kubenetes k8s label控制pod位置及創建SVC、外網訪問

一、k8s label控制pod位置

1 默認情況下，Scheduler會將pod調度到所有可用的node。不過有些情況我們希望將pod部署到指定的node, 使用label可以實現這個功能。

kubectl get node --show-lables

2 查看label是否生效

[root@k8s-master01 ~]# kubectl get node --show-labels

NAME STATUS ROLES AGE VERSION LABELS

k8s-master01 Ready master 41d v1.15.1 beta.kubernetes.io/arch=amd64,beta.kubernetes.io/os=linux,kubernetes.io/arch=amd64,kubernetes.io/hostname=k8s-master01,kubernetes.io/os=linux,node-role.kubernetes.io/master=

k8s-node01 Ready <none> 41d v1.15.1 beta.kubernetes.io/arch=amd64,beta.kubernetes.io/os=linux,kubernetes.io/arch=amd64,kubernetes.io/hostname=k8s-node01,kubernetes.io/os=linux,onsite=kxc

k8s-node02 Ready <none> 41d v1.15.1 beta.kubernetes.io/arch=amd64,beta.kubernetes.io/os=linux,kubernetes.io/arch=amd64,kubernetes.io/hostname=k8s-node02,kubernetes.io/os=linux

3 編輯yml文件

[root@k8s-master01 ~]# vi nginx.yaml

apiVersion: extensions/v1beta1

kind: Deployment

metadata:

name: nginx-deployment0814

spec:

replicas: 3

template:

metadata:

labels:

app: web-server

spec:

containers:

- name: nginx

image: nginx:1.7.9

nodeSelector:

onsite: kxc

4 執行創建pod

[root@k8s-master01 ~]# kubectl apply -f nginx.yaml

deployment.extensions/nginx-deployment0814 created

5 查看是否pod是否都部署在node01上面

[root@k8s-master01 ~]# kubectl get pod -o wide

NAME READY STATUS RESTARTS AGE IP NODE NOMINATED NODE READINESS GATES

http-displayment-6dbfc78c44-djjqg 1/1 Running 9 35d 10.255.1.64 k8s-node01 <none> <none>

http-displayment-6dbfc78c44-qzkdz 1/1 Running 9 35d 10.255.1.65 k8s-node01 <none> <none>

httpd-deployment-5dbd9b4457-4vfnm 1/1 Running 8 30d 10.255.1.69 k8s-node01 <none> <none>

httpd-deployment-5dbd9b4457-c4gf4 1/1 Running 8 30d 10.255.2.43 k8s-node02 <none> <none>

httpd-deployment-5dbd9b4457-ptzkl 1/1 Running 8 30d 10.255.1.68 k8s-node01 <none> <none>

httpd0814-5f4d9c656d-c7p5z 1/1 Running 0 20m 10.255.2.50 k8s-node02 <none> <none>

httpd0814-5f4d9c656d-vf9rw 1/1 Running 0 22m 10.255.1.71 k8s-node01 <none> <none>

myapp-pod 1/1 Running 68 36d 10.255.1.70 k8s-node01 <none> <none>

myhttpd-deploy-86c586bc96-89pmw 1/1 Running 4 6d7h 10.255.2.45 k8s-node02 <none> <none>

myhttpd-deploy-86c586bc96-cvqtz 1/1 Running 4 6d7h 10.255.2.47 k8s-node02 <none> <none>

myhttpd-deploy-86c586bc96-tttk4 1/1 Running 4 6d7h 10.255.1.66 k8s-node01 <none> <none>

nginx-deployment-557c97577b-kx4cx 1/1 Running 9 35d 10.255.2.46 k8s-node02 <none> <none>

nginx-deployment-557c97577b-q48lf 1/1 Running 9 35d 10.255.1.67 k8s-node01 <none> <none>

nginx-deployment-557c97577b-sl9l6 1/1 Running 9 35d 10.255.2.44 k8s-node02 <none> <none>

nginx-deployment0814-b98dfdc97-26lbf 1/1 Running 0 57s 10.255.1.74 k8s-node01 <none> <none>

nginx-deployment0814-b98dfdc97-44f4p 1/1 Running 0 57s 10.255.1.73 k8s-node01 <none> <none>

nginx-deployment0814-b98dfdc97-pm82h 1/1 Running 0 57s 10.255.1.72 k8s-node01 <none> <none>

