Docker之swarm v1集群创建

Posted 2020-10-10

tags:

篇首语：本文由小常识网(cha138.com)小编为大家整理，主要介绍了Docker之swarm v1集群创建相关的知识，希望对你有一定的参考价值。

Docker swarm 是docker官方的三大项目之一，提供docker容器集群服务，是docker官方对容器云生态支持的核心方案，Docker Swarm项目开始于2014年，是Docker公司推出的第一个容器集群项目。使用docker swarm可以将多个docker主机封装为一个大型的虚拟docker主机，swarm集群提供给用户管理集群内所有容器的操作接口与使用一台docker主机几乎相同，从而可以快速打造一套容器云服务

Docker Swarmkit项目开始于2016年，是Docker公司推出的第二个容器集群项目，于Docker1.12版本正式发布。虽然也叫Swarm，但是与第一个项目完全不同。该项目直接在Docker Engine上内嵌了集群管理功能，并新增了集群管理的用户接口。

两个容器集群项目可能实现了相同的功能，但其上层接口还是有很大的不同，Docker公司推荐用户使用更适合自己的项目，如果都没有使用过，推荐使用后者。另外，Docker Swarm项目并没有被Docker公司列为不推荐的项目，仍然会继续支持新的Docker Engine的功能。

swarm v1是典型的mater-slave结构，需要通过发现服务来选举出manager，而manager是中心管理节点，而各个节点通过运行agent接受manager的统一管理

swarm v2中，swarm集群会自动通过Raft协议分布式选举出manager节点，因此无需配置额外的发现服务，从而避免了单点瓶颈；且swarm v2内置了DNS负载均衡和对外部负载均衡机制的支持

本实验基于docker swarm v1版本，实验环境如下：

docker-1 192.168.1.193

docker-2 192.168.1.194

docker-3 192.168.1.195

在各个docker主机上安装swarm，启动docker daemon

[email protected]:~# docker pull swarm

[email protected]:~# docker run --rm swarm -v

swarm version 1.2.8 (48d86b1)

[email protected]:~# service docker stop

docker stop/waiting

[email protected]:~# dockerd -H tcp://0.0.0.0:2375 -H unix:///var/run/docker.sock

[email protected]:~# netstat -tunlp|grep docker

tcp6 0 0 :::2375 :::* LISTEN 1698/dockerd

[email protected]:~# docker pull swarm

[email protected]:~# service docker stop

docker stop/waiting

[email protected]:~# dockerd -H tcp://0.0.0.0:2375 -H unix:///var/run/docker.sock

[email protected]:~# docker pull swarm

[email protected]:~# service docker stop

docker stop/waiting

[email protected]:~# dockerd -H tcp://0.0.0.0:2375 -H unix:///var/run/docker.sock

在任意一个节点上使用docker swarm 命令来在docker hub上进行注册（采用docker hub的服务发现后端，但必须要求所有docker主机可以访问外网），且会产生一个token，用来标识和管理集群

[email protected]:~# docker run --rm swarm create

1081dc3745b8dfd45ff863c13d74d96c

在所有要加入swarm集群的docker主机上执行swarm join命令，将各个节点加入swarm集群

[email protected]:~# docker run -d swarm join --addr=192.168.1.193:2375 token://1081dc3745b8dfd45ff863c13d74d96c

fbc0c47268e1e631c4839b41107cac08bd33c9b27380283768efda84ab3ae373

[email protected]:~# docker run -d swarm join --addr=192.168.1.194:2375 token://1081dc3745b8dfd45ff863c13d74d96c

b88ab2e5eb4e787ad56df06fd6f7e879aacbd35b36743d2943002b882cd8865f

[email protected]:~# docker run -d swarm join --addr=192.168.1.195:2375 token://1081dc3745b8dfd45ff863c13d74d96c

1b62af7b1ecf7d428f7dd25df71a0523742cecdb1341eb76560225a77336b12f

因为没有配置manager节点，所以此命令无法使用

[email protected]:~# docker node ls

Error response from daemon: This node is not a swarm manager. Use "docker swarm init" or "docker swarm join" to connect this node to swarm and try again.

