Github.com/huayin-open…
The cluster to check
Before deploying applications, you need to check the cluster environment to ensure that the cluster environment is normal, the cluster version information, and nodes in the cluster are running properly.
View context
> kubectl config get-contexts
CURRENT NAME CLUSTER AUTHINFO NAMESPACE
docker-desktop docker-desktop docker-desktop
* minikube minikube minikube default
Copy the codeContext switching
> kubectl config use-context minikube
CURRENT NAME CLUSTER AUTHINFO NAMESPACE
docker-desktop docker-desktop docker-desktop
* minikube minikube minikube default
Copy the codeView the K8S version information
> kubectl version
Client Version: version.Info{Major:"1", Minor:"23", GitVersion:"v1.23.1", GitCommit:"86ec240af8cbd1b60bcc4c03c20da9b98005b92e", GitTreeState:"clean", BuildDate:"2021-12-16T11:33:37Z", GoVersion:"go1.17.5", Compiler:"gc", Platform:"darwin/arm64"}
Server Version: version.Info{Major:"1", Minor:"22", GitVersion:"v1.22.4", GitCommit:"b695d79d4f967c403a96986f1750a35eb75e75f1", GitTreeState:"clean", BuildDate:"2021-11-17T15:42:41Z", GoVersion:"go1.16.10", Compiler:"gc", Platform:"linux/arm64"}
Copy the codeViewing Cluster Status
If the cluster is not in a running state, you can check the status of Kubelet because Kube-Apiserver is managed by Kubelet.
> kubectl cluster-info Kubernetes control plane is running at https://kubernetes.docker.internal:6443 CoreDNS is running at https://kubernetes.docker.internal:6443/api/v1/namespaces/kube-system/services/kube-dns:dns/proxy To further debug and diagnose cluster problems, use'kubectl cluster-info dump'.
Copy the codeView cluster nodes. There is only one node
> kubectl get no -o wide NAME STATUS ROLES AGE VERSION INTERNAL-IP EXTERNAL-IP OS-IMAGE KERNEL-VERSION CONTAINER-RUNTIME Docker-desktop Ready Control-plane, Master 3D21h v1.22.4 192.168.65.4 < None > Docker Desktop 5.10.76-linuxkit Docker: / / 20.10.11Copy the codeViewing a node
> kubectl explain no
KIND: Node
VERSION: v1
DESCRIPTION:
Node is a worker node in Kubernetes. Each node will have a unique
identifier in the cache (i.e. in etcd).
FIELDS:
apiVersion <string>
APIVersion defines the versioned schema of this representation of an
object. Servers should convert recognized schemas to the latest internal
value, and may reject unrecognized values. More info:
https://git.k8s.io/community/contributors/devel/sig-architecture/api-conventions.md#resources
kind <string>
Kind is a string value representing the REST resource this object
represents. Servers may infer this from the endpoint the client submits
requests to. Cannot be updated. In CamelCase. More info:
https://git.k8s.io/community/contributors/devel/sig-architecture/api-conventions.md#types-kinds
metadata <Object>
Standard object's metadata. More info: https://git.k8s.io/community/contributors/devel/sig-architecture/api-conventions.md#metadata spec Copy the codeDeploy the back-end Redis
Create primary Redis Deployment [create]
> kubectl create -f redis-leader-deployment.yaml
deployment.apps/redis-leader created
Copy the codeView the Deployment status
> kubectl get deployments -l app=redis -l role=leader
NAME READY UP-TO-DATE AVAILABLE AGE
redis-leader 1/1 1 1 63m
Copy the codeCheck Pod status [YAML]
> kubectl get po -l app=redis -l role=leader -o yaml
apiVersion: v1
kind: Pod
metadata:
creationTimestamp: "2022-01-02T12:43:25Z"
generateName: redis-leader-5d66d78fcb-
labels:
app: redis
pod-template-hash: 5d66d78fcb
role: leader
tier: backend
name: redis-leader-5d66d78fcb-l2drh
