Docker Swarm 核心概念及详细使用

Docker Swarm 介绍

Docker Swarm 是 Docker 的原生集群管理工具。它的主要作用是将多个 Docker 主机集成到一个虚拟的 Docker 主机中，为 Docker 容器提供集群和调度功能。通过 Docker Swarm，您可以轻松地管理多个 Docker 主机，并能在这些主机上调度容器的部署。下面是 Docker Swarm 的一些核心功能和特点：

集群管理：Docker Swarm 允许您将多个 Docker 主机作为一个单一的虚拟主机来管理。这意味着您可以在多个不同的服务器上运行 Docker 容器，而这些服务器被统一管理。
容错和高可用性：Swarm 提供高可用性服务，即使集群中的一部分节点失败，服务仍然可以继续运行。
负载均衡：Swarm 自动分配容器到集群中的不同节点，从而实现负载均衡。它还可以根据需要自动扩展或缩减服务实例的数量。
声明式服务模型：Swarm 使用 Docker Compose 文件格式，使您可以以声明式方式定义应用的多个服务。
服务发现：Swarm 集群中的每个服务都可以通过服务名自动进行服务发现，这简化了不同服务之间的通信。
安全性：Swarm 集群内的通信是加密的，提供了安全的节点间通信机制。
易用性：作为 Docker 的一部分，Swarm 的使用和 Docker 非常类似，对于熟悉 Docker 的用户来说非常容易上手。

总体来说，Docker Swarm 是一种轻量级且易于使用的容器编排工具，适合那些希望利用 Docker 的强大功能，同时需要简单集群管理和服务编排功能的场景。虽然它不像 Kubernetes 那样功能强大和复杂，但对于中小型项目或者对 Kubernetes 的复杂性有所顾虑的用户来说，它是一个很好的选择。

Node

Swarm 集群由 Manager 节点（管理者角色，管理成员和委托任务）和 Worker 节点（工作者角色，运行 Swarm 服务）组成。一个节点就是 Swarm 集群中的一个实例，也就是一个 Docker 主机。你可以运行一个或多个节点在单台物理机或云服务器上，但是生产环境上，典型的部署方式是：Docker 节点交叉分布式部署在多台物理机或云主机上。节点名称默认为机器的 hostname。

Manager：负责整个集群的管理工作包括集群配置、服务管理、容器编排等所有跟集群有关的工作，它会选举出一个 leader 来指挥编排任务；
Worker：工作节点接收和执行从管理节点分派的任务（Tasks）运行在相应的服务（Services）上。

Service

服务（Service）是一个抽象的概念，是对要在管理节点或工作节点上执行的任务的定义。它是集群系统的中心结构，是用户与集群交互的主要根源。

Task

任务（Task）包括一个 Docker 容器和在容器中运行的命令。任务是一个集群的最小单元，任务与容器是一对一的关系。管理节点根据服务规模中设置的副本数量将任务分配给工作节点。一旦任务被分配到一个节点，便无法移动到另一个节点。它只能在分配的节点上运行或失败。

工作流程

Swarm Manager：

API：接受命令并创建 service 对象（创建对象） $\Downarrow$
orchestrator：为 service 对象创建的 task 进行编排工作（服务编排） $\Downarrow$
allocater：为各个 task 分配 IP 地址（分配 IP） $\Downarrow$
dispatcher：将 task 分发到 nodes（分发任务） $\Downarrow$
scheduler：安排一个 worker 节点运行 task（运行任务） $\Downarrow$

Worker Node：

worker：连接到调度器，检查分配的 task（检查任务） $\Uparrow$
executor：执行分配给 worker 节点的 task（执行任务）

Dcoker Swarm 集群部署

机器环境
IP：192.168.1.51 主机名： Manager 担任角色： Manager

IP：192.168.1.52 主机名： Node1 担任角色： Node

IP：192.168.1.53 主机名： Node2 担任角色： Node

安装基础环境

# 修改主机名

[root@localhost ~]# hostnamectl set-hostname Manager
[root@localhost ~]# hostnamectl set-hostname Node1
[root@localhost ~]# hostnamectl set-hostname Node2


# 设置防火墙
# 关闭三台机器上的防火墙。如果开启防火墙，则需要在所有节点的防火墙上依次放行2377/tcp（管理端口）、7946/udp（节点间通信端口）、4789/udp（overlay 网络端口）端口。

[root@localhost ~]# systemctl disable firewalld.service
[root@localhost ~]# systemctl stop firewalld.service

# 安装docker
curl -fsSL https://get.docker.com | bash -s docker --mirror Aliyun

# 启动docker
systemctl enable docker
systemctl start docker

配置加速器

# 用你自己的阿里云加速器
[root@chenby ~]# cat > /etc/docker/daemon.json <<EOF
{
  "exec-opts": ["native.cgroupdriver=systemd"],
  "insecure-registries": ["z.oiox.cn:18082"],
  "registry-mirrors": [
    "https://xxxxx.mirror.aliyuncs.com"
  ],
  "max-concurrent-downloads": 10,
  "log-driver": "json-file",
  "log-level": "warn",
  "log-opts": {
    "max-size": "10m",
    "max-file": "3"
    },
  "data-root": "/var/lib/docker"
}
EOF

# 重新启动docker
[root@chenby ~]# systemctl restart docker && systemctl status docker -l

创建Swarm并添加节点

# 创建Swarm集群

[root@Manager ~]# docker swarm init --advertise-addr 192.168.1.51
Swarm initialized: current node (nuy82gjzc2c0wip9agbava3z9) is now a manager.