查看各个节点的容器情况，可以与后续实验做对比

[email protected]:~# docker ps

CONTAINER ID IMAGE COMMAND CREATED STATUS PORTS NAMES

fbc0c47268e1 swarm "/swarm join --add..." 6 minutes ago Up 6 minutes 2375/tcp competent_benz

[email protected]:~# docker ps -a

CONTAINER ID IMAGE COMMAND CREATED STATUS PORTS NAMES

fbc0c47268e1 swarm "/swarm join --add..." 6 minutes ago Up 6 minutes 2375/tcp competent_benz

[email protected]:~# docker ps

CONTAINER ID IMAGE COMMAND CREATED STATUS PORTS NAMES

b88ab2e5eb4e swarm "/swarm join --add..." 4 minutes ago Up 4 minutes 2375/tcp romantic_poincare

[email protected]:~# docker ps -a

CONTAINER ID IMAGE COMMAND CREATED STATUS PORTS NAMES

b88ab2e5eb4e swarm "/swarm join --add..." 4 minutes ago Up 4 minutes 2375/tcp romantic_poincare

[email protected]:~# docker ps

CONTAINER ID IMAGE COMMAND CREATED STATUS PORTS NAMES

b88ab2e5eb4e swarm "/swarm join --add..." 4 minutes ago Up 4 minutes 2375/tcp romantic_poincare

[email protected]:~# docker ps -a

CONTAINER ID IMAGE COMMAND CREATED STATUS PORTS NAMES

b88ab2e5eb4e swarm "/swarm join --add..." 4 minutes ago Up 4 minutes 2375/tcp romantic_poincare

用swarm manage命令将docker-1节点配置成为管理节点该命令将启用manager服务,且默认监听到2375端口，所有集群的管理都可以通过该服务的接口进行操作，但是manager服务和docker服务

的监听端口相同，而这样做是为了兼容其他基于docker的服务，可以无缝的切换到swarm平台；但有与本次实验采用的是docker容器的方式启用manager服务，本地的2375端口已被docker daemon占用，

所以将manager服务的端口映射到一个空闲的端口12375

[email protected]:~# docker run -d -p 12375:2375 swarm manage token://1081dc3745b8dfd45ff863c13d74d96c

ad81e842302de642ba7bf5514b12ce6ea46070abc68c6e15a4eefc0b8e5dfc57

[email protected]:~# netstat -tunlp |grep docker

tcp6 0 0 :::12375 :::* LISTEN 2191/docker-proxy

tcp6 0 0 :::2375 :::* LISTEN 1698/dockerd

产看docker-1节点运行的容器和所有容器

[email protected]:~# docker ps

CONTAINER ID IMAGE COMMAND CREATED STATUS PORTS NAMES

ad81e842302d swarm "/swarm manage tok..." 4 seconds ago Up 3 seconds 0.0.0.0:12375->2375/tcp hungry_benz

fbc0c47268e1 swarm "/swarm join --add..." 19 minutes ago Up 19 minutes 2375/tcp competent_benz

[email protected]:~# docker ps -a

CONTAINER ID IMAGE COMMAND CREATED STATUS PORTS NAMES

ad81e842302d swarm "/swarm manage tok..." 13 seconds ago Up 12 seconds 0.0.0.0:12375->2375/tcp hungry_benz

fbc0c47268e1 swarm "/swarm join --add..." 19 minutes ago Up 19 minutes 2375/tcp competent_benz

可以再任意节点执行swarm list 命令查看集群的节点列表

[email protected]:~# docker run --rm swarm list token://1081dc3745b8dfd45ff863c13d74d96c

192.168.1.193:2375

192.168.1.195:2375

192.168.1.194:2375

[email protected]:~# docker run --rm swarm list token://1081dc3745b8dfd45ff863c13d74d96c

192.168.1.193:2375

192.168.1.195:2375

192.168.1.194:2375

可以再任意节点可以创建集群容器，如docker-3

[email protected]:~# docker -H 192.168.1.193:12375 run -d centos ping www.baidu.com

41ca94b3da41767ecd87de7d37a3611141dc8b36aad52211b75374b153628312

查看集群所有节点运行的容器

[email protected]:~# docker -H 192.168.1.193:12375 ps

CONTAINER ID IMAGE COMMAND CREATED STATUS PORTS NAMES

41ca94b3da41 centos "ping www.baidu.com" 3 minutes ago Up 3 minutes docker-2/vigilant_bose

查看集群所有节点的容器

[email protected]:~# docker -H 192.168.1.193:12375 ps -a

CONTAINER ID IMAGE COMMAND CREATED STATUS PORTS NAMES

41ca94b3da41 centos "ping www.baidu.com" 3 minutes ago Up 3 minutes docker-2/vigilant_bose

ad81e842302d swarm "/swarm manage tok..." 13 minutes ago Up 13 minutes 192.168.1.193:12375->2375/tcp docker-1/hungry_benz

