive-functions
+        port: 80
+        localPort: 8084
       - resourceType: service
         resourceName: send-email-link
         namespace: constructive-functions
diff --git a/templates/k8s/skaffold-profile-python.yaml b/templates/k8s/skaffold-profile-python.yaml
@@ -0,0 +1,46 @@
+  - name: {{name}}
+    build:
+      artifacts:
+        - image: constructive-functions-python
+          context: .
+          docker:
+            dockerfile: Dockerfile.python.dev
+          sync:
+            manual:
+              - src: 'functions/**/*.py'
+                dest: /usr/src/app
+              - src: 'generated/**/*.py'
+                dest: /usr/src/app
+      local:
+        push: false
+    manifests:
+      kustomize:
+        paths:
+          - k8s/overlays/local-simple
+      rawYaml:
+        - generated/{{dir}}/k8s/local-deployment.yaml
+        - generated/{{dir}}/k8s/functions-configmap.yaml
+    deploy:
+      kubectl:
+        defaultNamespace: {{namespace}}
+    portForward:
+      - resourceType: service
+        resourceName: {{name}}
+        namespace: {{namespace}}
+        port: 80
+        localPort: {{port}}
+      - resourceType: service
+        resourceName: knative-job-service
+        namespace: {{namespace}}
+        port: 8080
+        localPort: 8080
+      - resourceType: service
+        resourceName: postgres
+        namespace: {{namespace}}
+        port: 5432
+        localPort: 5432
+      - resourceType: service
+        resourceName: constructive-server
+        namespace: {{namespace}}
+        port: 3000
+        localPort: 3002
diff --git a/templates/k8s/skaffold.yaml b/templates/k8s/skaffold.yaml
@@ -21,6 +21,7 @@ profiles:
             manual:
               - src: 'functions/**/*.ts'
                 dest: /usr/src/app
+{{python_artifacts}}
       local:
         push: false
     manifests:
diff --git a/templates/python/Dockerfile b/templates/python/Dockerfile
@@ -0,0 +1,13 @@
+FROM python:3.11-slim
+
+WORKDIR /app
+
+COPY generated/{{name}}/requirements.txt .
+RUN pip install --no-cache-dir -r requirements.txt
+
+COPY generated/{{name}}/ .
+
+ENV PORT=8080
+EXPOSE 8080
+
+CMD ["python", "main.py"]
diff --git a/templates/python/README.md b/templates/python/README.md
@@ -0,0 +1,3 @@
+# {{name}}-fn
+
+{{description}}
diff --git a/templates/python/k8s/local-deployment.yaml b/templates/python/k8s/local-deployment.yaml
@@ -0,0 +1,48 @@
+apiVersion: apps/v1
+kind: Deployment
+metadata:
+  name: {{name}}
+  labels:
+    app: {{name}}
+spec:
+  replicas: 1
+  selector:
+    matchLabels:
+      app: {{name}}
+  template:
+    metadata:
+      labels:
+        app: {{name}}
+    spec:
+      containers:
+        - name: {{name}}
+          image: constructive-functions-python:local
+          command: ["watchmedo"]
+          args: ["auto-restart", "--directory=generated/{{name}}", "--pattern=*.py", "--recursive", "--", "python", "generated/{{name}}/main.py"]
+          ports:
+            - containerPort: 8080
+          env:
+            - name: PORT
+              value: "8080"
+            - name: LOG_LEVEL
+              value: "info"
+            - name: PYTHONUNBUFFERED
+              value: "1"
+          resources:
+            requests:
+              memory: "256Mi"
+              cpu: "100m"
+            limits:
+              memory: "1Gi"
+              cpu: "500m"
+---
+apiVersion: v1
+kind: Service
+metadata:
+  name: {{name}}
+spec:
+  selector:
+    app: {{name}}
+  ports:
+    - port: 80
+      targetPort: 8080
diff --git a/templates/python/main.py b/templates/python/main.py
@@ -0,0 +1,36 @@
+import os
+import logging
+from fastapi import FastAPI, Request
+from fastapi.responses import JSONResponse
+import uvicorn
+
+from handler import handler
+
+logging.basicConfig(level=logging.INFO)
+logger = logging.getLogger("{{name}}")
+
+app = FastAPI(title="{{name}}")
+
+
+@app.get("/health")
+async def health():
+    return {"status": "ok"}
+
+
+@app.post("/")
+async def handle(request: Request):
+    try:
+        payload = await request.json()
+        logger.info(f"Received job: {payload}")
+        result = await handler(payload)
+        logger.info(f"Job completed: {result}")
+        return JSONResponse(content=result)
+    except Exception as e:
+        logger.error(f"Job failed: {e}")
+        return JSONResponse(content={"error": str(e)}, status_code=500)
+
+
+if __name__ == "__main__":
+    port = int(os.getenv("PORT", 8080))
+    logger.info(f"Starting {{name}} on port {port}")
+    uvicorn.run(app, host="0.0.0.0", port=port)
diff --git a/templates/python/requirements.txt b/templates/python/requirements.txt
@@ -0,0 +1,3 @@
+fastapi>=0.104.0
+uvicorn>=0.24.0
+pydantic>=2.0.0
diff --git a/tests/e2e/__tests__/python-example.e2e.test.ts b/tests/e2e/__tests__/python-example.e2e.test.ts

Original file line number	Diff line number	Diff line change
`@@ -0,0 +1,3 @@`
	`1`	`+# {{name}}-fn`
	`2`	`+`
	`3`	`+{{description}}`