swarm是docker公司自己的容器集群管理工具，本文介绍了使用docker 1.12 搭建多主机docker swarm集群，分享给大家
准备
- 准备至少两台的centos 7 主机(全新最小安装, 可以使用虚拟机安装)
- 开放端口2377 tcp端口, 7946 4789 tcp udp 端口
- 本文使用192.168.99.101(hostname:centos-node4) 作为swarm manager
- 192.168.99.102(hostname:centos-node5) 作为swarm agent1
安装docker engine 1.12
在每台机器上执行以下命令
# sudo tee /etc/yum.repos.d/docker.repo <<-'EOF' [dockerrepo] name=Docker Repository baseurl=https://yum.dockerproject.org/repo/main/centos/7/ enabled=1 gpgcheck=1 gpgkey=https://yum.dockerproject.org/gpg EOF # sudo yum install docker-engine # sudo systemctl enable docker # sudo systemctl start docker
安装完后查看Docker 版本
[root@centos-node4 ~]# docker version Client: Version: 1.12.0 API version: 1.24 Go version: go1.6.3 Git commit: 8eab29e Built: OS/Arch: linux/amd64 Server: Version: 1.12.0 API version: 1.24 Go version: go1.6.3 Git commit: 8eab29e Built: OS/Arch: linux/amd64
开放端口相关命令
firewall-cmd --zone=public --add-port=2377/tcp --permanent firewall-cmd --zone=public --add-port=7946/tcp --permanent firewall-cmd --zone=public --add-port=7946/udp --permanent firewall-cmd --zone=public --add-port=4789/tcp --permanent firewall-cmd --zone=public --add-port=4789/udp --permanent firewall-cmd --reload
新版docker swarm 命令详情
有关集群的docker命令如下：
- docker swarm：集群管理，子命令有init, join,join-token, leave, update
- docker node：节点管理，子命令有demote, inspect,ls, promote, rm, ps, update
- docker service：服务管理，子命令有create, inspect, ps, ls ,rm , scale, update
- docker stack/deploy：试验特性，用于多应用部署
创建swarm 集群
查看docker swarm 命令说明
[root@centos-node4 ~]# docker swarm -h Flag shorthand -h has been deprecated, please use --help Usage: docker swarm COMMAND Manage Docker Swarm Options: --help Print usage Commands: init Initialize a swarm join Join a swarm as a node and/or manager join-token Manage join tokens update Update the swarm leave Leave a swarm Run 'docker swarm COMMAND --help' for more information on a command.
在swarm manager(centos-node4:192.168.99.101)初始化swarm集群
用--listen-addr指定监听的ip与端口
#命令格式: docker swarm init --listen-addr <MANAGER-IP>:<PORT> [root@centos-node4 ~]# docker swarm init --listen-addr 192.168.99.101:2377 Swarm initialized: current node (a60d5c3ttymvtozr46uvk17q4) is now a manager.
查看结果
[root@centos-node4 ~]# docker node ls ID HOSTNAME MEMBERSHIP STATUS AVAILABILITY MANAGER STATUS a60d5c3ttymvtozr46uvk17q4 * centos-node4 Accepted Ready Active Leader
把swarm-agent1(centos-node5: 192.168.99.102)添加到swarm集群
在swarm-agent1上执行:
#命令格式: docker swarm join <MANAGER-IP>:<PORT> [root@centos-node5 ~]# docker swarm join 192.168.99.101:2377 This node joined a Swarm as a worker.
