目录
Pod 资源
spec.containers <[]object>
- name <string>
image <string>
imagePullPolicy <string>
Always, Never, IfNotPresent标签
key=value
key: 字母 、 数字 、
-、.
value: 可以为空，只能字母或数字开头结尾，中间可使用-、.
查看pods 的标签：
[root@master manifests]# kubectl get pods --show-labels
NAME READY STATUS RESTARTS AGE LABELS
myapp-84cd4b7f95-44qch 1/1 Running 0 7d5h pod-template-hash=84cd4b7f95,run=myapp
myapp-84cd4b7f95-fzvsd 1/1 Running 0 7d5h pod-template-hash=84cd4b7f95,run=myapp
myapp-84cd4b7f95-mlphg 1/1 Running 0 7d5h pod-template-hash=84cd4b7f95,run=myapp
nginx-deploy-7689897d8d-lf8p7 1/1 Running 0 7d6h pod-template-hash=7689897d8d,run=nginx-deploy
pod-demo 2/2 Running 0 29s app=myapp,tier=frontend使用 -l 参数，来过滤标签
[root@master manifests]# kubectl get pods -l app
NAME READY STATUS RESTARTS AGE
pod-demo 2/2 Running 0 3m21s给资源打标签
使用 kubectl label
Usage:
kubectl label [--overwrite] (-f FILENAME | TYPE NAME) KEY_1=VAL_1 ... KEY_N=VAL_N [--resource-version=version] [options]标签选择器
- 等之关系：=、==、!= 来进行操作
- 集合关系
KEY in (VALUE1,VALUE2,...)
KEY notin (VALUE1,VALUE2,...)
[root@master manifests]# kubectl get pods -l release
NAME READY STATUS RESTARTS AGE
nginx-deploy-7689897d8d-lf8p7 1/1 Running 0 7d6h
pod-demo 2/2 Running 0 11m
[root@master manifests]# kubectl get pods -l release=canary
NAME READY STATUS RESTARTS AGE
nginx-deploy-7689897d8d-lf8p7 1/1 Running 0 7d6h
[root@master manifests]# kubectl get pods -l release,app
NAME READY STATUS RESTARTS AGE
pod-demo 2/2 Running 0 12m
[root@master manifests]# kubectl get pods -l release=stable,app=myapp
NAME READY STATUS RESTARTS AGE
pod-demo 2/2 Running 0 12m许多资源支持内嵌字段定义其使用的标签选择器：
- matchLabels: 直接给定键值
- matchExpressions: 基于给定的表达式来定义使用标签选择器，{key:"KEY", operator: "OPERATOR", values: [VAL1,VAL2,...]}
操作符:
In, NotIn: values 字段的值必须为非空列表；
Exists, NotExists: values字段的值必须为空列表；
nodeSelector <map[string]string>
节点标签选择器，是可以影响pods调度算法的。案例:
[root@master manifests]# kubectl get pods -o wide
NAME READY STATUS RESTARTS AGE IP NODE NOMINATED NODE READINESS GATES
nginx-deploy-7689897d8d-lf8p7 1/1 Running 0 8d 10.244.3.2 node02.kubernetes <none> <none>
[root@master manifests]# kubectl delete -f pod-demo.yaml
pod "pod-demo" deleted
[root@master manifests]# vim pod-demo.yaml
apiVersion: v1
kind: Pod
metadata:
name: pod-demo
namespace: default
labels:
app: myapp
tier: frontend
spec:
containers:
- name: myapp
image: ikubernetes/myapp:v1
- name: busybox
image: busybox:latest
imagePullPolicy: IfNotPresent
command:
- "/bin/sh"
- "-c"
- "sleep 3600"
nodeSelector:
disktype: ssd
[root@master manifests]# kubectl create -f pod-demo.yaml
pod/pod-demo created
[root@master manifests]# kubectl get pods -o wide
NAME READY STATUS RESTARTS AGE IP NODE NOMINATED NODE READINESS GATES
pod-demo 2/2 Running 0 4s 10.244.3.10 node01.kubernetes <none> <none>nodeName
指定调度到节点的名称annoitations
与label不同的是，不能用于挑选资源对象，仅用于为对象提供"元数据"。Pod 生命周期
Pod声明周期主要分为两个阶段：
1. 初始化容器初始化阶段
2. 主容器正常运行阶段Pod 状态：
1. 首先Pod进入初始化阶段，使用初始化容器完成初始化，可以有多个初始化容器，但是串行。