namespace: default
ownerReferences:
- apiVersion: apps/v1
blockOwnerDeletion: true
controller: true
kind: ReplicaSet
name: redis-leader-5d66d78fcb
uid: 942d6581-6ab6-4f5a-b849-1f80ab2e7e21
resourceVersion: "161467"
uid: a5fc9aa2-9534-43af-b09b-7240457cda1a
spec:
containers:
- image: registry.cn-shenzhen.aliyuncs.com/kubeops/redis:6.0.5
imagePullPolicy: IfNotPresent
name: leader
ports:
- containerPort: 6379
protocol: TCP
resources:
requests:
cpu: 100m
memory: 100Mi
terminationMessagePath: /dev/termination-log
terminationMessagePolicy: File
volumeMounts:
- mountPath: /var/run/secrets/kubernetes.io/serviceaccount
name: kube-api-access-kjzqs
readOnly: true
dnsPolicy: ClusterFirst
enableServiceLinks: true
nodeName: docker-desktop
preemptionPolicy: PreemptLowerPriority
priority: 0
restartPolicy: Always
schedulerName: default-scheduler
securityContext: {}
serviceAccount: default
serviceAccountName: default
terminationGracePeriodSeconds: 30
tolerations:
- effect: NoExecute
key: node.kubernetes.io/not-ready
operator: Exists
tolerationSeconds: 300
- effect: NoExecute
key: node.kubernetes.io/unreachable
operator: Exists
tolerationSeconds: 300
volumes:
- name: kube-api-access-kjzqs
projected:
defaultMode: 420
sources:
- serviceAccountToken:
expirationSeconds: 3607
path: token
- configMap:
items:
- key: ca.crt
path: ca.crt
name: kube-root-ca.crt
- downwardAPI:
items:
- fieldRef:
apiVersion: v1
fieldPath: metadata.namespace
path: namespace
status:
conditions:
- lastProbeTime: null
lastTransitionTime: "2022-01-02T12:43:25Z"
status: "True"
type: Initialized
- lastProbeTime: null
lastTransitionTime: "2022-01-02T12:43:26Z"
status: "True"
type: Ready
- lastProbeTime: null
lastTransitionTime: "2022-01-02T12:43:26Z"
status: "True"
type: ContainersReady
- lastProbeTime: null
lastTransitionTime: "2022-01-02T12:43:25Z"
status: "True"
type: PodScheduled containerStatuses: - containerID: Docker: / / 30 b948eff36f3bbc4489e4b338e7e95f1150a4c5281e4d33031d9f28027f2819 image: redis: 6.0.5/6.5.4 imageID: docker-pullable://redis@sha256:800f2587bf3376cb01e6307afe599ddce9439deafbd4fb8562829da96085c9c5 lastState: {} name: leader ready:true
restartCount: 0
started: true
state:
running:
startedAt: "2022-01-02T12:43:25Z"HostIP: 192.168.65.4 Phase: Running podIP: 10.1.0.51 podIPs: -ip: 10.1.0.51 qosClass: Burstable startTime:"2022-01-02T12:43:25Z"
Copy the codeCheck the Pod startup failure
If Pod STATUS has not changed to Running for a long time, you can view Pod details via Kubectl describe Pod
> kubectl describe po redis-leader-fb76b4755-nw4x4 Name: redis-leader-fb76b4755-nw4x4 Namespace: default Priority: 0 Node: Docker-desktop /192.168.65.4 Start Time: Sun, 02 Jan 2022 20:10:26 +0800 Labels: App =redis pod-template-hash=fb76b4755 Role =leader Tier = Backend Annotations: < None > Status: Running IP: 10.1.0.46 IPs: IP: 10.1.0.46 Controlled By: ReplicaSet/ Redis-leader-Fb76b4755 Containers: leader: Container ID: Docker: / / 8 df17907fec2b38966ec46c9d71bfc89fe77519952df327449d54150c4e1384b Image: docker. IO/redis: 6.0.5/6.5.4 Image ID: docker-pullable://redis@sha256:800f2587bf3376cb01e6307afe599ddce9439deafbd4fb8562829da96085c9c5 Port: 6379/TCP Host Port: 0/TCP State: Running Started: Sun, 02 Jan 2022 20:10:27 +0800 Ready: True Restart Count: 0 Requests: cpu: 100m memory: 100Mi Environment: <none> Mounts: /var/run/secrets/kubernetes.io/serviceaccount from kube-api-access-ggts8 (ro) Conditions: Type Status Initialized True Ready True ContainersReady True PodScheduled True Volumes: kube-api-access-ggts8: Type: Projected (a volume that contains injected data from multiple sources) TokenExpirationSeconds: 3607 ConfigMapName: kube-root-ca.crt ConfigMapOptional: <nil> DownwardAPI:true
