k8s基本概念-如何使用Deployments
2018/1/5
Deployments 使用示例
- 創建一個 app
- 查看 app 狀態
- 更新 app
- 回滾 app
- 擴縮容 app
- 刪除 app
創建一個 app
-
通過 yaml 配置文件來定義 Deployment
- 關於 apiVersion 的寫法，請參考：
- https://github.com/kubernetes/kubernetes/blob/630dbedef9de9ef678f16132796b103b8a03fcda/pkg/api/testing/defaulting_test.go
- 關於 metadata 中的 name
- 定義來 deployment 的名稱
- 同一個 namespace 下名稱不能重複
- 關於 metadata 中的 labels
- k/v 鍵值對
- key 的命名規則
- 必須
- 包含一個可選的 prefix 和 name 並小於 64 字符
- name 以字母和數字 [a-z0-9A-Z] 開頭和結尾，中間可以是 dashes (-)，underscores (_)，dots (.)，字母和數字
- prefix 是可選的，類似這樣："kubernetes.io/" 暫不討論
- Value 的命名規則
- 可以爲空，或小於 64 字符
- 以字母和數字 [a-z0-9A-Z] 開頭和結尾，中間可以是 dashes (-)，underscores (_)，dots (.)，字母和數字
- 關於 metadata 中的 namespace
- 默認使用 default
[root@tvm-00 ~]# cat ~/k8s_install/test/whoami/app.yaml apiVersion: apps/v1 # for versions before 1.9.0 use apps/v1beta2 kind: Deployment metadata: name: test-deployment-app-whoami labels: app: whoami spec: replicas: 3 selector: matchLabels: app: whoami template: metadata: labels: app: whoami spec: containers: - name: whoami image: opera443399/whoami:0.9 ports: - containerPort: 80
- 運行 app
### 注意：使用 --record 可以記錄指令的 history 便於後續 rolling update 選擇 [root@tvm-00 ~]# kubectl apply -f ~/k8s_install/test/whoami/app.yaml --record deployment "test-deployment-app-whoami" created
查看 app 狀態
- 查看信息
[root@tvm-00 ~]# kubectl get deployments NAME DESIRED CURRENT UP-TO-DATE AVAILABLE AGE test-deployment-app-whoami 3 3 3 3 5m [root@tvm-00 ~]# kubectl get rs NAME DESIRED CURRENT READY AGE test-deployment-app-whoami-6cf9cd6bf4 3 3 3 5m [root@tvm-00 ~]# kubectl get pods NAME READY STATUS RESTARTS AGE test-deployment-app-whoami-6cf9cd6bf4-59h9x 1/1 Running 0 5m test-deployment-app-whoami-6cf9cd6bf4-978ht 1/1 Running 0 5m test-deployment-app-whoami-6cf9cd6bf4-w5dhk 1/1 Running 0 5m [root@tvm-00 ~]# kubectl get pods --show-labels NAME READY STATUS RESTARTS AGE LABELS test-deployment-app-whoami-6cf9cd6bf4-59h9x 1/1 Running 0 7m app=whoami,pod-template-hash=2795782690 test-deployment-app-whoami-6cf9cd6bf4-978ht 1/1 Running 0 7m app=whoami,pod-template-hash=2795782690 test-deployment-app-whoami-6cf9cd6bf4-w5dhk 1/1 Running 0 7m app=whoami,pod-template-hash=2795782690
更新 app
- 試着更新 1 次鏡像後，查看信息，重點留意版本歷史
### 更新 image 爲其他版本： [root@tvm-00 ~]# kubectl set image deployments/test-deployment-app-whoami whoami=opera443399/whoami:0.7 deployment "test-deployment-app-whoami" image updated
查看信息
[root@tvm-00 ~]# kubectl rollout status deployments/test-deployment-app-whoami
deployment "test-deployment-app-whoami" successfully rolled out
[root@tvm-00 ~]# kubectl get deployments
NAME DESIRED CURRENT UP-TO-DATE AVAILABLE AGE
test-deployment-app-whoami 3 3 3 3 11m
[root@tvm-00 ~]# kubectl get rs
NAME DESIRED CURRENT READY AGE
test-deployment-app-whoami-68c6cd964 3 3 3 42s
test-deployment-app-whoami-6cf9cd6bf4 0 0 0 11m
[root@tvm-00 ~]# kubectl get pods
NAME READY STATUS RESTARTS AGE
test-deployment-app-whoami-68c6cd964-bfznh 1/1 Running 0 54s
test-deployment-app-whoami-68c6cd964-r7vp5 1/1 Running 0 56s
