一.容器外部訪問容器內部服務
1.使用hostNetwork參數（容器內部服務與宿主機同一網段）
特點:當Pod調度到哪個節點就使用哪個節點的IP地址，客戶端使用IP地址訪問容器里面的服務。一個node只能啟動一個pod端口，端口不能沖突。
[root@k8s01 yaml]# cat end-nginx.yaml
apiVersion: v1
kind: Pod
metadata:
name: nginx1
labels:
app: web
spec:
hostNetwork:
true
containers:
- name: ng-web
image: nginx:latest
imagePullPolicy: Never
|
[root@k8s01 yaml]# kubectl apply -f end-nginx.yaml
pod/nginx1 created
[root@k8s01 yaml]# kubectl get pods -o wide
NAME READY STATUS RESTARTS AGE IP NODE NOMINATED NODE READINESS GATES
nginx1 1/1 Running 0 72s 192.168.54.129 k8s02 <none> <none>
HTTP/1.1 200 OK
Server: nginx/1.17.5
Date: Wed, 27 Nov 2019 07:52:02 GMT
Content-Type: text/html
Content-Length: 612
Last-Modified: Tue, 22 Oct 2019 14:30:00 GMT
Connection: keep-alive
ETag: "5daf1268-264"
Accept-Ranges: bytes
[root@k8s01 yaml]#
2.使用hostPort參數 （將容器內端口暴露出來）
特點：Pod調度到哪個節點就用哪個節點的IP址訪問， 端口可以隨機指定。生產環境pod必須與宿機綁定才可使用。
[root@k8s01 yaml]# cat end-nginx2.yaml
apiVersion: v1
kind: Pod
metadata:
name: nginx2
labels:
app: web
spec:
containers:
- name: ng-web2
image: nginx:latest
imagePullPolicy: Never
ports:
- name: http
containerPort: 80 --容器端口
hostPort: 80 --暴露端口
protocol: TCP
|
[root@k8s01 yaml]# kubectl apply -f end-nginx2.yaml
pod/nginx2 created
[root@k8s01 yaml]# kubectl get pods -o wide
NAME READY STATUS RESTARTS AGE IP NODE NOMINATED NODE READINESS GATES
nginx2 1/1 Running 0 4m31s 10.244.1.67 k8s02 <none> <none>
HTTP/1.1 200 OK
Server: nginx/1.17.5
Date: Wed, 27 Nov 2019 08:15:24 GMT
Content-Type: text/html
Content-Length: 612
Last-Modified: Tue, 22 Oct 2019 14:30:00 GMT
Connection: keep-alive
ETag: "5daf1268-264"
Accept-Ranges: bytes
3.使用NodePort參數
特 點：使用node節點的IP加端口可以訪問Pod服務，master節點IP不可以訪問。端口范圍30000-32767。
[root@k8s01 yaml]# cat end-nginx3.yaml
apiVersion: v1
kind: Pod
metadata:
name: nginx3
labels:
app: web
spec:
containers:
- name: ng-web3
image: nginx:latest
imagePullPolicy: Never
ports:
- containerPort: 80
---
kind: Service
apiVersion: v1
metadata:
name: ng-service
spec:
type
: NodePort
ports:
- name: http
port: 80
nodePort: 31000
selector: --后端Pod標簽
app: web
|
[root@k8s01 yaml]# kubectl apply -f end-nginx3.yaml
pod/nginx3 created
service/ng-service created
[root@k8s01 yaml]# kubectl get pods -o wide
NAME READY STATUS RESTARTS AGE IP NODE NOMINATED NODE READINESS GATES
nginx3 1/1 Running 0 63s 10.244.1.77 k8s02 <none> <none>
[root@k8s01 yaml]# kubectl get svc -o wide
NAME TYPE CLUSTER-IP EXTERNAL-IP PORT(S) AGE SELECTOR
ng-service NodePort 10.102.52.148 <none> 80:31000/TCP 66s app=web
HTTP/1.1 200 OK
Server: nginx/1.17.5
Date: Wed, 27 Nov 2019 08:47:33 GMT
Content-Type: text/html
Content-Length: 612
Last-Modified: Tue, 22 Oct 2019 14:30:00 GMT
Connection: keep-alive
ETag: "5daf1268-264"
Accept-Ranges: bytes
4.使用 LoadBalancer參數
特點：必須使用雲服務商提供一個VIP地址，只能node節點的IP地址可以訪問，master地址不能訪問。
[root@k8s01 yaml]# cat end-nginx4.yaml
apiVersion: v1
kind: Pod
metadata:
name: nginx4
labels:
app: web
spec:
containers:
- name: ng-web4
image: nginx:latest
imagePullPolicy: Never
ports:
- containerPort: 80
---
kind: Service
apiVersion: v1
metadata:
name: ng-lb
spec:
type
: LoadBalancer
ports:
- name: http
port: 80
selector:
app: web
status: --如果有vip就要寫，沒有就不用寫。
loadBalancer:
ingress:
- ip: 192.168.54.131
|
