一、 Controllers

官网https://kubernetes.io/docs/concepts/workloads/controllers/


1、ReplicationController(RC)

官网https://kubernetes.io/docs/concepts/workloads/controllers/replicationcontroller/

1.1、简介

ReplicationController确保任何时期都在运行指定数量的Pod副本。 换句话说,ReplicationController确保一个容器或一组相同的容器始终处于可用状态。

  • Pod期待的副本数(replicas)
  • 用于筛选目标Pod的Label Selector
  • 当Pod的副本数量小于预期数量时,用于创建新Pod的Pod模板(template)

也就是说通过RC实现了集群中Pod的高可用,减少了传统IT环境中手工运维的工作。

常见配置参数:

  • (1)kind:表示要新建对象的类型。
  • (2)spec.selector:表示需要管理的Pod的label,这里表示包含。
  • (3)app: nginx的label的Pod都会被该RC管理。
  • (4)spec.replicas:表示受此RC管理的Pod需要运行的副本数。
  • (5)spec.template:表示用于定义Pod的模板,比如Pod名称、拥有的label以及Pod中运行的应用等。

通过改变RC里Pod模板中的镜像版本,可以实现Pod的升级功能。

常用命令:

  • (1)依据yaml文件配置创建pod
    kubectl apply -f yaml文件名
  • (2)扩/缩容命令
    kubectl scale rc nginx --replicas=指定扩/缩容副本数量

1.2、测试
(1)创建nginx_replication.yaml

创建nginx_replication.yaml文件:

[root@m test]# vi nginx_replication.yaml

内容如下(replicas: 3,即创建3个副本):

apiVersion: v1
kind: ReplicationController
metadata:
  name: nginx
spec:
  replicas: 3
  selector:
    app: nginx
  template:
    metadata:
      name: nginx
      labels:
        app: nginx
    spec:
      containers:
      - name: nginx
        image: nginx
        ports:
        - containerPort: 80
(2)根据yaml创建pod
[root@m test]# kubectl apply -f nginx_replication.yaml
(3)查看pod、查看RC
# 查看pod
[root@m test]# kubectl get pods -o wide
NAME          READY   STATUS    RESTARTS   AGE    IP               NODE   NOMINATED NODE   READINESS GATES
nginx-c57tk   1/1     Running   0          109s   192.168.190.69   w1     <none>           <none>
nginx-dhv9m   1/1     Running   0          109s   192.168.190.68   w1     <none>           <none>
nginx-v5cbm   1/1     Running   0          109s   192.168.80.195   w2     <none>           <none>
[root@m test]# 

#查看RC
[root@m test]# kubectl get rc
NAME    DESIRED   CURRENT   READY   AGE
nginx   3         3         3       2m12s
[root@m test]# 
(4)尝试删除一个pod
#(1)删除
[root@m test]# kubectl delete pods nginx-v5cbm
pod "nginx-v5cbm" deleted
[root@m test]#

#(2)查看pod(发现又自动创建了一个新的)
[root@m test]# kubectl get pods -o wide
NAME          READY   STATUS    RESTARTS   AGE     IP               NODE   NOMINATED NODE   READINESS GATES
nginx-9f4ht   1/1     Running   0          22s     192.168.80.196   w2     <none>           <none>
nginx-c57tk   1/1     Running   0          3m36s   192.168.190.69   w1     <none>           <none>
nginx-dhv9m   1/1     Running   0          3m36s   192.168.190.68   w1     <none>           <none>
[root@m test]# 
(5)对pod进行扩/缩容
#(1)使用RC进行扩容(5个副本)
[root@m test]# kubectl scale rc nginx --replicas=5
replicationcontroller/nginx scaled
[root@m test]# 

#(2)查看pod(发现变成了5个副本,分布再集群节点上)
[root@m test]# kubectl get pods -o wide
NAME          READY   STATUS    RESTARTS   AGE     IP               NODE   NOMINATED NODE   READINESS GATES
nginx-9f4ht   1/1     Running   0          2m57s   192.168.80.196   w2     <none>           <none>
nginx-c57tk   1/1     Running   0          6m11s   192.168.190.69   w1     <none>           <none>
nginx-dhv9m   1/1     Running   0          6m11s   192.168.190.68   w1     <none>           <none>
nginx-j68nb   1/1     Running   0          77s     192.168.80.197   w2     <none>           <none>
nginx-zfz4h   1/1     Running   0          77s     192.168.80.198   w2     <none>           <none>
[root@m test]# 
(6)删除测试资源(自行选择
#(1)使用RC进行扩容(5个副本)
[root@m test]# kubectl delete -f nginx_replication.yaml
replicationcontroller "nginx" deleted
[root@m test]# 

#(2)查看pod
[root@m test]# kubectl get pods
No resources found in default namespace.
[root@m test]# 

#(3)删除nginx_replication.yaml(自行选择)
[root@m test]# rm nginx_replication.yaml
rm:是否删除普通文件 "nginx_replication.yaml"?y
[root@m test]# 

2、ReplicaSet(RS)

官网https://kubernetes.io/docs/concepts/workloads/controllers/replicaset/

2.1、简介

ReplicaSet的目的是维护在任何给定时间运行的稳定的副本Pod集。 因此,它通常用于保证指定数量的相同Pod的可用性。

  • Kubernetes v1.2时,RC就升级成了另外一个概念:Replica Set,官方解释为“下一代RC”。

  • ReplicaSet和RC没有本质的区别,kubectl中绝大部分作用于RC的命令同样适用于RS。

  • RS与RC唯一的区别是:RS支持基于集合的Label Selector(Set-based selector),而RC只支持基于等式的Label Selector(equality-based selector),这使得Replica Set的功能更强。

2.2、测试(见deployment)

一般情况下,我们很少单独使用Replica Set,它主要是被Deployment这个更高的资源对象所使用,从而形成一整套Pod创建、删除、更新的编排机制。当我们使用Deployment时,无须关心它是如何创建和维护Replica Set的,这一切都是自动发生的。同时,无需担心跟其他机制的不兼容问题(比如ReplicaSet不支持rolling-update但Deployment支持)。

apiVersion: extensions/v1beta1
kind: ReplicaSet
metadata:
  name: frontend
spec:
  matchLabels: 
    tier: frontend
  matchExpressions: 
    - {key:tier,operator: In,values: [frontend]}
  template:
  ...

