yamlip 安装_k8s-YAML配置文件

一、YAML基础

YAML是专门用来写配置文件的语言，非常简洁和强大，使用比json更方便。它实质上是一种通用的数据串行化格式。

YAML语法规则：

大小写敏感

使用缩进表示层级关系

缩进时不允许使用Tal键，只允许使用空格

缩进的空格数目不重要，只要相同层级的元素左侧对齐即可

”#” 表示注释，从这个字符一直到行尾，都会被解析器忽略

在Kubernetes中，只需要知道两种结构类型即可：

Lists

Maps

1.1 YAML Maps

Map顾名思义指的是字典，即一个Key:Value 的键值对信息。例如：

---

apiVersion: v1

kind: Pod

注：---为可选的分隔符 ，当需要在一个文件中定义多个结构的时候需要使用。上述内容表示有两个键apiVersion和kind，分别对应的值为v1和Pod。

Maps的value既能够对应字符串也能够对应一个Maps。例如：

---

apiVersion: v1

kind: Pod

metadata:

name: kube100-site

labels:

app: web

注：上述的YAML文件中，metadata这个KEY对应的值为一个Maps，而嵌套的labels这个KEY的值又是一个Map。实际使用中可视情况进行多层嵌套。

YAML处理器根据行缩进来知道内容之间的关联。上述例子中，使用两个空格作为缩进，但空格的数据量并不重要，只是至少要求一个空格并且所有缩进保持一致的空格数 。例如，name和labels是相同缩进级别，因此YAML处理器知道他们属于同一map；它知道app是lables的值因为app的缩进更大。

注意：在YAML文件中绝对不要使用tab键

1.2 YAML Lists

List即列表，说白了就是数组，例如：

args

-beijing

-shanghai

-shenzhen

-guangzhou

可以指定任何数量的项在列表中，每个项的定义以破折号(-)开头，并且与父元素之间存在缩进。在JSON格式中，表示如下：

{

"args": ["beijing", "shanghai", "shenzhen", "guangzhou"]

}

当然Lists的子项也可以是Maps，Maps的子项也可以是List，例如：

---

apiVersion: v1

kind: Pod

metadata:

name: kube100-site

labels:

app: web

spec:

containers:

- name: front-end

image: nginx

ports:

- containerPort: 80

- name: flaskapp-demo

image: jcdemo/flaskapp

ports: 8080

如上述文件所示，定义一个containers的List对象，每个子项都由name、image、ports组成，每个ports都有一个KEY为containerPort的Map组成，转成JSON格式文件：

{

"apiVersion": "v1",

"kind": "Pod",

"metadata": {

"name": "kube100-site",

"labels": {

"app": "web"

},

},

"spec": {

"containers": [{

"name": "front-end",

"image": "nginx",

"ports": [{

"containerPort": "80"

}]

}, {

"name": "flaskapp-demo",

"image": "jcdemo/flaskapp",

"ports": [{

"containerPort": "5000"

}]

}]

}

}

二、说明

定义配置时，指定最新稳定版API

配置文件应该存储在集群之外的版本控制仓库中。如果需要，可以快速回滚配置、重新创建和恢复

应该使用YAML格式编写配置文件，而不是json。YAML对用户更加友好

可以将相关对象组合成单个文件，通常会更容易管理

不要没必要指定默认值，简单和最小配置减小错误

在注释中说明一个对象描述更好维护

三、使用YAML创建Pod

---

apiVersion: v1

kind: Pod

metadata:

name: kube100-site

labels:

app: web

spec:

containers:

- name: front-end

image: nginx

ports:

- containerPort: 80

- name: flaskapp-demo

image: jcdemo/flaskapp

ports:

- containerPort: 5000

apiVersion：此处值是v1，这个版本号需要根据安装的Kubernetes版本和资源类型进行变化，记住不是写死的。

kind：此处创建的是Pod，根据实际情况，此处资源类型可以是Deployment、Job、Ingress、Service等。

metadata：包含Pod的一些meta信息，比如名称、namespace、标签等信息。

spe：包括一些container，storage，volume以及其他Kubernetes需要的参数，以及诸如是否在容器失败时重新启动容器的属性。可在特定Kubernetes API找到完整的Kubernetes Pod的属性。

(1)查看apiVersion

# kubectl api-versions

admissionregistration.k8s.io/v1beta1

apiextensions.k8s.io/v1beta1

apiregistration.k8s.io/v1

apiregistration.k8s.io/v1beta1

apps/v1

apps/v1beta1

apps/v1beta2

authentication.k8s.io/v1

authentication.k8s.io/v1beta1

authorization.k8s.io/v1

authorization.k8s.io/v1beta1

autoscaling/v1

autoscaling/v2beta1

batch/v1

batch/v1beta1

certificates.k8s.io/v1beta1

events.k8s.io/v1beta1

extensions/v1beta1

networking.k8s.io/v1

policy/v1beta1

rbac.authorization.k8s.io/v1

rbac.authorization.k8s.io/v1beta1

storage.k8s.io/v1

storage.k8s.io/v1beta1

v1

(2)下面是一个典型的容器定义：

…

spec:

containers:

- name: front-end

image: nginx

ports:

- containerPort: 80

…

上述例子只是一个简单的最小定义：一个名字(front-end)、基于nginx的镜像，以及容器将会监听的指定端口号(80)。

除了上述的基本属性外，还能够指定复杂的属性，包括容器启动运行的命令、使用的参数、工作目录以及每次实例化是否拉取新的副本。 还可以指定更深入的信息，例如容器的退出日志的位置。容器可选的设置属性包括：

name、image、command、args、workingDir、ports、env、resource、volumeMounts、livenessProbe、readinessProbe、livecycle、terminationMessagePath、imagePullPolicy、securityContext、stdin、stdinOnce、tty

(3)kubectl创建Pod

# kubectl create -f test_pod.yaml

pod "kube100-site" created

(4)查看Pod状态

# kubectl get pod

NAME READY STATUS RESTARTS AGE

kube100-site 2/2 Running 0 2m

四、创建Deployment

名词解释

#test-pod

apiVersion: v1 #指定api版本，此值必须在kubectl apiversion中

kind: Pod #指定创建资源的角色/类型

metadata: #资源的元数据/属性

name: test-pod #资源的名字，在同一个namespace中必须唯一

labels: #设定资源的标签

k8s-app: apache

version: v1

kubernetes.io/cluster-service: "true"

annotations: #自定义注解列表

- name: String #自定义注解名字

spec: #specification of the resource content 指定该资源的内容

restartPolicy: Always #表明该容器一直运行，默认k8s的策略，在此容器退出后，会立即创建一个相同的容器

nodeSelector: #节点选择，先给主机打标签kubectl label nodes kube-node1 zone=node1

zone: node1

containers:

- name: test-pod #容器的名字

image: 10.192.21.18:5000/test/chat:latest #容器使用的镜像地址

imagePullPolicy: Never #三个选择Always、Never、IfNotPresent，每次启动时检查和更新(从registery)images的策略，

# Always，每次都检查

# Never，每次都不检查(不管本地是否有)

# IfNotPresent，如果本地有就不检查，如果没有就拉取

command: ['sh'] #启动容器的运行命令，将覆盖容器中的Entrypoint,对应Dockefile中的ENTRYPOINT

args: ["$(str)"] #启动容器的命令参数，对应Dockerfile中CMD参数

env: #指定容器中的环境变量

- name: str #变量的名字

value: "/etc/run.sh" #变量的值

resources: #资源管理

requests: #容器运行时，最低资源需求，也就是说最少需要多少资源容器才能正常运行

cpu: 0.1 #CPU资源(核数)，两种方式，浮点数或者是整数+m，0.1=100m，最少值为0.001核(1m)

memory: 32Mi #内存使用量

limits: #资源限制

cpu: 0.5

memory: 1000Mi

ports:

- containerPort: 80 #容器开发对外的端口

name: httpd #名称

protocol: TCP

livenessProbe: #pod内容器健康检查的设置

httpGet: #通过httpget检查健康，返回200-399之间，则认为容器正常

path: / #URI地址

port: 80

#host: 127.0.0.1 #主机地址

scheme: HTTP

initialDelaySeconds: 180 #表明第一次检测在容器启动后多长时间后开始

timeoutSeconds: 5 #检测的超时时间

periodSeconds: 15 #检查间隔时间

#也可以用这种方法

#exec: 执行命令的方法进行监测，如果其退出码不为0，则认为容器正常

# command:

# - cat

# - /tmp/health

#也可以用这种方法

#tcpSocket: //通过tcpSocket检查健康

# port: number

lifecycle: #生命周期管理

postStart: #容器运行之前运行的任务

exec:

command:

- 'sh'

- 'yum upgrade -y'

preStop:#容器关闭之前运行的任务

exec:

command: ['service httpd stop']

volumeMounts: #挂载持久存储卷

- name: volume #挂载设备的名字，与volumes[*].name 需要对应

mountPath: /data #挂载到容器的某个路径下

readOnly: True

volumes: #定义一组挂载设备

- name: volume #定义一个挂载设备的名字

#meptyDir: {}

hostPath:

path: /opt #挂载设备类型为hostPath，路径为宿主机下的/opt,这里设备类型支持很多种

#nfs

(1)创建一个yaml文件

apiVersion: apps/v1beta2

kind: Deployment

metadata:

name: nginx-deployment

spec:

replicas: 3

selector:

matchLabels:

app: nginx

template:

metadata:

labels:

app: nginx

spec:

containers:

- name: nginx

image: nginx:1.10

ports:

- containerPort: 80

(2)创建deployment

[root@master-01 YAML_k8s]# kubectl create -f nginx-deployment.yaml

deployment.apps "nginx-deployment" created

[root@master-01 YAML_k8s]# kubectl get pod -o wide

NAME READY STATUS RESTARTS AGE IP NODE

nginx-deployment-6b7b4d57b4-26wzj 1/1 Running 0 2m 10.20.184.83 master-01

nginx-deployment-6b7b4d57b4-9w7tm 1/1 Running 0 2m 10.20.190.60 node-01

nginx-deployment-6b7b4d57b4-mhh8t 1/1 Running 0 2m 10.20.254.108 node-03

[root@master-01 YAML_k8s]# kubectl get deployment

NAME DESIRED CURRENT UP-TO-DATE AVAILABLE AGE

nginx-deployment 3 3 3 3 2m

(3)查看标签

[root@master-01 YAML_k8s]# kubectl get pod --show-labels

NAME READY STATUS RESTARTS AGE LABELS

nginx-deployment-6b7b4d57b4-26wzj 1/1 Running 0 3m app=nginx,pod-template-hash=2636081360

nginx-deployment-6b7b4d57b4-9w7tm 1/1 Running 0 3m app=nginx,pod-template-hash=2636081360

nginx-deployment-6b7b4d57b4-mhh8t 1/1 Running 0 3m app=nginx,pod-template-hash=2636081360

(4)通过标签查找Pod

[root@master-01 YAML_k8s]# kubectl get pod -l app=nginx

NAME READY STATUS RESTARTS AGE

nginx-deployment-6b7b4d57b4-26wzj 1/1 Running 0 6m

nginx-deployment-6b7b4d57b4-9w7tm 1/1 Running 0 6m

nginx-deployment-6b7b4d57b4-mhh8t 1/1 Running 0 6m

(5)deployment创建过程

Deployment 管理的是replicaset-controller，RC会创建Pod。Pod自身会下载镜像并启动镜像

[root@master-01 YAML_k8s]# kubectl describe rs nginx-deployment

...

...

...

Events:

Type Reason Age From Message

---- ------ ---- ---- -------

Normal SuccessfulCreate 33m replicaset-controller Created pod: nginx-deployment-6b7b4d57b4-9w7tm

Normal SuccessfulCreate 33m replicaset-controller Created pod: nginx-deployment-6b7b4d57b4-26wzj

Normal SuccessfulCreate 33m replicaset-controller Created pod: nginx-deployment-6b7b4d57b4-mhh8t

[root@master-01 YAML_k8s]# kubectl describe pod nginx-deployment-6b7b4d57b4-26wzj

...

...

...

Events:

Type Reason Age From Message

---- ------ ---- ---- -------

Normal Scheduled 36m default-scheduler Successfully assigned nginx-deployment-6b7b4d57b4-26wzj to master-01

Normal SuccessfulMountVolume 36m kubelet, master-01 MountVolume.SetUp succeeded for volume "default-token-v5vw9"

Normal Pulled 36m kubelet, master-01 Container image "nginx:1.10" already present on machine

Normal Created 36m kubelet, master-01 Created container

Normal Started 36m kubelet, master-01 Started container

(6)升级镜像(nginx1.10-->nginx1.11)

[root@master-01 YAML_k8s]# kubectl set image deploy/nginx-deployment nginx=nginx:1.11

deployment.apps "nginx-deployment" image updated

[root@master-01 YAML_k8s]# kubectl exec -it nginx-deployment-b96c97dc-2pxjf bash

root@nginx-deployment-b96c97dc-2pxjf:/# nginx -V

nginx version: nginx/1.11.13

升级镜像的过程是逐步进行的，pod不会一下子全部关闭，而是一个一个升级

(7)查看发布状态

[root@master-01 ~]# kubectl rollout status deploy/nginx-deployment

deployment "nginx-deployment" successfully rolled out

(8)查看deployment历史修订版本

[root@master-01 ~]# kubectl rollout history deploy/nginx-deployment

deployments "nginx-deployment"

REVISION CHANGE-CAUSE

1

2

# 显示历史有两个版本

[root@master-01 ~]# kubectl rollout history deploy/nginx-deployment --revision=1

deployments "nginx-deployment" with revision #1

Pod Template:

Labels:app=nginx

pod-template-hash=2636081360

Containers:

nginx:

Image:nginx:1.10

Port:80/TCP

Host Port:0/TCP

Environment:

Mounts:

Volumes:

[root@master-01 ~]# kubectl rollout history deploy/nginx-deployment --revision=2

deployments "nginx-deployment" with revision #2

Pod Template:

Labels:app=nginx

pod-template-hash=65275387

Containers:

nginx:

Image:nginx:1.11

Port:80/TCP

Host Port:0/TCP

Environment:

Mounts:

Volumes:

(8)编辑deployment

[root@master-01 ~]# kubectl edit deploy/nginx-deployment

# 将nginx版本改为1.12

...