6 刪除label

[root@k8s-master01 ~]# kubectl label node k8s-node01 onsite-

node/k8s-node01 labeled

查看label是否消失

[root@k8s-master01 ~]# kubectl get node --show-labels

NAME STATUS ROLES AGE VERSION LABELS

k8s-master01 Ready master 41d v1.15.1 beta.kubernetes.io/arch=amd64,beta.kubernetes.io/os=linux,kubernetes.io/arch=amd64,kubernetes.io/hostname=k8s-master01,kubernetes.io/os=linux,node-role.kubernetes.io/master=

k8s-node01 Ready <none> 41d v1.15.1 beta.kubernetes.io/arch=amd64,beta.kubernetes.io/os=linux,kubernetes.io/arch=amd64,kubernetes.io/hostname=k8s-node01,kubernetes.io/os=linux

k8s-node02 Ready <none> 41d v1.15.1 beta.kubernetes.io/arch=amd64,beta.kubernetes.io/os=linux,kubernetes.io/arch=amd64,kubernetes.io/hostname=k8s-node02,kubernetes.io/os=linux

不過此時pod並不會重新部署，依舊在node01上運行

[root@k8s-master01 ~]# kubectl get pod -o wide

NAME READY STATUS RESTARTS AGE IP NODE NOMINATED NODE READINESS GATES

http-displayment-6dbfc78c44-djjqg 1/1 Running 9 35d 10.255.1.64 k8s-node01 <none> <none>

http-displayment-6dbfc78c44-qzkdz 1/1 Running 9 35d 10.255.1.65 k8s-node01 <none> <none>

httpd-deployment-5dbd9b4457-4vfnm 1/1 Running 8 30d 10.255.1.69 k8s-node01 <none> <none>

httpd-deployment-5dbd9b4457-c4gf4 1/1 Running 8 30d 10.255.2.43 k8s-node02 <none> <none>

httpd-deployment-5dbd9b4457-ptzkl 1/1 Running 8 30d 10.255.1.68 k8s-node01 <none> <none>

httpd0814-5f4d9c656d-c7p5z 1/1 Running 0 28m 10.255.2.50 k8s-node02 <none> <none>

httpd0814-5f4d9c656d-vf9rw 1/1 Running 0 30m 10.255.1.71 k8s-node01 <none> <none>

myapp-pod 1/1 Running 68 36d 10.255.1.70 k8s-node01 <none> <none>

myhttpd-deploy-86c586bc96-89pmw 1/1 Running 4 6d7h 10.255.2.45 k8s-node02 <none> <none>

myhttpd-deploy-86c586bc96-cvqtz 1/1 Running 4 6d7h 10.255.2.47 k8s-node02 <none> <none>

myhttpd-deploy-86c586bc96-tttk4 1/1 Running 4 6d7h 10.255.1.66 k8s-node01 <none> <none>

nginx-deployment-557c97577b-kx4cx 1/1 Running 9 35d 10.255.2.46 k8s-node02 <none> <none>

nginx-deployment-557c97577b-q48lf 1/1 Running 9 35d 10.255.1.67 k8s-node01 <none> <none>

nginx-deployment-557c97577b-sl9l6 1/1 Running 9 35d 10.255.2.44 k8s-node02 <none> <none>

nginx-deployment0814-b98dfdc97-26lbf 1/1 Running 0 9m15s 10.255.1.74 k8s-node01 <none> <none>

nginx-deployment0814-b98dfdc97-44f4p 1/1 Running 0 9m15s 10.255.1.73 k8s-node01 <none> <none>

nginx-deployment0814-b98dfdc97-pm82h 1/1 Running 0 9m15s 10.255.1.72 k8s-node01 <none> <none>

除非在nginx.yml中刪除nodeSelector-設置，然后通過kubectl apply重新部署。

修改如下：

apiVersion: extensions/v1beta1

kind: Deployment

metadata:

name: nginx-deployment0814

spec:

replicas: 3

template:

metadata:

labels:

app: web-server

spec:

containers:

- name: nginx

image: nginx:1.7.9

# nodeSelector:

# onsite: kxc

重新執行

[root@k8s-master01 ~]# kubectl apply -f nginx.yaml

deployment.extensions/nginx-deployment0814 configured

結果看下，有調度到node02節點

[root@k8s-master01 ~]# kubectl get pod -o wide

NAME READY STATUS RESTARTS AGE IP NODE NOMINATED NODE READINESS GATES

http-displayment-6dbfc78c44-djjqg 1/1 Running 9 35d 10.255.1.64 k8s-node01 <none> <none>

http-displayment-6dbfc78c44-qzkdz 1/1 Running 9 35d 10.255.1.65 k8s-node01 <none> <none>

httpd-deployment-5dbd9b4457-4vfnm 1/1 Running 8 30d 10.255.1.69 k8s-node01 <none> <none>

httpd-deployment-5dbd9b4457-c4gf4 1/1 Running 8 30d 10.255.2.43 k8s-node02 <none> <none>

httpd-deployment-5dbd9b4457-ptzkl 1/1 Running 8 30d 10.255.1.68 k8s-node01 <none> <none>

httpd0814-5f4d9c656d-c7p5z 1/1 Running 0 31m 10.255.2.50 k8s-node02 <none> <none>

httpd0814-5f4d9c656d-vf9rw 1/1 Running 0 33m 10.255.1.71 k8s-node01 <none> <none>

myapp-pod 1/1 Running 68 36d 10.255.1.70 k8s-node01 <none> <none>

myhttpd-deploy-86c586bc96-89pmw 1/1 Running 4 6d7h 10.255.2.45 k8s-node02 <none> <none>

myhttpd-deploy-86c586bc96-cvqtz 1/1 Running 4 6d7h 10.255.2.47 k8s-node02 <none> <none>

myhttpd-deploy-86c586bc96-tttk4 1/1 Running 4 6d7h 10.255.1.66 k8s-node01 <none> <none>

nginx-deployment-557c97577b-kx4cx 1/1 Running 9 35d 10.255.2.46 k8s-node02 <none> <none>

nginx-deployment-557c97577b-q48lf 1/1 Running 9 35d 10.255.1.67 k8s-node01 <none> <none>

nginx-deployment-557c97577b-sl9l6 1/1 Running 9 35d 10.255.2.44 k8s-node02 <none> <none>

nginx-deployment0814-557c97577b-4c7rq 1/1 Running 0 27s 10.255.1.75 k8s-node01 <none> <none>

nginx-deployment0814-557c97577b-876l4 1/1 Running 0 25s 10.255.1.76 k8s-node01 <none> <none>

nginx-deployment0814-557c97577b-s7ghh 1/1 Running 0 27s 10.255.2.51 k8s-node02 <none> <none>

二、創建SVC

1 將nginx.yaml修改以下內容

[root@k8s-master01 ~]# cat nginx.yaml

apiVersion: extensions/v1beta1

kind: Deployment

metadata:

name: nginx-deployment0814

spec:

replicas: 3

template:

metadata:

labels:

app: nginx0814-server

spec:

containers:

- name: nginx

image: nginx:1.7.9

# nodeSelector:

# onsite: kxc

2 創建SVC文件nginx-svc.yml

[root@k8s-master01 ~]# cat nginx-svc.yml

apiVersion: v1

kind: Service

metadata:

name: nginx-svc0814

namespace: default

spec:

type: ClusterIP

selector:

app: nginx0814-server

# release: stabel

ports:

- name: nginx-port0814

protocol: TCP

port: 30014

targetPort: 80

3 刪除原來的 nginx-deployment0814，重新部署

[root@k8s-master01 ~]# kubectl delete deployment nginx-deployment0814

deployment.extensions "nginx-deployment0814" deleted

 

[root@k8s-master01 ~]# kubectl apply -f nginx.yaml

deployment.extensions/nginx-deployment0814 created

 

查看pod相關信息

[root@k8s-master01 ~]# kubectl get deployment

NAME READY UP-TO-DATE AVAILABLE AGE

http-displayment 2/2 2 2 36d

httpd-deployment 3/3 3 3 30d

httpd0814 2/2 2 2 12h

myhttpd-deploy 3/3 3 3 6d19h

nginx-deployment 3/3 3 3 35d

nginx-deployment0814 3/3 3 3 5s

[root@k8s-master01 ~]# kubectl get pod -o wide

NAME READY STATUS RESTARTS AGE IP NODE NOMINATED NODE READINESS GATES

http-displayment-6dbfc78c44-djjqg 1/1 Running 10 35d 10.255.1.86 k8s-node01 <none> <none>

http-displayment-6dbfc78c44-qzkdz 1/1 Running 10 36d 10.255.1.85 k8s-node01 <none> <none>

httpd-deployment-5dbd9b4457-4vfnm 1/1 Running 9 30d 10.255.1.81 k8s-node01 <none> <none>

httpd-deployment-5dbd9b4457-c4gf4 1/1 Running 9 30d 10.255.2.53 k8s-node02 <none> <none>

httpd-deployment-5dbd9b4457-ptzkl 1/1 Running 9 30d 10.255.1.82 k8s-node01 <none> <none>