说明:ReplicaSet的测试会结合下一节Deployment一起测试,参见下一节测试。


3、Deployment

官网https://kubernetes.io/docs/concepts/workloads/controllers/deployment/

3.1、简介

Deployment为Pod和ReplicaSet提供了声明式更新(即我们可以随时知道当前Pod“部署”的进度)。

可以在Deployment中描述预期的状态,然后Deployment控制器将实际状态以受控的速率更改为所预期的状态。

创建一个Deployment对象来生成对应的Replica Set,并完成Pod副本的创建过程。我们可以检查Deploymnet的状态来看部署动作是否完成(Pod副本的数量是否达到预期的值)。


3.2、测试
(1)创建nginx_deployment.yaml文件
[root@m test]# vi nginx_deployment.yaml

内容如下(replicas: 3,即创建3个副本):

apiVersion: apps/v1
kind: Deployment
metadata:
  name: nginx-deployment
  labels:
    app: nginx
spec:
  replicas: 3
  selector:
    matchLabels:
      app: nginx
  template:
    metadata:
      labels:
        app: nginx
    spec:
      containers:
      - name: nginx
        image: nginx:1.7.9
        ports:
        - containerPort: 80
(2)根据yaml文件创建pod

根据nginx_deployment.yaml文件创建pod:

[root@m test]# kubectl apply -f nginx_deployment.yaml
deployment.apps/nginx-deployment created
[root@m test]# 
(3)查看pod创建情况
# 查看pod
[root@m test]# kubectl get pods -o wide
NAME                               READY   STATUS    RESTARTS   AGE   IP               NODE   NOMINATED NODE   READINESS GATES
nginx-deployment-6dd86d77d-kdvh2   1/1     Running   0          16m   192.168.80.204   w2     <none>           <none>
nginx-deployment-6dd86d77d-q4l7l   1/1     Running   0          16m   192.168.80.205   w2     <none>           <none>
nginx-deployment-6dd86d77d-s59nl   1/1     Running   0          16m   192.168.190.72   w1     <none>           <none>
[root@m test]# 

# 查看deployment
[root@m test]# kubectl get deployment
NAME               READY   UP-TO-DATE   AVAILABLE   AGE
nginx-deployment   3/3     3            3           18m
[root@m test]# 

# 查看RS
[root@m test]# kubectl get rs
NAME                         DESIRED   CURRENT   READY   AGE
nginx-deployment-6dd86d77d   3         3         3       17m
[root@m test]# 

查看pod创建情况命令(可看到异常原因):
[root@m test]# kubectl describe pod


(4)查看nginx的版本

通过查看deployment来查看nginx版本:

# (1)查看nginx版本(通过deployment来查看nginx版本)
[root@m test]# kubectl get deployment -o wide
NAME               READY   UP-TO-DATE   AVAILABLE   AGE   CONTAINERS   IMAGES        SELECTOR
nginx-deployment   3/3     3            3           18m   nginx        nginx:1.7.9   app=nginx
[root@m test]# 

#(2)更新nginx镜像版本
[root@m test]# kubectl set image deployment nginx-deployment nginx=nginx:1.9.1
deployment.extensions/nginx-deployment image updated
[root@m test]# 

# (3)再次查看nginx版本
[root@m test]# kubectl get deployment -o wide
NAME               READY   UP-TO-DATE   AVAILABLE   AGE   CONTAINERS   IMAGES        SELECTOR
nginx-deployment   3/3     1            3           41m   nginx        nginx:1.9.1   app=nginx
[root@m test]# 
(5)删除测试资源(自行选择
#(1)删除pod
[root@m test]# kubectl delete -f nginx_deployment.yaml
deployment.apps "nginx-deployment" deleted
[root@m test]# 

#(2)删除nginx_deployment.yaml文件
[root@m test]# rm nginx_deployment.yaml
rm:是否删除普通文件 "nginx_deployment.yaml"?y
[root@m test]# 

二、Labels and Selectors

官网https://kubernetes.io/docs/concepts/overview/working-with-objects/labels/

Labels就是key/value键值对,可以打在任何资源或对象上。如,在前面的测试的yaml文件中,有很多label,就是给一些资源打上标签的。

例如:

apiVersion: v1
kind: Pod
metadata:
  name: nginx-pod
  labels:
    app: nginx

其中,名称为nginx-pod的pod,有一个label,key为app,value为nginx。

我们还可以将具有同一个label的pod,交给selector管理(如下):

apiVersion: apps/v1
kind: Deployment
metadata: 
  name: nginx-deployment
  labels:
    app: nginx
spec:
  replicas: 3
  selector:             # 匹配具有同一个label属性的pod标签
    matchLabels:
      app: nginx         
  template:             # 定义pod的模板
    metadata:
      labels:
        app: nginx      # 定义当前pod的label属性,app为key,value为nginx
    spec:
      containers:
      - name: nginx
        image: nginx:1.7.9
        ports:
        - containerPort: 80

查看pod的label标签命令:
[root@m test]# kubectl get pods --show-labels


三、Namespace(命名空间)

1、简介

命名空间就是为了隔离不同的资源,比如:Pod、Service、Deployment等。可以在输入命令的时候指定命名空间-n,如果不指定,则使用默认的命名空间default

常用命令:

  • (1)查看默认(default)命名空间的pod
    [root@m test]# kubectl get pods
  • (2)查看指定命名空间(kube-system)的pod
    [root@m test]# kubectl get pods -n kube-system
  • (3)查看当前命名空间
    [root@m test]# kubectl get namespaces

    [root@m test]# kubectl get ns
  • (4)查看指定命名空间(myns)下的所有资源对象
    [root@m test]# kubectl get all -n myns
  • (5)查看所有命名空间下的pod
    [root@m test]# kubectl get pods --all-namespaces
[root@m test]# kubectl get ns
NAME              STATUS   AGE
default           Active   44h
kube-node-lease   Active   44h
kube-public       Active   44h
kube-system       Active   44h
[root@m test]#

2、测试

2.1、创建namespace

(1)创建myns-namespace.yaml
[root@m test]# vi myns-namespace.yaml

内容:

apiVersion: v1
kind: Namespace
metadata:
  name: myns
(2)依据yaml配置创建namespace
[root@m test]# kubectl apply -f myns-namespace.yaml
namespace/myns created
[root@m test]# 
(3)查看命名空间
[root@m test]# kubectl get ns

在这里插入图片描述


2.2、创建pod

(1)创建一个pod(在myns命名空间下创建)

创建nginx-pod.yaml文件:

[root@m test]# vi nginx-pod.yaml

内容:

apiVersion: v1
kind: Pod
metadata:
  name: nginx-pod
  namespace: myns
spec:
  containers:
  - name: nginx-container
    image: nginx
    ports:
    - containerPort: 80
(2)依据yaml配置创建pod

注意: 此步骤的前提是 myns 命名空间已经被创建成功。

[root@m test]# kubectl apply -f nginx-pod.yaml
pod/nginx-pod created
[root@m test]# 
(3)查看myns命名空间下的Pod和资源
# 查看pod(default命名空间下的pod)
[root@m test]# kubectl get pods