2. 初始化之后主容器进入正式运行阶段。
3. 主容器启动之后，会执行一次命令，就是 'post start'，也就是启动后钩子，执行结束后就退出了。
4. 命令执行只有，会有一个主容器存活状态检测，就是'liveness probe'。
5. 同时也会做就容器就绪性检测，检测主容器是否正常运行，就是 'readiness probe'。
6. 当主容器要退出的时候，也会有个结束前执行的命令，就是 'pre stop'，结束前钩子，这个Pod就退出。探测行为：
- liveness probe # 用于探测主容器是否存活
readiness probe # 判定容器中的主进程是否就绪，是否对外提供服务
无论哪一种，都支持三种。
- 自定义命令
- 向指定的TCP套接字发请求
- 向指定的HTTP服务发请求
Pod 状态：
Pending : 调度尚未完成，没有适合创建的节点，不满足存活的状态。
Runing : 运行状态
Failed : 失败状态
Succeeded : 成功状态
Unknown : 位置状态创建Pod
1. 当用户创建Pod的时候，会去请求提交给apiserver，然后会把目标状态保存在ETCD中，
2. 然后 apiserver 会去请求 scheduler进行调度，并且把调度的结果保存在ETCD中之前保存的Pod状态中。
3. 一旦存在ETCD中发生更新，假如调度在node01上，node01 上的kubelet通过apiserver当中状态变化会知道。restartPolicy:
Always, OnFailure, Never实际操作
探针类型有三种：
1. ExecAction
2. TCPsocketAction
3. HTTPGetAction这三种探针，livenessProbe 和 readinessProbe 都可以使用。
livenessProbe 实战
livenessProbe exec 测试
创建Pod的yaml文件：
[root@master manifests]# cat liveness-exec.yaml
apiVersion: v1
kind: Pod
metadata:
name: liveness-exec-pod
namespace: default
spec:
containers:
- name: liveness-exec-container
image: busybox:latest
imagePullPolicy: IfNotPresent
command: ["/bin/sh", "-c", "touch /tmp/healthy; sleep 30; rm -rf /tmp/healthy; sleep 3600"] # 生成存活性文件
livenessProbe:
exec:
command: ["test", "-e", "/tmp/healthy"] # 使用命令探测文件是否存在
initialDelaySeconds: 1 # 容器启动后，多久开始探测，单位秒
periodSeconds: 3 # 每次探测间隔时间，单位秒
successThreshold: 1 # 成功几次
failureThreshold: 2 # 失败几次后重启
timeoutSeconds: 2 # 开始探测后的超时时间，单位秒
[root@master manifests]# kubectl create -f liveness-exec.yaml
pod/liveness-exec-pod created
[root@master manifests]# kubectl get pods
NAME READY STATUS RESTARTS AGE
liveness-exec-pod 1/1 Running 0 4s等一会之后：
[root@master manifests]#kubectl get pods
NAME READY STATUS RESTARTS AGE
liveness-exec-pod 1/1 Running 1 2m20s
[root@master manifests]# kubectl get pods
NAME READY STATUS RESTARTS AGE
liveness-exec-pod 1/1 Running 2 2m40s查看详细信息：
[root@master manifests]# kubectl describe pod liveness-exec-pod
Name: liveness-exec-pod
Namespace: default
Priority: 0
Node: node03.kubernetes/10.0.20.23
Start Time: Fri, 19 Jul 2019 11:13:19 +0800
Labels: <none>
Annotations: <none>
Status: Running
IP: 10.244.1.8
Containers:
liveness-exec-container:
Container ID: docker://e028a5c4796c9e138e9669292f5b82fc76244017463039ef2141dab3da9d5cdd
Image: busybox:latest
Image ID: docker-pullable://busybox@sha256:c94cf1b87ccb80f2e6414ef913c748b105060debda482058d2b8d0fce39f11b9
Port: <none>
Host Port: <none>
Command:
/bin/sh
-c
touch /tmp/healthy; sleep 30; rm -rf /tmp/healthy; sleep 3600
State: Running
Started: Fri, 19 Jul 2019 11:14:34 +0800
Last State: Terminated
Reason: Error # 这里提示错误
Exit Code: 137
Started: Fri, 19 Jul 2019 11:13:20 +0800
Finished: Fri, 19 Jul 2019 11:14:34 +0800
Ready: True
Restart Count: 1 # 提示被重启过一次
Liveness: exec [test -e /tmp/healthy] delay=1s timeout=2s period=10s #success=1 #failure=2
Environment: <none>
Mounts:
/var/run/secrets/kubernetes.io/serviceaccount from default-token-bc86p (ro)
........