test-deployment-app-whoami-68c6cd964-v***j 1/1 Running 0 53s
| [root@tvm-00 ~]# kubectl describe deployments/test-deployment-app-whoami Name: test-deployment-app-whoami Namespace: default CreationTimestamp: Wed, 27 Dec 2017 17:44:30 +0800 Labels: app=whoami Annotations: deployment.kubernetes.io/revision=2 kubectl.kubernetes.io/last-applied-configuration=（略） kubernetes.io/change-cause=kubectl set image deployments/test-deployment-app-whoami whoami=opera443399/whoami:0.7 Selector: app=whoami Replicas: 3 desired |
3 updated | 3 total | 3 available | 0 unavailable StrategyType: RollingUpdate MinReadySeconds: 0 RollingUpdateStrategy: 25% max unavailable, 25% max surge Pod Template: Labels: app=whoami Containers: whoami: Image: opera443399/whoami:0.7 Port: 80/TCP Environment: <none> Mounts: <none> Volumes: <none> Conditions: Type Status Reason |
|---|
Available True MinimumReplicasAvailable
Progressing True NewReplicaSetAvailable
OldReplicaSets: <none>
NewReplicaSet: test-deployment-app-whoami-68c6cd964 (3/3 replicas created)
Events:
Type Reason Age From Message
Normal ScalingReplicaSet 12m deployment-controller Scaled up replica set test-deployment-app-whoami-6cf9cd6bf4 to 3
Normal ScalingReplicaSet 1m deployment-controller Scaled up replica set test-deployment-app-whoami-68c6cd964 to 1
Normal ScalingReplicaSet 1m deployment-controller Scaled down replica set test-deployment-app-whoami-6cf9cd6bf4 to 2
Normal ScalingReplicaSet 1m deployment-controller Scaled up replica set test-deployment-app-whoami-68c6cd964 to 2
Normal ScalingReplicaSet 1m deployment-controller Scaled down replica set test-deployment-app-whoami-6cf9cd6bf4 to 1
Normal ScalingReplicaSet 1m deployment-controller Scaled up replica set test-deployment-app-whoami-68c6cd964 to 3
Normal ScalingReplicaSet 1m deployment-controller Scaled down replica set test-deployment-app-whoami-6cf9cd6bf4 to 0
[root@tvm-00 ~]# kubectl rollout history deployments/test-deployment-app-whoami
deployments "test-deployment-app-whoami"
REVISION CHANGE-CAUSE
1 kubectl apply --filename=/root/k8s_install/test/whoami/app.yaml --record=true
2 kubectl set image deployments/test-deployment-app-whoami whoami=opera443399/whoami:0.7
- 再更新 1 次鏡像後，再次查看信息
```bash
[root@tvm-00 ~]# kubectl set image deployments/test-deployment-app-whoami whoami=opera443399/whoami:0.8
deployment "test-deployment-app-whoami" image updated
[root@tvm-00 ~]# kubectl rollout status deployments/test-deployment-app-whoami
deployment "test-deployment-app-whoami" successfully rolled out
[root@tvm-00 ~]# kubectl get deployments
NAME DESIRED CURRENT UP-TO-DATE AVAILABLE AGE
test-deployment-app-whoami 3 3 3 3 17m
[root@tvm-00 ~]# kubectl get rs
NAME DESIRED CURRENT READY AGE
test-deployment-app-whoami-68b94dd7bf 3 3 3 46s
test-deployment-app-whoami-68c6cd964 0 0 0 6m
test-deployment-app-whoami-6cf9cd6bf4 0 0 0 17m
[root@tvm-00 ~]# kubectl get pods
NAME READY STATUS RESTARTS AGE
test-deployment-app-whoami-68b94dd7bf-5g89x 1/1 Running 0 45s