在swarm manager查看结果
[root@centos-node4 ~]# docker node ls ID HOSTNAME MEMBERSHIP STATUS AVAILABILITY MANAGER STATUS 0ypcw58hjlcvr0xqbtizmau62 centos-node5 Accepted Ready Active a60d5c3ttymvtozr46uvk17q4 * centos-node4 Accepted Ready Active Leader
创建一个overlay 跨主机网络
查看原有网络
[root@centos-node4 ~]# docker network ls NETWORK ID NAME DRIVER SCOPE abec77415f48 bridge bridge local e2fff9d572a6 docker_gwbridge bridge local 166bd71f7d0e host host local 9gr6bfff1rv9 ingress overlay swarm 1d2bfc590294 none null local
可以看到在swarm上默认已有一个名为ingress的overlay 网络,默认在swarm里使用，本文会创建一个新的
创建一个新的overlay网络
[root@centos-node4 ~]# docker network create --driver overlay docker-net aoqs3p835s5glx69hi46ou2dw [root@centos-node4 ~]# docker network ls NETWORK ID NAME DRIVER SCOPE abec77415f48 bridge bridge local aoqs3p835s5g docker-net overlay swarm e2fff9d572a6 docker_gwbridge bridge local 166bd71f7d0e host host local 9gr6bfff1rv9 ingress overlay swarm 1d2bfc590294 none null local
新的网络(docker-net)已创建
在新的跨主机overlay 网络(docker-net)上创建应用
部署
用alpine镜像在docker-net网络上启动两个实例, 并编排为一组服务
[root@centos-node4 ~]# docker service create --replicas 2 --name helloworld --network=docker-net alpine ping docker.com 5lgdq3ihiez0o7h2uegu4fgd3
查看部署结果
[root@centos-node4 ~]# docker service ls ID NAME REPLICAS IMAGE COMMAND 5lgdq3ihiez0 helloworld 0/2 alpine ping docker.com [root@centos-node4 ~]# docker service tasks helloworld ID NAME SERVICE IMAGE LAST STATE DESIRED STATE NODE eul3bus45qz3b555wekotdmo5 helloworld.1 helloworld alpine Running 14 seconds Running centos-node5 55uhq6xxcv53xlkqv2f0be9b9 helloworld.2 helloworld alpine Running 14 seconds Running centos-node4
可以看到两个实例分别运行在两个节点上
测试两个主机的网络是否能互通
分别查看两个实例的名称
# 在swarm-manager 上执行 [root@centos-node4 ~]# docker ps -a CONTAINER ID IMAGE COMMAND CREATED STATUS PORTS NAMES f4a197abdb0b alpine:latest "ping docker.com" 42 minutes ago Up 42 minutes helloworld.2.55uhq6xxcv53xlkqv2f0be9b9 # 在swarm-agnet1 上执行 [root@centos-node5 ~]# docker ps -a CONTAINER ID IMAGE COMMAND CREATED STATUS PORTS NAMES 39cc35cd54b5 alpine:latest "ping docker.com" 50 seconds ago Up 49 seconds helloworld.1.eul3bus45qz3b555wekotdmo5
在swarm-manager 上测试
[root@centos-node4 ~]# docker exec -ti helloworld.2.55uhq6xxcv53xlkqv2f0be9b9 sh / # ping helloworld.1.eul3bus45qz3b555wekotdmo5 PING helloworld.1.eul3bus45qz3b555wekotdmo5 (10.0.9.3): 56 data bytes 64 bytes from 10.0.9.3: seq=0 ttl=64 time=0.514 ms 64 bytes from 10.0.9.3: seq=1 ttl=64 time=0.508 ms 64 bytes from 10.0.9.3: seq=2 ttl=64 time=0.381 ms 64 bytes from 10.0.9.3: seq=3 ttl=64 time=0.408 ms ^C --- helloworld.1.eul3bus45qz3b555wekotdmo5 ping statistics --- 4 packets transmitted, 4 packets received, 0% packet loss round-trip min/avg/max = 0.381/0.452/0.514 ms
在swarm-agent1 上测试
[root@centos-node5 ~]# docker ps -a CONTAINER ID IMAGE COMMAND CREATED STATUS PORTS NAMES 39cc35cd54b5 alpine:latest "ping docker.com" 50 seconds ago Up 49 seconds helloworld.1.eul3bus45qz3b555wekotdmo5 [root@centos-node5 ~]# docker exec -ti helloworld.1.eul3bus45qz3b555wekotdmo5 sh / # ping helloworld.2.55uhq6xxcv53xlkqv2f0be9b9 PING helloworld.2.55uhq6xxcv53xlkqv2f0be9b9 (10.0.9.4): 56 data bytes 64 bytes from 10.0.9.4: seq=0 ttl=64 time=0.892 ms 64 bytes from 10.0.9.4: seq=1 ttl=64 time=0.463 ms 64 bytes from 10.0.9.4: seq=2 ttl=64 time=0.462 ms 64 bytes from 10.0.9.4: seq=3 ttl=64 time=0.478 ms 64 bytes from 10.0.9.4: seq=4 ttl=64 time=0.468 ms 64 bytes from 10.0.9.4: seq=5 ttl=64 time=0.459 ms ^C --- helloworld.2.55uhq6xxcv53xlkqv2f0be9b9 ping statistics --- 6 packets transmitted, 6 packets received, 0% packet loss round-trip min/avg/max = 0.459/0.537/0.892 ms
现在新版的docker swarm 管理非常简单, 可以快速的搭建起一个跨主机的集群并部署应用
dokcer swarm自带的负载均衡
创建一组服务
复制代码 代码如下:
docker service create --replicas 2 --name whoami -p 8080:80 daocloud.io/nginx:alpine
访问服务(可以多执行几次)
# 访问地址格式: swarm-manager.ip + (-p映射的端口) curl -v 192.168.99.101:8080
然后用docker logs 查看容器中nginx的访问日志, 可以现两个容器都有访问记录
以上就是本文的全部内容，希望对大家的学习有所帮助，也希望大家多多支持。
