Switch to Kubernetes Watch API

camera-deployment.yml

@@ -32,13 +32,16 @@ spec:
       containers:
         - name: camdetect
           image: harbor.k-space.ee/k-space/camera-motion-detect:latest
+          ports:
+          - containerPort: 5000
+            name: "http"
           resources:
             requests:
               memory: "64Mi"
-              cpu: "250m"
+              cpu: "200m"
             limits:
               memory: "128Mi"
-              cpu: "500m"
+              cpu: "1"
           securityContext:
             readOnlyRootFilesystem: true
             runAsNonRoot: true

camera-operator.py

@@ -1,100 +1,135 @@
 import asyncio
+import os
 import yaml
 from base64 import b64decode
 from kubernetes_asyncio.client.api_client import ApiClient
-from kubernetes_asyncio import client, config
+from kubernetes_asyncio import client, config, watch
 from os import path
 from time import time
 from urllib.parse import urlparse
 
+NAMESPACE = os.environ["MY_POD_NAMESPACE"]
+
 LABEL_MANAGED_BY = "camera-operator"
 with open("camera-service.yml") as stream:
   SERVICE_BODY = stream.read()
 with open("camera-deployment.yml") as stream:
   DEPLOYMENT_BODY = stream.read()
 
+async def apply_changes(item, v1, now, apps_api):
+    target = item["spec"]["target"]
+    replicas = item["spec"].get("replicas")
+
+    # Pull in secrets for the target URL
+    secret_ref = item["spec"].get("secretRef")
+    if secret_ref:
+        secret = await v1.read_namespaced_secret(secret_ref, NAMESPACE)
+        username = b64decode(secret.data.get("username", b"")).decode("ascii")
+        password = b64decode(secret.data.get("password", b"")).decode("ascii")
+        o = urlparse(target)
+        netloc = o.netloc
+        if "@" in netloc:
+            _, netloc = o.netloc.split("@", 1)
+        target = o._replace(netloc="%s:%s@%s" % (username, password, netloc)).geturl()
+
+    name = "camera-%s" % item["metadata"]["name"]
+    print("Applying changes for", name, "CRD")
+
+    # Generate Deployment
+    body = yaml.safe_load(DEPLOYMENT_BODY.replace("foobar", name))
+    body["metadata"]["labels"] ["app.kubernetes.io/managed-by"] = LABEL_MANAGED_BY
+    body["metadata"]["labels"] ["modified"] = now
+    body["spec"]["template"]["spec"]["containers"][0]["args"] = [target]
+
+    if replicas:
+        body["spec"]["replicas"] = replicas
+    try:
+        await apps_api.replace_namespaced_deployment(
+            name = name, body = body, namespace=NAMESPACE)
+        print("  * Updated deployment %s/%s" % (NAMESPACE, name))
+    except client.exceptions.ApiException as e:
+        await apps_api.create_namespaced_deployment(
+            body = body, namespace=NAMESPACE)
+        print("  * Created deployment %s/%s" % (NAMESPACE, name))
+
+    # Generate Service
+    body = yaml.safe_load(SERVICE_BODY.replace("foobar", name))
+    body["metadata"]["labels"] ["app.kubernetes.io/managed-by"] = LABEL_MANAGED_BY
+    body["metadata"]["labels"] ["modified"] = now
+    try:
+        await v1.replace_namespaced_service(
+            name = name, body = body, namespace=NAMESPACE)
+        print("  * Updated service %s/%s" % (NAMESPACE, name))
+    except client.exceptions.ApiException as e:
+        await v1.create_namespaced_service(
+            body = body, namespace=NAMESPACE)
+        print("  * Created service %s/%s" % (NAMESPACE, name))
+
+
 async def main():
-
-  await config.load_kube_config()
+  if os.getenv("KUBECONFIG"):
+      await config.load_kube_config()
+  else:
+      await config.load_incluster_config()
   async with ApiClient() as api:
-
     v1 = client.CoreV1Api(api)
     apps_api = client.AppsV1Api()
-
-    print("Listing namespaces")
-    ret = await v1.list_namespace()
     api_instance = client.CustomObjectsApi(api)
     now = str(time())
 
-    for i in ret.items:
-        try:
-            resp = await api_instance.list_namespaced_custom_object(
-                "k-space.ee", "v1alpha1", i.metadata.name, "cams")
-        except client.exceptions.ApiException:
+    w = watch.Watch()
+    args = "k-space.ee", "v1alpha1", NAMESPACE, "cams"
+
+    resp = await api_instance.list_namespaced_custom_object(*args)
+    for i in resp["items"]:
+        await apply_changes(i, v1, now, apps_api)
+
+    print("Cleaning up dangling deployments and services")
+    resp = await v1.list_namespaced_service(NAMESPACE)
+    for i in resp.items:
+        if not i.metadata.labels:
             continue
-        for item in resp["items"]:
-            target = item["spec"]["target"]
-            replicas = item["spec"].get("replicas")
+        if i.metadata.labels.get("app.kubernetes.io/managed-by") != LABEL_MANAGED_BY:
+            continue
+        if i.metadata.labels.get("modified") == now:
+            continue
+        print("  * Removing service: %s/%s" % (NAMESPACE, i.metadata.name))
+        await v1.delete_namespaced_service(i.metadata.name, NAMESPACE)
 