test-deployment-app-whoami-68b94dd7bf-75xjd 1/1 Running 0 52s
test-deployment-app-whoami-68b94dd7bf-pchpw 1/1 Running 0 49s
[root@tvm-00 ~]# kubectl describe deployments/test-deployment-app-whoami
Name: test-deployment-app-whoami
Namespace: default
CreationTimestamp: Wed, 27 Dec 2017 17:44:30 +0800
Labels: app=whoami
Annotations: deployment.kubernetes.io/revision=3
kubectl.kubernetes.io/last-applied-configuration=（略）
kubernetes.io/change-cause=kubectl set image deployments/test-deployment-app-whoami whoami=opera443399/whoami:0.8
Selector: app=whoami
Replicas: 3 desired | 3 updated | 3 total | 3 available | 0 unavailable
StrategyType: RollingUpdate
MinReadySeconds: 0
RollingUpdateStrategy: 25% max unavailable, 25% max surge
Pod Template:
Labels: app=whoami
Containers:
whoami:
Image: opera443399/whoami:0.8
Port: 80/TCP
Environment: <none>
Mounts: <none>
Volumes: <none>
Conditions:
Type Status Reason
---- ------ ------
Available True MinimumReplicasAvailable
Progressing True NewReplicaSetAvailable
OldReplicaSets: <none>
NewReplicaSet: test-deployment-app-whoami-68b94dd7bf (3/3 replicas created)
Events:
Type Reason Age From Message
---- ------ ---- ---- -------
Normal ScalingReplicaSet 18m deployment-controller Scaled up replica set test-deployment-app-whoami-6cf9cd6bf4 to 3
Normal ScalingReplicaSet 7m deployment-controller Scaled up replica set test-deployment-app-whoami-68c6cd964 to 1
Normal ScalingReplicaSet 7m deployment-controller Scaled down replica set test-deployment-app-whoami-6cf9cd6bf4 to 2
Normal ScalingReplicaSet 7m deployment-controller Scaled up replica set test-deployment-app-whoami-68c6cd964 to 2
Normal ScalingReplicaSet 7m deployment-controller Scaled down replica set test-deployment-app-whoami-6cf9cd6bf4 to 1
Normal ScalingReplicaSet 7m deployment-controller Scaled up replica set test-deployment-app-whoami-68c6cd964 to 3
Normal ScalingReplicaSet 7m deployment-controller Scaled down replica set test-deployment-app-whoami-6cf9cd6bf4 to 0
Normal ScalingReplicaSet 2m deployment-controller Scaled up replica set test-deployment-app-whoami-68b94dd7bf to 1
Normal ScalingReplicaSet 2m deployment-controller Scaled down replica set test-deployment-app-whoami-68c6cd964 to 2
Normal ScalingReplicaSet 2m deployment-controller Scaled up replica set test-deployment-app-whoami-68b94dd7bf to 2
Normal ScalingReplicaSet 2m (x3 over 2m) deployment-controller (combined from similar events): Scaled down replica set test-deployment-app-whoami-68c6cd964 to 0
[root@tvm-00 ~]# kubectl rollout history deployments/test-deployment-app-whoami
deployments "test-deployment-app-whoami"
REVISION CHANGE-CAUSE
1 kubectl apply --filename=/root/k8s_install/test/whoami/app.yaml --record=true
2 kubectl set image deployments/test-deployment-app-whoami whoami=opera443399/whoami:0.7
3 kubectl set image deployments/test-deployment-app-whoami whoami=opera443399/whoami:0.8
### 符合預期，我們現在有了 3 個版本回滾 app
- 回滾到上一個版本
