部署扩缩容
kubectl get deploy
C:\Users\zhang>kubectl get deploy
NAME READY UP-TO-DATE AVAILABLE AGE
hello-k8s-deployment 3/3 3 3 5h56m通过上面的命令，我们先找到一个deploy用来进行测试。现在看他是3个副本，现在我们把他先缩到1个。
kubectl scale deploy hello-k8s-deployment --replicas=1
C:\Users\zhang>kubectl scale deploy hello-k8s-deployment --replicas=1
deployment.apps/hello-k8s-deployment scaled
C:\Users\zhang>kubectl get deploy
NAME READY UP-TO-DATE AVAILABLE AGE
hello-k8s-deployment 1/1 1 1 5h58m然后再加到5个。
kubectl scale deploy hello-k8s-deployment --replicas=5
C:\Users\zhang>kubectl scale deploy hello-k8s-deployment --replicas=5
deployment.apps/hello-k8s-deployment scaled
C:\Users\zhang>kubectl get deploy
NAME READY UP-TO-DATE AVAILABLE AGE
hello-k8s-deployment 1/5 5 1 6h17m
C:\Users\zhang>kubectl get deploy
NAME READY UP-TO-DATE AVAILABLE AGE
hello-k8s-deployment 5/5 5 5 6h18m通过命令可以看出来，它不是马上就建好5个的，而是有一定的时间，逐渐建立起来的。
滚动更新
建一个新版本
docker build -t hello-k8s:1.0 .
D:\LEO\project\test3\k8s-test>docker build -t hello-k8s:1.0 .
[+] Building 0.3s (10/10) FINISHED docker:desktop-linux
=> [internal] load build definition from Dockerfile 0.0s
=> => transferring dockerfile: 204B 0.0s
=> [internal] load metadata for docker.io/library/python:3.10-slim 0.1s
=> [internal] load .dockerignore 0.0s
=> => transferring context: 2B 0.0s
=> [1/5] FROM docker.io/library/python:3.10-slim@sha256:70f65c721aaddfb22b20ed6ec12606c59d9592493c5fcb6639f3d0e8 0.0s
=> => resolve docker.io/library/python:3.10-slim@sha256:70f65c721aaddfb22b20ed6ec12606c59d9592493c5fcb6639f3d0e8 0.0s
=> [internal] load build context 0.0s
=> => transferring context: 63B 0.0s
=> CACHED [2/5] WORKDIR /app 0.0s
=> CACHED [3/5] COPY requirements.txt . 0.0s
=> CACHED [4/5] RUN pip install --no-cache-dir -r requirements.txt 0.0s
=> CACHED [5/5] COPY app.py . 0.0s
=> exporting to image 0.1s
=> => exporting layers 0.0s
=> => exporting manifest sha256:14484ee5ad887573cfd12ac62cbf7eb5547ff03226021a1c4234d5e12b02f89b 0.0s
=> => exporting config sha256:d69d28bf3d152a2e5b862be56583bac59c13ab81873688aa94be4c2403458c43 0.0s
=> => exporting attestation manifest sha256:693e5b58682b01e416285b2a47593679eee55578474b79d3e8a6866ea7158774 0.0s
=> => exporting manifest list sha256:f989154c957c2aaba2e37f7abf7ca172b0a54e53f6532dd7ed10ea4d5ac9d43d 0.0s
=> => naming to docker.io/library/hello-k8s:1.0 0.0s
=> => unpacking to docker.io/library/hello-k8s:1.0 0.0s更换版本
D:\LEO\project\test3\k8s-test>kubectl set image deploy hello-k8s-deployment hello-k8s=hello-k8s:1.0
deployment.apps/hello-k8s-deployment image updated
D:\LEO\project\test3\k8s-test>kubectl rollout status deploy hello-k8s-deployment
deployment "hello-k8s-deployment" successfully rolled out
查看更换版本的情况可以用下面的方式来确认
D:\LEO\project\test3\k8s-test>kubectl rollout history deploy hello-k8s-deployment
deployment.apps/hello-k8s-deployment
REVISION CHANGE-CAUSE
1 <none>
2 <none>
D:\LEO\project\test3\k8s-test>kubectl rollout history deploy hello-k8s-deployment --revision=2
deployment.apps/hello-k8s-deployment with revision #2
Pod Template:
Labels: app=hello-k8s
pod-template-hash=5dbcc46558
Containers:
hello-k8s:
Image: hello-k8s:1.0
Port: 5000/TCP
Host Port: 0/TCP
Liveness: http-get http://:5000/health delay=5s timeout=1s period=10s #success=1 #failure=3
Readiness: http-get http://:5000/health delay=5s timeout=1s period=5s #success=1 #failure=3
Environment: <none>
Mounts: <none>
Volumes: <none>
Node-Selectors: <none>
Tolerations: <none>
D:\LEO\project\test3\k8s-test>kubectl rollout history deploy hello-k8s-deployment --revision=1
deployment.apps/hello-k8s-deployment with revision #1
Pod Template:
Labels: app=hello-k8s
pod-template-hash=54d8cb895d
Containers:
hello-k8s:
Image: hello-k8s:latest
Port: 5000/TCP
Host Port: 0/TCP
Liveness: http-get http://:5000/health delay=5s timeout=1s period=10s #success=1 #failure=3
Readiness: http-get http://:5000/health delay=5s timeout=1s period=5s #success=1 #failure=3
Environment: <none>
Mounts: <none>
Volumes: <none>
Node-Selectors: <none>
Tolerations: <none>最后一步，咱们再试一下回退。
kubectl rollout undo deploy hello-k8s-deployment
D:\LEO\project\test3\k8s-test>kubectl rollout history deploy hello-k8s-deployment
deployment.apps/hello-k8s-deployment
REVISION CHANGE-CAUSE
1 <none>
2 <none>
D:\LEO\project\test3\k8s-test>kubectl rollout undo deploy hello-k8s-deployment
deployment.apps/hello-k8s-deployment rolled back
D:\LEO\project\test3\k8s-test>kubectl rollout history deploy hello-k8s-deployment
deployment.apps/hello-k8s-deployment
REVISION CHANGE-CAUSE
2 <none>
3 <none>验证成果，还可以通过查看当前的配置文件来完成，这个更好一点。
kubectl get deploy hello-k8s-deployment -o yaml
可以通过输出看到 image: hello-k8s:latest，这就很明显了。说明已经回退到了之前的版本。
完成。下次再研究一下分环境的功能。