........livenessProbe httpGet 测试
创建Pod的yaml文件：
[root@master manifests]# cat liveness-httpget.yaml
apiVersion: v1
kind: Pod
metadata:
name: liveness-httpget-pod
namespace: default
spec:
containers:
- name: liveness-httpget-container
image: ikubernetes/myapp:v1 # 此镜像自带80端口
imagePullPolicy: IfNotPresent
ports:
- name: http # 这里定义映射端口名称
containerPort: 80 # 指定端口
livenessProbe:
httpGet:
port: http # 这里直接使用定义的端口名称即可
path: /index.html # 定义探测http对应的路径
initialDelaySeconds: 1
periodSeconds: 3
successThreshold: 1
failureThreshold: 2
timeoutSeconds: 2
[root@master manifests]# kubectl create -f liveness-httpget.yaml
pod/liveness-httpget-pod created
[root@master manifests]# kubectl get pods
NAME READY STATUS RESTARTS AGE
liveness-httpget-pod 1/1 Running 0 3s手动进入到容器中，然后删除index.html 文件
[root@master ~]# kubectl exec -it liveness-httpget-pod -- /bin/sh
/ # rm -f /usr/share/nginx/html/index.html
/ # command terminated with exit code 137再来查看刚刚创建的pod状态：
[root@master manifests]# kubectl get pods
NAME READY STATUS RESTARTS AGE
liveness-httpget-pod 1/1 Running 1 7m14s # 这里可以看到已经被重启过一次了
[root@master manifests]# kubectl describe pods liveness-httpget-pod # 查看详细信息
Name: liveness-httpget-pod
Namespace: default
Priority: 0
Node: node02.kubernetes/10.0.20.22
Start Time: Fri, 19 Jul 2019 11:26:56 +0800
Labels: <none>
Annotations: <none>
Status: Running
IP: 10.244.2.6
Containers:
liveness-httpget-container:
Container ID: docker://39d3905acd7dac561905e77772522e652843dc3f2e0023a07586d3db088ca87f
Image: ikubernetes/myapp:v1
Image ID: docker-pullable://ikubernetes/myapp@sha256:9c3dc30b5219788b2b8a4b065f548b922a34479577befb54b03330999d30d513
Port: 80/TCP
Host Port: 0/TCP
State: Running
Started: Fri, 19 Jul 2019 11:29:06 +0800
Last State: Terminated # 状态不正常
Reason: Completed
Exit Code: 0
Started: Fri, 19 Jul 2019 11:26:57 +0800
Finished: Fri, 19 Jul 2019 11:29:06 +0800
Ready: True
Restart Count: 1 # 这里看到被重启过一次
Liveness: http-get http://:http/index.html delay=1s timeout=2s period=3s #success=1 #failure=2
Environment: <none>
Mounts:
/var/run/secrets/kubernetes.io/serviceaccount from default-token-bc86p (ro)
.... ....
.... ....这里只会被重启过一次，因为当readinessProbe侦察到容器不处于就绪状态后，就会重启容器，重启的容器中index.html 文件又会被重新生产。
readinessProbe 就绪性探针
创建Pod的yaml文件，配置readinessProbe就绪性探针：
[root@master manifests]# cat readiness-httpget.yaml
apiVersion: v1
kind: Pod
metadata:
name: readiness-httpget-pod
namespace: default
spec:
containers:
- name: readiness-httpget-container
image: ikubernetes/myapp:v1
imagePullPolicy: IfNotPresent
ports:
- name: http
containerPort: 80
readinessProbe:
httpGet:
port: http
path: /index.html
initialDelaySeconds: 1
periodSeconds: 3
successThreshold: 1
failureThreshold: 2
timeoutSeconds: 2
[root@master manifests]# kubectl get pods
NAME READY STATUS RESTARTS AGE
readiness-httpget-pod 1/1 Running 0 53s进入到 readiness-httpget-pod 中，手动删除index.html 主页文件，再次查看：
[root@master ~]# kubectl exec -it readiness-httpget-pod -- /bin/sh
/ # rm -rf /usr/share/nginx/html/index.html
/ # ps aux
PID USER TIME COMMAND
1 root 0:00 nginx: master process nginx -g daemon off; # nginx依然运行这
6 nginx 0:00 nginx: worker process
7 root 0:00 /bin/sh
13 root 0:00 ps aux[root@master manifests]# kubectl get pods
NAME READY STATUS RESTARTS AGE
readiness-httpget-pod 0/1 Running 0 60s # 就绪状态的pod为 0 个
[root@master manifests]# kubectl describe pods readiness-httpget-pod
Name: readiness-httpget-pod
Namespace: default
Priority: 0
Node: node03.kubernetes/10.0.20.23
Start Time: Mon, 22 Jul 2019 09:09:50 +0800
Labels: <none>
Annotations: <none>
Status: Running
IP: 10.244.1.9
Containers:
readiness-httpget-container:
Container ID: docker://71009463c970b6712d97c8692990caa8c2192841b6e075a1d0db9ac15a2d1cd7
Image: ikubernetes/myapp:v1
Image ID: docker-pullable://ikubernetes/myapp@sha256:9c3dc30b5219788b2b8a4b065f548b922a34479577befb54b03330999d30d513
Port: 80/TCP
Host Port: 0/TCP
State: Running
Started: Mon, 22 Jul 2019 09:09:51 +0800
Ready: False
Restart Count: 0
Readiness: http-get http://:http/index.html delay=1s timeout=2s period=3s #success=1 #failure=2
Environment: <none>
Mounts:
/var/run/secrets/kubernetes.io/serviceaccount from default-token-bc86p (ro)
Conditions:
Type Status
Initialized True
Ready False # 详细信息中，显示为错误。
ContainersReady False
PodScheduled True
.... ....