...

...

spec:

containers:

- image: nginx:1.12

imagePullPolicy: IfNotPresent

name: nginx

ports:

- containerPort: 80

升级过程：

[root@master-01 ~]# kubectl rollout status deploy/nginx-deployment

Waiting for rollout to finish: 1 out of 3 new replicas have been updated...

Waiting for rollout to finish: 1 out of 3 new replicas have been updated...

Waiting for rollout to finish: 1 out of 3 new replicas have been updated...

Waiting for rollout to finish: 2 out of 3 new replicas have been updated...

Waiting for rollout to finish: 2 out of 3 new replicas have been updated...

Waiting for rollout to finish: 2 out of 3 new replicas have been updated...

Waiting for rollout to finish: 1 old replicas are pending termination...

Waiting for rollout to finish: 1 old replicas are pending termination...

deployment "nginx-deployment" successfully rolled out

(10)扩容/缩容(指定--replicas的数量)

[root@master-01 ~]# kubectl get pod

NAME READY STATUS RESTARTS AGE

nginx-deployment-6b47cf4878-8mjkr 1/1 Running 0 1m

nginx-deployment-6b47cf4878-kr978 1/1 Running 0 1m

nginx-deployment-6b47cf4878-tvhvl 1/1 Running 0 1m

[root@master-01 ~]# kubectl scale deploy/nginx-deployment --replicas=5

deployment.extensions "nginx-deployment" scaled

[root@master-01 ~]# kubectl get pod

NAME READY STATUS RESTARTS AGE

nginx-deployment-6b47cf4878-6r5dz 0/1 ContainerCreating 0 4s

nginx-deployment-6b47cf4878-7sjtt 0/1 ContainerCreating 0 4s

nginx-deployment-6b47cf4878-8mjkr 1/1 Running 0 2m

nginx-deployment-6b47cf4878-kr978 1/1 Running 0 2m

nginx-deployment-6b47cf4878-tvhvl 1/1 Running 0 2m

(11)创建Service提供对外访问的接口

apiVersion: v1

kind: Service

metadata:

name: nginx-service

labels:

app: nginx

spec:

ports:

- port: 88

targetPort: 80

selector:

app: nginx

####

apiVersion: 指定版本

kind: 类型

name: 指定服务名称

labels: 标签

port: Service 服务暴露的端口

targetPort: 容器暴露的端口

seletor: 关联的Pod的标签

创建service

# kubectl create -f nginx-service.yaml

查看service(访问Pod是有负载均衡的)

[root@master-01 YAML_k8s]# kubectl get svc/nginx-service

NAME TYPE CLUSTER-IP EXTERNAL-IP PORT(S) AGE

nginx-service ClusterIP 10.254.131.176 88/TCP 1m

# curl 10.254.131.176:88

Welcome to nginx!

body {

width: 35em;

margin: 0 auto;

font-family: Tahoma, Verdana, Arial, sans-serif;

}

Welcome to nginx!

If you see this page, the nginx web server is successfully installed and

working. Further configuration is required.

For online documentation and support please refer to

nginx.org.

Commercial support is available at

nginx.com.

Thank you for using nginx.

对service的描述

# kubectl describe svc/nginx-service

Name: nginx-service

Namespace: default

Labels: app=nginx

Annotations:

Selector: app=nginx

Type: ClusterIP

IP: 10.254.131.176

Port: 88/TCP

TargetPort: 80/TCP

Endpoints: 10.20.184.19:80,10.20.184.84:80,10.20.190.62:80 + 2 more...

Session Affinity: None

Events:

(12)回滚到以前的版本

# kubectl rollout history deploy/nginx-deployment

deployments "nginx-deployment"

REVISION CHANGE-CAUSE

1

2

3

# kubectl rollout history deploy/nginx-deployment --revision=3

deployments "nginx-deployment" with revision #3

Pod Template:

Labels:app=nginx

pod-template-hash=2603790434

Containers:

nginx:

Image:nginx:1.12

Port:80/TCP

Host Port:0/TCP

Environment:

Mounts:

Volumes:

# 回滚到上一个版本

# kubectl rollout undo deploy/nginx-deployment

deployment.apps "nginx-deployment"

# 查看版本

# kubectl describe deploy/nginx-deployment

...

...

Labels: app=nginx

Containers:

nginx:

Image: nginx:1.11

(13)回滚到指定版本

# kubectl rollout history deploy/nginx-deployment

deployments "nginx-deployment"

REVISION CHANGE-CAUSE

1

3

4

# 指定版本

# kubectl rollout undo deploy/nginx-deployment --to-revision=1

deployment.apps "nginx-deployment"