-            # Pull in secrets for the target URL
-            secret_ref = item["spec"].get("secretRef")
-            if secret_ref:
-                secret = await v1.read_namespaced_secret(secret_ref, i.metadata.name)
-                username = b64decode(secret.data.get("username", b"")).decode("ascii")
-                password = b64decode(secret.data.get("password", b"")).decode("ascii")
-                o = urlparse(target)
-                netloc = o.netloc
-                if "@" in netloc:
-                    _, netloc = o.netloc.split("@", 1)
-                target = o._replace(netloc="%s:%s@%s" % (username, password, netloc)).geturl()
+    resp = await apps_api.list_namespaced_deployment(NAMESPACE)
+    for i in resp.items:
+        if not i.metadata.labels:
+            continue
+        if i.metadata.labels.get("app.kubernetes.io/managed-by") != LABEL_MANAGED_BY:
+            continue
+        if i.metadata.labels.get("modified") == now:
+            continue
+        print("  * Removing deployment: %s/%s" % (NAMESPACE, i.metadata.name))
+        await apps_api.delete_namespaced_deployment(i.metadata.name, NAMESPACE)
 
-            name = "camera-%s" % item["metadata"]["name"]
-            print("Applying", name)
+    print("Subscribing to updates")
 
-            # Generate Deployment
-            body = yaml.safe_load(DEPLOYMENT_BODY.replace("foobar", name))
-            body["metadata"]["labels"] ["app.kubernetes.io/managed-by"] = LABEL_MANAGED_BY
-            body["metadata"]["labels"] ["modified"] = now
-            body["spec"]["template"]["spec"]["containers"][0]["args"] = [target]
-
-            if replicas:
-                body["spec"]["replicas"] = replicas
+    async for event in w.stream(api_instance.list_namespaced_custom_object, *args):
+        if event["type"] == "ADDED":
+            await apply_changes(event["object"], v1, now, apps_api)
+        elif event["type"] == "DELETED":
+            name = "camera-%s" % event["object"]["metadata"]["name"]
             try:
-                await apps_api.replace_namespaced_deployment(
-                    name = name, body = body, namespace=i.metadata.name)
-                print("Updated deployment %s/%s" % (i.metadata.name, name))
+                await v1.delete_namespaced_service(name, NAMESPACE)
             except client.exceptions.ApiException as e:
-                await apps_api.create_namespaced_deployment(
-                    body = body, namespace=i.metadata.name)
-                print("Created deployment %s/%s" % (i.metadata.name, name))
-
-            # Generate Service
-            body = yaml.safe_load(SERVICE_BODY.replace("foobar", name))
-            body["metadata"]["labels"] ["app.kubernetes.io/managed-by"] = LABEL_MANAGED_BY
-            body["metadata"]["labels"] ["modified"] = now
+                pass
+            else:
+                print("Removed service: %s/%s" % (NAMESPACE, name))
             try:
-                await v1.replace_namespaced_service(
-                    name = name, body = body, namespace=i.metadata.name)
-                print("Updated service %s/%s" % (i.metadata.name, name))
+                await apps_api.delete_namespaced_deployment(name, NAMESPACE)
             except client.exceptions.ApiException as e:
-                await v1.create_namespaced_service(
-                    body = body, namespace=i.metadata.name)
-                print("Created service %s/%s" % (i.metadata.name, name))
+                pass
+            else:
+                print("Removed deployment: %s/%s" % (NAMESPACE, name))
 
-    deployments = await apps_api.list_deployment_for_all_namespaces()
-    for dep in deployments.items:
-        if not dep.metadata.labels:
-            continue
-        if dep.metadata.labels.get("app.kubernetes.io/managed-by") != LABEL_MANAGED_BY:
-            continue
-        if dep.metadata.labels.get("modified") == now:
-            continue
-        print("Removing deployment: %s/%s" % (dep.metadata.namespace, dep.metadata.name))
-        await apps_api.delete_namespaced_deployment(name=dep.metadata.name, namespace=dep.metadata.namespace)
-    print("Done")
 
 if __name__ == '__main__':
-    loop = asyncio.get_event_loop()
+    loop = asyncio.new_event_loop()
     loop.run_until_complete(main())
     loop.close()