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

    docker swarm join --token SWMTKN-1-0mbfykukl6fwl1mziipzqbakqmoo4iz1ti135uuyoj7zfgxgy2-4qbs0bm04iz0l52nm3bljvuoy 192.168.1.51:2377

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

[root@Manager ~]#

# 其余的Node节点执行加入操作
[root@Node1 ~]# docker swarm join --token SWMTKN-1-0mbfykukl6fwl1mziipzqbakqmoo4iz1ti135uuyoj7zfgxgy2-4qbs0bm04iz0l52nm3bljvuoy 192.168.1.51:2377
This node joined a swarm as a worker.
[root@Node1 ~]# 

[root@Node2 ~]# docker swarm join --token SWMTKN-1-0mbfykukl6fwl1mziipzqbakqmoo4iz1ti135uuyoj7zfgxgy2-4qbs0bm04iz0l52nm3bljvuoy 192.168.1.51:2377
This node joined a swarm as a worker.
[root@Node2 ~]#

查看集群的相关信息

[root@Manager ~]# docker info
Client: Docker Engine - Community
 Version:    27.3.1
 Context:    default
 Debug Mode: false
 Plugins:
  buildx: Docker Buildx (Docker Inc.)
    Version:  v0.17.1
    Path:     /usr/libexec/docker/cli-plugins/docker-buildx
  compose: Docker Compose (Docker Inc.)
    Version:  v2.29.7
    Path:     /usr/libexec/docker/cli-plugins/docker-compose

Server:
 Containers: 0
  Running: 0
  Paused: 0
  Stopped: 0
 Images: 0
 Server Version: 27.3.1
 Storage Driver: overlay2
  Backing Filesystem: xfs
  Supports d_type: true
  Using metacopy: false
  Native Overlay Diff: true
  userxattr: false
 Logging Driver: json-file
 Cgroup Driver: systemd
 Cgroup Version: 2
 Plugins:
  Volume: local
  Network: bridge host ipvlan macvlan null overlay
  Log: awslogs fluentd gcplogs gelf journald json-file local splunk syslog
 Swarm: active
  NodeID: nuy82gjzc2c0wip9agbava3z9
  Is Manager: true
  ClusterID: hiki507c9yp8p4lrb8icp0rcs
  Managers: 1
  Nodes: 3
  Data Path Port: 4789
  Orchestration:
   Task History Retention Limit: 5
  Raft:
   Snapshot Interval: 10000
   Number of Old Snapshots to Retain: 0
   Heartbeat Tick: 1
   Election Tick: 10
  Dispatcher:
   Heartbeat Period: 5 seconds
  CA Configuration:
   Expiry Duration: 3 months
   Force Rotate: 0
  Autolock Managers: false
  Root Rotation In Progress: false
  Node Address: 192.168.1.51
  Manager Addresses:
   192.168.1.51:2377
 Runtimes: io.containerd.runc.v2 runc
 Default Runtime: runc
 Init Binary: docker-init
 containerd version: 57f17b0a6295a39009d861b89e3b3b87b005ca27
 runc version: v1.1.14-0-g2c9f560
 init version: de40ad0
 Security Options:
  seccomp
   Profile: builtin
  cgroupns
 Kernel Version: 5.14.0-503.el9.x86_64
 Operating System: CentOS Stream 9
 OSType: linux
 Architecture: x86_64
 CPUs: 1
 Total Memory: 1.921GiB
 Name: Manager
 ID: fb7ffc06-ccc6-4faf-bf8a-4e05f13c14d6
 Docker Root Dir: /var/lib/docker
 Debug Mode: false
 Experimental: false
 Insecure Registries:
  127.0.0.0/8
 Live Restore Enabled: false

WARNING: bridge-nf-call-iptables is disabled
WARNING: bridge-nf-call-ip6tables is disabled
[root@Manager ~]# 
[root@Manager ~]# 
[root@Manager ~]# 
[root@Manager ~]# docker node ls
ID                            HOSTNAME   STATUS    AVAILABILITY   MANAGER STATUS   ENGINE VERSION
nuy82gjzc2c0wip9agbava3z9 *   Manager    Ready     Active         Leader           27.3.1
6vdnp73unqh3qe096vv3iitwm     Node1      Ready     Active                          27.3.1
9txw7h8w3wfkjj85rulu7jnen     Node2      Ready     Active                          27.3.1
[root@Manager ~]# 
[root@Manager ~]#