QoS Class: Burstable
Node-Selectors: <none>
Tolerations: node.kubernetes.io/not-ready:NoExecute op=Exists for 300s
node.kubernetes.io/unreachable:NoExecute op=Exists for300s Events: Type Reason Age From Message ---- ------ ---- ---- ------- Normal Scheduled 4m9s default-scheduler Successfully assigned default/redis-leader-fb76b4755-nw4x4 to docker-desktop Normal Pulled 4m8s kubelet Container image"Docker. IO/redis: 6.0.5/6.5.4." already present on machine
Normal Created 4m8s kubelet Created container leader
Normal Started 4m8s kubelet Started container leader
Copy the codeCreate the primary Redis Service
> kubectl create -f redis-leader-service.yaml
service/redis-leader created
Copy the codeCheck primary Redis service status [wide]
> kubectl get svc -l app=redis -l role=leader -o wide NAME TYPE CLUSTER-IP EXTERNAL-IP PORT(S) AGE SELECTOR redis-leader ClusterIP 10.105.105.38 < None > 6379/TCP 23M app=redis,role=leader,tier=backendCopy the codeCreate two copies from Redis
> kubectl create -f redis-follower-deployment.yaml
deployment.apps/redis-follower created
Copy the codeVerify that two copies from Redis are running
> kubectl get po -l app=redis -l role=follower
NAME READY STATUS RESTARTS AGE
redis-follower-74cc7db576-fstd2 1/1 Running 0 106s
redis-follower-74cc7db576-kwbsc 1/1 Running 0 106s
Copy the codeCreate a service from Redis
> kubectl create -f redis-follower-service.yaml
service/redis-follower created
Copy the codeRedis service status [json]
> kubectl get svc -l app=redis -l role=follower -o json
{
"apiVersion": "v1"."items": [{"apiVersion": "v1"."kind": "Service"."metadata": {
"creationTimestamp": "2022-01-02T12:46:02Z"."labels": {
"app": "redis"."role": "follower"."tier": "backend"
},
"name": "redis-follower"."namespace": "default"."resourceVersion": "161635"."uid": "92c2298a-cc31-4c3b-b1fb-bdbf25f80975"
},
"spec": {
"clusterIP": "10.105.1.89"."clusterIPs": [
"10.105.1.89"]."internalTrafficPolicy": "Cluster"."ipFamilies": [
"IPv4"]."ipFamilyPolicy": "SingleStack"."ports": [{"port": 6379,
"protocol": "TCP"."targetPort": 6379}]."selector": {
"app": "redis"."role": "follower"."tier": "backend"
},
"sessionAffinity": "None"."type": "ClusterIP"
},
"status": {
"loadBalancer": {}}}],"kind": "List"."metadata": {
"resourceVersion": ""."selfLink": ""}}Copy the codeDeploy the message board front end
Create a front-end Deployment [apply]
> kubectl apply -f frontend-deployment.yaml
Copy the codeVerify that three front-end replicas are running
> kubectl get po -l app=guestbook -l tier=frontend -o wide NAME READY STATUS RESTARTS AGE IP NODE NOMINATED NODE READINESS GATES Frontend - 57756596Cb-m2jj7 1/1 Running 0 6m51s 10.1.0.54 Docker-desktop < None > < None > Frontend -57756596cb-skz9h 1/1 Running 0 6m51s 10.1.0.53 docker-desktop <none> <none> frontend-57756596cb-xqc6n 1/1 Running 0 6m51s 10.1.0.55 docker-desktop <none> <none>Copy the codeCreating front-end services
> kubectl apply -f frontend-service.yaml
service/frontend created
Copy the codeVerify that the front-end service is running
> kubectl get SVC -l tier=frontend NAME TYPE cluster-ip external-ip PORT(S) AGE frontend ClusterIP 10.105.140.183 <none> 80/TCP 18mCopy the codethroughkubectl port-forwardViewing Front-end Services
Run the following command to forward port 8080 on the local machine to port 80 on the service.
