Kubernetes¶

MINIKUBE install on local machine¶

https://github.com/kubernetes/minikube/blob/v0.9.0/README.md http://kubernetes.io/docs/getting-started-guides/minikube/

curl -Lo minikube https://storage.googleapis.com/minikube/releases/v0.9.0/minikube-linux-amd64 && chmod +x minikube && sudo mv minikube /usr/local/bin/

curl -Lo kubectl http://storage.googleapis.com/kubernetes-release/release/v1.3.6/bin/linux/amd64/kubectl && chmod +x kubectl && sudo mv kubectl /usr/local/bin/
# where v1.3.6 - last version of kubernetes

minikube start      # start kubernetes
    stop            # stop kubernetes
    dashboard       # open web-interface
    ip              # show dashboard ip
    service NAME    # open ip in browser

curl $(minikube service hello-minikube --url)    # show ip

KUBECTL¶

POD - one or group of containers, combined for common goals (launch as a single unit)

$HOME/.kube/config    # config

kubectl get pods --all-namespaces
        pod
            -o wide             # show ip and nodes (gcloud compute ssh <NODE>    # ssh logout)
        deployments
        nodes                   # show nodes
        services <service>      # show ip and ports
        rc                      # show replication controllers
        events                  # show events

kubectl config view             # show config

kubectl set image deployment/test2 test2=eu.gcr.io/test/php7-apache:latest    # update source image

kubectl describe pod <NAME>
                 services <NAME>

kubectl cluster-info

Deployment¶

kubectl run <NAME> --image=<image_hub>                                  # create pod, create deployment object
                                    [--env="key=value"]
                                    [--port=port]
                                    [--replicas=replicas]
                                    [--dry-run=bool]
                                    [--overrides=inline-json]
                                    [--command] -- [COMMAND] [args...]


kubectl expose (-f FILENAME | TYPE NAME)
                                    [--port=port]
                                    [--protocol=TCP|UDP]
                                    [--target-port=number-or-name]
                                    [--name=name]
                                    [--external-ip=external-ip-of-service]
                                    [--type=type]
                                        --type="LoadBalancer"    # for expose external ip

kubectl scale deployment <deployment_name> --replicas=4
kubectl autoscale deploymeent <deployment_name> --min=1 --max=3

kubectl proxy --port=8001 &                 # connect to proxy (& - backround)
# http://localhost:8001/ui


kubectl create -f ./<deployment>.yaml       # create deployment
kubectl create -f ./<service>.yaml          # create service

kubectl apply -f <file>.yaml                # compare the version of the configuration with the previous version and apply the changes,
                                            # without overwriting any automated changes to properties you haven’t specified.

kubectl delete pod,service <name> <name> ...
               deployment  <name> <name> ...

kubectl logs <POD-NAME>

kubectl exec <pod-name> date
             <pod-name> -c <container-name> date

kubectl exec -ti <pod-name> /bin/bash    # Get an interactive TTY and run /bin/bash from pod <pod-name>. By default, output is from the first container.

Abbreviation¶

componentstatuses - cs

daemonsets - ds

events - ev

endpoints - ep

horizontalpodautoscalers - hpa

ingress - ing

limitranges - limits

nodes - no

namespaces - ns

pods - po

persistentvolumes - pv

persistentvolumeclaims - pvc

resourcequotas - quota

replicasets - rs

replicationcontrollers - rc

serviceaccounts - sa

services - svc

Example¶

apiVersion: v1
kind: Service
metadata:
  name: ms1
  labels:
    app: ms1
spec:
  type: LoadBalancer
  ports:
  - port: 3000
    targetPort: 3000
  selector:
    app: ms1
---
apiVersion: extensions/v1beta1
kind: Deployment
metadata:
  name: ms1
spec:
  replicas: 1
  template:
    metadata:
      labels:
        app: ms1
    spec:
      restartPolicy: Always
      containers:
      - name: ms1
        image: eu.gcr.io/vsiryk-test/ms1
        ports:
        - containerPort: 3000
        env:
        - name: MICROSERVICE_DB_HOST
          value: db_host
        - name: MYSQL_ROOT_PASSWORD
          value: password
        - name: MYSQL_DATABASE
          value: database
        - name: MYSQL_USER
          value: user
        - name: MYSQL_PASSWORD
          value: password