k8s start pod at specific node

specify nodeSelector or nodeName in Pod or VirtualMachineInstance manifest

these selectors are in the spec field

1
2

kubectl run <pod name> --image=<image name> -it --rm --overrides='{"spec":{"nodeName": "<node name>"}}' -- /bin/sh

to label a node, run:

1
2

kubectl label node <node_name> <key>=<value>

k8s python api library

install the official library with pip install kubernetes

the default api config path for k8s is at ~/.kube/config

k3s is at /etc/rancher/k3s/k3s.yaml

microk8s is at /var/snap/microk8s/current/credentials/kubelet.config

you can also set KUBECONFIG environment variable to let kubernetes python library know where the config is

to use it:

https://github.com/kubernetes-client/python/blob/master/kubernetes/README.md

1
2
3
4
5
6
7
8
9
10

from kubernetes import client, config
# Configs can be set in Configuration class directly or using helper utility
config_path = ...
config.load_kube_config(config_path)
v1 = client.CoreV1Api()
print("Listing pods with their IPs:")
ret = v1.list_pod_for_all_namespaces(watch=False)
for i in ret.items:
print("%s\t%s\t%s" % (i.status.pod_ip, i.metadata.namespace, i.metadata.name))