Docker 容器無法在one.network中通信

Question

我相信這個話題不止一次被提出過。 但是我找不到任何合理的解決方案。 所以這里是...

我已經在容器中部署了 Zabbix。 我只有一台運行 3 個容器的主機： zabbix-server 、 zabbix-web-nginx-mysql 、 zabbix-agent 。 所有 3 個都在一個docker-compose.yaml中定義：

我運行 Ubuntu 20.04 和 Docker 版本 20.10.1，構建 831ebea

version: '3.5'
networks:
 zbx_net:
  driver: bridge

services:
 zabbix-server:
  image: zabbix/zabbix-server-mysql:alpine-5.2-latest
  ports:
   - "10051:10051"
  volumes:
   - /etc/localtime:/etc/localtime:ro
   - /etc/timezone:/etc/timezone:ro
   - ./zbx_env/usr/lib/zabbix/alertscripts:/usr/lib/zabbix/alertscripts:ro
   - ./zbx_env/usr/lib/zabbix/externalscripts:/usr/lib/zabbix/externalscripts:ro
   - ./zbx_env/var/lib/zabbix/export:/var/lib/zabbix/export:rw
   - ./zbx_env/var/lib/zabbix/modules:/var/lib/zabbix/modules:ro
   - ./zbx_env/var/lib/zabbix/enc:/var/lib/zabbix/enc:ro
   - ./zbx_env/var/lib/zabbix/ssh_keys:/var/lib/zabbix/ssh_keys:ro
   - ./zbx_env/var/lib/zabbix/mibs:/var/lib/zabbix/mibs:ro
  ulimits:
   nproc: 65535
   nofile:
    soft: 20000
    hard: 40000
  env_file:
   - .env_db_mysql
   - .env_srv
  secrets:
   - MYSQL_USER
   - MYSQL_PASSWORD
  networks:
   zbx_net:
    aliases:
    - zabbix-server
    - zabbix-server-mysql
    - zabbix-server-alpine-mysql
    - zabbix-server-mysql-alpine
  stop_grace_period: 30s
  sysctls:
   - net.ipv4.ip_local_port_range=1024 65000
   - net.ipv4.conf.all.accept_redirects=0
   - net.ipv4.conf.all.secure_redirects=0
   - net.ipv4.conf.all.send_redirects=0
  labels:
   com.zabbix.description: "Zabbix server with MySQL database support"
   com.zabbix.company: "Zabbix LLC"
   com.zabbix.component: "zabbix-server"
   com.zabbix.dbtype: "mysql"
   com.zabbix.os: "alpine"

 zabbix-web-nginx-mysql:
  image: zabbix/zabbix-web-nginx-mysql:alpine-5.2-latest
  ports:
   - "8081:8080"
   - "8443:8443"
  volumes:
   - /etc/localtime:/etc/localtime:ro
   - /etc/timezone:/etc/timezone:ro
   - ./zbx_env/etc/ssl/nginx:/etc/ssl/nginx:ro
   - ./zbx_env/usr/share/zabbix/modules/:/usr/share/zabbix/modules/:ro
  env_file:
   - .env_db_mysql
   - .env_web
  secrets:
   - MYSQL_USER
   - MYSQL_PASSWORD
  depends_on:
   - zabbix-server
  healthcheck:
   test: ["CMD", "curl", "-f", "http://localhost:8080/"]
   interval: 10s
   timeout: 5s
   retries: 3
   start_period: 30s
  networks:
   zbx_net:
    aliases:
     - zabbix-web-nginx-mysql
     - zabbix-web-nginx-alpine-mysql
     - zabbix-web-nginx-mysql-alpine
  stop_grace_period: 10s
  sysctls:
   - net.core.somaxconn=65535
  labels:
   com.zabbix.description: "Zabbix frontend on Nginx web-server with MySQL database support"
   com.zabbix.company: "Zabbix LLC"
   com.zabbix.component: "zabbix-frontend"
   com.zabbix.webserver: "nginx"
   com.zabbix.dbtype: "mysql"
   com.zabbix.os: "alpine"