[root@k8s01 yaml]# kubectl apply -f end-nginx4.yaml
pod/nginx4 created
service/ng-lb created
[root@k8s01 yaml]# kubectl get pods -o wide
NAME READY STATUS RESTARTS AGE IP NODE NOMINATED NODE READINESS GATES
nginx4 1/1 Running 0 4m6s 10.244.1.80 k8s02 <none> <none>
[root@k8s01 yaml]# kubectl get svc -o wide
NAME TYPE CLUSTER-IP EXTERNAL-IP PORT(S) AGE SELECTOR
ng-lb LoadBalancer 10.99.49.195 <pending> 80:30183/TCP 4m10s app=web --沒有VIP地址
HTTP/1.1 200 OK
Server: nginx/1.17.5
Date: Wed, 27 Nov 2019 09:11:01 GMT
Content-Type: text/html
Content-Length: 612
Last-Modified: Tue, 22 Oct 2019 14:30:00 GMT
Connection: keep-alive
ETag: "5daf1268-264"
Accept-Ranges: bytes
二.容器內部服務訪問外部服務
1.使用 hostNetwork參數（Pod與宿主機IP在同一網段）
[root@k8s01 yaml]# cat mysql.yaml
apiVersion: v1
kind: Pod
metadata:
name: nginx5
labels:
app: mysql
spec:
hostNetwork:
true
containers:
- name: db-mysql
image: nginx:latest
imagePullPolicy: Never
|
[root@k8s01 yaml]# kubectl apply -f mysql.yaml
pod/nginx5 created
[root@k8s01 yaml]# kubectl exec -it nginx5 /bin/bash
root@nginx5:/# apt-get update --更新創建
root@nginx5:/# apt-get install mysql* --安裝mysql包
root@nginx5:/# mysql -h 192.168.54.130 -u repl -p123456 --登陸mysql數據庫
Welcome to the MariaDB monitor. Commands end with ; or \g.
Your MySQL connection id is 16
Server version: 5.7.27 MySQL Community Server (GPL)
Copyright (c) 2000, 2018, Oracle, MariaDB Corporation Ab and others.
Type 'help;' or '\h' for help. Type '\c' to clear the current input statement.
MySQL [(none)]> show databases;
+--------------------+
| Database |
+--------------------+
| information_schema |
| mysql |
| performance_schema |
| sys |
| wuhan |
+--------------------+
5 rows in set (0.001 sec)
MySQL [(none)]>
2.使用endpoints組件
[root@k8s01 yaml]# cat endpoint.yaml
apiVersion: v1
kind: Endpoints
metadata:
name: mysql-
test
namespace: default
subsets:
- addresses:
- ip: 192.168.54.130 --指定宿機主mysql服務器
ports:
- port: 3306 --指定端口
---
apiVersion: v1
kind: Service
metadata:
name: mysql-
test
--service后端指向endpoints地址
labels:
app: abc
spec:
ports:
- port: 3306
---
apiVersion: v1
kind: Pod
metadata:
name: nginx6 --啟動一個容器，測試連接mysql
labels:
app: db
spec:
containers:
- name: mysql-
test
image: nginx:latest
imagePullPolicy: Never
|
endpoints/mysql-test created
service/mysql-test created
pod/nginx6 created
[root@k8s01 yaml]# kubectl get pods -o wide
NAME READY STATUS RESTARTS AGE IP NODE NOMINATED NODE READINESS GATES
nginx6 1/1 Running 0 12s 10.244.1.85 k8s02 <none> <none>
[root@k8s01 yaml]# kubectl get svc -o wide
NAME TYPE CLUSTER-IP EXTERNAL-IP PORT(S) AGE SELECTOR
mysql-test ClusterIP 10.98.57.89 <none> 3306/TCP 16s <none>
[root@k8s01 yaml]# kubectl get endpoints -o wide
NAME ENDPOINTS AGE
mysql-test 192.168.54.130:3306 21s
[root@k8s01 yaml]# kubectl exec -it nginx6 /bin/bash
root@ nginx6:/# mysql -h mysql-test -u repl -p123456 --使用endpoints名字（映射到service，service映射到192.168.54.130）
Welcome to the MariaDB monitor. Commands end with ; or \g.
Your MySQL connection id is 19
Server version: 5.7.27 MySQL Community Server (GPL)
+--------------------+
| Database |
+--------------------+
| information_schema |
| mysql |
| performance_schema |
| sys |
| wuhan |
+--------------------+
5 rows in set (0.001 sec)
MySQL [(none)]>