# 查看pod(myns命名空间下的pod)
[root@m test]# kubectl get pods -n myns
NAME        READY   STATUS    RESTARTS   AGE
nginx-pod   1/1     Running   0          81s
[root@m test]# 

# 查看所有资源对象(myns命名空间下的)
[root@m test]# kubectl get all -n myns

# 查看pod(所有命名空间下的)
[root@m test]# kubectl get pods --all-namespaces
(4)删除测试资源(自行选择
# (1)删除pod
[root@m test]# kubectl delete -f nginx-pod.yaml
pod "nginx-pod" deleted
[root@m test]# 

# (2)删除namespace
[root@m test]# kubectl delete -f myns-namespace.yaml
namespace "myns" deleted
[root@m test]# 

# (3)删除nginx-pod.yaml文件
[root@m test]# rm nginx-pod.yaml
rm:是否删除普通文件 "nginx-pod.yaml"?y
[root@m test]# 

# (4)删除myns-namespace.yaml文件
[root@m test]# rm myns-namespace.yaml
rm:是否删除普通文件 "myns-namespace.yaml"?y
[root@m test]# 

在这里插入图片描述


四、Network

接下来,了解下Kubernetes网络通信相关的内容。

K8S最小的操作单位是Pod。


1、集群内:同一个Pod中的容器通信

Kubernetes中,每个Pod分配有一个唯一的IP地址。 Pod中的每个容器都共享网络命名空间,包括IP地址和网络端口,即同一个pod中的容器是共享网络IP地址和端口号的,通信畅通无阻

思考: 如果通过容器的名称将如何进行通信呢?

答:需要将所有pod中的容器加入到同一个容器的网络中,我们把该容器称作为pod中的 pause container


2、集群内:Pod之间的通信

我们都知道每个Pod会有独立的IP地址,这个IP地址是被Pod中所有的Container共享的,那么多个Pod之间的通信是通过这个IP地址进行的吗?

我们分析两个维度:
(1)集群中同一台机器中的Pod。
(2)集群中不同机器中的Pod。


2.1、测试准备

准备两个pod,一个nginx,一个busybox。

(1)创建并编辑nginx_pod.yaml文件
[root@m test]# vi nginx_pod.yaml

内容:

apiVersion: v1
kind: Pod
metadata:
  name: nginx-pod
  labels:
    app: nginx
spec:
  containers:
  - name: nginx-container
    image: nginx
    ports:
    - containerPort: 80
(2)创建并编辑busybox_pod.yaml文件
[root@m test]# vi busybox_pod.yaml

内容:

apiVersion: v1
kind: Pod
metadata:
  name: busybox
  labels:
    app: busybox
spec:
  containers:
  - name: busybox
    image: busybox
    command: ['sh', '-c', 'echo The app is running! && sleep 3600']
(3)创建两个pod,并查看
#(1)依据yaml配置创建nginx_pod
[root@m test]# kubectl apply -f nginx_pod.yaml
pod/nginx-pod created
[root@m test]# 

#(2)依据yaml配置创建busybox_pod
[root@m test]# kubectl apply -f busybox_pod.yaml
pod/busybox created
[root@m test]# 

#(3)查看pod
[root@m test]# kubectl get pod -o wide
NAME        READY   STATUS    RESTARTS   AGE   IP               NODE   NOMINATED NODE   READINESS GATES
busybox     1/1     Running   0          38s   192.168.80.208   w2     <none>           <none>
nginx-pod   1/1     Running   0          77s   192.168.190.75   w1     <none>           <none>
[root@m test]# 

其中,nginx-pod的IP为192.168.190.75,分布于w1(worker01)节点;busybox-pod的IP为192.168.80.208,分布于w2(worker02)节点。


2.2、测试:同一个集群中同一台机器节点

说明: 在准备环境中,
(1)nginx-pod的IP为192.168.190.75,分布于w1(worker01)节点;
(2)busybox-pod的IP为192.168.80.208,分布于w2(worker02)节点。

(1)在worker01节点,ping本节点IP(ping成功
[root@w1 ~]# ping 192.168.190.75
(2)在worker01节点,curl本节点IP(curl成功
[root@w1 ~]# curl 192.168.190.75
<!DOCTYPE html>
<html>
<head>
<title>Welcome to nginx!</title>
<style>
    body {
        width: 35em;
        margin: 0 auto;
        font-family: Tahoma, Verdana, Arial, sans-serif;
    }
</style>
</head>
<body>
<h1>Welcome to nginx!</h1>
<p>If you see this page, the nginx web server is successfully installed and
working. Further configuration is required.</p>

<p>For online documentation and support please refer to
<a href="http://nginx.org/">nginx.org</a>.<br/>
Commercial support is available at
<a href="http://nginx.com/">nginx.com</a>.</p>

<p><em>Thank you for using nginx.</em></p>
</body>
</html>
[root@w1 ~]#

2.3、测试:同一个集群中不同机器节点

说明: 在准备环境中,
(1)nginx-pod的IP为192.168.190.75,分布于w1(worker01)节点;
(2)busybox-pod的IP为192.168.80.208,分布于w2(worker02)节点。

注意:worker01上的nginx会监听80端口,所以使用curl测试时,master和worker02均能curl测通,但反之不能。

(1)在worker02节点,ping测试worker01节点中nginx-pod的IP(ping成功
[root@w2 ~]# ping 192.168.190.75
(2)在worker02节点,curl测试worker01节点中nginx-pod的IP(curl成功
[root@w2 ~]# curl 192.168.190.75
<!DOCTYPE html>
<html>
<head>
<title>Welcome to nginx!</title>
<style>
    body {
        width: 35em;
        margin: 0 auto;
        font-family: Tahoma, Verdana, Arial, sans-serif;
    }
</style>
</head>
<body>
<h1>Welcome to nginx!</h1>
<p>If you see this page, the nginx web server is successfully installed and
working. Further configuration is required.</p>

<p>For online documentation and support please refer to
<a href="http://nginx.org/">nginx.org</a>.<br/>
Commercial support is available at
<a href="http://nginx.com/">nginx.com</a>.</p>

<p><em>Thank you for using nginx.</em></p>
</body>
</html>
[root@w2 ~]#
(3)在worker01节点,ping测试worker02节点中busybox-pod的IP(ping成功
[root@w1 ~]# ping 192.168.80.208
(4)在master节点

说明: 在准备环境中,
(1)nginx-pod的IP为192.168.190.75,分布于w1(worker01)节点;
(2)busybox-pod的IP为192.168.80.208,分布于w2(worker02)节点。

