helloworld sample update (istio#45355)

* update helloworld to use gunicorn; bind TCP6 by default but offer a fallback option if necessary; introduce dual stack manifest for helloworld on k8s Signed-off-by: ilrudie <ian.rudie@solo.io> * python lint fix Signed-off-by: ilrudie <ian.rudie@solo.io> * Adding curl to the image, the old image had it and was used by some folks as a client as a result Signed-off-by: ilrudie <ian.rudie@solo.io> * fixing Dockerfile lint issues Signed-off-by: ilrudie <ian.rudie@solo.io> --------- Signed-off-by: ilrudie <ian.rudie@solo.io>
WillardHu · Jun 15, 2023 · ae5a7e3 · ae5a7e3
1 parent 1f91b25
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Showing 4 changed files with 85 additions and 2 deletions.
diff --git a/samples/helloworld/helloworld-dual-stack.yaml b/samples/helloworld/helloworld-dual-stack.yaml
@@ -0,0 +1,75 @@
+apiVersion: v1
+kind: Service
+metadata:
+  name: helloworld
+  labels:
+    app: helloworld
+    service: helloworld
+spec:
+  ipFamilyPolicy: RequireDualStack
+  ipFamilies:
+  - IPv6
+  - IPv4
+  ports:
+  - port: 5000
+    name: http
+  selector:
+    app: helloworld
+---
+apiVersion: apps/v1
+kind: Deployment
+metadata:
+  name: helloworld-v1
+  labels:
+    app: helloworld
+    version: v1
+spec:
+  replicas: 1
+  selector:
+    matchLabels:
+      app: helloworld
+      version: v1
+  template:
+    metadata:
+      labels:
+        app: helloworld
+        version: v1
+    spec:
+      containers:
+      - name: helloworld
+        image: docker.io/istio/examples-helloworld-v1
+        resources:
+          requests:
+            cpu: "100m"
+        imagePullPolicy: IfNotPresent #Always
+        ports:
+        - containerPort: 5000
+---
+apiVersion: apps/v1
+kind: Deployment
+metadata:
+  name: helloworld-v2
+  labels:
+    app: helloworld
+    version: v2
+spec:
+  replicas: 1
+  selector:
+    matchLabels:
+      app: helloworld
+      version: v2
+  template:
+    metadata:
+      labels:
+        app: helloworld
+        version: v2
+    spec:
+      containers:
+      - name: helloworld
+        image: docker.io/istio/examples-helloworld-v2
+        resources:
+          requests:
+            cpu: "100m"
+        imagePullPolicy: IfNotPresent #Always
+        ports:
+        - containerPort: 5000
diff --git a/samples/helloworld/src/Dockerfile b/samples/helloworld/src/Dockerfile
@@ -21,9 +21,16 @@ COPY requirements.txt ./
 # install the dependencies and packages in the requirements file
 RUN pip install --no-cache-dir -r requirements.txt
 
+# old image had curl and could be used as a sample client if desired
+RUN apt-get update \
+  && apt-get install curl --no-install-recommends -y \
+  && rm -rf /var/lib/apt/lists/*
+
 EXPOSE 5000
 
 ARG service_version
 ENV SERVICE_VERSION ${service_version:-v1}
 
-CMD ["python", "app.py"]
+# image will bind on TCP6 by default. In k8s pod spec (in a deployment pod template most likely) override for explicit IPv4 if needed with the command shown below:
+# ["gunicorn", "-b", "[0.0.0.0]:5000", "app:app", "-k", "gevent"]
+CMD ["gunicorn", "-b", "[::]:5000", "app:app", "-k", "gevent"]
diff --git a/samples/helloworld/src/app.py b/samples/helloworld/src/app.py
@@ -38,4 +38,4 @@ def health():
 
 
 if __name__ == "__main__":
-    app.run(host='::', threaded=True)
+    app.run(host='127.0.0.1', threaded=True)  # listen on IPv4; gunicorn will accept IPv6 from outside the pod
diff --git a/samples/helloworld/src/requirements.txt b/samples/helloworld/src/requirements.txt
@@ -5,3 +5,4 @@ flask_bootstrap
 json2html
 simplejson
 gevent
+gunicorn
Original file line number	Diff line number	Diff line change
Expand Up		@@ -38,4 +38,4 @@ def health():


		if __name__ == "__main__":
		app.run(host='::', threaded=True)
		app.run(host='127.0.0.1', threaded=True) # listen on IPv4; gunicorn will accept IPv6 from outside the pod