一、系统环境
系统 centos 7.6
主机 4台 （1管理节点+3工作节点）
docker版本 19.03.13
禁用防火墙
开启以下配置：
cat >> /etc/sysctl.conf << EOF
net.bridge.bridge-nf-call-ip6tables = 1
net.bridge.bridge-nf-call-iptables = 1
net.ipv4.ip_forward = 1
EOF
sysctl -p
二、集群部署
1）选一台主机为master作为管理节点 在master创建Swarm（要保存初始化后token，因为在节点加入时要使用token作为通讯的密钥）
[root@v7-01 ~]# docker swarm init --advertise-addr 172.16.2.22
2）添加节点到swarm集群中
在其他工作节点上执行此操作（本列用了3台工作节点）
docker swarm join --token SWMTKN-1-3ta7uc5whuhjyvy08uvxn1mtcy07bow67c05cyr0ayi7wzzdio-3rghhvhjuj3l1lnsge14v0mx8 172.16.2.22:2377
在master上查看集群节点的状态
docker node ls
三、在Swarm中部署服务
docker service create --replicas 4 -p 9999:80 --name nginx nginx
查看nginx分布得节点及副本数
docker service ps nginx
docker service ls
查看运行的服务分布在哪些节点上运行：
docker service ls -q | xargs docker service ps | grep -i running
四.服务扩容
docker service scale nginx=5
更新service副本数：
docker service update --replicas 3 nginx
五.部署多服务集群
docker-compose.yml 为提前编排好的配置文件
命令格式：
docker stack deploy -c <docker-compose.yml> <service_name>
docker stack deploy -c docker-compose.yml nginx-demo
六.Swarm持久化共享存储
- 选择一台主机安装NFS服务
yum -y install nfs-utils rpcbind
mkdir /opt/nfs_share
vim /etc/exports
/opt/nfs_share 192.168.205.0/24(rw,no_root_squash,sync)
systemctl start rpcbind
systemctl start nfs
systemctl enable nfs
- swarm所有节点安装nfs-utils
yum -y install nfs-utils
systemctl start nfs
systemctl enable nfs
- 持久化创建服务
3.1 命令行创建（参考的官网命令）
docker-sewram-volume
$ docker service create \
-p 80:80
--mount 'type=volume,src=nginxhtml,dst=/usr/share/nginx/html,volume-nocopy=true,volume-driver=local,volume-opt=type=nfs,volume-opt=device=192.168.205.135:/opt/nfs_share,"volume-opt=o=addr=192.168.205.135,vers=4,soft,timeo=180,bg,tcp,rw"'
--name nginx-demo \
nginx:latest
3.2 docker-compose.yml文件编排
version: '3.8'
services:
nginx:
image: nginx:latest
deploy:
mode: replicated
replicas: 3
restart_policy:
condition: on-failure
ports:
- "88:80"
networks:
ng_vol:
volumes:
- "nginxhtml:/usr/share/nginx/html"
volumes:
nginxhtml:
driver: local
driver_opts:
type: "nfs"
o: "addr=192.168.205.135,rw"
device: ":/opt/nfs_share"
networks:
ng_vol:
driver: overlay
部署服务
docker stack deploy -c docker-compose.yml nginx-demo
查看服务运行的节点分布
[root@swarm-master _data]# docker service ls | grep nginx-demo | awk '{print $1}' | xargs docker service ps | grep -i running
kkecr966hg1d nginx-demo_nginx.1 nginx:latest swarm-master Running Running 16 minutes ago
gli71ut5nru1 nginx-demo_nginx.2 nginx:latest swarm-master Running Running 15 minutes ago
ldd5r3csu7lp nginx-demo_nginx.3 nginx:latest swarm-node1 Running Running 16 minutes ago查看NFS共享目录及挂载卷
# NFS共享目录
[root@swarm-master nfs_share]# ls
123 50x.html index.html
# work节点挂载卷目录（由于服务运行节点有2个都被分配到主节点上所以node2节点暂时没数据）
[root@swarm-node1 _data]# ls
123 50x.html index.html
# 现在我们把运行容器任务更新到6个看看
[root@swarm-master _data]# docker service update --replicas 6 nginx-demo_nginx
nginx-demo_nginx
overall progress: 6 out of 6 tasks
1/6: running [==================================================>]
2/6: running [==================================================>]
3/6: running [==================================================>]
4/6: running [==================================================>]
5/6: running [==================================================>]
6/6: running [==================================================>]
verify: Service converged
[root@swarm-master _data]# docker service ls
ID NAME MODE REPLICAS IMAGE PORTS
r7iem955bk5y nginx replicated 3/3 nginx:latest *:9999->80/tcp
wcbf9dpwxwki nginx-demo_nginx replicated 6/6 nginx:latest *:88->80/tcp
[root@swarm-master _data]# docker service ls | grep nginx-demo | awk '{print $1}' | xargs docker service ps | grep -i running
kkecr966hg1d nginx-demo_nginx.1 nginx:latest swarm-master Running Running 50 minutes ago
gli71ut5nru1 nginx-demo_nginx.2 nginx:latest swarm-master Running Running 49 minutes ago
ldd5r3csu7lp nginx-demo_nginx.3 nginx:latest swarm-node1 Running Running 50 minutes ago
fu90vw0u1l0t nginx-demo_nginx.4 nginx:latest swarm-node1 Running Running 8 minutes ago
3vguvr71lsch nginx-demo_nginx.5 nginx:latest swarm-node2 Running Running about a minute ago
cphhmb1dr44z nginx-demo_nginx.6 nginx:latest swarm-node2 Running Running about a minute ago # 可以看到每个节点都有2个容器在运行了，在看下挂载卷已经有数据了
[root@swarm-node2 _data]# ls
123 50x.html index.html
测试访问下 看：
[root@swarm-node2 _data]# curl http://192.168.205.137:88
<!DOCTYPE html>
<html>
<head>
<title>Welcome to nginx!</title>
<style>
html { color-scheme: light dark; }
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>