feat: script to build docker image with examples

Author: tomplus

examples/in_cluster_config.py

@@ -14,27 +14,70 @@
 
 # Simple example to show loading config from the cluster
 
+#
+# If you get 403 errors from API server you will have to configure
+# RBAC to add necessay permissions.
+#
+# ---
+# kind: ClusterRole
+# apiVersion: rbac.authorization.k8s.io/v1
+# metadata:
+#   name: pods-list
+# rules:
+# - apiGroups: [""]
+#   resources: ["pods"]
+#   verbs: ["list"]
+# ---
+# kind: ClusterRoleBinding
+# apiVersion: rbac.authorization.k8s.io/v1
+# metadata:
+#   name: pods-list
+# subjects:
+# - kind: ServiceAccount
+#   name: default
+#   namespace: default
+# roleRef:
+#   kind: ClusterRole
+#   name: pods-list
+#   apiGroup: rbac.authorization.k8s.io
+# ---
+#
+# Doc: https://kubernetes.io/docs/reference/access-authn-authz/rbac/
+#
+# This example can be run from the image: https://hub.docker.com/r/tpimages/kubernetes_asyncio_examples/
+#
+# $ kubectl run kubernetes-asyncio-examples --image tpimages/kubernetes_asyncio_examples 
+# 
+
 import asyncio
+import sys
+import traceback
 
 from kubernetes_asyncio import client, config
 
 
 async def main():
 
-    # it works only if this script is run by K8s as a POD
-    config.load_incluster_config()
-
     while True:
 
-        v1 = client.CoreV1Api()
-        print("Listing pods with their IPs:")
-        ret = await v1.list_pod_for_all_namespaces()
+        try:
+
+            # it works only if this script is run by K8s as a POD
+            config.load_incluster_config()
+
+            v1 = client.CoreV1Api()
+            print("Listing pods with their IPs:")
+            ret = await v1.list_pod_for_all_namespaces()
+
+            for i in ret.items:
+                print(i.status.pod_ip, i.metadata.namespace, i.metadata.name)
 
-        for i in ret.items:
-            print(i.status.pod_ip, i.metadata.namespace, i.metadata.name)
+        except Exception:
+            traceback.print_exc(file=sys.stdout)
 
-        print("sleep 10s")
-        await asyncio.sleep(10)
+        finally:
+            print("sleep 10s")
+            await asyncio.sleep(10)
 
 
 if __name__ == '__main__':

scripts/docker.sh

@@ -0,0 +1,18 @@
+#!/bin/bash
+
+# script to build docker image with examples
+
+TMP=$(mktemp -d)
+
+cat << EOF > $TMP/Dockerfile
+FROM python:3.7-alpine
+WORKDIR /examples
+RUN pip install kubernetes_asyncio
+COPY examples/in_cluster_config.py /examples/
+CMD ["python", "/examples/in_cluster_config.py"]
+EOF
+
+cp -r examples $TMP/
+docker build -t tpimages/kubernetes_asyncio_examples:latest $TMP
+
+rm -fr $TMP