> kubectl port-forward SVC /frontend 8080:80 Forwarding from 127.0.0.1:8080 -> 80 Forwarding from [::1]:8080 -> 80Copy the codeExtending the Web front end
> kubectl scale deployment frontend --replicas=5
Copy the codeVerify the number of front-end pods running
> kubectl get po -l app=guestbook -l tier=frontend
NAME READY STATUS RESTARTS AGE
frontend-57756596cb-g76s5 1/1 Running 0 46s
frontend-57756596cb-h8xhm 1/1 Running 0 46s
frontend-57756596cb-m2jj7 1/1 Running 0 38m
frontend-57756596cb-skz9h 1/1 Running 0 38m
frontend-57756596cb-xqc6n 1/1 Running 0 38m
Copy the codeView the Redis Pod log
> kubectl logs redis-leader-5d66d78fcb-pvd84
1:C 02 Jan 2022 12:44:53.370 # oO0OoO0OoO0Oo Redis is starting oO0OoO0OoO0Oo
1:C 02 Jan 2022 12:44:53.370 # Redis version=6.0.5, bits=64, commit=00000000, Modified =0, PID =1, just started
1:C 02 Jan 2022 12:44:53.370 # Warning: no config file specified, using the default config. In order to specify a config file use redis-server /path/to/redis.conf1:M 02 Jan 2022 12:44:53.370 * Running mode=standalone, port= 6379.1 :M 02 Jan 2022 12:44:53.370# Server initialized
1:M 02 Jan 2022 12:44:53.370 # WARNING you have Transparent Huge Pages (THP) support enabled in your kernel. This will create latency and memory usage issues with Redis. To fix this issue run the command 'echo never > /sys/kernel/mm/transparent_hugepage/enabled' as root, and add it to your /etc/rc.local in order to retain the setting after a reboot. Redis must be restarted after THP is disabled.
1:M 02 Jan 2022 12:44:53.371 * Ready to accept connections
1:M 02 Jan 2022 12:44:53.975 * Replica 10.1.0.50:6379 asks forSynchronization 1:M 02 Jan 2022 12:44:53.975 * Partial resynchronization not accepted: Replication ID mismatch (Replica askedfor '5f3f86fcc80e66d778048b0d0876f094154ebb65', my replication IDs are 'ef5856ce660b088d5e8f1a75a50d07d624d18326' and '0000000000000000000000000000000000000000')
1:M 02 Jan 2022 12:44:53.975 * Replication backlog created, my new replication IDs are '6e7879f5f854ed376103ea1eb10c5579d21f2d64' and '0000000000000000000000000000000000000000'
1:M 02 Jan 2022 12:44:53.975 * Starting BGSAVE for SYNC with target: disk
1:M 02 Jan 2022 12:44:53.975 * Background saving started by pid 21
1:M 02 Jan 2022 12:44:53.976 * Replica 10.1.0.49:6379 asks forSynchronization 1:M 02 Jan 2022 12:44:53.977 * Partial resynchronization not accepted: Replication ID mismatch (Replica askedfor '5f3f86fcc80e66d778048b0d0876f094154ebb65', my replication IDs are '6e7879f5f854ed376103ea1eb10c5579d21f2d64' and '0000000000000000000000000000000000000000')
1:M 02 Jan 2022 12:44:53.977 * Waiting for end of BGSAVE for SYNC
21:C 02 Jan 2022 12:44:53.978 * DB saved on disk
21:C 02 Jan 2022 12:44:53.979 * RDB: 0 MB of memory used by copy-on-write
1:M 02 Jan 2022 12:44:54.073 * Background saving terminated with success
1:M 02 Jan 2022 12:44:54.073 * Synchronization with replica 10.1.0.50:6379 succeeded
1:M 02 Jan 2022 12:44:54.073 * Synchronization with replica 10.1.0.49:6379 succeeded