① ping测试worker02节点中busybox-pod的IP(ping成功
[root@m test]# ping 192.168.80.208
② ping测试worker01节点中nginx-pod的IP(ping成功
[root@m test]# ping 192.168.190.75
③ curl测试worker01节点中nginx-pod的IP(curl成功
[root@m test]# curl 192.168.190.75
<!DOCTYPE html>
<html>
<head>
<title>Welcome to nginx!</title>
<style>
    body {
        width: 35em;
        margin: 0 auto;
        font-family: Tahoma, Verdana, Arial, sans-serif;
    }
</style>
</head>
<body>
<h1>Welcome to nginx!</h1>
<p>If you see this page, the nginx web server is successfully installed and
working. Further configuration is required.</p>

<p>For online documentation and support please refer to
<a href="http://nginx.org/">nginx.org</a>.<br/>
Commercial support is available at
<a href="http://nginx.com/">nginx.com</a>.</p>

<p><em>Thank you for using nginx.</em></p>
</body>
</html>
[root@m test]# 
2.4、删除测试资源
#(1)删除2个pod
[root@m test]# kubectl delete -f nginx_pod.yaml
pod "nginx-pod" deleted
[root@m test]# 
[root@m test]# kubectl delete -f busybox_pod.yaml
pod "busybox" deleted
[root@m test]# 

#(2)删除2个yaml配置文件
[root@m test]# rm  nginx_pod.yaml
rm:是否删除普通文件 "nginx_pod.yaml"?y
[root@m test]# 
[root@m test]# rm busybox_pod.yaml
rm:是否删除普通文件 "busybox_pod.yaml"?y
[root@m test]# 

3、集群内:通过Service-Cluster IP通信

Service官网https://kubernetes.io/docs/concepts/services-networking/service/

对于上述的Pod虽然实现了集群内部互相通信,但是 Pod是不稳定的,比如通过Deployment管理Pod,随时可能对Pod进行扩缩容,这时候Pod的IP地址是变化的。能够有一个固定的IP,使得集群内能够访问。也就是之前在架构描述的时候所提到的,能够把相同或者具有关联的Pod,打上Label,组成Service。而 Service有固定的IP,不管Pod怎么创建和销毁,都可以通过Service的IP进行访问。

Service将运行在一组Pod上的应用程序暴露(expose)为网络服务的抽象方法。
使用Kubernetes,您无需修改应用程序即可使用不熟悉的服务发现机制(unfamiliar service discovery mechanism)。 Kubernetes为Pods提供自己的IP地址和一组Pod的单个DNS名称,并且可以在它们之间进行负载平衡。


3.1、测试Service-Cluster IP
(1)创建并编辑whoami-deployment.yaml文件
[root@m ~]# vi whoami-deployment.yaml

内容(创建3个副本、端口:8000):

apiVersion: apps/v1
kind: Deployment
metadata:
  name: whoami-deployment
  labels:
    app: whoami
spec:
  replicas: 3
  selector:
    matchLabels:
      app: whoami
  template:
    metadata:
      labels:
        app: whoami
    spec:
      containers:
      - name: whoami
        image: jwilder/whoami
        ports:
        - containerPort: 8000
(2)创建pod
[root@m test]# kubectl apply -f whoami-deployment.yaml
deployment.apps/whoami-deployment created
[root@m test]#
(3)查看pod、deployment
#(1)查看pod
[root@m test]# kubectl get pod -o wide
NAME                                 READY   STATUS    RESTARTS   AGE   IP               NODE   NOMINATED NODE   READINESS GATES
whoami-deployment-678b64444d-4l9sh   1/1     Running   0          15m   192.168.190.77   w1     <none>           <none>
whoami-deployment-678b64444d-5vb8x   1/1     Running   0          15m   192.168.80.210   w2     <none>           <none>
whoami-deployment-678b64444d-cvqhl   1/1     Running   0          15m   192.168.190.78   w1     <none>           <none>
[root@m test]# 

#(2)查看deployment
[root@m test]# kubectl get deployment
NAME                READY   UP-TO-DATE   AVAILABLE   AGE
whoami-deployment   3/3     3            3           3m1s
[root@m test]# 
(4)在集群内正常访问pod

pod分布信息(端口:8000

whoami-deployment-678b64444d-4l9sh        192.168.190.77         w1(worker01)
whoami-deployment-678b64444d-5vb8x        192.168.80.210        w2(worker02)
whoami-deployment-678b64444d-cvqhl         192.168.190.78         w1(worker01)

分别在3个节点通过curl访问pod,均可测通:

[root@m test]# curl 192.168.190.77:8000
I am whoami-deployment-678b64444d-4l9sh
[root@m test]# 

[root@m test]# curl 192.168.80.210:8000
I am whoami-deployment-678b64444d-5vb8x
[root@m test]# 

[root@m test]# curl 192.168.190.78:8000
I am whoami-deployment-678b64444d-cvqhl
[root@m test]# 
(5)创建service并查看
#(1)查看Service(目前只有kubernetes,因为whoami-deployment的service还没有创建呢!)
[root@m test]# kubectl get svc
NAME         TYPE        CLUSTER-IP   EXTERNAL-IP   PORT(S)   AGE
kubernetes   ClusterIP   10.96.0.1    <none>        443/TCP   2d11h
[root@m test]# 

#(2)暴露Service(即创建Service)
[root@m test]# kubectl expose deployment whoami-deployment
service/whoami-deployment exposed
[root@m test]# 

#(3)再次查看Service(可以看到whoami-deployment的service已被创建)
[root@m test]# kubectl get svc
NAME                TYPE        CLUSTER-IP      EXTERNAL-IP   PORT(S)    AGE
kubernetes          ClusterIP   10.96.0.1       <none>        443/TCP    2d12h
whoami-deployment   ClusterIP   10.98.239.156   <none>        8000/TCP   13s
[root@m test]# 

如上,可以发现有一个Cluster IP类型的service,名称为whoami-deployment,IP为10.98.239.156,端口为8000

附: 删除service命令
kubectl delete service whoami-deployment


(6)通过Service的Cluster IP访问(10.98.239.156)

可以发现,通信成功,并进行了 负载平衡

[root@m test]# curl 10.98.239.156:8000
I am whoami-deployment-678b64444d-4l9sh
[root@m test]# curl 10.98.239.156:8000
I am whoami-deployment-678b64444d-cvqhl
[root@m test]# curl 10.98.239.156:8000
I'm whoami-deployment-678b64444d-5vb8x
[root@m test]# 
(7)查看service详细信息

查看whoami-deployment的service详情信息,发现有一个Endpoints连接了具体3个Pod(IP):