节点上下线

更改节点的availablity状态

swarm集群中node的availability状态可以为 active或者drain

active状态下，node可以接受来自manager节点的任务分派

drain状态下，node节点会结束task，且不再接受来自manager节点的任务分派（也就是下线节点）

# 设置节点为Drain

[root@Manager ~]# docker node update --availability drain Node1
Node1
[root@Manager ~]# 
[root@Manager ~]# docker node ls
ID                            HOSTNAME   STATUS    AVAILABILITY   MANAGER STATUS   ENGINE VERSION
nuy82gjzc2c0wip9agbava3z9 *   Manager    Ready     Active         Leader           27.3.1
6vdnp73unqh3qe096vv3iitwm     Node1      Ready     Drain                           27.3.1
9txw7h8w3wfkjj85rulu7jnen     Node2      Ready     Active                          27.3.1
[root@Manager ~]# 
[root@Manager ~]# 


# 删除节点
[root@Manager ~]# docker node rm --force Node1
Node1
[root@Manager ~]# 
[root@Manager ~]# docker node ls
ID                            HOSTNAME   STATUS    AVAILABILITY   MANAGER STATUS   ENGINE VERSION
nuy82gjzc2c0wip9agbava3z9 *   Manager    Ready     Active         Leader           27.3.1
9txw7h8w3wfkjj85rulu7jnen     Node2      Ready     Active                          27.3.1
[root@Manager ~]# 



# 重新加入节点
[root@Node1 ~]# docker swarm leave -f
Node left the swarm.
[root@Node1 ~]# 
[root@Node1 ~]# 
[root@Node1 ~]# docker swarm join --token SWMTKN-1-0mbfykukl6fwl1mziipzqbakqmoo4iz1ti135uuyoj7zfgxgy2-4qbs0bm04iz0l52nm3bljvuoy 192.168.1.51:2377
This node joined a swarm as a worker.
[root@Node1 ~]# 


# 查看现有状态
[root@Manager ~]# docker node ls
ID                            HOSTNAME   STATUS    AVAILABILITY   MANAGER STATUS   ENGINE VERSION
nuy82gjzc2c0wip9agbava3z9 *   Manager    Ready     Active         Leader           27.3.1
uec5t9039ef02emg963fean4u     Node1      Ready     Active                          27.3.1
9txw7h8w3wfkjj85rulu7jnen     Node2      Ready     Active                          27.3.1
[root@Manager ~]#

在Swarm中部署服务

# 创建网络
[root@Manager ~]# docker network create -d overlay nginx_net
resh5jevjdzfawrbc0tbxpns0
[root@Manager ~]# 
[root@Manager ~]# docker network ls | grep nginx_net
resh5jevjdzf   nginx_net         overlay   swarm
[root@Manager ~]# 

# 部署服务
[root@Manager ~]# docker service create --replicas 1 --network nginx_net --name my_nginx -p 80:80 nginx
ry7y3p039614jmvqytshxvnb3
overall progress: 1 out of 1 tasks 
1/1: running   [==================================================>] 
verify: Service ry7y3p039614jmvqytshxvnb3 converged 
[root@Manager ~]# 

# 使用 docker service ls 查看正在运行服务的列表
[root@Manager ~]# docker service ls
ID             NAME       MODE         REPLICAS   IMAGE          PORTS
ry7y3p039614   my_nginx   replicated   1/1        nginx:latest   *:80->80/tcp
[root@Manager ~]# 


# 查询Swarm中服务的信息
# -pretty 使命令输出格式化为可读的格式，不加 --pretty 可以输出更详细的信息：
[root@Manager ~]# docker service inspect --pretty my_nginx
ID:        ry7y3p039614jmvqytshxvnb3
Name:        my_nginx
Service Mode:    Replicated
 Replicas:    1
Placement:
UpdateConfig:
 Parallelism:    1
 On failure:    pause
 Monitoring Period: 5s
 Max failure ratio: 0
 Update order:      stop-first
RollbackConfig:
 Parallelism:    1
 On failure:    pause
 Monitoring Period: 5s
 Max failure ratio: 0
 Rollback order:    stop-first
ContainerSpec:
 Image:        nginx:latest@sha256:bc5eac5eafc581aeda3008b4b1f07ebba230de2f27d47767129a6a905c84f470
 Init:        false
Resources:
Networks: nginx_net 
Endpoint Mode:    vip
Ports:
 PublishedPort = 80
  Protocol = tcp
  TargetPort = 80
  PublishMode = ingress 

[root@Manager ~]# 

# 查看运行状态
[root@Manager ~]# docker service ps my_nginx
ID             NAME         IMAGE          NODE      DESIRED STATE   CURRENT STATE           ERROR     PORTS
x6rn5w1hv2ip   my_nginx.1   nginx:latest   Node2     Running         Running 2 minutes ago           
[root@Manager ~]# 