.... ....当就绪性探针发现此Pod不可用时，service 调度会把此pod剔除集群
手动此创建Pod中的index.html文件：
/ # echo 'hi' > /usr/share/nginx/html/index.html[root@master manifests]# kubectl get pods
NAME READY STATUS RESTARTS AGE
readiness-httpget-pod 1/1 Running 0 118s已经恢复，此时service 又会把此Pod 重新加入到集群中。
Pod 控制器
ReplicaSet:
- 用户期望的Pod副本数量，支持多删少补
- 标签选择器，一遍选择自己管理和控制Pod副本
- Pod资源模板来完成Pod资源的新建
Deployment:
- 工作在ReplicaSet之上，不直接控制Pod，而是控制ReplicaSet
- 支持滚动更新和回滚等， 可滚动更新或回滚
- 提供声明式配置功能
DaemonSet
- 无状态的，必须是守护进程类的，
- 确保kubernetes所有节点只运行一个Pod
- 保障系统级的后台任务
- 只能管控无状态应用，关注群体，不关注个体
Job
- 只能执行一次性的作业
Cronjob
- 周期性执行，不执行不启动
StatefulSet
- 管理有状态应用
TPR
Third Party Resources, 1.2 版本开始能用，1.7版本后不可用
第三方资源CDR
Custom Defined Resource, 1.8 版本之后可用
第三方资源
ReplicaSet 控制器
创建一个ReplicaSet清单文件
[root@master manifests]# cat rs-demo.yaml
apiVersion: apps/v1
kind: ReplicaSet
metadata:
name: myapp
namespace: default
spec:
replicas: 2 # Pod 副本数为 2
selector:
matchLabels: # 定义标签选择器
app: myapp
release: canary
template: # 这里以下定义的和一个单独的Pod清单文件一样
metadata: # 定义Pod对应的标签，会被ReplicaSet控制器选择
name: myapp-pod
namespace: default
labels:
app: myapp
release: canary
environment: qa
spec:
containers:
- name: myapp-container
image: ikubernetes/myapp:v1
imagePullPolicy: IfNotPresent
ports:
- name: http
containerPort: 80
[root@master manifests]# kubectl create -f rs-demo.yaml
replicaset.apps/myapp created
[root@master manifests]# kubectl get pods -o wide
NAME READY STATUS RESTARTS AGE IP NODE NOMINATED NODE READINESS GATES
myapp-k4m9l 1/1 Running 0 27s 10.244.1.13 node03.kubernetes <none> <none>
myapp-p9dk9 1/1 Running 0 27s 10.244.3.14 node01.kubernetes <none> <none>两个副本的Pod已经被创建。
可以直接使用kubectl edit 来编辑：
[root@master manifests]# kubectl edit rs myapp
replicaset.extensions/myapp edited # 这里打开后，把replicas的值变更为3，也就是增加一个后。
[root@master manifests]# kubectl get pods -o wide
NAME READY STATUS RESTARTS AGE IP NODE NOMINATED NODE READINESS GATES
myapp-p9dk9 1/1 Running 0 14m 10.244.3.14 node01.kubernetes <none> <none>
myapp-vjnlq 1/1 Running 0 8s 10.244.1.14 node03.kubernetes <none> <none>
myapp-wl9nh 1/1 Running 0 10m 10.244.2.10 node02.kubernetes <none> <none> # 这里立刻就会再次创建一个Pod 出来道理相同，减少replicas的数量的时候，Pod对应的数量也会减少，、
也可以直接编辑对应的Pod版本，只是编辑后不会自动更新，但当手动删除一个Pod的时候，再次自动创建新的Pod的时候，就会更新清单中的Pod。[root@master manifests]# kubectl edit rs myapp
replicaset.extensions/myapp edited
[root@master manifests]# kubectl get rs -o wide