[root@m test]# kubectl describe svc whoami-deployment
Name:              whoami-deployment
Namespace:         default
Labels:            app=whoami
Annotations:       <none>
Selector:          app=whoami
Type:              ClusterIP
IP Families:       <none>
IP:                10.98.239.156
IPs:               <none>
Port:              <unset>  8000/TCP
TargetPort:        8000/TCP
Endpoints:         192.168.190.77:8000,192.168.190.78:8000,192.168.80.210:8000
Session Affinity:  None
Events:            <none>
[root@m test]# 
(8)测试:pod扩容后,使用curl访问
#(1)对whoami-deployment的pod进行扩容成5个副本
[root@m test]# kubectl scale deployment whoami-deployment --replicas=5
deployment.extensions/whoami-deployment scaled
[root@m test]#

#(2)查看pod详情
[root@m test]# kubectl get pod -o wide
NAME                                 READY   STATUS    RESTARTS   AGE    IP               NODE   NOMINATED NODE   RE
whoami-deployment-678b64444d-4l9sh   1/1     Running   0          50m    192.168.190.77   w1     <none>           <n
whoami-deployment-678b64444d-5vb8x   1/1     Running   0          50m    192.168.80.210   w2     <none>           <n
whoami-deployment-678b64444d-cvqhl   1/1     Running   0          50m    192.168.190.78   w1     <none>           <n
whoami-deployment-678b64444d-q4wfj   1/1     Running   0          2m6s   192.168.190.79   w1     <none>           <n
whoami-deployment-678b64444d-x4tqg   1/1     Running   0          2m6s   192.168.80.211   w2     <none>           <n
[root@m test]# 

#(3)通过Service的Cluster IP访问(通信成功,并进行了负载平衡)
[root@m test]# curl 10.98.239.156:8000
I am whoami-deployment-678b64444d-cvqhl
[root@m test]# curl 10.98.239.156:8000
I am whoami-deployment-678b64444d-4l9sh
[root@m test]# curl 10.98.239.156:8000
I am whoami-deployment-678b64444d-q4wfj
[root@m test]# curl 10.98.239.156:8000
I am whoami-deployment-678b64444d-5vb8x
[root@m test]# curl 10.98.239.156:8000
I am whoami-deployment-678b64444d-x4tqg
[root@m test]# 

(9)再次查看service具体信息
[root@m test]# kubectl describe svc whoami-deployment
Name:              whoami-deployment
Namespace:         default
Labels:            app=whoami
Annotations:       <none>
Selector:          app=whoami
Type:              ClusterIP
IP Families:       <none>
IP:                10.98.239.156
IPs:               <none>
Port:              <unset>  8000/TCP
TargetPort:        8000/TCP
Endpoints:         192.168.190.77:8000,192.168.190.78:8000,192.168.190.79:8000 + 2 more...
Session Affinity:  None
Events:            <none>
[root@m test]# 

(10)测试总结

总结: Service存在的意义就是为了解决Pod的不稳定性,而上述探讨的就是关于Service的一种类型Cluster IP,只能供集群内访问。


(11)删除测试资源
#(1)删除pod
[root@m test]# kubectl delete -f whoami-deployment.yaml
deployment.apps "whoami-deployment" deleted
[root@m test]# 

#(2)删除service(删除whoami-deployment)
[root@m test]# kubectl delete svc whoami-deployment
service "whoami-deployment" deleted
[root@m test]# 

#(3)删除yaml配置文件
[root@m test]# rm whoami-deployment.yaml
rm:是否删除普通文件 "whoami-deployment.yaml"?y
[root@m test]# 

4、Pod访问外部服务

比较简单,没太多好说的内容,直接访问即可。


5、外部服务访问集群中的Pod(通过Service-NodePort通信)

Service-NodePort也是Service的一种类型,可以通过NodePort的方式

说白了,因为外部能够访问到集群的物理机器IP,所以就是在集群中每台物理机器节点上暴露一个相同的端口,如:31689。

5.1、测试Service-NodePort
(1)创建并编辑whoami-deployment.yaml文件

创建whoami-deployment.yaml:

[root@m test]# vi whoami-deployment.yaml

内容:

apiVersion: apps/v1
kind: Deployment
metadata:
  name: whoami-deployment
  labels:
    app: whoami
spec:
  replicas: 3
  selector:
    matchLabels:
      app: whoami
  template:
    metadata:
      labels:
        app: whoami
    spec:
      containers:
      - name: whoami
        image: jwilder/whoami
        ports:
        - containerPort: 8000
(2)创建pod
#(1)创建pod
[root@m test]# kubectl apply -f whoami-deployment.yaml
deployment.apps/whoami-deployment created
[root@m test]# 

#(2)查看pod
[root@m test]# kubectl get pod -o wide
NAME                                 READY   STATUS    RESTARTS   AGE   IP               NODE   NOMINATED NODE   READINESS GATES
whoami-deployment-678b64444d-dcgxn   1/1     Running   0          37s   192.168.80.212   w2     <none>           <none>
whoami-deployment-678b64444d-f7wxt   1/1     Running   0          37s   192.168.80.213   w2     <none>           <none>
whoami-deployment-678b64444d-nsqgp   1/1     Running   0          37s   192.168.190.80   w1     <none>           <none>
[root@m test]# 
(3)创建service并查看
#(1)查看Service(目前只有kubernetes,因为whoami-deployment的service还没有创建呢!)
[root@m test]# kubectl get svc
NAME         TYPE        CLUSTER-IP   EXTERNAL-IP   PORT(S)   AGE
kubernetes   ClusterIP   10.96.0.1    <none>        443/TCP   2d12h
[root@m test]#

#(2)暴露Service(即创建Service)
[root@m test]# kubectl expose deployment whoami-deployment --type=NodePort
service/whoami-deployment exposed
[root@m test]# 

#(3)再次查看Service(可以看到whoami-deployment的service已被创建)
[root@m test]# kubectl get svc
NAME                TYPE        CLUSTER-IP      EXTERNAL-IP   PORT(S)          AGE
kubernetes          ClusterIP   10.96.0.1       <none>        443/TCP          2d13h
whoami-deployment   NodePort    10.99.165.184   <none>        8000:31689/TCP   5s
[root@m test]# 

附:删除service命令
kubectl delete service whoami-deployment


(4)查看暴露在集群中各节点端口情况

如上,名为whoami-deployment的service,类型: NodePort,IP:10.99.165.184,端口:8000:31689/TCP

查看暴露在集群中各个物理机器节点上的端口情况:

常用端口查询命令:

  • (1)lsof -i tcp:端口
  • (2)netstat -ntlp | grep 端口
#(1)在master节点,查看端口
[root@m ~]# netstat -ntlp | grep 31689
tcp6       0      0 :::31689                :::*                    LISTEN      2856/kube-proxy     
[root@m ~]# 