# 访问测试
[root@Manager ~]# curl -I 192.168.1.53
HTTP/1.1 200 OK
Server: nginx/1.27.2
Date: Tue, 19 Nov 2024 11:00:07 GMT
Content-Type: text/html
Content-Length: 615
Last-Modified: Wed, 02 Oct 2024 15:13:19 GMT
Connection: keep-alive
ETag: "66fd630f-267"
Accept-Ranges: bytes

[root@Manager ~]#

调整副本数

# 增加副本数
[root@Manager ~]# docker service scale my_nginx=4
my_nginx scaled to 4
overall progress: 4 out of 4 tasks 
1/4: running   [==================================================>] 
2/4: running   [==================================================>] 
3/4: running   [==================================================>] 
4/4: running   [==================================================>] 
verify: Service my_nginx converged 
[root@Manager ~]#

# 查看是否正常运行
[root@Manager ~]#  docker service ps my_nginx
ID             NAME         IMAGE          NODE      DESIRED STATE   CURRENT STATE            ERROR     PORTS
x6rn5w1hv2ip   my_nginx.1   nginx:latest   Node2     Running         Running 12 minutes ago           
mi0wb3e0eixi   my_nginx.2   nginx:latest   Node1     Running         Running 8 minutes ago            
grm4mtucb2io   my_nginx.3   nginx:latest   Manager   Running         Running 8 minutes ago            
u8gdmihpkqty   my_nginx.4   nginx:latest   Node1     Running         Running 8 minutes ago            
[root@Manager ~]#

模拟节点宕机

# 模拟宕机node节点
[root@Node2 ~]# systemctl stop docker
Warning: Stopping docker.service, but it can still be activated by:
  docker.socket
[root@Node2 ~]# 

# 查看节点是否正常
[root@Manager ~]# docker node ls
ID                            HOSTNAME   STATUS    AVAILABILITY   MANAGER STATUS   ENGINE VERSION
nuy82gjzc2c0wip9agbava3z9 *   Manager    Ready     Active         Leader           27.3.1
uec5t9039ef02emg963fean4u     Node1      Ready     Active                          27.3.1
9txw7h8w3wfkjj85rulu7jnen     Node2      Down      Active                          27.3.1
[root@Manager ~]# 

# 查看容器是否正常
# 节点异常后，容器会在其他的节点上启动起来
[root@Manager ~]#  docker service ps my_nginx
ID             NAME             IMAGE          NODE      DESIRED STATE   CURRENT STATE            ERROR     PORTS
6yf6qs3rv6gx   my_nginx.1       nginx:latest   Manager   Running         Running 18 seconds ago           
x6rn5w1hv2ip    \_ my_nginx.1   nginx:latest   Node2     Shutdown        Running 14 minutes ago           
mi0wb3e0eixi   my_nginx.2       nginx:latest   Node1     Running         Running 9 minutes ago            
grm4mtucb2io   my_nginx.3       nginx:latest   Manager   Running         Running 9 minutes ago            
u8gdmihpkqty   my_nginx.4       nginx:latest   Node1     Running         Running 9 minutes ago            
[root@Manager ~]#

缩小已加的副本

# Swarm 动态缩容服务(scale)
[root@Manager ~]# docker service scale my_nginx=1
my_nginx scaled to 1
overall progress: 1 out of 1 tasks 
1/1: running   [==================================================>] 
verify: Service my_nginx converged 
[root@Manager ~]# 
[root@Manager ~]# 
[root@Manager ~]# docker service ls
ID             NAME       MODE         REPLICAS   IMAGE          PORTS
ry7y3p039614   my_nginx   replicated   1/1        nginx:latest   *:80->80/tcp
[root@Manager ~]# 
[root@Manager ~]# 
[root@Manager ~]# docker service ps my_nginx
ID             NAME             IMAGE          NODE      DESIRED STATE   CURRENT STATE                 ERROR     PORTS
6yf6qs3rv6gx   my_nginx.1       nginx:latest   Manager   Running         Running 4 minutes ago                 
x6rn5w1hv2ip    \_ my_nginx.1   nginx:latest   Node2     Shutdown        Shutdown about a minute ago           
[root@Manager ~]#

