Deploying Applications to a Kubernetes Cluster

2023-09-14

Kubernetes

Run from the command line#

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kubectl run testapp --image=ccr.ccs.tencentyun.com/k8s-tutorial/test-k8s:v1
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kubectl get pod 查看是否成功建立

Deploy with a YAML file#

pod.yaml file#

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apiVersion: v1
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kind: Pod
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metadata:
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  name: test-pod
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spec:
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  # Define containers; can be multiple
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  containers:
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    - name: test-k8s # Container name
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      image: ccr.ccs.tencentyun.com/k8s-tutorial/test-k8s:v1 # Image

Deployment commands#

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mkdir Deployment && cd Deployment
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vim pod.yml # Fill in the content above
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kubectl apply -f pod.yml # Create Pod

Using a Deployment#

app.yml file#

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apiVersion: apps/v1
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kind: Deployment
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metadata:
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  # Deployment name
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  name: test-k8s
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spec:
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  replicas: 2
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  # Used to select and associate Pods; all labels must match
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  selector:
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    matchLabels:
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      app: test-k8s
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  # Define Pod-related data
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  template:
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    metadata:
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      labels:
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        app: test-k8s
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    spec:
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      # Define containers; can be multiple
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      containers:
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      - name: test-k8s # Container name
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        image: ccr.ccs.tencentyun.com/k8s-tutorial/test-k8s:v1 # Image

Deployment commands#

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kubectl apply -f app.yml
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kubectl get deployment

How a Deployment associates Pods via labels#

Common commands#

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# View Pod IPs and other details
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kubectl get pod -o wide
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# Deploy an application
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kubectl apply -f app.yaml
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# View Deployments
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kubectl get deployment
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# View Pods
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kubectl get pod -o wide
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# View Pod details
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kubectl describe pod pod-name
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# View logs
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kubectl logs pod-name
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# Open an interactive shell into a Pod container; use -c container-name to select a container
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kubectl exec -it pod-name -- bash
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# Scale replicas up or down
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kubectl scale deployment test-k8s --replicas=5
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# Forward a port from the cluster to the node
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kubectl port-forward pod-name 8090:8080
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# View rollout history
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kubectl rollout history deployment test-k8s
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# Roll back to the previous revision
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kubectl rollout undo deployment test-k8s
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# Roll back to a specific revision
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kubectl rollout undo deployment test-k8s --to-revision=2
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# Delete a Deployment
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kubectl delete deployment test-k8s