[root@tvm-00 ~]# kubectl rollout undo deployments/test-deployment-app-whoami deployment "test-deployment-app-whoami" [root@tvm-00 ~]# kubectl rollout history deployments/test-deployment-app-whoami deployments "test-deployment-app-whoami" REVISION CHANGE-CAUSE 1 kubectl apply --filename=/root/k8s_install/test/whoami/app.yaml --record=true 3 kubectl set image deployments/test-deployment-app-whoami whoami=opera443399/whoami:0.8 4 kubectl set image deployments/test-deployment-app-whoami whoami=opera443399/whoami:0.7
[root@tvm-00 ~]# kubectl get rs
NAME DESIRED CURRENT READY AGE
test-deployment-app-whoami-68b94dd7bf 0 0 0 16m
test-deployment-app-whoami-68c6cd964 3 3 3 22m
test-deployment-app-whoami-6cf9cd6bf4 0 0 0 33m
| [root@tvm-00 ~]# kubectl describe deployments/test-deployment-app-whoami Name: test-deployment-app-whoami Namespace: default CreationTimestamp: Wed, 27 Dec 2017 17:44:30 +0800 Labels: app=whoami Annotations: deployment.kubernetes.io/revision=4 kubectl.kubernetes.io/last-applied-configuration=（略） kubernetes.io/change-cause=kubectl set image deployments/test-deployment-app-whoami whoami=opera443399/whoami:0.7 Selector: app=whoami Replicas: 3 desired |
3 updated | 3 total | 3 available | 0 unavailable StrategyType: RollingUpdate MinReadySeconds: 0 RollingUpdateStrategy: 25% max unavailable, 25% max surge Pod Template: Labels: app=whoami Containers: whoami: Image: opera443399/whoami:0.7 Port: 80/TCP Environment: <none> Mounts: <none> Volumes: <none> Conditions: Type Status Reason |
|---|
Available True MinimumReplicasAvailable
Progressing True NewReplicaSetAvailable
OldReplicaSets: <none>
NewReplicaSet: test-deployment-app-whoami-68c6cd964 (3/3 replicas created)
Events:
Type Reason Age From Message
Normal ScalingReplicaSet 27m deployment-controller Scaled up replica set test-deployment-app-whoami-6cf9cd6bf4 to 3
Normal ScalingReplicaSet 17m deployment-controller Scaled down replica set test-deployment-app-whoami-6cf9cd6bf4 to 2
Normal ScalingReplicaSet 17m deployment-controller Scaled up replica set test-deployment-app-whoami-68c6cd964 to 2
Normal ScalingReplicaSet 17m deployment-controller Scaled down replica set test-deployment-app-whoami-6cf9cd6bf4 to 1
Normal ScalingReplicaSet 17m deployment-controller Scaled up replica set test-deployment-app-whoami-68c6cd964 to 3
Normal ScalingReplicaSet 16m deployment-controller Scaled down replica set test-deployment-app-whoami-6cf9cd6bf4 to 0
Normal ScalingReplicaSet 11m deployment-controller Scaled up replica set test-deployment-app-whoami-68b94dd7bf to 1
Normal ScalingReplicaSet 11m deployment-controller Scaled down replica set test-deployment-app-whoami-68c6cd964 to 2
Normal ScalingReplicaSet 11m deployment-controller Scaled up replica set test-deployment-app-whoami-68b94dd7bf to 2
Normal ScalingReplicaSet 1m (x2 over 17m) deployment-controller Scaled up replica set test-deployment-app-whoami-68c6cd964 to 1
Normal DeploymentRollback 1m deployment-controller Rolled back deployment "test-deployment-app-whoami" to revision 2