更新参数镜像信息

# 可以使用 update 更新参数
[root@Manager ~]# docker ps -a
CONTAINER ID   IMAGE          COMMAND                   CREATED         STATUS         PORTS     NAMES
64e2f72522a2   nginx:latest   "/docker-entrypoint.…"   6 minutes ago   Up 6 minutes   80/tcp    my_nginx.1.6yf6qs3rv6gxbnrc032mhrwf1
[root@Manager ~]# docker service update --replicas 3 my_nginx
my_nginx
overall progress: 3 out of 3 tasks 
1/3: running   [==================================================>] 
2/3: running   [==================================================>] 
3/3: running   [==================================================>] 
verify: Service my_nginx converged 
[root@Manager ~]# 
[root@Manager ~]# docker service ls
ID             NAME       MODE         REPLICAS   IMAGE          PORTS
ry7y3p039614   my_nginx   replicated   3/3        nginx:latest   *:80->80/tcp
[root@Manager ~]# 
[root@Manager ~]#
[root@Manager ~]# docker service ps my_nginx
ID             NAME             IMAGE          NODE      DESIRED STATE   CURRENT STATE            ERROR     PORTS
6yf6qs3rv6gx   my_nginx.1       nginx:latest   Manager   Running         Running 7 minutes ago            
x6rn5w1hv2ip    \_ my_nginx.1   nginx:latest   Node2     Shutdown        Shutdown 4 minutes ago           
pkc7bzqkpppz   my_nginx.2       nginx:latest   Node2     Running         Running 22 seconds ago           
jfok9cwixbi6   my_nginx.3       nginx:latest   Node1     Running         Running 23 seconds ago           
[root@Manager ~]# 

# 通过update参数进行升级镜像
[root@Manager ~]# docker service update --image nginx:new my_nginx
[root@Manager ~]# docker service ls
ID                  NAME                MODE                REPLICAS            IMAGE               PORTS
zs7fw4ereo5w        my_nginx            replicated          3/3                 nginx:new           *:80->80/tcp

删除服务

[root@Manager ~]# docker service rm my_nginx
my_nginx
[root@Manager ~]# 
[root@Manager ~]# docker service ps my_nginx
no such service: my_nginx
[root@Manager ~]#

存储卷的挂载

# Swarm中使用Volume(挂在目录，mount命令)
# 创建一个volume
[root@Manager ~]# docker volume create --name testvolume
testvolume
[root@Manager ~]# 

# 查看创建的volume
[root@Manager ~]# docker volume ls
DRIVER    VOLUME NAME
local     testvolume
[root@Manager ~]# 

# 查看volume详情
[root@Manager ~]# docker volume inspect testvolume
[
    {
        "CreatedAt": "2024-11-19T19:23:42+08:00",
        "Driver": "local",
        "Labels": null,
        "Mountpoint": "/var/lib/docker/volumes/testvolume/_data",
        "Name": "testvolume",
        "Options": null,
        "Scope": "local"
    }
]
[root@Manager ~]#

创建服务使用存储卷挂载

# 创建新的服务并挂载testvolume
[root@Manager ~]# docker service create --replicas 3 --mount type=volume,src=testvolume,dst=/usr/share/nginx/html --network nginx_net --name test_nginx -p 80:80 nginx
4ol5e2jxvs446q4mr9brs3cfk
overall progress: 3 out of 3 tasks 
1/3: running   [==================================================>] 
2/3: running   [==================================================>] 
3/3: running   [==================================================>] 
verify: Service 4ol5e2jxvs446q4mr9brs3cfk converged 
[root@Manager ~]# 
[root@Manager ~]# 


# 查看创建服务
[root@Manager ~]# docker service ls
ID             NAME         MODE         REPLICAS   IMAGE          PORTS
4ol5e2jxvs44   test_nginx   replicated   3/3        nginx:latest   *:80->80/tcp
[root@Manager ~]# 
[root@Manager ~]# 
[root@Manager ~]# docker service ps test_nginx
ID             NAME           IMAGE          NODE      DESIRED STATE   CURRENT STATE            ERROR     PORTS
jvaokj73sv0q   test_nginx.1   nginx:latest   Node2     Running         Running 35 seconds ago           
28kwulxo957w   test_nginx.2   nginx:latest   Manager   Running         Running 35 seconds ago           
odx5ejqph369   test_nginx.3   nginx:latest   Node1     Running         Running 35 seconds ago           
[root@Manager ~]#

测试是否成功挂载

# 查看有没有挂载成功
# 写入内容到网页内容中
[root@Manager ~]# echo "192.168.1.51" > /var/lib/docker/volumes/testvolume/_data/index.html
[root@Manager ~]# 
[root@Node1 ~]# echo "192.168.1.52" > /var/lib/docker/volumes/testvolume/_data/index.html
[root@Node1 ~]# 
[root@Node2 ~]# echo "192.168.1.53" > /var/lib/docker/volumes/testvolume/_data/index.html 
[root@Node2 ~]# 

# 测试是否生效
# 访问任意的节点IP即可，会轮询到这个节点上
[root@Manager ~]# curl 192.168.1.51
192.168.1.51
[root@Manager ~]# curl 192.168.1.51
192.168.1.53
[root@Manager ~]# curl 192.168.1.51
192.168.1.52
[root@Manager ~]#