Copy the codeEnter the Redis container to view the data
> kubectl exec-redis-leader-5d66d78fcb-pvd84 -- redis-cli 127.0.0.1:6379> KEYS * 1)"guestbook"127.0.0.1:6379 > GET guestbook",test,hello"
Copy the codefollow-up
Add the status tag to all Redis pods
> kubectl label pods -l app=redis status=healthy
pod/redis-follower-74cc7db576-fstd2 labeled
pod/redis-follower-74cc7db576-kwbsc labeled
pod/redis-leader-5d66d78fcb-pvd84 labeled
Copy the codeCheck the Redis Pod label [–show-labels]
> kubectl get po -l app=redis --show-labels
NAME READY STATUS RESTARTS AGE LABELS
redis-follower-74cc7db576-fstd2 1/1 Running 0 96m app=redis,pod-template-hash=74cc7db576,role=follower,status=healthy,tier=backend
redis-follower-74cc7db576-kwbsc 1/1 Running 0 96m app=redis,pod-template-hash=74cc7db576,role=follower,status=healthy,tier=backend
redis-leader-5d66d78fcb-pvd84 1/1 Running 0 85m app=redis,pod-template-hash=5d66d78fcb,role=leader,status=healthy,tier=backend
Copy the codeUpdate the main Redis Pod label
> kubectl label pods -l app=redis -l role=leader status=unhealthy --overwrite
pod/redis-leader-5d66d78fcb-pvd84
Copy the codeView primary Redis resource usage
> kubectl top po -l app=redis -l role=leader
NAME CPU(cores) MEMORY(bytes)
redis-leader-5d66d78fcb-9bm92 2m 3Mi
Copy the codeUpdate the number of copies from Redis Pod using Edit
> kubectl edit deploy/redis-follower
deployment.apps/redis-follower edited
# change the number of Pod copies from 2 to 3
> kubectl get pods -l app=redis -l role=follower
NAME READY STATUS RESTARTS AGE
redis-follower-74cc7db576-cvf2q 1/1 Running 0 9m29s
redis-follower-74cc7db576-mz6h8 1/1 Running 0 25s
redis-follower-74cc7db576-twq9x 1/1 Running 0 9m29s
Copy the codeResolve mirror pull problem
Guestbook front-end image is based on Google’s GCR. IO, so if no proxy is available, synchronize the image from the Hong Kong server to the Ali Cloud container image service.
Pull the mirror
> docker pull gcr.io/google_samples/gb-frontend:v5
v5: Pulling from google_samples/gb-frontend
72a69066d2fe: Pull complete
fbf13c1e88c3: Pull complete
cddf91161400: Pull complete
2c396aa97b98: Pull complete
1d9707294ce1: Pull complete
443be0efd1a3: Pull complete
f40e54f5a6bb: Pull complete
449e25c19260: Pull complete
4116245e7948: Pull complete
063a257bdaed: Pull complete
ba6b06b0aa4f: Pull complete
331cb0169fcf: Pull complete
7889266700ad: Pull complete
2648f8d3ecd7: Pull complete
2b19c0592f6e: Pull complete
c3b640245fb3: Pull complete
4a8a6bc16a1b: Pull complete
Digest: sha256:1ffc7816e028b2e2f2b592594383a0139b9f570ff5fcc5fdfd81806aa8d403bf
Status: Downloaded newer image for gcr.io/google_samples/gb-frontend:v5
gcr.io/google_samples/gb-frontend:v5
Copy the codeRename image
> docker tag gcr.io/google_samples/gb-frontend:v5
Copy the codeLog in to ali Cloud container image service
> docker login registry.cn-shenzhen.aliyuncs.com -ukubeops
Password:
WARNING! Your password will be stored unencrypted in /root/.docker/config.json.