#(2)在worker01节点,查看端口
[root@w1 ~]# netstat -ntlp | grep 31689
tcp6       0      0 :::31689                :::*                    LISTEN      2519/kube-proxy     
[root@w1 ~]# 

#(3)在worker02节点,查看端口
[root@w2 ~]# netstat -ntlp | grep 31689
tcp6       0      0 :::31689                :::*                    LISTEN      2461/kube-proxy     
[root@w2 ~]# 

(5)外部浏览器访问(通过集群各节点物理机IP和暴露的端口)

如上,名为whoami-deployment的service,类型: NodePort,IP:10.99.165.184,端口:8000:31689/TCP

  • 其各物理机IP为:

master节点IP:192.168.116.170         暴露的端口:31689
worker01节点IP:192.168.116.171     暴露的端口:31689
worker02节点IP:192.168.116.172     暴露的端口:31689

浏览器访问如下:
在这里插入图片描述


(6)测试总结

NodePort能够实现外部访问Pod的需求,唯一的缺点:占用了各个物理主机上的端口


(7)删除测试资源
#(1)删除pod
[root@m test]# kubectl delete -f whoami-deployment.yaml
deployment.apps "whoami-deployment" deleted
[root@m test]# 

#(2)删除Service
[root@m test]# kubectl delete service whoami-deployment
service "whoami-deployment" deleted
[root@m test]# 

#(3)删除yaml配置文件
[root@m test]# rm whoami-deployment.yaml
rm:是否删除普通文件 "whoami-deployment.yaml"?y
[root@m test]# 

6、外部服务访问集群中的Pod(通过Service-LoadBalance通信)

测试思路: 在K8S集群中部署tomcat,浏览器想要访问这个tomcat,也就是外部要访问该tomcat,用之前的Service-NodePort的方式是可以的,比如暴露一个32008端口,只需要访问http://192.168.161.170:32008即可。

6.1、测试环境准备
(1)创建并编辑my-tomcat.yaml文件
[root@m test]# vi my-tomcat.yaml

内容:

apiVersion: apps/v1
kind: Deployment
metadata:
  name: tomcat-deployment
  labels:
    app: tomcat
spec:
  replicas: 1
  selector:
    matchLabels:
      app: tomcat
  template:
    metadata:
      labels:
        app: tomcat
    spec:
      containers:
      - name: tomcat
        image: tomcat
        ports:
        - containerPort: 8080
---
apiVersion: v1
kind: Service
metadata:
  name: tomcat-service
spec:
  ports:
  - port: 80   
    protocol: TCP
    targetPort: 8080
  selector:
    app: tomcat
  type: NodePort 
(2)创建pod和service

根据my-tomcat.yaml文件,创建pod和service:

[root@m test]# kubectl apply -f my-tomcat.yaml
deployment.apps/tomcat-deployment created
service/tomcat-service created
[root@m test]# 
(3)查看pod、deployment、service
#(1)查看pod
[root@m test]# kubectl get pod -o wide
NAME                                 READY   STATUS    RESTARTS   AGE    IP               NODE   NOMINATED NODE   READINESS GATES
tomcat-deployment-6b9d6f8547-56bz6   1/1     Running   0          2m9s   192.168.80.214   w2     <none>           <none>
[root@m test]# 

#(2)查看deployment
[root@m test]# kubectl get deployment
NAME                READY   UP-TO-DATE   AVAILABLE   AGE
tomcat-deployment   1/1     1            1           2m24s
[root@m test]# 

#(3)查看service
[root@m test]# kubectl get svc
NAME             TYPE        CLUSTER-IP      EXTERNAL-IP   PORT(S)        AGE
kubernetes       ClusterIP   10.96.0.1       <none>        443/TCP        2d20h
tomcat-service   NodePort    10.101.44.115   <none>        80:31427/TCP   2m32s
[root@m test]# 
(4)删除测试资源

以下删除pod的同时,其对应的tomcat-service也会自动删除:

#(1)删除pod和service
[root@m test]# kubectl delete -f my-tomcat.yaml
deployment.apps "tomcat-deployment" deleted
service "tomcat-service" deleted
[root@m test]# 

# (2)删除yaml配置文件
[root@m test]# rm my-tomcat.yaml
rm:是否删除普通文件 "my-tomcat.yaml"?y
[root@m test]# 

Service-NodePort的方式生产环境不推荐使用,那接下来就基于上述需求,使用Ingress实现访问tomcat的需求


6.2、测试Ingress插件
(1)Ingress简介

一个API对象,用于管理对集群中服务的外部访问,通常是HTTP。

Ingress可以提供负载平衡,SSL终端和基于名称的虚拟主机。

Ingress公开了从群集外部到群集内服务的HTTP和HTTPS路由 。流量路由由Ingress资源上定义的规则控制。

如下是一个简单的示例,其中Ingress将所有流量发送到一个Service:

在这里插入图片描述
可以将Ingress配置为提供服务可外部访问的URL,负载平衡流量,终止SSL / TLS并提供基于名称的虚拟主机。一个入口控制器负责履行入口,通常有一个负载均衡器,虽然它也可以配置您的边缘路由器或额外的前端,以帮助处理流量。

入口不会公开任意端口或协议。将HTTP和HTTPS以外的服务公开到Internet时,通常使用Service.Type = NodePort或 Service.Type = LoadBalancer类型的服务。


(1)创建并编辑mandatory.yaml文件

以Deployment方式创建Pod,该Pod为Ingress Nginx Controller,要想让外界访问,可以通过Service的NodePort或者HostPort方式,这里选择HostPort,比如指定worker01运行

创建并编辑mandatory.yaml文件:

[root@m test]# vi mandatory.yaml

mandatory.yaml内容:

apiVersion: v1
kind: Namespace
metadata:
  name: ingress-nginx
  labels:
    app.kubernetes.io/name: ingress-nginx
    app.kubernetes.io/part-of: ingress-nginx

---

kind: ConfigMap
apiVersion: v1
metadata:
  name: nginx-configuration
  namespace: ingress-nginx
  labels:
    app.kubernetes.io/name: ingress-nginx
    app.kubernetes.io/part-of: ingress-nginx

---
kind: ConfigMap
apiVersion: v1
metadata:
  name: tcp-services
  namespace: ingress-nginx
  labels:
    app.kubernetes.io/name: ingress-nginx
    app.kubernetes.io/part-of: ingress-nginx

---
kind: ConfigMap
apiVersion: v1
metadata:
  name: udp-services
  namespace: ingress-nginx
  labels:
    app.kubernetes.io/name: ingress-nginx
    app.kubernetes.io/part-of: ingress-nginx