 zabbix-agent:
  image: zabbix/zabbix-agent:alpine-5.2-latest
  ports:
   - "10050:10050"
  volumes:
   - /etc/localtime:/etc/localtime:ro
   - /etc/timezone:/etc/timezone:ro
   - ./zbx_env/etc/zabbix/zabbix_agentd.d:/etc/zabbix/zabbix_agentd.d:ro
   - ./zbx_env/var/lib/zabbix/modules:/var/lib/zabbix/modules:ro
   - ./zbx_env/var/lib/zabbix/enc:/var/lib/zabbix/enc:ro
   - ./zbx_env/var/lib/zabbix/ssh_keys:/var/lib/zabbix/ssh_keys:ro
  env_file:
   - .env_agent
  privileged: true
  pid: "host"
  networks:
   zbx_net:
      aliases:
       - zabbix-agent
       - zabbix-agent-passive
       - zabbix-agent-alpine
  stop_grace_period: 5s
  labels:
   com.zabbix.description: "Zabbix agent"
   com.zabbix.company: "Zabbix LLC"
   com.zabbix.component: "zabbix-agentd"
   com.zabbix.os: "alpine"
secrets:
  MYSQL_USER:
    file: ./.MYSQL_USER
  MYSQL_PASSWORD:
    file: ./.MYSQL_PASSWORD

所有 3 個容器都在同一個用戶定義的網絡中。 因此，根據 Docker Compose 文檔，他們能夠進行通信就足夠了。 但是，如果嘗試從zabbix-agent容器中nc zabbix-server 10051連接失敗，我在zabbix-server上看不到任何連接嘗試。

我檢查了它是否可能是由防火牆引起的。 我使用nftables並創建了一個規則，允許172.0.0.0/8和172.0.0.0/8之間的所有流量。 它以某種方式幫助我連接到<host IP>:10051 （如 172.26.0.1:10051）。 雖然zabbix-agent日志仍然顯示連接被拒絕的錯誤所以我認為它仍然無法正常工作。

無論如何，我主要關心的是容器能夠按照預期的方式直接相互通信。 我也嘗試從zabbix-agent連接到zabbix-web-nginx-mysql:8081但它也沒有連接。 所以我的理解是容器間通信根本不起作用。

如果我查看zabbix_zbx.net .network，我可以看到所有 3 個容器都在那里：

[
    {
        "Name": "zabbix_zbx_net",
        "Id": "def0d254c1077d3874c74ebd6f93a9a9895683a2cc97ffe53a0fa2524649f790",
        "Created": "2020-12-22T10:02:59.55942359+01:00",
        "Scope": "local",
        "Driver": "bridge",
        "EnableIPv6": false,
        "IPAM": {
            "Driver": "default",
            "Options": null,
            "Config": [
                {
                    "Subnet": "172.27.0.0/16",
                    "Gateway": "172.27.0.1"
                }
            ]
        },
        "Internal": false,
        "Attachable": true,
        "Ingress": false,
        "ConfigFrom": {
            "Network": ""
        },
        "ConfigOnly": false,
        "Containers": {
            "95ed96686a7607b5c8aa22bc86f69916dcc117ae118859a5254d3e001df70de9": {
                "Name": "zabbix_zabbix-server_1",
                "EndpointID": "98e7c97886308716b5bf85bf5c8a4bb9655df9e3d79d34a05c8b9d6bca10ae15",
                "MacAddress": "02:42:ac:1b:00:03",
                "IPv4Address": "172.27.0.3/16",
                "IPv6Address": ""
            },
            "ab9216585795561226e608dc5f8a074de3d551f4e09f4caba48a111ec2d89c2b": {
                "Name": "zabbix_zabbix-web-nginx-mysql_1",
                "EndpointID": "0159042e1b64b7ac7f5ca3d675b7a855fa7d22aa42b4765877f4f09723f73307",
                "MacAddress": "02:42:ac:1b:00:04",
                "IPv4Address": "172.27.0.4/16",
                "IPv6Address": ""
            },
            "d17b6314e3f0ade5af7f7bf770fa72f82677e3d6fe82b62bea3ae05567ceb836": {
                "Name": "zabbix_zabbix-agent_1",
                "EndpointID": "8799fe8af03e945fb020d39e66912a20501c08d7b715b3f4aeed531f57392c65",
                "MacAddress": "02:42:ac:1b:00:02",
                "IPv4Address": "172.27.0.2/16",
                "IPv6Address": ""
            }
        },
        "Options": {},
        "Labels": {
            "com.docker.compose.network": "zbx_net",
            "com.docker.compose.project": "zabbix",
            "com.docker.compose.version": "1.25.0"
        }
    }
]

所以我不知道還有什么可以檢查的。

Answer 1

好的，在我的案例中，罪魁禍首是nftables 。 似乎 Docker 不適用於一個（ https://github.com/moby/moby/issues/26824 ）。

所以我卸載了 nftables 並將所有規則移至 iptables。 重新啟動后（但僅在此之后）問題就消失了。