创建官方的可视化面板

# 安装一个官方的可视化面板
[root@Manager ~]# docker run -it -d -p 8080:8080 -v /var/run/docker.sock:/var/run/docker.sock dockersamples/visualizer
Unable to find image 'dockersamples/visualizer:latest' locally
latest: Pulling from dockersamples/visualizer
ddad3d7c1e96: Pull complete 
3a8370f05d5d: Pull complete 
71a8563b7fea: Pull complete 
119c7e14957d: Pull complete 
28bdf67d9c0d: Pull complete 
12571b9c0c9e: Pull complete 
e1bd03793962: Pull complete 
3ab99c5ebb8e: Pull complete 
94993ebc295c: Pull complete 
021a328e5f7b: Pull complete 
Digest: sha256:530c863672e7830d7560483df66beb4cbbcd375a9f3ec174ff5376616686a619
Status: Downloaded newer image for dockersamples/visualizer:latest
a6a71d4a6d59d8a1e321c70add627bb3c407ae2d4c1e5e9f5a1202bbaa4a24a9
[root@Manager ~]#
[root@Manager ~]# 
[root@Manager ~]# curl -I 192.168.1.51:8080
HTTP/1.1 200 OK
X-Powered-By: Express
Content-Type: text/html; charset=utf-8
Content-Length: 1920
ETag: W/"780-E5yvqIM13yhGsvY/rSKjKKqkVno"
Date: Tue, 19 Nov 2024 11:43:05 GMT
Connection: keep-alive
Keep-Alive: timeout=5
[root@Manager ~]#

Docker Swarm 容器网络

swarm模式的覆盖网络包括以下功能：

可以附加多个服务到同一个网络。
可以给每个swarm服务分配一个虚拟IP地址(vip)和DNS名称
使得在同一个网络中容器之间可以使用服务名称为互相连接
可以配置使用DNS轮循而不使用VIP
为了可以使用swarm的覆盖网络，在启用swarm模式之间你需要在swarm节点之间开放以下端口：

TCP/UDP端口7946 – 用于容器网络发现

UDP端口4789 – 用于容器覆盖网络

# 创建网络
[root@Manager ~]# docker network create --driver overlay --opt encrypted --subnet 192.168.2.0/24 cby_net
j26skr271gjkzpbx91wu1okt9
[root@Manager ~]# 

参数解释：
–opt encrypted  默认情况下swarm中的节点通信是加密的。在不同节点的容器之间，可选的–opt encrypted参数能在它们的vxlan流量启用附加的加密层。
--subnet 命令行参数指定overlay网络使用的子网网段。当不指定一个子网时，swarm管理器自动选择一个子网并分配给网络。


[root@Manager ~]# 
[root@Manager ~]# docker network ls
NETWORK ID     NAME              DRIVER    SCOPE
239c159fade4   bridge            bridge    local
j26skr271gjk   cby_net           overlay   swarm
ee7340b82a36   docker_gwbridge   bridge    local
82ce5e09d333   host              host      local
dkhebie7aja7   ingress           overlay   swarm
resh5jevjdzf   nginx_net         overlay   swarm
60d6545d6b8e   none              null      local
[root@Manager ~]# 


# 创建的容器使用此网络
[root@Manager ~]# docker service create --replicas 5 --network cby_net --name my-cby -p 8088:80 nginx
58j0x31f072f12njv8oz2ibwf
overall progress: 5 out of 5 tasks 
1/5: running   [==================================================>] 
2/5: running   [==================================================>] 
3/5: running   [==================================================>] 
4/5: running   [==================================================>] 
5/5: running   [==================================================>] 
verify: Service 58j0x31f072f12njv8oz2ibwf converged 
[root@Manager ~]# 



[root@Manager ~]# docker service ls | grep my-cby
58j0x31f072f   my-cby       replicated   5/5        nginx:latest   *:8088->80/tcp
[root@Manager ~]# 


在manager-node节点上，通过下面的命令查看哪些节点有处于running状态的任务：
[root@Manager ~]# docker service ps my-cby
ID             NAME       IMAGE          NODE      DESIRED STATE   CURRENT STATE                ERROR     PORTS
hrppcl25yba0   my-cby.1   nginx:latest   Node2     Running         Running about a minute ago           
xw55qx98dgby   my-cby.2   nginx:latest   Manager   Running         Running about a minute ago           
izx4jb8aen5w   my-cby.3   nginx:latest   Node1     Running         Running about a minute ago           
tdkm03dxjzv2   my-cby.4   nginx:latest   Manager   Running         Running about a minute ago           
h6lcj91v01cm   my-cby.5   nginx:latest   Node1     Running         Running about a minute ago           
[root@Manager ~]#

