Docker Swarm 概念

概念
简单来说可以理解为：docker 容器的集群管理，分为 manager 节点和worker节点，其他节点可以加入/离开到这个集群

节点
集群中的一个机器，是以Docker Swarn 为维度的概念，集群中的容器就分布在这些节点上

服务
docker swarm 集群中的所有容器的，对外提供同一个服务，构成整个服务

任务
容器内的任务，即具体提供功能

网络

"Ports": [
                {
                    "Protocol": "tcp",
                    "TargetPort": 80,
                    "PublishedPort": 18080,
                    "PublishMode": "ingress"
                }
            ]

网络
ingress 也是一种overlay网路，内部实现了负载均衡，所有docker 实际运行在一个ingress网络里面

[root@swarm01 ~]# docker network inspect ingress 

[
    {
        "Name": "ingress",
        "Id": "uwovkdxlpynvubozhnjvg37c8",
        "Created": "2021-08-30T14:14:32.277175705+08:00",
        "Scope": "swarm",
        "Driver": "overlay",
        "EnableIPv6": false,
        "IPAM": {
            "Driver": "default",
            "Options": null,
            "Config": [
                {
                    "Subnet": "10.0.0.0/24",
                    "Gateway": "10.0.0.1"
                }
            ]
        },
        "Internal": false,
        "Attachable": false,
        "Ingress": true,
        "ConfigFrom": {
            "Network": ""
        },
        "ConfigOnly": false,
        "Containers": {
            "18019dc5c7a9ff3feaee523533f7e3ace099d5a28885c69300b27c1bcf9e176c": {
                "Name": "mynginx.6.02jx5w6z5d9tvdk7zkqmcdufv",
                "EndpointID": "699e46a9a2b60d6f34ca2f0dbe0117395dc4e68eed8483484fce1eeb052a4512",
                "MacAddress": "02:42:0a:00:00:18",
                "IPv4Address": "10.0.0.24/24",
                "IPv6Address": ""
            },
            "fdc759275968f832ca3f4b107074bc615fd68626c6eef51ff6a395da2b0dcdb8": {
                "Name": "mynginx.1.qb2jmcxvuet3zvjqlq4ppurs4",
                "EndpointID": "90eef44512386e745449f4406af48650a56f2063e671dc858b55247f67e48830",
                "MacAddress": "02:42:0a:00:00:13",
                "IPv4Address": "10.0.0.19/24",
                "IPv6Address": ""
            },
            "ingress-sbox": {
                "Name": "ingress-endpoint",
                "EndpointID": "ecb29c63f5012d877578b8cd12d793c85889a6cea9e6218a8ba93ddebf4b3e73",
                "MacAddress": "02:42:0a:00:00:02",
                "IPv4Address": "10.0.0.2/24",
                "IPv6Address": ""
            }
        },
        "Options": {
            "com.docker.network.driver.overlay.vxlanid_list": "4096"
        },
        "Labels": {},
        "Peers": [
            {
                "Name": "d2d1dff6424e",
                "IP": "192.168.130.154"
            },
            {
                "Name": "1c5996e44049",
                "IP": "192.168.130.150"
            },
            {
                "Name": "8361369e2625",
                "IP": "192.168.130.152"
            },
            {
                "Name": "e85a5856c71e",
                "IP": "192.168.130.153"
            },
            {
                "Name": "7b077e02a60c",
                "IP": "192.168.130.151"
            }
        ]
    }
]

可以看到所有机器都在这个 ingress 网络里面

Docker Stack
与 Docker-compose 相对概念，部署集群

方式	命令	结果
docker	docker run	docker 启动单个容器（单机）
docker-compose	docker-compose up	docker 启动一组容器（单机）
docker swarm	docker service create	docker 启动单个容器（集群）
docker stack	docker stack deploy	docker 启动一组容器（集群）

stack 启动文件和 compose 类似，随便扒一个，留个印象

version: "3"
services:
  redis:
    image: redis:alpine
    ports:
      - "6379"
    networks:
      - frontend
    deploy:
      replicas: 2
      update_config:
        parallelism: 2
        delay: 10s
      restart_policy:
        condition: on-failure

  db:
    image: postgres:9.4
    volumes:
      - db-data:/var/lib/postgresql/data
    networks:
      - backend
    deploy:
      placement:
        constraints: [node.role == manager]
  result:
    image: dockersamples/examplevotingapp_result:before
    ports:
      - 5001:80
    networks:
      - backend
    depends_on:
      - db
    deploy:
      replicas: 1
      update_config:
        parallelism: 2
        delay: 10s
      restart_policy:
        condition: on-failure
  visualizer:
    image: dockersamples/visualizer:stable
    ports:
      - "8080:8080"
    stop_grace_period: 1m30s
    volumes:
      - "/var/run/docker.sock:/var/run/docker.sock"
    deploy:
      placement:
        constraints: [node.role == manager]
        
  portainer:
    image: portainer/portainer
    ports:
      - "9000:9000"
    volumes:
      - "/var/run/docker.sock:/var/run/docker.sock"
    deploy:
      replicas: 1
      placement:
        constraints: [node.role == manager]

networks:
  frontend:
  // 连接已有网络，没找到时报错，false时，不存在对应网络时，自动创建网络然后使用
    external: true
  backend:

volumes:
  db-data:

Docker Secret
docker 安全配置

[root@swarm01 ~]# docker secret --help

Usage:  docker secret COMMAND

Manage Docker secrets

Commands:
  create      Create a secret from a file or STDIN as content
  inspect     Display detailed information on one or more secrets
  ls          List secrets
  rm          Remove one or more secrets

Run 'docker secret COMMAND --help' for more information on a command.

Docker Config
全局配置

[root@swarm01 ~]# docker config --help

Usage:  docker config COMMAND

Manage Docker configs

Commands:
  create      Create a config from a file or STDIN
  inspect     Display detailed information on one or more configs
  ls          List configs
  rm          Remove one or more configs

Run 'docker config COMMAND --help' for more information on a command.