httpd0814-5f4d9c656d-c7p5z 1/1 Running 1 12h 10.255.2.52 k8s-node02 <none> <none>

httpd0814-5f4d9c656d-vf9rw 1/1 Running 1 12h 10.255.1.77 k8s-node01 <none> <none>

myapp-pod 1/1 Running 73 36d 10.255.1.79 k8s-node01 <none> <none>

myhttpd-deploy-86c586bc96-89pmw 1/1 Running 5 6d19h 10.255.2.55 k8s-node02 <none> <none>

myhttpd-deploy-86c586bc96-cvqtz 1/1 Running 5 6d19h 10.255.2.54 k8s-node02 <none> <none>

myhttpd-deploy-86c586bc96-tttk4 1/1 Running 5 6d19h 10.255.1.80 k8s-node01 <none> <none>

nginx-deployment-557c97577b-kx4cx 1/1 Running 10 35d 10.255.2.57 k8s-node02 <none> <none>

nginx-deployment-557c97577b-q48lf 1/1 Running 10 35d 10.255.1.78 k8s-node01 <none> <none>

nginx-deployment-557c97577b-sl9l6 1/1 Running 10 35d 10.255.2.56 k8s-node02 <none> <none>

nginx-deployment0814-59574fff8f-d7pmh 1/1 Running 0 18s 10.255.2.59 k8s-node02 <none> <none>

nginx-deployment0814-59574fff8f-f9d9t 1/1 Running 0 18s 10.255.1.87 k8s-node01 <none> <none>

nginx-deployment0814-59574fff8f-nzs98 1/1 Running 0 18s 10.255.2.60 k8s-node02 <none> <none>

4 創建svc

[root@k8s-master01 ~]# kubectl apply -f nginx-svc.yml

service/nginx-svc0814 created

[root@k8s-master01 ~]# kubectl get svc

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

kubernetes ClusterIP 10.254.0.1 <none> 443/TCP 41d

mydb ClusterIP 10.254.129.95 <none> 80/TCP 36d

myhttpd-deploy ClusterIP 10.254.220.221 <none> 80/TCP 6d17h

myservice ClusterIP 10.254.217.74 <none> 80/TCP 36d

nginx-svc0814 ClusterIP 10.254.160.183 <none> 30014/TCP 9s

5 檢測網絡是否正常訪問，在集群任意節點

[root@k8s-master01 ~]# curl http://10.254.160.183:30014

<!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

三、外網訪問

service ClusterIP只能在集群訪問，當然可以使用外部NAT或者LVS實現外網訪問，k8s自帶的NodePort可以輕易實現外部訪問。

1 修改nginx-svc

[root@k8s-master01 ~]# vi nginx-svc.yml

 

apiVersion: v1

kind: Service

metadata:

name: nginx-svc0814

namespace: default

spec:

type: NodePort

selector:

app: nginx0814-server

# release: stabel

ports:

- name: nginx-port0814

protocol: TCP

port: 30014

targetPort: 80

nodePort: 31014

~

2 重新應用nginx-svc.yml

[root@k8s-master01 ~]# kubectl apply -f nginx-svc.yml

service/nginx-svc0814 configured

[root@k8s-master01 ~]# kubectl get svc

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

kubernetes ClusterIP 10.254.0.1 <none> 443/TCP 41d

mydb ClusterIP 10.254.129.95 <none> 80/TCP 36d

myhttpd-deploy ClusterIP 10.254.220.221 <none> 80/TCP 6d17h

myservice ClusterIP 10.254.217.74 <none> 80/TCP 36d

nginx-svc0814 NodePort 10.254.160.183 <none> 30014:31014/TCP 18m

3 檢驗所有node節點的地址都可以訪問

master01:

[root@k8s-master01 ~]# curl http://192.168.3.91:31014

<!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>

node01：

[root@k8s-master01 ~]# curl http://192.168.3.94:31014

<!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>

node02：

[root@k8s-master01 ~]# curl http://192.168.3.95:31014

<!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>

iptables映射：

[root@k8s-master01 ~]# iptables-save | grep 31014

-A KUBE-NODEPORTS -p tcp -m comment --comment "default/nginx-svc0814:nginx-port0814" -m tcp --dport 31014 -j KUBE-MARK-MASQ

-A KUBE-NODEPORTS -p tcp -m comment --comment "default/nginx-svc0814:nginx-port0814" -m tcp --dport 31014 -j KUBE-SVC-3MFC53WNCMNMNMFD