Add Kubernetes Metrics API support to utils module

examples/metrics_example.py

@@ -0,0 +1,190 @@
+#!/usr/bin/env python
+# Copyright 2024 The Kubernetes Authors.
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+"""
+Example demonstrating how to fetch and display metrics from the Kubernetes
+metrics-server using the Python client.
+
+This example shows:
+1. Fetching node metrics
+2. Fetching pod metrics in a namespace
+3. Fetching pod metrics across multiple namespaces
+4. Filtering pod metrics by labels
+
+Prerequisites:
+- A running Kubernetes cluster with metrics-server installed
+- kubectl configured to access the cluster
+- The kubernetes Python client library installed
+"""
+
+from kubernetes import client, config, utils
+
+
+def print_node_metrics(api_client):
+    """Fetch and display node metrics."""
+    print("\n" + "="*60)
+    print("NODE METRICS")
+    print("="*60)
+
+    try:
+        metrics = utils.get_nodes_metrics(api_client)
+
+        print(f"Found {len(metrics.get('items', []))} nodes\n")
+
+        for node in metrics.get('items', []):
+            node_name = node['metadata']['name']
+            timestamp = node.get('timestamp', 'N/A')
+            window = node.get('window', 'N/A')
+            usage = node.get('usage', {})
+
+            print(f"Node: {node_name}")
+            print(f"  Timestamp: {timestamp}")
+            print(f"  Window: {window}")
+            print(f"  CPU Usage: {usage.get('cpu', 'N/A')}")
+            print(f"  Memory Usage: {usage.get('memory', 'N/A')}")
+            print()
+
+    except Exception as e:
+        print(f"Error fetching node metrics: {e}")
+
+
+def print_pod_metrics(api_client, namespace):
+    """Fetch and display pod metrics for a namespace."""
+    print("\n" + "="*60)
+    print(f"POD METRICS IN NAMESPACE: {namespace}")
+    print("="*60)
+
+    try:
+        metrics = utils.get_pods_metrics(api_client, namespace)
+
+        print(f"Found {len(metrics.get('items', []))} pods\n")
+
+        for pod in metrics.get('items', []):
+            pod_name = pod['metadata']['name']
+            timestamp = pod.get('timestamp', 'N/A')
+            window = pod.get('window', 'N/A')
+
+            print(f"Pod: {pod_name}")
+            print(f"  Timestamp: {timestamp}")
+            print(f"  Window: {window}")
+            print(f"  Containers:")
+
+            for container in pod.get('containers', []):
+                container_name = container['name']
+                usage = container.get('usage', {})
+                print(f"    - {container_name}:")
+                print(f"        CPU: {usage.get('cpu', 'N/A')}")
+                print(f"        Memory: {usage.get('memory', 'N/A')}")
+            print()
+
+    except Exception as e:
+        print(f"Error fetching pod metrics: {e}")
+
+
+def print_filtered_pod_metrics(api_client, namespace, labels):
+    """Fetch and display pod metrics filtered by labels."""
+    print("\n" + "="*60)
+    print(f"POD METRICS IN NAMESPACE: {namespace}")
+    print(f"FILTERED BY LABELS: {labels}")
+    print("="*60)
+
+    try:
+        metrics = utils.get_pods_metrics(api_client, namespace, labels)
+
+        pods = metrics.get('items', [])
+        print(f"Found {len(pods)} pods matching labels\n")
+
+        for pod in pods:
+            pod_name = pod['metadata']['name']
+            print(f"Pod: {pod_name}")
+
+            for container in pod.get('containers', []):
+                container_name = container['name']
+                usage = container.get('usage', {})
+                print(f"  {container_name}: CPU={usage.get('cpu')}, Memory={usage.get('memory')}")
+            print()
+
+    except Exception as e:
+        print(f"Error fetching filtered pod metrics: {e}")
+
+
+def print_multi_namespace_metrics(api_client, namespaces):
+    """Fetch and display pod metrics across multiple namespaces."""
+    print("\n" + "="*60)
+    print(f"POD METRICS ACROSS MULTIPLE NAMESPACES")
+    print("="*60)
+
+    try:
+        all_metrics = utils.get_pods_metrics_in_all_namespaces(api_client, namespaces)
+
+        for ns, result in all_metrics.items():
+            print(f"\nNamespace: {ns}")
+
+            if 'error' in result:
+                print(f"  Error: {result['error']}")
+            else:
+                pod_count = len(result.get('items', []))
+                print(f"  Pods: {pod_count}")
+
+                # Calculate total resource usage for namespace
+                total_containers = 0
+                for pod in result.get('items', []):
+                    total_containers += len(pod.get('containers', []))
+
+                print(f"  Total containers: {total_containers}")
+
+    except Exception as e:
+        print(f"Error fetching multi-namespace metrics: {e}")
+
+
+def main():
+    """Main function to demonstrate metrics API usage."""
+    # Load kubernetes configuration
+    # This will use your current kubectl context
+    config.load_kube_config()
+
+    # Create API client
+    api_client = client.ApiClient()
+
+    print("\nKubernetes Metrics API Example")
+    print("================================")
+    print("\nThis example demonstrates fetching resource usage metrics")
+    print("from the Kubernetes metrics-server.")
+    print("\nNote: metrics-server must be installed in your cluster for this to work.")
+
+    # Example 1: Fetch node metrics
+    print_node_metrics(api_client)
+
+    # Example 2: Fetch pod metrics in default namespace
+    print_pod_metrics(api_client, 'default')
+
+    # Example 3: Fetch pod metrics in kube-system namespace
+    print_pod_metrics(api_client, 'kube-system')
+
+    # Example 4: Fetch pod metrics with label filter
+    # Uncomment and modify the label selector to match your pods
+    # print_filtered_pod_metrics(api_client, 'default', 'app=nginx')
+
+    # Example 5: Fetch metrics across multiple namespaces
+    namespaces_to_query = ['default', 'kube-system']
+    print_multi_namespace_metrics(api_client, namespaces_to_query)
+
+    print("\n" + "="*60)
+    print("Example completed successfully!")
+    print("="*60 + "\n")
+
+
+if __name__ == '__main__':
+    main()