查看网络详细信息

可以查询某个节点上关于my-network的详细信息：
[root@Manager ~]# docker network inspect cby_net
[
    {
        "Name": "cby_net",
        "Id": "j26skr271gjkzpbx91wu1okt9",
        "Created": "2024-11-19T20:10:07.207940854+08:00",
        "Scope": "swarm",
        "Driver": "overlay",
        "EnableIPv6": false,
        "IPAM": {
            "Driver": "default",
            "Options": null,
            "Config": [
                {
                    "Subnet": "192.168.2.0/24",
                    "Gateway": "192.168.2.1"
                }
            ]
        },
        "Internal": false,
        "Attachable": false,
        "Ingress": false,
        "ConfigFrom": {
            "Network": ""
        },
        "ConfigOnly": false,
        "Containers": {
            "2f101603351b388e2820dd576b2ab9490863b65ae04e8cb4f6a3bf2d0df2a590": {
                "Name": "my-cby.4.tdkm03dxjzv20acx6shajxhjg",
                "EndpointID": "b2a5885c2efe87370eb34b4da2103f979a8fa95fe9bff71f037eee569f1ffb0b",
                "MacAddress": "02:42:c0:a8:02:06",
                "IPv4Address": "192.168.2.6/24",
                "IPv6Address": ""
            },
            "8cbd44885c579fa9bc267bcb3eea11b8edcd696b0c75180da5c9237330afcba6": {
                "Name": "my-cby.2.xw55qx98dgbyrdi6jxt9kguvc",
                "EndpointID": "e2f04749c1b55c25b75ec677fd95cc0bd1941a58c69a9b3eed8754d2cfb6de32",
                "MacAddress": "02:42:c0:a8:02:04",
                "IPv4Address": "192.168.2.4/24",
                "IPv6Address": ""
            },
            "lb-cby_net": {
                "Name": "cby_net-endpoint",
                "EndpointID": "f93daf78ca41922a4be4c4b3dde01bb7a919d9008304a4a31950f09281ae30f9",
                "MacAddress": "02:42:c0:a8:02:0a",
                "IPv4Address": "192.168.2.10/24",
                "IPv6Address": ""
            }
        },
        "Options": {
            "com.docker.network.driver.overlay.vxlanid_list": "4098",
            "encrypted": ""
        },
        "Labels": {},
        "Peers": [
            {
                "Name": "33a2908a261b",
                "IP": "192.168.1.53"
            },
            {
                "Name": "d7847005824e",
                "IP": "192.168.1.51"
            },
            {
                "Name": "7640904bfcc4",
                "IP": "192.168.1.52"
            }
        ]
    }
]
[root@Manager ~]# 



[root@Node1 ~]# docker network inspect cby_net
............................................
        "Containers": {
            "01f42aaeb9667b8d07683f5e2d60f643cc61aa9ceda0d0adb8bc642d1093bfc9": {
                "Name": "my-cby.3.izx4jb8aen5wbwkvy5b7tz1lz",
                "EndpointID": "46892992ac400bc1cfc40f62610ff3321ae079929170912d861556f8d1f4645f",
                "MacAddress": "02:42:c0:a8:02:05",
                "IPv4Address": "192.168.2.5/24",
                "IPv6Address": ""
            },
            "a214a33e86c95b3ea84aae6eee705b633ac5a31854425317d2a0d9693cee00ca": {
                "Name": "my-cby.5.h6lcj91v01cmhf03644nqarxq",
                "EndpointID": "a1ec3f28877fb82ba86c2b6312c592489bb59d354caa274a6b5d98aae3c4ee17",
                "MacAddress": "02:42:c0:a8:02:07",
                "IPv4Address": "192.168.2.7/24",
                "IPv6Address": ""
            },
            "lb-cby_net": {
                "Name": "cby_net-endpoint",
                "EndpointID": "05f1e89be3036367a729c1a50430bcd6181ed4bc7ec4e37bd025ba5591b6b3bf",
                "MacAddress": "02:42:c0:a8:02:09",
                "IPv4Address": "192.168.2.9/24",
                "IPv6Address": ""
            }
        },
............................................

[root@Node2 ~]# docker network inspect cby_net
............................................
        "Containers": {
            "6ac3a65fa5a2501a5ad6d4183895e4e6b13beaf6b8642c360e19e9bc0849f74c": {
                "Name": "my-cby.1.hrppcl25yba05o26q1my5abmc",
                "EndpointID": "a0e8246bc74b8e9b9f964b1efb51ad59d9b7dff219b7f10fc027970145503f34",
                "MacAddress": "02:42:c0:a8:02:03",
                "IPv4Address": "192.168.2.3/24",
                "IPv6Address": ""
            },
            "lb-cby_net": {
                "Name": "cby_net-endpoint",
                "EndpointID": "aa739df579790e8147877ce79220cf5387740f11a581344756502f9212314c24",
                "MacAddress": "02:42:c0:a8:02:08",
                "IPv4Address": "192.168.2.8/24",
                "IPv6Address": ""
            }
        },
.............................................