1b62af7b1ecf swarm "/swarm join --add..." 30 minutes ago Up 30 minutes 2375/tcp docker-3/ecstatic_elion

b88ab2e5eb4e swarm "/swarm join --add..." 30 minutes ago Up 30 minutes 2375/tcp docker-2/romantic_poincare

fbc0c47268e1 swarm "/swarm join --add..." 32 minutes ago Up 32 minutes 2375/tcp docker-1/competent_benz

查看本节点docker-3 正在运行的容器

[email protected]:~# docker ps

CONTAINER ID IMAGE COMMAND CREATED STATUS PORTS NAMES

1b62af7b1ecf swarm "/swarm join --add..." 31 minutes ago Up 31 minutes 2375/tcp ecstatic_elion

查看本节点docker-3 的所有容器

[email protected]:~# docker ps -a

CONTAINER ID IMAGE COMMAND CREATED STATUS PORTS NAMES

1b62af7b1ecf swarm "/swarm join --add..." 31 minutes ago Up 31 minutes 2375/tcp ecstatic_elion

[email protected]:~#

在docker-1主机上分别执行节点和集群的docker info看看，可以对比一下

[email protected]:~# docker info

Containers: 2

Running: 2

Paused: 0

Stopped: 0

Images: 1

Server Version: 17.05.0-ce

Storage Driver: aufs

Root Dir: /var/lib/docker/aufs

Backing Filesystem: extfs

Dirs: 7

Dirperm1 Supported: true

Logging Driver: json-file

Cgroup Driver: cgroupfs

Plugins:

Volume: local

Network: bridge host macvlan null overlay

Swarm: inactive

Runtimes: runc

Default Runtime: runc

Init Binary: docker-init

containerd version: 9048e5e50717ea4497b757314bad98ea3763c145

runc version: 9c2d8d184e5da67c95d601382adf14862e4f2228

init version: 949e6fa

Security Options:

apparmor

Kernel Version: 4.4.0-31-generic

Operating System: Ubuntu 14.04.5 LTS

OSType: linux

Architecture: x86_64

CPUs: 1

Total Memory: 726.7MiB

Name: docker-1

ID: A3OC:Z223:S7IY:6KF6:U2TE:N26E:CEMT:2VEH:5AR6:LVY5:U2KI:52P5

Docker Root Dir: /var/lib/docker

Debug Mode (client): false

Debug Mode (server): false

Registry: https://index.docker.io/v1/

Experimental: false

Insecure Registries:

127.0.0.0/8

Live Restore Enabled: false

WARNING: No swap limit support

[email protected]:~# docker -H 192.168.1.193:12375 info

Containers: 5

Running: 5

Paused: 0

Stopped: 0

Images: 5

Server Version: swarm/1.2.8

Role: primary

Strategy: spread

Filters: health, port, containerslots, dependency, affinity, constraint, whitelist

Nodes: 3

docker-1: 192.168.1.193:2375

└ ID: A3OC:Z223:S7IY:6KF6:U2TE:N26E:CEMT:2VEH:5AR6:LVY5:U2KI:52P5|192.168.1.193:2375

└ Status: Healthy

└ Containers: 2 (2 Running, 0 Paused, 0 Stopped)

└ Reserved CPUs: 0 / 1

└ Reserved Memory: 0 B / 763 MiB

└ Labels: kernelversion=4.4.0-31-generic, operatingsystem=Ubuntu 14.04.5 LTS, ostype=linux, storagedriver=aufs

└ UpdatedAt: 2017-10-15T13:18:50Z

└ ServerVersion: 17.05.0-ce

docker-2: 192.168.1.194:2375

└ ID: LTSZ:NUCW:U7PJ:E2MB:UD4K:QNS4:EOYG:YC5B:XEYU:BNM5:MZGE:X4R4|192.168.1.194:2375

└ Status: Healthy

└ Containers: 2 (2 Running, 0 Paused, 0 Stopped)

└ Reserved CPUs: 0 / 1

└ Reserved Memory: 0 B / 776.6 MiB

└ Labels: kernelversion=4.4.0-31-generic, operatingsystem=Ubuntu 14.04.5 LTS, ostype=linux, storagedriver=aufs

