Simplify operator design

camera-operator.py

@@ -10,7 +10,7 @@ from time import time
 from urllib.parse import urlparse
 import useful.logs
 
-useful.logs.setup(json_fields={"msg": "message", "level": "levelname"})
+useful.logs.setup(json_fields={"msg": "message", "level": "levelname", "traceback": "exc_text"})
 logger = logging.getLogger()
 
 NAMESPACE = os.environ["MY_POD_NAMESPACE"]
@@ -22,6 +22,36 @@ with open("camera-deployment.yml") as stream:
     DEPLOYMENT_BODY = stream.read()
 
 
+def object_managed(i, now):
+    """
+    Check if Kubernetes object is managed according to CRD-s
+    """
+    if not i.metadata.labels:
+        return False
+    if i.metadata.labels.get("app.kubernetes.io/managed-by") != LABEL_MANAGED_BY:
+        return False
+    if i.metadata.labels.get("modified") == now:
+        return False
+    return True
+
+
+async def cleanup_dangling_objects(v1, apps_api, now):
+    await asyncio.sleep(2)
+    logger.info("Cleaning up dangling deployments and services")
+    resp = await v1.list_namespaced_service(NAMESPACE)
+    for i in resp.items:
+        if not object_managed(i, now):
+            continue
+        logger.debug("Removing service: %s/%s", NAMESPACE, i.metadata.name)
+        await v1.delete_namespaced_service(i.metadata.name, NAMESPACE)
+    resp = await apps_api.list_namespaced_deployment(NAMESPACE)
+    for i in resp.items:
+        if not object_managed(i, now):
+            continue
+        logger.debug("Removing deployment: %s/%s", NAMESPACE, i.metadata.name)
+        await apps_api.delete_namespaced_deployment(i.metadata.name, NAMESPACE)
+
+
 async def apply_changes(item, v1, now, apps_api):
     target = item["spec"]["target"]
     replicas = item["spec"].get("replicas")
@@ -68,6 +98,37 @@ async def apply_changes(item, v1, now, apps_api):
         logger.debug("Created service %s/%s", NAMESPACE, name)
 
 
+async def update_loop(v1, apps_api, api_instance):
+    cleanup_task = None
+    latest_version = None
+    now = str(time())
+    w = watch.Watch()
+    args = "k-space.ee", "v1alpha1", NAMESPACE, "cams"
+    logger.info("Subscribing to updates")
+    async for event in w.stream(api_instance.list_namespaced_custom_object, *args, resource_version=latest_version):
+        latest_version = event["object"]["metadata"]["resourceVersion"]
+        if event["type"] == "ADDED":
+            await apply_changes(event["object"], v1, now, apps_api)
+        elif event["type"] == "DELETED":
+            name = "camera-%s" % event["object"]["metadata"]["name"]
+            logger.info("Remove %s" % name)
+            try:
+                await v1.delete_namespaced_service(name, NAMESPACE)
+            except client.exceptions.ApiException:
+                pass
+            else:
+                logger.debug("Remove service: %s/%s", NAMESPACE, name)
+            try:
+                await apps_api.delete_namespaced_deployment(name, NAMESPACE)
+            except client.exceptions.ApiException:
+                pass
+            else:
+                logger.debug("Remove deployment: %s/%s", NAMESPACE, name)
+        if cleanup_task:
+            cleanup_task.cancel()
+        cleanup_task = asyncio.create_task(cleanup_dangling_objects(v1, apps_api, now))
+
+
 async def main():
     if os.getenv("KUBECONFIG"):
         await config.load_kube_config()
@@ -77,57 +138,11 @@ async def main():
         v1 = client.CoreV1Api(api)
         apps_api = client.AppsV1Api()
         api_instance = client.CustomObjectsApi(api)
-        now = str(time())
-
-        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)
-
-        logger.info("Cleaning up dangling deployments and services")
-        resp = await v1.list_namespaced_service(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
-            logger.debug("Removing service: %s/%s", NAMESPACE, i.metadata.name)
-            await v1.delete_namespaced_service(i.metadata.name, NAMESPACE)
-
-        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
-            logger.debug("Removing deployment: %s/%s", NAMESPACE, i.metadata.name)
-            await apps_api.delete_namespaced_deployment(i.metadata.name, NAMESPACE)
-
-        logger.info("Subscribing to updates")
-
-        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"]
+        while True:
             try:
-                    await v1.delete_namespaced_service(name, NAMESPACE)
-                except client.exceptions.ApiException:
+                await update_loop(v1, apps_api, api_instance)
+            except asyncio.exceptions.TimeoutError:
                 pass
-                else:
-                    logger.debug("Removed service: %s/%s", NAMESPACE, name)
-                try:
-                    await apps_api.delete_namespaced_deployment(name, NAMESPACE)
-                except client.exceptions.ApiException:
-                    pass
-                else:
-                    logger.debug("Removed deployment: %s/%s", NAMESPACE, name)
 
 
 if __name__ == "__main__":