---
apiVersion: v1
kind: ServiceAccount
metadata:
  name: nginx-ingress-serviceaccount
  namespace: ingress-nginx
  labels:
    app.kubernetes.io/name: ingress-nginx
    app.kubernetes.io/part-of: ingress-nginx

---
apiVersion: rbac.authorization.k8s.io/v1beta1
kind: ClusterRole
metadata:
  name: nginx-ingress-clusterrole
  labels:
    app.kubernetes.io/name: ingress-nginx
    app.kubernetes.io/part-of: ingress-nginx
rules:
  - apiGroups:
      - ""
    resources:
      - configmaps
      - endpoints
      - nodes
      - pods
      - secrets
    verbs:
      - list
      - watch
  - apiGroups:
      - ""
    resources:
      - nodes
    verbs:
      - get
  - apiGroups:
      - ""
    resources:
      - services
    verbs:
      - get
      - list
      - watch
  - apiGroups:
      - ""
    resources:
      - events
    verbs:
      - create
      - patch
  - apiGroups:
      - "extensions"
      - "networking.k8s.io"
    resources:
      - ingresses
    verbs:
      - get
      - list
      - watch
  - apiGroups:
      - "extensions"
      - "networking.k8s.io"
    resources:
      - ingresses/status
    verbs:
      - update

---
apiVersion: rbac.authorization.k8s.io/v1beta1
kind: Role
metadata:
  name: nginx-ingress-role
  namespace: ingress-nginx
  labels:
    app.kubernetes.io/name: ingress-nginx
    app.kubernetes.io/part-of: ingress-nginx
rules:
  - apiGroups:
      - ""
    resources:
      - configmaps
      - pods
      - secrets
      - namespaces
    verbs:
      - get
  - apiGroups:
      - ""
    resources:
      - configmaps
    resourceNames:
      # Defaults to "<election-id>-<ingress-class>"
      # Here: "<ingress-controller-leader>-<nginx>"
      # This has to be adapted if you change either parameter
      # when launching the nginx-ingress-controller.
      - "ingress-controller-leader-nginx"
    verbs:
      - get
      - update
  - apiGroups:
      - ""
    resources:
      - configmaps
    verbs:
      - create
  - apiGroups:
      - ""
    resources:
      - endpoints
    verbs:
      - get

---
apiVersion: rbac.authorization.k8s.io/v1beta1
kind: RoleBinding
metadata:
  name: nginx-ingress-role-nisa-binding
  namespace: ingress-nginx
  labels:
    app.kubernetes.io/name: ingress-nginx
    app.kubernetes.io/part-of: ingress-nginx
roleRef:
  apiGroup: rbac.authorization.k8s.io
  kind: Role
  name: nginx-ingress-role
subjects:
  - kind: ServiceAccount
    name: nginx-ingress-serviceaccount
    namespace: ingress-nginx

---
apiVersion: rbac.authorization.k8s.io/v1beta1
kind: ClusterRoleBinding
metadata:
  name: nginx-ingress-clusterrole-nisa-binding
  labels:
    app.kubernetes.io/name: ingress-nginx
    app.kubernetes.io/part-of: ingress-nginx
roleRef:
  apiGroup: rbac.authorization.k8s.io
  kind: ClusterRole
  name: nginx-ingress-clusterrole
subjects:
  - kind: ServiceAccount
    name: nginx-ingress-serviceaccount
    namespace: ingress-nginx

---

apiVersion: apps/v1
kind: Deployment
metadata:
  name: nginx-ingress-controller
  namespace: ingress-nginx
  labels:
    app.kubernetes.io/name: ingress-nginx
    app.kubernetes.io/part-of: ingress-nginx
spec:
  replicas: 1
  selector:
    matchLabels:
      app.kubernetes.io/name: ingress-nginx
      app.kubernetes.io/part-of: ingress-nginx
  template:
    metadata:
      labels:
        app.kubernetes.io/name: ingress-nginx
        app.kubernetes.io/part-of: ingress-nginx
      annotations:
        prometheus.io/port: "10254"
        prometheus.io/scrape: "true"
    spec:
      # wait up to five minutes for the drain of connections
      terminationGracePeriodSeconds: 300
      serviceAccountName: nginx-ingress-serviceaccount
      hostNetwork: true
      nodeSelector:
        name: ingress
        kubernetes.io/os: linux
      containers:
        - name: nginx-ingress-controller
          image: quay.io/kubernetes-ingress-controller/nginx-ingress-controller:0.26.1
          args:
            - /nginx-ingress-controller
            - --configmap=$(POD_NAMESPACE)/nginx-configuration
            - --tcp-services-configmap=$(POD_NAMESPACE)/tcp-services
            - --udp-services-configmap=$(POD_NAMESPACE)/udp-services
            - --publish-service=$(POD_NAMESPACE)/ingress-nginx
            - --annotations-prefix=nginx.ingress.kubernetes.io
          securityContext:
            allowPrivilegeEscalation: true
            capabilities:
              drop:
                - ALL
              add:
                - NET_BIND_SERVICE
            # www-data -> 33
            runAsUser: 33
          env:
            - name: POD_NAME
              valueFrom:
                fieldRef:
                  fieldPath: metadata.name
            - name: POD_NAMESPACE
              valueFrom:
                fieldRef:
                  fieldPath: metadata.namespace
          ports:
            - name: http
              containerPort: 80
            - name: https
              containerPort: 443
          livenessProbe:
            failureThreshold: 3
            httpGet:
              path: /healthz
              port: 10254
              scheme: HTTP
            initialDelaySeconds: 10
            periodSeconds: 10
            successThreshold: 1
            timeoutSeconds: 10
          readinessProbe:
            failureThreshold: 3
            httpGet:
              path: /healthz
              port: 10254
              scheme: HTTP
            periodSeconds: 10
            successThreshold: 1
            timeoutSeconds: 10
          lifecycle:
            preStop:
              exec:
                command:
                  - /wait-shutdown
---

说明: 在上面的mandatory.yaml中,

  • (1)使用HostPort方式运行,需要增加配置(上面已配置)hostNetwork: true
  • (2)搜索nodeSelector,并且要确保w1(worker01)节点上的80和443端口没有被占用。
  • (3)需要注意,这里镜像拉取需要较长的时间。

(2)给worker01节点打lable

在master节点,给worker01节点打lable,确保nginx-controller运行到w1节点上:

[root@m test]# kubectl label node w1 name=ingress
node/w1 labeled
[root@m test]# 

(3)应用mandatory.yaml
[root@m test]# kubectl apply -f mandatory.yaml 
namespace/ingress-nginx created
configmap/nginx-configuration created
configmap/tcp-services created
configmap/udp-services created
serviceaccount/nginx-ingress-serviceaccount created
clusterrole.rbac.authorization.k8s.io/nginx-ingress-clusterrole created
role.rbac.authorization.k8s.io/nginx-ingress-role created
rolebinding.rbac.authorization.k8s.io/nginx-ingress-role-nisa-binding created
clusterrolebinding.rbac.authorization.k8s.io/nginx-ingress-clusterrole-nisa-binding created
deployment.apps/nginx-ingress-controller created
[root@m test]# 

(4)查看所有资源/pod

说明: 等待全部资源创建完成,需要等待时间很长。

# (1)查看指定命名空间下的pod(确实分配到了worker01节点)
[root@m test]# kubectl get pod -o wide -n ingress-nginx
NAME                                        READY   STATUS    RESTARTS   AGE   IP                NODE   NOMINATED NODE   READINESS GATES
nginx-ingress-controller-7c66dcdd6c-nttzp   1/1     Running   0          37m   192.168.116.171   w1     <none>           <none>
[root@m test]# 

# (2)查看所有资源或对象
[root@m test]# kubectl get all -n ingress-nginx
NAME                                            READY   STATUS    RESTARTS   AGE
pod/nginx-ingress-controller-7c66dcdd6c-nttzp   1/1     Running   0          36m

NAME                                       READY   UP-TO-DATE   AVAILABLE   AGE
deployment.apps/nginx-ingress-controller   1/1     1            1           36m

NAME                                                  DESIRED   CURRENT   READY   AGE
replicaset.apps/nginx-ingress-controller-7c66dcdd6c   1         1         1       36m
[root@m test]# 

(5)查看worker01节点的80和443端口

在worker01节点,查看80和443端口使用情况(可看到nginx占用):

[root@w1 ~]# lsof -i tcp:80

[root@w1 ~]# lsof -i tcp:443

(6)创建并编辑tomcat.yaml
① 创建并编辑tomcat.yaml
[root@m test]# vi tomcat.yaml

内容:

apiVersion: apps/v1
kind: Deployment
metadata:
  name: tomcat-deployment
  labels:
    app: tomcat
spec:
  replicas: 1
  selector:
    matchLabels:
      app: tomcat
  template:
    metadata:
      labels:
        app: tomcat
    spec:
      containers:
      - name: tomcat
        image: tomcat
        ports:
        - containerPort: 8080
---
apiVersion: v1
kind: Service
metadata:
  name: tomcat-service
spec:
  ports:
  - port: 80   
    protocol: TCP
    targetPort: 8080
  selector:
    app: tomcat
② 应用tomcat.yaml(创建tomcat的pod、service)
[root@m test]# kubectl apply -f tomcat.yaml
deployment.apps/tomcat-deployment created
service/tomcat-service created
[root@m test]#
③ 查看pod和service
#(1)查看pod
[root@m test]# kubectl get pod -o wide
NAME                                 READY   STATUS    RESTARTS   AGE   IP               NODE   NOMINATED NODE   READINESS GATES
tomcat-deployment-6b9d6f8547-4d4fx   1/1     Running   0          80s   192.168.80.215   w2     <none>           <none>
[root@m test]# 

#(2)查看service
[root@m test]# kubectl get svc
NAME             TYPE        CLUSTER-IP       EXTERNAL-IP   PORT(S)   AGE
kubernetes       ClusterIP   10.96.0.1        <none>        443/TCP   2d21h
tomcat-service   ClusterIP   10.100.157.237   <none>        80/TCP    87s
[root@m test]# 

#(3)查看tomcat-service详情(主要看其Endpoints属性)
[root@m test]# kubectl describe svc tomcat-service
Name:              tomcat-service
Namespace:         default
Labels:            <none>
Annotations:       <none>
Selector:          app=tomcat
Type:              ClusterIP
IP Families:       <none>
IP:                10.100.157.237
IPs:               <none>
Port:              <unset>  80/TCP
TargetPort:        8080/TCP
Endpoints:         192.168.80.215:8080
Session Affinity:  None
Events:            <none>
[root@m test]# 

(7)创建Ingress,并定义转发规则
① 创建并编辑nginx-ingress.yaml
[root@m test]# vi nginx-ingress.yaml

内容:

#ingress
apiVersion: extensions/v1beta1
kind: Ingress
metadata:
  name: nginx-ingress
spec:
  rules:
  - host: tomcat.jack.com
    http:
      paths:
      - path: /
        backend:
          serviceName: tomcat-service
          servicePort: 80
② 应用nginx-ingress.yaml(创建ingress)
[root@m test]# kubectl apply -f nginx-ingress.yaml
ingress.extensions/nginx-ingress created
[root@m test]# 
③ 查看ingress
#(1)查看ingress
[root@m test]# kubectl get ingress
NAME            HOSTS             ADDRESS   PORTS   AGE
nginx-ingress   tomcat.jack.com             80      27s
[root@m test]# 

#(2) 查看ingress详情
[root@m test]# kubectl describe ingress nginx-ingress
Name:             nginx-ingress
Namespace:        default
Address:          
Default backend:  default-http-backend:80 (<error: endpoints "default-http-backend" not found>)
Rules:
  Host             Path  Backends
  ----             ----  --------
  tomcat.jack.com  
                   /   tomcat-service:80 (192.168.80.215:8080)
Annotations:       <none>
Events:
  Type    Reason  Age   From                      Message
  ----    ------  ----  ----                      -------
  Normal  CREATE  117s  nginx-ingress-controller  Ingress default/nginx-ingress
[root@m test]# 

(8)通过域名访问
① 修改hosts文件,配置域名解析

修改windows系统的hosts文件(C:\Windows\System32\drivers\etc\hosts),添加dns解析:
在这里插入图片描述

注: 其中,192.168.116.171为worker01节点IP,其他IP不可以,因为我们在创建时就指定了创建在worker01节点。


②浏览器访问(通过ingress配置的域名访问)

访问URL:http://tomcat.jack.com

在这里插入图片描述


(9)Ingress总结

总结:如果以后想要使用Ingress网络,其实只要定义ingress,service和pod即可,前提是要保证nginx ingress controller已经配置好了。


(10)删除测试资源
#(1)删除pod和service等资源
[root@m test]# kubectl delete -f nginx-ingress.yaml
[root@m test]# kubectl delete -f tomcat.yaml
[root@m test]# kubectl delete -f mandatory.yaml

#(2)删除yaml配置文件
[root@m test]# rm nginx-ingress.yaml
[root@m test]# rm tomcat.yaml
[root@m test]# rm mandatory.yaml

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