# 可以通过查询服务来获得服务的虚拟IP地址，如下：
[root@Manager ~]# docker service inspect --format='{
  {json .Endpoint.VirtualIPs}}' my-cby
[{"NetworkID":"dkhebie7aja768y8agz4xdpwt","Addr":"10.0.0.27/24"},{"NetworkID":"j26skr271gjkzpbx91wu1okt9","Addr":"192.168.2.2/24"}]
[root@Manager ~]# 
```shell

### 创建测试容器

```shell
[root@Manager ~]# docker service create --name my-by_net  --network cby_net busybox ping www.baidu.com

u7eana0p9xp9auw9p02d8z1wx
overall progress: 1 out of 1 tasks 
1/1: running   [==================================================>] 
verify: Service u7eana0p9xp9auw9p02d8z1wx converged 
[root@Manager ~]# 
[root@Manager ~]# 
[root@Manager ~]# 
[root@Manager ~]# docker service ps my-by_net
ID             NAME          IMAGE            NODE      DESIRED STATE   CURRENT STATE            ERROR     PORTS
7l1fpecym4kc   my-by_net.1   busybox:latest   Node2     Running         Running 31 seconds ago           
[root@Manager ~]# 
```shell

### 进行网络测试

```shell
# 测试其他的IP的是否在容器内正常
[root@Node2 ~]# docker exec -ti 1b1a6f6c5a7b /bin/sh
/ # 
/ # ping 192.168.2.8
PING 192.168.2.8 (192.168.2.8): 56 data bytes
64 bytes from 192.168.2.8: seq=0 ttl=64 time=0.095 ms
64 bytes from 192.168.2.8: seq=1 ttl=64 time=0.073 ms
64 bytes from 192.168.2.8: seq=2 ttl=64 time=0.101 ms
^C
--- 192.168.2.8 ping statistics ---
3 packets transmitted, 3 packets received, 0% packet loss
round-trip min/avg/max = 0.073/0.089/0.101 ms
/ # ping 192.168.2.7
PING 192.168.2.7 (192.168.2.7): 56 data bytes
64 bytes from 192.168.2.7: seq=0 ttl=64 time=0.434 ms
64 bytes from 192.168.2.7: seq=1 ttl=64 time=0.430 ms
64 bytes from 192.168.2.7: seq=2 ttl=64 time=0.401 ms
64 bytes from 192.168.2.7: seq=3 ttl=64 time=0.386 ms
^C
--- 192.168.2.7 ping statistics ---
4 packets transmitted, 4 packets received, 0% packet loss
round-trip min/avg/max = 0.386/0.412/0.434 ms
/ # ping 192.168.2.2
PING 192.168.2.2 (192.168.2.2): 56 data bytes
64 bytes from 192.168.2.2: seq=0 ttl=64 time=0.081 ms
64 bytes from 192.168.2.2: seq=1 ttl=64 time=0.075 ms
64 bytes from 192.168.2.2: seq=2 ttl=64 time=0.093 ms
64 bytes from 192.168.2.2: seq=3 ttl=64 time=0.073 ms
^C
--- 192.168.2.2 ping statistics ---
4 packets transmitted, 4 packets received, 0% packet loss
round-trip min/avg/max = 0.073/0.080/0.093 ms
/ # 


# 服务发现功能
# 查询service的虚拟IP地址
/ # nslookup my-cby
Server:        127.0.0.11
Address:    127.0.0.11:53

Non-authoritative answer:

Non-authoritative answer:
Name:    my-cby
Address: 192.168.2.2

/ #


# 查询所有的容器IP
/ # nslookup tasks.my-cby
Server:        127.0.0.11
Address:    127.0.0.11:53

Non-authoritative answer:

Non-authoritative answer:
Name:    tasks.my-cby
Address: 192.168.2.73
Name:    tasks.my-cby
Address: 192.168.2.74
Name:    tasks.my-cby
Address: 192.168.2.7
Name:    tasks.my-cby
Address: 192.168.2.5
Name:    tasks.my-cby
Address: 192.168.2.3

/ #

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Docker Swarm 核心概念及详细使用

Docker Swarm 核心概念及详细使用

Docker Swarm 介绍

Node

Service

Task

工作流程

Dcoker Swarm 集群部署

安装基础环境

配置加速器

创建Swarm并添加节点

查看集群的相关信息

节点上下线

在Swarm中部署服务

调整副本数

模拟节点宕机

缩小已加的副本

更新参数镜像信息

删除服务

存储卷的挂载

创建服务使用存储卷挂载

测试是否成功挂载

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Docker Swarm 核心概念及详细使用

Docker Swarm 核心概念及详细使用

Docker Swarm 介绍

Node

Service

Task

工作流程

Dcoker Swarm 集群部署

安装基础环境

配置加速器

创建Swarm并添加节点

查看集群的相关信息

节点上下线

在Swarm中部署服务

调整副本数

模拟节点宕机

缩小已加的副本

更新参数镜像信息

删除服务

存储卷的挂载

创建服务使用存储卷挂载

测试是否成功挂载

创建官方的可视化面板

Docker Swarm 容器网络

查看网络详细信息

热门文章

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