NAME DESIRED CURRENT READY AGE CONTAINERS IMAGES SELECTOR
myapp 3 3 3 15m myapp-container ikubernetes/myapp:v2 app=myapp,release=canary
[root@master manifests]# curl 10.244.3.14
Hello MyApp | Version: v1 | <a href="hostname.html">Pod Name</a>
[root@master manifests]# kubectl delete pods myapp-p9dk9
pod "myapp-p9dk9" deleted
[root@master manifests]# kubectl get pods -o wide
NAME READY STATUS RESTARTS AGE IP NODE NOMINATED NODE READINESS GATES
myapp-fwnwz 1/1 Running 0 14s 10.244.3.15 node01.kubernetes <none> <none>
myapp-vjnlq 1/1 Running 0 2m33s 10.244.1.14 node03.kubernetes <none> <none>
myapp-wl9nh 1/1 Running 0 12m 10.244.2.10 node02.kubernetes <none> <none>
[root@master manifests]# curl 10.244.3.15
Hello MyApp | Version: v2 | <a href="hostname.html">Pod Name</a>基于这种策略，可以实现蓝绿发布，具体实现如下图：
Deployment 控制器
这里直接使用声明式创建，使用kubectl apply命令
首先创建清单
root@master manifests]# cat deploy-demo.yaml
apiVersion: apps/v1
kind: Deployment
metadata:
name: myapp-deploy
namespace: default
spec:
replicas: 2 # 副本数为 2
selector:
matchLabels:
app: myapp
release: canary
template:
metadata:
labels:
app: myapp
release: canary
spec:
containers:
- name: myapp
image: ikubernetes/myapp:v1
ports:
- name: http
containerPort: 80
[root@master manifests]# kubectl apply -f deploy-demo.yaml
deployment.apps/myapp-deploy created查看：
root@master manifests]# kubectl get pods
NAME READY STATUS RESTARTS AGE
myapp-deploy-f4db5d79c-md2kk 1/1 Running 0 4s
myapp-deploy-f4db5d79c-wwx5n 1/1 Running 0 4s
[root@master manifests]# kubectl get deploy
NAME READY UP-TO-DATE AVAILABLE AGE
myapp-deploy 2/2 2 2 11s
[root@master manifests]# kubectl get rs
NAME DESIRED CURRENT READY AGE
myapp-deploy-f4db5d79c 2 2 2 43s- 2个Pod创建成功并正常运行
- Deployment 正常
- Deployment 会自动创建一个ReplicaSet，通过管理ReplicaSet，ReplicaSet再去管理Pod。
- Pod的名称是Deployment名称加上ReplicaSet最后面生产的hash值，再跟上自己的Hash值组成
查看 deployment 详细信息
root@master manifests]# kubectl get deploy
NAME READY UP-TO-DATE AVAILABLE AGE
myapp-deploy 3/3 3 3 2m34s
[root@master manifests]# kubectl describe deploy myapp-deploy
Name: myapp-deploy
Namespace: default
CreationTimestamp: Tue, 23 Jul 2019 17:05:49 +0800
Labels: <none>
Annotations: deployment.kubernetes.io/revision: 1 # 每次的变化，都会被保存在 Annotations当中
kubectl.kubernetes.io/last-applied-configuration:
{"apiVersion":"apps/v1","kind":"Deployment","metadata":{"annotations":{},"name":"myapp-deploy","namespace":"default"},"spec":{"replicas":3...