└ UpdatedAt: 2017-10-15T13:19:04Z

└ ServerVersion: 17.05.0-ce

docker-3: 192.168.1.195:2375

└ ID: A42N:WYIC:KJRG:SPED:IJIS:IYQP:23T4:EWDP:6CT7:IFMB:ZIDF:37WN|192.168.1.195:2375

└ Status: Healthy

└ Containers: 1 (1 Running, 0 Paused, 0 Stopped)

└ Reserved CPUs: 0 / 1

└ Reserved Memory: 0 B / 513.1 MiB

└ Labels: kernelversion=4.4.0-31-generic, operatingsystem=Ubuntu 14.04.5 LTS, ostype=linux, storagedriver=aufs

└ UpdatedAt: 2017-10-15T13:19:03Z

└ ServerVersion: 17.05.0-ce

Plugins:

Volume:

Network:

Swarm:

NodeID:

Is Manager: false

Node Address:

Kernel Version: 4.4.0-31-generic

Operating System: linux

Architecture: amd64

CPUs: 3

Total Memory: 2.005GiB

Name: ad81e842302d

Docker Root Dir:

Debug Mode (client): false

Debug Mode (server): false

Experimental: false

Live Restore Enabled: false

可以发现docker-1上运行有创建manager服务和swarm join时的两个容器，docker-2上运行有swarm join和 ping www.baidu.com

(这个容器是在docker-3上通过manager服务创建的，但却运行在docker-2上，可见是swarm集群调度策略分配的）的两个容器，docker-3上只有swarm join

创建一个nginx服务

[email protected]:~# docker -H 192.168.1.193:12375 run -d --name my-web --publish 8080:80 nginx

2a888979b129767ff73562587e5cf6672aac13c47d69ea4673887d87f6be552a

通过下面命令可以看到nginx运行在docker-3上（swarm调度策略分配的）

[email protected]:~# docker -H 192.168.1.193:12375 ps

CONTAINER ID IMAGE COMMAND CREATED STATUS PORTS NAMES

2a888979b129 nginx "nginx -g ‘daemon ..." 15 seconds ago Up 14 seconds 192.168.1.195:8080->80/tcp docker-3/my-web

41ca94b3da41 centos "ping www.baidu.com" 2 hours ago Up 2 hours docker-2/vigilant_bose

[email protected]:~# netstat -tunlp

Active Internet connections (only servers)

Proto Recv-Q Send-Q Local Address Foreign Address State PID/Program name

tcp 0 0 0.0.0.0:22 0.0.0.0:* LISTEN 910/sshd

tcp6 0 0 :::22 :::* LISTEN 910/sshd

tcp6 0 0 :::2375 :::* LISTEN 1549/dockerd

tcp6 0 0 :::8080 :::* LISTEN 3761/docker-proxy

[email protected]:~# curl http://192.168.1.195:8080

<!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>

进入nginx容器进行服务修改

[email protected]:~# docker -H 192.168.1.193:12375 exec -it 2a888979b129 /bin/bash

[email protected]:/# apt-get update &&apt-get install -y vim net-tools

[email protected]:/# netstat -tunlp

Active Internet connections (only servers)

Proto Recv-Q Send-Q Local Address Foreign Address State PID/Program name

tcp 0 0 0.0.0.0:80 0.0.0.0:* LISTEN 1/nginx: master pro

修改nginx服务的配置文件

[email protected]:/# vim /etc/nginx/conf.d/default.conf

location / {

root /var/www/html/;

index index.html index.htm;

}

[email protected]:/# mkdir /var/www/html/ -p

[email protected]:/# vim /var/www/html/index.html

<h1> Hello,Docker ^_^</h1>

[email protected]:/# service nginx restart

[....] Restarting nginx: nginx

重启nginx后，nginx容器会终止，需要重新启动

[email protected]:~# docker -H 192.168.1.193:12375 start 2a888979b129

2a888979b129

修改后，访问成功

[email protected]:~# curl http://192.168.1.195:8080

<h1> Hello,Docker ^_^</h1>

本文出自 “11097124” 博客，请务必保留此出处http://11107124.blog.51cto.com/11097124/1972599

以上是关于Docker之swarm v1集群创建的主要内容，如果未能解决你的问题，请参考以下文章

docker version 1.12+ swarm 集群

Docker系列之swarm集群搭建

docker 三剑客之docker swarm

Docker 三剑客之Docker Swarm

Docker 三剑客之 Docker Swarm

Linux企业运维——Docker三剑客之Docker Swarm