(1). Deployment
- Deployment部署的应用是无状态的.
- Pod都是一样的.
- 启动没有顺序要求.
- 不需要考虑在哪个Node节点运行.
- 可以随意的伸缩和扩展.
(2). StatefulSet
- StatefulSet部署的应用是有状态的.
- 它要求每个Pod是独立的,并且要保证Pod启动顺序(比如:数据库有master和slave,要先启动master才能启动slave).
- 每个Pod有唯一的网络标识符.
- 需要利用无头Service生成唯一标识(实际就是设置:ClusterIP:none).
- StatefulSet会为每一个应用生成一个domain,生成规则(主机名称.service名称.namespace.svc.cluster.local).
(3). 部署StatefulSet
cat pod-statefulset.yaml
apiVersion: v1
kind: Service
metadata:
name: nginx
labels:
app: nginx
spec:
ports:
- port: 80
name: web
clusterIP: None
selector:
app: nginx
---
apiVersion: apps/v1
kind: StatefulSet
metadata:
name: nginx-statefulset
spec:
serviceName: nginx
replicas: 3
selector:
matchLabels:
app: nginx
template:
metadata:
labels:
app: nginx
spec:
containers:
- name: myapp
image: nginx:latest
ports:
- containerPort: 80
(4). 应用配置
[root@master ~]# kubectl apply -f pod-statefulset.yaml
service/nginx created
statefulset.apps/nginx-statefulset created
(5). 查看pod和service信息
# 查看pod和service信息
# statefulset是身份(即:唯一标识的)
# 每个pod都会有一个唯一的主机名称,并会生成唯一的域名.
# 唯一域名生成规则:
# 主机名称.service名称.namespace.svc.cluster.local
# nginx-statefulset-0.nginx.default.svc.cluster.local
[root@master ~]# kubectl get pods,svc
NAME READY STATUS RESTARTS AGE
pod/hello-world-5f8d77c9f7-589kd 1/1 Running 7 2d
pod/hello-world-5f8d77c9f7-hg5fx 1/1 Running 8 2d
pod/hello-world-5f8d77c9f7-sndnh 1/1 Running 1 149m
pod/nginx-statefulset-0 1/1 Running 1 73m
pod/nginx-statefulset-1 1/1 Running 0 67m
pod/nginx-statefulset-2 1/1 Running 0 45m
NAME TYPE CLUSTER-IP EXTERNAL-IP PORT(S) AGE
service/hello-world NodePort 10.1.232.6 <none> 9090:31355/TCP 3d2h
service/kubernetes ClusterIP 10.1.0.1 <none> 443/TCP 6d3h
service/nginx ClusterIP None <none> 80/TCP 73m
(6). 测试访问域名
# 进入某个容器内部
[root@master ~]# kubectl exec -it hello-world-5f8d77c9f7-589kd /bin/bash
# 测试domain
# [root@hello-world-5f8d77c9f7-589kd /]# ping nginx-statefulset-0.nginx
[root@hello-world-5f8d77c9f7-589kd /]# ping nginx-statefulset-0.nginx.default.svc.cluster.local
PING nginx-statefulset-0.nginx.default.svc.cluster.local (10.244.1.64) 56(84) bytes of data.
64 bytes from nginx-statefulset-0.nginx.default.svc.cluster.local (10.244.1.64): icmp_seq=3 ttl=62 time=0.430 ms
# [root@hello-world-5f8d77c9f7-589kd /]# ping nginx-statefulset-1.nginx
[root@hello-world-5f8d77c9f7-589kd /]# ping nginx-statefulset-1.nginx.default.svc.cluster.local
PING nginx-statefulset-1.nginx.default.svc.cluster.local (10.244.2.69) 56(84) bytes of data.
64 bytes from nginx-statefulset-1.nginx.default.svc.cluster.local (10.244.2.69): icmp_seq=1 ttl=64 time=0.148 ms
# [root@hello-world-5f8d77c9f7-589kd /]# ping nginx-statefulset-2.nginx
[root@hello-world-5f8d77c9f7-589kd /]# ping nginx-statefulset-2.nginx.default.svc.cluster.local
PING nginx-statefulset-2.nginx.default.svc.cluster.local (10.244.2.72) 56(84) bytes of data.
64 bytes from nginx-statefulset-2.nginx.default.svc.cluster.local (10.244.2.72): icmp_seq=1 ttl=64 time=0.350 ms