Selector: app=myapp,release=canary
Replicas: 3 desired | 3 updated | 3 total | 3 available | 0 unavailable
StrategyType: RollingUpdate # 默认的更新策略，滚动更新
MinReadySeconds: 0
RollingUpdateStrategy: 25% max unavailable, 25% max surge # 最大不可用是25%，最大可用是25%，不足一个的时候，补足一个
Pod Template:
Labels: app=myapp
release=canary
Containers:
myapp:
Image: ikubernetes/myapp:v1
Port: 80/TCP
Host Port: 0/TCP
Environment: <none>
Mounts: <none>
Volumes: <none>
Conditions:
Type Status Reason
---- ------ ------
Progressing True NewReplicaSetAvailable
Available True MinimumReplicasAvailable
OldReplicaSets: <none>
NewReplicaSet: myapp-deploy-f4db5d79c (3/3 replicas created)
Events:
Type Reason Age From Message
---- ------ ---- ---- -------
Normal ScalingReplicaSet 3m15s deployment-controller Scaled up replica set myapp-deploy-f4db5d79c to 2
Normal ScalingReplicaSet 50s deployment-controller Scaled up replica set myapp-deploy-f4db5d79c to 3测试滚动更新
在一个窗口上来监控标签 app=myapp 的Pod
[root@master manifests]# kubectl get pods -l app=myapp -w # 这里执行后，会一直等待不动，知道有变化才会有更新
NAME READY STATUS RESTARTS AGE
myapp-deploy-f4db5d79c-cvvl6 1/1 Running 0 2m20s
myapp-deploy-f4db5d79c-md2kk 1/1 Running 0 4m45s
myapp-deploy-f4db5d79c-wwx5n 1/1 Running 0 4m45s在另一个窗口，重新编辑清单deploy-demo.yaml文件中的副本数为 5
[root@master manifests]# cat deploy-demo.yaml
apiVersion: apps/v1
kind: Deployment
metadata:
name: myapp-deploy
namespace: default
spec:
replicas: 5 # 这里副本数修改为 5
selector:
matchLabels:
app: myapp
release: canary
template:
metadata:
labels:
app: myapp
release: canary
spec:
containers:
- name: myapp
image: ikubernetes/myapp:v2
ports:
- name: http
containerPort: 80然后直接使用kubectl apply命令 声明式方式来变更
[root@master manifests]# kubectl apply -f deploy-demo.yaml
deployment.apps/myapp-deploy configured当执行完成后，监控的窗口就会出现变化
[root@master manifests]# kubectl get pods -l app=myapp -w
NAME READY STATUS RESTARTS AGE
myapp-deploy-f4db5d79c-cvvl6 1/1 Running 0 2m20s
myapp-deploy-f4db5d79c-md2kk 1/1 Running 0 4m45s
myapp-deploy-f4db5d79c-wwx5n 1/1 Running 0 4m45s
myapp-deploy-f4db5d79c-cvvl6 1/1 Terminating 0 3m26s
myapp-deploy-55b78d8548-zsl5d 0/1 Pending 0 0s
myapp-deploy-55b78d8548-zsl5d 0/1 Pending 0 0s
myapp-deploy-55b78d8548-zsl5d 0/1 ContainerCreating 0 0s
myapp-deploy-f4db5d79c-cvvl6 0/1 Terminating 0 3m27s
myapp-deploy-55b78d8548-zsl5d 1/1 Running 0 1s
myapp-deploy-f4db5d79c-md2kk 1/1 Terminating 0 5m52s
myapp-deploy-55b78d8548-l264b 0/1 Pending 0 0s
myapp-deploy-55b78d8548-l264b 0/1 Pending 0 0s
myapp-deploy-55b78d8548-l264b 0/1 ContainerCreating 0 0s
myapp-deploy-f4db5d79c-cvvl6 0/1 Terminating 0 3m28s
myapp-deploy-f4db5d79c-cvvl6 0/1 Terminating 0 3m28s
myapp-deploy-f4db5d79c-md2kk 0/1 Terminating 0 5m53s
myapp-deploy-55b78d8548-l264b 1/1 Running 0 2s
myapp-deploy-f4db5d79c-wwx5n 1/1 Terminating 0 5m54s
myapp-deploy-f4db5d79c-wwx5n 0/1 Terminating 0 5m54s
myapp-deploy-f4db5d79c-md2kk 0/1 Terminating 0 6m1s
myapp-deploy-f4db5d79c-md2kk 0/1 Terminating 0 6m1s
myapp-deploy-f4db5d79c-wwx5n 0/1 Terminating 0 6m4s
myapp-deploy-f4db5d79c-wwx5n 0/1 Terminating 0 6m4s此时来再查看
[root@master manifests]# kubectl get pods
NAME READY STATUS RESTARTS AGE
myapp-deploy-55b78d8548-cw4r5 1/1 Running 0 5s
myapp-deploy-55b78d8548-jwj2j 1/1 Running 0 5s
myapp-deploy-55b78d8548-l264b 1/1 Running 0 4m20s
myapp-deploy-55b78d8548-mnm95 1/1 Running 0 5s
