k8s: Find daemonsets with pod to delete for update, and print the corresponding node names

deprecated-pods.py

import json
import subprocess

nodes_str = subprocess.check_output(
    ["kubectl", "get", "nodes",  "-o", "json"]
)
nodes = json.loads(nodes_str)

node_data = {}
for node in nodes.get("items"):
    node_data[node.get("metadata").get("name")] = {
        "kiwix_role": node.get("metadata").get("labels").get("k8s.kiwix.org/role")
    }


daemonsets_str = subprocess.check_output(
    ["kubectl", "get", "ds", "--all-namespaces", "-o", "json"]
)
daemonsets = json.loads(daemonsets_str)


def filter_ds(ds):
    ds_status = ds.get("status")
    if ds_status.get("currentNumberScheduled") == 0:
        return False

    return ds_status.get("currentNumberScheduled") != ds_status.get(
        "updatedNumberScheduled"
    )


daemonsets_with_old_pods = list(filter(filter_ds, daemonsets.get("items")))

if len(daemonsets_with_old_pods) == 0:
    print("No daemonset with pod to update")
    exit()

print()
print("Some pods have to be deleted for update.")
for daemonset in daemonsets_with_old_pods:
    print()
    daemonset_namespace = daemonset.get("metadata").get("namespace")
    daemonset_name = daemonset.get("metadata").get("name")
    print(f"Daemonset {daemonset_namespace}/{daemonset_name}:")

    match_labels = daemonset.get("spec").get("selector").get("matchLabels")
    command = [
        "kubectl",
        "get",
        "pods",
        "--all-namespaces",
        "-o",
        "json",
    ]
    for key, value in match_labels.items():
        command.append(f"-l={key}={value}")

    expected_template_generation = daemonset.get("metadata").get("generation")
    pods_str = subprocess.check_output(command)
    pods = json.loads(pods_str)
    for pod in pods.get("items"):
        current_generation = (
            pod.get("metadata").get("labels").get("pod-template-generation")
        )
        if int(current_generation) == int(expected_template_generation):
            continue
        nodeName = pod.get('spec').get('nodeName')
        print(
            f"- node {nodeName} ({node_data[nodeName]['kiwix_role']}): generation "
            f"{current_generation} instead of generation {expected_template_generation}"
        )


print()