Kubernetes Free CPU Requests

kubernetes_cpu_requests.py

# Print out CPU requests of nodes and free amount of CPU
# This shows at a glance if we have room to deploy more pods.
# needs package kubernetes

import kubernetes.client
import os
from kubernetes import config

def get_pods():
    v1 = kubernetes.client.CoreV1Api()
    ret = v1.list_pod_for_all_namespaces(watch=False)
    pods = ret.items
    # sort pods

    new_pods = []
    for i in pods:
        if i.spec.node_name is None:
            i.spec.node_name = ""

        cpu_request = 0
        for container in i.spec.containers:
            try:
                cpu_request += normalize_cpu(container.resources.requests['cpu'])
            except:
                pass

        new_pods.append({
            "node_name": i.spec.node_name,
            "namespace": i.metadata.namespace,
            "name": i.metadata.name,
            "cpu_request": cpu_request
        })

    new_pods.sort(key=lambda x: x['namespace'])
    new_pods.sort(key=lambda x: x['node_name'])

    return new_pods

def get_nodes():
    v1 = kubernetes.client.CoreV1Api()
    ret = v1.list_node(watch=False)
    nodes = ret.items
    new_nodes = []
    for n in nodes:
        cpu = normalize_cpu(n.status.allocatable['cpu'])
        memory = normalize_memory( n.status.allocatable['memory'])
        new_nodes.append({
            "name": n.metadata.name,
            "cpu": cpu,
            "memory": memory,
        })

    return new_nodes

def main():
    home_path = os.path.expanduser("~")
    kube_config_path = os.path.join(home_path, ".kube/config")
    config.load_kube_config(kube_config_path)
    print("Node,Namespace,Name,CPU Request")
    pods = get_pods()
    nodes_total_cpu = {}
    highest_request_pod = {"cpu_request": 0}

    nodes = get_nodes()
    nodes_cpu = {}
    for n in nodes:
        nodes_cpu[n["name"]] = n["cpu"]

    for p in pods:
        if p["node_name"] == "":
            continue

        print("%s,%s,%s,%s" % (p["node_name"], p["namespace"], p["name"], p["cpu_request"]))
        if p["node_name"] in nodes_total_cpu:
            nodes_total_cpu[p["node_name"]] += p["cpu_request"]
        else:
            nodes_total_cpu[p["node_name"]] = p["cpu_request"]

        if p["cpu_request"] > highest_request_pod["cpu_request"]:
            highest_request_pod = p

    for node, total_cpu in nodes_total_cpu.items():
        print("Node %s has a total CPU request of %s mCPU, free mCPU: %s" % (node, total_cpu, nodes_cpu[node] - total_cpu))

    print("The highest requested pod is %s with %s mCPU" % (highest_request_pod["name"], highest_request_pod["cpu_request"]))

def normalize_cpu(cpu):
    if cpu.endswith('m'):
        return int(cpu.rstrip('m'))
    else:
        return int(float(cpu) * 1000)

def normalize_memory(memory):
    if memory.endswith('Ki'):
        return int(int(memory.rstrip('Ki')) / 1024)
    elif memory.endswith('Mi'):
        return int(memory.rstrip('Mi'))
    elif memory.endswith('Gi'):
        return int(int(memory.rstrip('Gi')) * 1024)
    else:
        return int(memory)

if __name__ == "__main__":
    main()