myapp-deploy-55b78d8548-zsl5d 1/1 Running 0 4m21s查看 ReplicaSet
[root@master manifests]# kubectl get rs -o wide
NAME DESIRED CURRENT READY AGE CONTAINERS IMAGES SELECTOR
myapp-deploy-55b78d8548 5 5 5 59s myapp ikubernetes/myapp:v2 app=myapp,pod-template-hash=55b78d8548,release=canary
myapp-deploy-f4db5d79c 0 0 0 6m50s myapp ikubernetes/myapp:v1 app=myapp,pod-template-hash=f4db5d79c,release=canary查看ReplicaSet后发现有两个，因为Deployment 会重新创建一个ReplicaSet来更新，IMAGES版本一列可以看出版本的不同，通过把新的Pod创建在新的ReplicaSet上来实现滚动更新
DaemonSet 控制器
DaemonSet 控制器主要用于系统级别的无状态环境。
默认创会在 kubernetes 集群中每一个节点创建一个Pod。创建一个DaemonSet配置清单
[root@master manifests]# cat daemonset-demo.yaml
apiVersion: apps/v1
kind: DaemonSet
metadata:
name: myapp-ds
namespace: default
spec:
selector:
matchLabels:
app: filebeat
release: stable
template:
metadata:
labels:
app: filebeat
release: stable
spec:
containers:
- name: filebeat
image: ikubernetes/filebeat:5.6.5-alpine # 这里使用filebeat来进行测试
env: # 增加两个环境变量
- name: REDIS_HOST # 指定redis地址
value: redis.default.svc.cluster.local # 这里使用集群域名来解析redis地址
- name: REDIS_LOG_LEVEL # 指定日志级别
value: info # 日志级别为info
[root@master manifests]# kubectl apply -f daemonset-demo.yaml
daemonset.apps/myapp-ds created
[root@master manifests]# kubectl get pods -o wide
NAME READY STATUS RESTARTS AGE IP NODE NOMINATED NODE READINESS GATES
myapp-ds-jxwfq 1/1 Running 0 9s 10.244.1.22 node03.kubernetes <none> <none>
myapp-ds-mw9vw 1/1 Running 0 9s 10.244.3.25 node01.kubernetes <none> <none>
myapp-ds-xjqdb 1/1 Running 0 9s 10.244.2.18 node02.kubernetes <none> <none>可以看到已经被创建成功，并且是每个节点都只有一个Pod。
查看详细信息
[root@master manifests]# kubectl describe ds myapp-ds
Name: myapp-ds
Selector: app=filebeat,release=stable
Node-Selector: <none>
Labels: <none>
Annotations: deprecated.daemonset.template.generation: 1
kubectl.kubernetes.io/last-applied-configuration:
{"apiVersion":"apps/v1","kind":"DaemonSet","metadata":{"annotations":{},"name":"myapp-ds","namespace":"default"},"spec":{"selector":{"matc...
Desired Number of Nodes Scheduled: 3
Current Number of Nodes Scheduled: 3
Number of Nodes Scheduled with Up-to-date Pods: 3
Number of Nodes Scheduled with Available Pods: 3
Number of Nodes Misscheduled: 0
Pods Status: 3 Running / 0 Waiting / 0 Succeeded / 0 Failed
Pod Template:
Labels: app=filebeat
release=stable
Containers:
filebeat:
Image: ikubernetes/filebeat:5.6.5-alpine
Port: <none>
Host Port: <none>
Environment:
REDIS_HOST: redis.default.svc.cluster.local
REDIS_LOG_LEVEL: info
Mounts: <none>
Volumes: <none>
Events:
Type Reason Age From Message
---- ------ ---- ---- -------
Normal SuccessfulCreate 22m daemonset-controller Created pod: myapp-ds-qjg6w
Normal SuccessfulCreate 22m daemonset-controller Created pod: myapp-ds-ftxzb
Normal SuccessfulCreate 22m daemonset-controller Created pod: myapp-ds-66hnj同样，一个配置清单中，可以把多个资源配置写在一个清单中，使用 --- 来分割
在相同的清单文件中，再定义一个redis 的 Deployment
[root@master manifests]# cat daemonset-demo.yaml
apiVersion: apps/v1
kind: Deployment
metadata:
name: redis
namespace: default
spec:
replicas: 1
selector:
matchLabels:
app: redis
role: logstor
template:
metadata:
labels:
app: redis
role: logstor
spec:
containers:
- name: redis
image: redis:4.0-alpine
ports:
- name: redis
containerPort: 6379
---
apiVersion: apps/v1
kind: DaemonSet
metadata:
name: myapp-ds
namespace: default
spec:
selector:
matchLabels:
app: filebeat
release: stable
template:
metadata:
labels:
app: filebeat
release: stable
spec:
containers:
- name: filebeat
image: ikubernetes/filebeat:5.6.5-alpine
env:
- name: REDIS_HOST
value: redis.default.svc.cluster.local
- name: REDIS_LOG_LEVEL
value: info再次使用 kubectl apply 来执行此清单文件
[root@master manifests]# kubectl apply -f daemonset-demo.yaml
deployment.apps/redis created
daemonset.apps/myapp-ds created
[root@master manifests]# kubectl get pods
NAME READY STATUS RESTARTS AGE
myapp-ds-66hnj 1/1 Running 0 59s
myapp-ds-ftxzb 1/1 Running 0 59s
myapp-ds-qjg6w 1/1 Running 0 59s
redis-5c998b644f-wnzrd 1/1 Running 0 59s创建一个redis 的service
[root@master manifests]# kubectl expose deployment redis --port=6379
service/redis exposed
[root@master manifests]# kubectl get svc
NAME TYPE CLUSTER-IP EXTERNAL-IP PORT(S) AGE
kubernetes ClusterIP 10.96.0.1 <none> 443/TCP 15d
redis ClusterIP 10.111.151.200 <none> 6379/TCP 4s进入到redis pod中，并尝试解析redis
[root@master manifests]# kubectl exec -it redis-5c998b644f-wnzrd -- /bin/sh
/data # netstat -tnl
Active Internet connections (only servers)
Proto Recv-Q Send-Q Local Address Foreign Address State
tcp 0 0 0.0.0.0:6379 0.0.0.0:* LISTEN
tcp 0 0 :::6379 :::* LISTEN
/data # ls
/data # nslookup redis.default.svc.cluster.local
nslookup: can't resolve '(null)': Name does not resolve
Name: redis.default.svc.cluster.local
Address 1: 10.111.151.200 redis.default.svc.cluster.local # 可以看到解析正常同样，DaemonSet 也支持滚动更新，但个Deployment不同的时候，DaemonSet只支持删除Pod后再次新建，来进行更新
更新方式有好几种，这里使用 kubectl set image 来更新
[root@master manifests]# kubectl set image daemonset myapp-ds filebeat=ikubernetes/filebeat:5.6.6-alpine
daemonset.extensions/myapp-ds image updated
[root@master manifests]# kubectl get pods -o wide -w
NAME READY STATUS RESTARTS AGE IP NODE NOMINATED NODE READINESS GATES
myapp-deploy-f4db5d79c-7hnfg 1/1 Running 0 22h 10.244.2.16 node02.kubernetes <none> <none>
myapp-deploy-f4db5d79c-85hpm 1/1 Running 0 22h 10.244.3.22 node01.kubernetes <none> <none>
myapp-deploy-f4db5d79c-b9h4s 1/1 Running 0 22h 10.244.2.15 node02.kubernetes <none> <none>
myapp-deploy-f4db5d79c-tm9mt 1/1 Running 0 22h 10.244.1.20 node03.kubernetes <none> <none>
myapp-deploy-f4db5d79c-xp8t6 1/1 Running 0 22h 10.244.3.23 node01.kubernetes <none> <none>
myapp-ds-8tvmc 0/1 ContainerCreating 0 10s <none> node03.kubernetes <none> <none>
myapp-ds-f2pp8 1/1 Running 0 30s 10.244.2.20 node02.kubernetes <none> <none>
myapp-ds-ftxzb 1/1 Running 0 25m 10.244.3.26 node01.kubernetes <none> <none>
redis-5c998b644f-wnzrd 1/1 Running 0 25m 10.244.1.24 node03.kubernetes <none> <none>
myapp-ds-8tvmc 1/1 Running 0 14s 10.244.1.25 node03.kubernetes <none> <none>
myapp-ds-ftxzb 1/1 Terminating 0 25m 10.244.3.26 node01.kubernetes <none> <none>
myapp-ds-ftxzb 0/1 Terminating 0 25m 10.244.3.26 node01.kubernetes <none> <none>
myapp-ds-ftxzb 0/1 Terminating 0 25m 10.244.3.26 node01.kubernetes <none> <none>
myapp-ds-ftxzb 0/1 Terminating 0 25m 10.244.3.26 node01.kubernetes <none> <none>
myapp-ds-cs2hw 0/1 Pending 0 0s <none> <none> <none> <none>
myapp-ds-cs2hw 0/1 Pending 0 0s <none> node01.kubernetes <none> <none>
myapp-ds-cs2hw 0/1 ContainerCreating 0 0s <none> node01.kubernetes <none> <none>
myapp-ds-cs2hw 1/1 Running 0 17s 10.244.3.27 node01.kubernetes <none> <none>这里会一个一个更新，删除后下载镜像更新启动Pod。