Normal ScalingReplicaSet 1m (x8 over 11m) deployment-controller (combined from similar events): Scaled down replica set test-deployment-app-whoami-68b94dd7bf to 0
- 回滾到指定的版本
```bash
[root@tvm-00 ~]# kubectl rollout undo deployments/test-deployment-app-whoami --to-revision=1
deployment "test-deployment-app-whoami"
[root@tvm-00 ~]# kubectl rollout history deployments/test-deployment-app-whoami
deployments "test-deployment-app-whoami"
REVISION CHANGE-CAUSE
3 kubectl set image deployments/test-deployment-app-whoami whoami=opera443399/whoami:0.8
4 kubectl set image deployments/test-deployment-app-whoami whoami=opera443399/whoami:0.7
5 kubectl apply --filename=/root/k8s_install/test/whoami/app.yaml --record=true
[root@tvm-00 ~]# kubectl get rs
NAME DESIRED CURRENT READY AGE
test-deployment-app-whoami-68b94dd7bf 0 0 0 16m
test-deployment-app-whoami-68c6cd964 0 0 0 22m
test-deployment-app-whoami-6cf9cd6bf4 3 3 3 33m
[root@tvm-00 ~]# kubectl describe deployments/test-deployment-app-whoami
Name: test-deployment-app-whoami
Namespace: default
CreationTimestamp: Wed, 27 Dec 2017 17:44:30 +0800
Labels: app=whoami
Annotations: deployment.kubernetes.io/revision=5
kubectl.kubernetes.io/last-applied-configuration=（略）
kubernetes.io/change-cause=kubectl apply --filename=/root/k8s_install/test/whoami/app.yaml --record=true
Selector: app=whoami
Replicas: 3 desired | 3 updated | 3 total | 3 available | 0 unavailable
StrategyType: RollingUpdate
MinReadySeconds: 0
RollingUpdateStrategy: 25% max unavailable, 25% max surge
Pod Template:
Labels: app=whoami
Containers:
whoami:
Image: opera443399/whoami:0.9
Port: 80/TCP
Environment: <none>
Mounts: <none>
Volumes: <none>
Conditions:
Type Status Reason
---- ------ ------
Available True MinimumReplicasAvailable
Progressing True NewReplicaSetAvailable
OldReplicaSets: <none>
NewReplicaSet: test-deployment-app-whoami-6cf9cd6bf4 (3/3 replicas created)
Events:
Type Reason Age From Message
---- ------ ---- ---- -------
Normal ScalingReplicaSet 29m deployment-controller Scaled up replica set test-deployment-app-whoami-6cf9cd6bf4 to 3
Normal ScalingReplicaSet 19m deployment-controller Scaled down replica set test-deployment-app-whoami-6cf9cd6bf4 to 2
Normal ScalingReplicaSet 19m deployment-controller Scaled up replica set test-deployment-app-whoami-68c6cd964 to 2
Normal ScalingReplicaSet 19m deployment-controller Scaled down replica set test-deployment-app-whoami-6cf9cd6bf4 to 1
Normal ScalingReplicaSet 19m deployment-controller Scaled up replica set test-deployment-app-whoami-68c6cd964 to 3
Normal ScalingReplicaSet 19m deployment-controller Scaled down replica set test-deployment-app-whoami-6cf9cd6bf4 to 0
Normal ScalingReplicaSet 13m deployment-controller Scaled up replica set test-deployment-app-whoami-68b94dd7bf to 1
Normal ScalingReplicaSet 13m deployment-controller Scaled down replica set test-deployment-app-whoami-68c6cd964 to 2
Normal ScalingReplicaSet 13m deployment-controller Scaled up replica set test-deployment-app-whoami-68b94dd7bf to 2
