Kubernetes

November 25, 2023

DOCS: https://kubernetes.io/docs/reference/generated/kubernetes-api/v1.10/#container-v1-core

ingress

https://kubernetes.io/docs/concepts/services-networking/ingress/

https://medium.com/@cashisclay/kubernetes-ingress-82aa960f658e

https://kubernetes.github.io/ingress-nginx/deploy/#minikube

addon

minikube addons enable ingress

running own

MUST start kubectl proxy

domains

local only domain.

edit host file on machine to point to minikube ip
edit host file on minikube vm as well

nginx

https://hackernoon.com/setting-up-nginx-ingress-on-kubernetes-2b733d8d2f45

https://github.com/gokulchandra/k8s-ingress-setup

https://kubernetes.github.io/ingress-nginx/user-guide/nginx-configuration/

https://github.com/kubernetes/ingress-nginx/blob/master/docs/user-guide/multiple-ingress.md#multiple-ingress-controllers

storage

https://supergiant.io/blog/persistent-storage-with-persistent-volumes-in-kubernetes

debugging

kubectl cluster-info dump

kubectl get pods -n kube-system

minikube

minikube start --kubernetes-version v1.11.4 --memory 4096

azure

https://docs.microsoft.com/en-us/azure/aks/developer-best-practices-resource-management

resources

https://kubernetes.io/docs/concepts/configuration/manage-compute-resources-container/

promql

https://medium.com/@amimahloof/kubernetes-promql-prometheus-cpu-aggregation-walkthrough-2c6fd2f941eb

Config Maps

Configure Pod Config Maps

Config maps are great to inject data into a pod.

kubectl create configmap rake-task --from-file=./lib/tasks/one_time/preprocess_active_storage.rake -n my-namespace

To use:

apiVersion: batch/v1
kind: Job
metadata:
  namespace: my-namespace
  name: process-attachments
spec:
  backoffLimit: 0
  template:
    spec:
      restartPolicy: Never
      volumes:
        - name: task-volume
          configMap:
            name: rake-task # Reference the created ConfigMap
            items:
              - key: preprocess_active_storage.rake
                path: preprocess_active_storage.rake
      containers:
        command:
        - /bin/bash
        - -c
        - |
          cat /usr/src/lib/tasks/one_time/preprocess_active_storage.rake
        volumeMounts:
          - name: task-volume
            mountPath: /usr/src/lib/tasks/one_time/

You can execute your task in container.