kubernetes

• Concept
• Command
  • get into container
  • how to get pod name
  • how to get container name
  • check pod status
  • continuous deploy

Concept

• cluster
  cluster is a set of physical or virtual machines and other infrastructure resources used by Kubernetes to run your applications.
• node
  node is a physical or virtual machine, cluster is a group of nodes.
• pod
  pod is a group of one or more containers, with shared storage/network, and a specification for how to run the containers.
  It can be understood as docker compose.
  one node can have multiple pods.

Command

get into container

kubectl exec -it [pod name] --container [container name] -- bash

how to get pod name

kubectl get pods

how to get container name

container name is defined in your yaml file.
this is a example of deployment yaml file.

apiVersion: apps/v1
kind: Deployment
metadata:
name: simu
namespace: default
spec:
replicas: 2
selector:
  matchLabels:
    app: simu
template:
  metadata:
    annotations:
      vke.volcengine.com/burst-to-vci: enforce
    labels:
      app: simu
  spec:
    containers:
      - image: cr-cn-beijing.volces.com/white-rhino/simu-web:latest
        name: simu-web
        ports:
          - containerPort: 3000
            protocol: TCP
      - image: cr-cn-beijing.volces.com/white-rhino/simu-api:latest
        name: simu-api
        ports:
          - containerPort: 8814
            protocol: TCP
    imagePullSecrets:
      - name: volc

check pod status

when a pod occurs error, not running as expect, for example:

$ simu kubectl get pods
NAME                    READY   STATUS             RESTARTS      AGE
simu-6ff6cbfd59-c9x8r   1/2     CrashLoopBackOff   4 (49s ago)   3m47s

you can get error info using this command:

kubectl describe pod simu-6ff6cbfd59-c9x8r

continuous deploy

kubectl rollout restart -f [yaml file]

job