Normal ScalingReplicaSet 3m (x2 over 19m) deployment-controller Scaled up replica set test-deployment-app-whoami-68c6cd964 to 1
Normal DeploymentRollback 3m deployment-controller Rolled back deployment "test-deployment-app-whoami" to revision 2
Normal DeploymentRollback 29s deployment-controller Rolled back deployment "test-deployment-app-whoami" to revision 1
Normal ScalingReplicaSet 27s (x12 over 13m) deployment-controller (combined from similar events): Scaled up replica set test-deployment-app-whoami-6cf9cd6bf4 to 3
Normal ScalingReplicaSet 27s deployment-controller Scaled down replica set test-deployment-app-whoami-68c6cd964 to 1
Normal ScalingReplicaSet 26s deployment-controller Scaled down replica set test-deployment-app-whoami-68c6cd964 to 0擴縮容 app
- 擴容
### 調整副本數量到 10 個 [root@tvm-00 ~]# kubectl scale deployments/test-deployment-app-whoami --replicas=10 deployment "test-deployment-app-whoami" scaled
查看信息
[root@tvm-00 ~]# kubectl get deployments
NAME DESIRED CURRENT UP-TO-DATE AVAILABLE AGE
test-deployment-app-whoami 10 10 10 10 39m
[root@tvm-00 ~]# kubectl get rs
NAME DESIRED CURRENT READY AGE
test-deployment-app-whoami-68b94dd7bf 0 0 0 23m
test-deployment-app-whoami-68c6cd964 0 0 0 29m
test-deployment-app-whoami-6cf9cd6bf4 10 10 10 39m
[root@tvm-00 ~]# kubectl get pods
NAME READY STATUS RESTARTS AGE
test-deployment-app-whoami-6cf9cd6bf4-2dd5m 1/1 Running 0 36s
test-deployment-app-whoami-6cf9cd6bf4-4nx7x 1/1 Running 0 36s
test-deployment-app-whoami-6cf9cd6bf4-bb7v7 1/1 Running 0 10m
test-deployment-app-whoami-6cf9cd6bf4-c7cht 1/1 Running 0 36s
test-deployment-app-whoami-6cf9cd6bf4-dph22 1/1 Running 0 36s
test-deployment-app-whoami-6cf9cd6bf4-jhtqz 1/1 Running 0 10m
test-deployment-app-whoami-6cf9cd6bf4-jjfp5 1/1 Running 0 36s
test-deployment-app-whoami-6cf9cd6bf4-nlqq5 1/1 Running 0 36s
test-deployment-app-whoami-6cf9cd6bf4-px24h 1/1 Running 0 10m
test-deployment-app-whoami-6cf9cd6bf4-rldhd 1/1 Running 0 36s
- 縮容
```bash
### 調整副本數量到 5 個
[root@tvm-00 ~]# kubectl scale deployments/test-deployment-app-whoami --replicas=5
deployment "test-deployment-app-whoami" scaled
### 查看信息
[root@tvm-00 ~]# kubectl get deployments
NAME DESIRED CURRENT UP-TO-DATE AVAILABLE AGE
test-deployment-app-whoami 5 5 5 5 41m
[root@tvm-00 ~]# kubectl get rs
NAME DESIRED CURRENT READY AGE
test-deployment-app-whoami-68b94dd7bf 0 0 0 25m
test-deployment-app-whoami-68c6cd964 0 0 0 30m
test-deployment-app-whoami-6cf9cd6bf4 5 5 5 41m
[root@tvm-00 ~]# kubectl get pods
NAME READY STATUS RESTARTS AGE
test-deployment-app-whoami-6cf9cd6bf4-2dd5m 1/1 Running 0 2m
test-deployment-app-whoami-6cf9cd6bf4-bb7v7 1/1 Running 0 12m
test-deployment-app-whoami-6cf9cd6bf4-c7cht 1/1 Running 0 2m
test-deployment-app-whoami-6cf9cd6bf4-jhtqz 1/1 Running 0 12m
test-deployment-app-whoami-6cf9cd6bf4-px24h 1/1 Running 0 12m刪除
[root@tvm-00 test]# kubectl delete deployments/test-deployment-app-whoami
deployment "test-deployment-app-whoami" deleted
[root@tvm-00 test]# kubectl get deployments
No resources found.