Configure a credential helper to remove this warning. See
https://docs.docker.com/engine/reference/commandline/login/#credentials-store
Login Succeeded
Copy the codePush image to Ali Cloud container image service
> docker push registry.cn-shenzhen.aliyuncs.com/kubeops/gb-frontend:v5
The push refers to repository [registry.cn-shenzhen.aliyuncs.com/kubeops/gb-frontend]
6fd1212aa9ea: Pushed
76f17e2309c9: Pushed
4b6e88f9653e: Pushed
2aecaf70d382: Pushed
80cd58a1bab0: Pushed
2e559a423c71: Pushed
ede4b550d621: Pushed
2dba6c06bdde: Pushed
ecd6a695b6ea: Pushed
b01bf213b941: Pushed
0ccbc08ded6d: Pushed
449cff66aba3: Pushed
643f1d079de7: Pushed
0104a3ee0257: Pushed
fd3ee495df7c: Pushed
00f117848faf: Pushed
ad6b69b54919: Pushed
v5: digest: sha256:1ffc7816e028b2e2f2b592594383a0139b9f570ff5fcc5fdfd81806aa8d403bf size: 3876
Copy the codeUpdate image
> kubectl set image deploy/redis-follower follower=registry.cn-shenzhen.aliyuncs.com/kubeops/gb-redis-follower:v2
deployment.apps/redis-follower image updated
Copy the codeDeploy using Kustomize
Add the kustomization.yaml configuration file
resources:
- redis-leader-service.yaml
- redis-leader-deployment.yaml
- redis-follower-service.yaml
- redis-follower-deployment.yaml
- frontend-service.yaml
- frontend-deployment.yaml
Copy the codeDelete the old deployment
All previous resources can also be deleted at this time.
> kubectl delete -k .
service "frontend" deleted
service "redis-follower" deleted
service "redis-leader" deleted
deployment.apps "frontend" deleted
deployment.apps "redis-follower" deleted
deployment.apps "redis-leader" deleted
Copy the codeA key deployment
> kubectl apply -k .
service/frontend created
service/redis-follower created
service/redis-leader created
deployment.apps/frontend created
deployment.apps/redis-follower created
deployment.apps/redis-leader created
Copy the codeThe rollback
Rollback is a very common operation and we use Kubectl rollout undo to do this.
View the Deployment version
> kubectl rollout history deploy redis-follower
deployment.apps/redis-follower
REVISION CHANGE-CAUSE
1 <none>
2 <none>
3 <none>
Copy the codeRoll back to the previous version
> kubectl rollout undo deploy redis-follower
Copy the codeRollback to the specified version
> kubectl rollout undo deploy redis-follower --to-revision=1
Copy the codePod horizontal automatic expansion
This is more powerful than Kubectl scale, which automatically scales based on current resource usage.
Create a Horizontal Pod Autoscaler
— CPU-percent =80 means that the HPA will increase or decrease (through Deployment) the number of Pod copies to keep the average CPU utilization of all pods around 80%.
> kubectl autoscale deploy frontend --min=5 --max=10 --cpu-percent=80
horizontalpodautoscaler.autoscaling/frontend autoscaled
Copy the codeView the status of Autoscaler
> kubectl get hpa
NAME REFERENCE TARGETS MINPODS MAXPODS REPLICAS AGE
frontend Deployment/frontend 1%/80% 5 10 5 3m32s
Copy the code