构建生产环境级的docker Swarm集群-2

构建生产环境级的docker Swarm集群。

Tags:

容器

此文档适用于不低于1.12版本的docker，因为swarm已内置于docker-engine里。

硬件需求

这里以5台PC服务器为例, 分别如下作用

manager0
manager1
node0
node1
node2

每台PC上安装docker-engine

一台一台的ssh上去执行，或者使用ansible批量部署工具。

安装docker-engine

curl -sSL https://get.docker.com/ | sh

启动之，并使之监听2375端口

sudo docker daemon -H tcp://0.0.0.0:2375 -H unix:///var/run/docker.sock

亦可修改配置，使之永久生效

mkdir /etc/systemd/system/docker.service.d
cat <<EOF >>/etc/systemd/system/docker.service.d/docker.conf
[Service]
  ExecStart=
  ExecStart=/usr/bin/docker daemon -H tcp://0.0.0.0:2375 -H unix:///var/run/docker.sock --dns 180.76.76.76  --insecure-registry registry.cecf.com -g /home/Docker/docker
EOF

如果开启了防火墙，需要开启如下端口

TCP port 2377 for cluster management communications
TCP and UDP port 7946 for communication among nodes
TCP and UDP port 4789 for overlay network traffic

创建swarm

docker swarm init --advertise-addr <MANAGER-IP>

我的实例里如下：

[root@manager0 ~]# docker swarm init --advertise-addr 10.42.0.243
Swarm initialized: current node (e5eqi0lue90uidzsfddeqwfl8) is now a manager.

To add a worker to this swarm, run the following command:

    docker swarm join \
    --token SWMTKN-1-3iskhw3lsc9pkdtijj1d23lg9tp7duj18f477i5ywgezry7zlt-dfwjbsjleoajcdj13psu702s6 \
    10.42.0.243:2377

To add a manager to this swarm, run 'docker swarm join-token manager' and follow the instructions.

使用 --advertise-addr 来声明manager0的IP，其他的nodes必须可以和此IP互通，一旦完整初始化，此node即是manger又是worker node.

通过docker info来查看

$ docker info

Containers: 2
Running: 0
Paused: 0
Stopped: 2
  ...snip...
Swarm: active
  NodeID: e5eqi0lue90uidzsfddeqwfl8
  Is Manager: true
  Managers: 1
  Nodes: 1
  ...snip...

通过docker node ls来查看集群的node信息

[root@manager0 ~]# docker node ls
ID                           HOSTNAME  STATUS  AVAILABILITY  MANAGER STATUS
e5eqi0lue90uidzsfddeqwfl8 *  manager0  Ready   Active        Leader

这里的*来指明docker client正在链接在这个node上。

加入swarm集群

执行在manager0上产生docker swarm init产生的结果即可

如果当时没记录下来，还可以在manager上补看想把node以worker身份加入，在manager0上执行下面的命令来补看。

docker swarm join-token worker

想把node以manager身份加入，在manager0上执行下面的命令来来补看。

docker swarm join-token manager

为了manager的高可用，我这里需要在manager1上执行

docker swarm join \
--token SWMTKN-1-3iskhw3lsc9pkdtijj1d23lg9tp7duj18f477i5ywgezry7zlt-86dk7l9usp1yh4uc3rjchf2hu \
10.42.0.243:2377

我这里就是依次在node0-2上执行

docker swarm join \
  --token SWMTKN-1-3iskhw3lsc9pkdtijj1d23lg9tp7duj18f477i5ywgezry7zlt-dfwjbsjleoajcdj13psu702s6 \
  10.42.0.243:2377

这样node就会加入之前我们创建的swarm集群里。

再通过docker node ls来查看现在的集群情况， swarm的集群里是以node为实例的

[root@manager0 ~]# docker node ls
ID                           HOSTNAME  STATUS  AVAILABILITY  MANAGER STATUS
0tr5fu8ebi27cp2ot210t67fx    manager1  Ready   Active        Reachable
46irkik4idjk8rjy7pqjb84x0    node1     Ready   Active
79hlu1m7x9p4cc4npa4xjuax3    node0     Ready   Active
9535h8ow82s8mzuw5kud2mwl3    consul0   Ready   Active
e5eqi0lue90uidzsfddeqwfl8 *  manager0  Ready   Active        Leader

这里MANAFER标明各node的身份，空即为worker身份。

部署服务

Usage:	docker service COMMAND

Manage Docker services

Options:
      --help   Print usage

Commands:
  create      Create a new service
  inspect     Display detailed information on one or more services
  ps          List the tasks of a service
  ls          List services
  rm          Remove one or more services
  scale       Scale one or multiple services
  update      Update a service

部署示例如下：

docker service create --replicas 2 --name helloworld alpine ping 300.cn

docker service ls罗列swarm集群的所有services docker service ps helloworld查看service部署到了哪个node上 docker service inspect helloworld 查看service 资源、状态等具体信息 docker servcie scale helloworld=5来扩容service的个数 docker service rm helloworld 来删除service docker service update 来实现更新service的各项属性，包括滚动升级等。

可更新的属性包含如下：

Usage:	docker service update [OPTIONS] SERVICE

Update a service

Options:
      --args string                    Service command args
      --constraint-add value           Add or update placement constraints (default [])
      --constraint-rm value            Remove a constraint (default [])
      --container-label-add value      Add or update container labels (default [])
      --container-label-rm value       Remove a container label by its key (default [])
      --endpoint-mode string           Endpoint mode (vip or dnsrr)
      --env-add value                  Add or update environment variables (default [])
      --env-rm value                   Remove an environment variable (default [])
      --help                           Print usage
      --image string                   Service image tag
      --label-add value                Add or update service labels (default [])
      --label-rm value                 Remove a label by its key (default [])
      --limit-cpu value                Limit CPUs (default 0.000)
      --limit-memory value             Limit Memory (default 0 B)
      --log-driver string              Logging driver for service
      --log-opt value                  Logging driver options (default [])
      --mount-add value                Add or update a mount on a service
      --mount-rm value                 Remove a mount by its target path (default [])
      --name string                    Service name
      --publish-add value              Add or update a published port (default [])
      --publish-rm value               Remove a published port by its target port (default [])
      --replicas value                 Number of tasks (default none)
      --reserve-cpu value              Reserve CPUs (default 0.000)
      --reserve-memory value           Reserve Memory (default 0 B)
      --restart-condition string       Restart when condition is met (none, on-failure, or any)
      --restart-delay value            Delay between restart attempts (default none)
      --restart-max-attempts value     Maximum number of restarts before giving up (default none)
      --restart-window value           Window used to evaluate the restart policy (default none)
      --stop-grace-period value        Time to wait before force killing a container (default none)
      --update-delay duration          Delay between updates
      --update-failure-action string   Action on update failure (pause|continue) (default "pause")
      --update-parallelism uint        Maximum number of tasks updated simultaneously (0 to update all at once) (default 1)
  -u, --user string                    Username or UID
      --with-registry-auth             Send registry authentication details to swarm agents
  -w, --workdir string                 Working directory inside the container

最后修改 January 23, 2022: 迁移陈年老文到新站 (1588b8b)