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adampweb
Asked: 2023-03-27 01:34:26 +0800 CST

Dnsmasq 转发拒绝 Docker 容器中的其他 Dnsmasq

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给定两个 DNS 服务器，一个在本地主机 (127.0.0.1:53) 上运行，另一个在 Docker 容器 (172.18.0.3:5300) 中运行。

当我尝试通过 localhost DNS使用dig或nslookup命令检查域解析时，请求被拒绝：

adam@adam-desktop:~$ nslookup whoami.docker
Server:     127.0.0.1
Address:    127.0.0.1#53

** server can't find whoami.docker: REFUSED

并检查dig但结果相似：

adam@adam-desktop:~$ dig A whoami.docker

; <<>> DiG 9.18.1-1ubuntu1.3-Ubuntu <<>> A whoami.docker
;; global options: +cmd
;; Got answer:
;; ->>HEADER<<- opcode: QUERY, status: REFUSED, id: 10447
;; flags: qr rd ra; QUERY: 1, ANSWER: 0, AUTHORITY: 0, ADDITIONAL: 1

;; OPT PSEUDOSECTION:
; EDNS: version: 0, flags:; udp: 4096
;; QUESTION SECTION:
;whoami.docker.         IN  A

;; Query time: 3 msec
;; SERVER: 127.0.0.1#53(127.0.0.1) (UDP)
;; WHEN: Sun Mar 26 18:59:31 CEST 2023
;; MSG SIZE  rcvd: 42

然后创建以下日志条目：

adam@adam-desktop:~$ tail -F /var/log/syslog:
[...]
Mar 26 18:45:27 adam-desktop dnsmasq[10105]: query[A] whoami.docker from 127.0.0.1
Mar 26 18:45:27 adam-desktop dnsmasq[10105]: forwarded whoami.docker to 172.18.0.3
Mar 26 18:45:32 adam-desktop dnsmasq[10105]: query[A] whoami.docker from 127.0.0.1
Mar 26 18:45:32 adam-desktop dnsmasq[10105]: config error is REFUSED

但是当我在命令中指定第二个 DNS 服务器时，响应是预期的：

adam@adam-desktop:~$ dig A @172.18.0.3 -p 5300 whoami.docker

; <<>> DiG 9.18.1-1ubuntu1.3-Ubuntu <<>> A @172.18.0.3 -p 5300 whoami.docker
; (1 server found)
;; global options: +cmd
;; Got answer:
;; ->>HEADER<<- opcode: QUERY, status: NOERROR, id: 5930
;; flags: qr aa rd ra ad; QUERY: 1, ANSWER: 1, AUTHORITY: 0, ADDITIONAL: 1

;; OPT PSEUDOSECTION:
; EDNS: version: 0, flags:; udp: 4096
;; QUESTION SECTION:
;whoami.docker.         IN  A

;; ANSWER SECTION:
whoami.docker.      0   IN  A   172.18.0.4

;; Query time: 3 msec
;; SERVER: 172.18.0.3#5300(172.18.0.3) (UDP)
;; WHEN: Sun Mar 26 18:58:08 CEST 2023
;; MSG SIZE  rcvd: 58

所以我不明白为什么不使用解析链：

请求（whoami.docker）->DNS1（127.0.0.1:53）-> DNS2（172.18.0.3）：找到条目（172.18.0.4-whoami.docker）->并返回给客户端。

本地主机 DNS 配置 ( dnsmasq.conf )：

port=53
domain-needed
bogus-priv
strict-order
no-resolv

# Private DNS server on Docker network
server=/docker/172.18.0.3

#Use the Google nameservers
server=8.8.8.8
server=1.1.1.1

rebind-domain-ok=/.docker/

user=dnsmasq
#group=dnsmasq

listen-address=172.18.0.1, 172.17.0.1, 127.0.0.1

bind-interfaces
cache-size=0
log-queries

NetworkManager 配置（/etc/NetworkManager/NetworkManager.conf）：

[main]
dns=dnsmasq
plugins=ifupdown,keyfile

[...]

第二个 DNS 服务器配置（在 Docker 容器内 - IP 地址：172.18.0.3）：

port=5300
domain-needed
bogus-priv
log-queries
no-resolv
no-hosts

strict-order

#Use the Google nameservers
server=8.8.8.8
server=8.8.4.4

#serve all company queries using a specific nameserver
domain=docker

#explicitly define host-ip mappings
# Testing container
address=/whoami.docker/172.18.0.4

/etc/resolv.conf的内容：

nameserver 127.0.0.1
search home
options edns0 trust-ad

定义DNS和whoami容器的 Docker-Compose 文件：

version: '3.9'

services:
  dnsmasq:
    image: jpillora/dnsmasq
    container_name: dnsmasq
    restart: always
    volumes:
        - /var/run/docker.sock:/tmp/docker.sock:ro
        - ./dnsmasq.conf:/etc/dnsmasq.conf:ro
        - ./dnsmasq.d:/etc/dnsmasq.d:rw
    networks:
      devnet:
        ipv4_address: 172.18.0.3
    logging:
      options:
        max-size: 100m
    ports:
      - "0.0.0.0:5300:53/udp"
      - "0.0.0.0:5300:53/tcp"
      - "0.0.0.0:5380:8080"
    environment:
      - HTTP_USER=foo
      - HTTP_PASS=bar
      # - VIRTUAL_HOST=ns.dev.home

  whoami:
      image: jwilder/whoami
      container_name: whoami
      restart: always
      ports:
        - "0.0.0.0:8000:8000"
      environment:
        - VIRTUAL_HOST=whoami.docker
      volumes:
        - /var/run/docker.sock:/tmp/docker.sock:ro
      networks:
        devnet:
          ipv4_address: 172.18.0.4

networks:
  devnet:
    driver: "bridge"
    external: true
    enable_ipv6: false
docker

1 个回答

  1. Best Answer

    我按照下一篇文章解决了我的问题。

    第一步：我使用 NetworkManager 内置的 dnsmasq 而不是独立安装：
    DNSMasq + Network Manager + Docker = Fun?

    第二步：我修改了 Docker Compose 文件：在端口映射中删除了主机端口定义：

    version: '3.9'

services:
  dnsmasq:
    image: jpillora/dnsmasq
    container_name: dnsmasq
    restart: always
    volumes:
        - /var/run/docker.sock:/tmp/docker.sock:ro
        - ./dnsmasq.conf:/etc/dnsmasq.conf:ro
        - ./dnsmasq.d:/etc/dnsmasq.d:rw
    networks:
      devnet:
        ipv4_address: 172.18.0.3
    logging:
      options:
        max-size: 100m
    ports:
      - "53/udp"
      - "53/tcp"
      - "0.0.0.0:5380:8080"
    environment:
      - HTTP_USER=foo
      - HTTP_PASS=bar

  whoami:
      image: jwilder/whoami
      container_name: whoami
      restart: always
      ports:
        - "0.0.0.0:8000:8000"
      environment:
        - VIRTUAL_HOST=whoami.dev.home
      volumes:
        - /var/run/docker.sock:/tmp/docker.sock:ro
      networks:
        devnet:
          ipv4_address: 172.18.0.4

networks:
  devnet:
    driver: "bridge"
    external: true
    enable_ipv6: false

    第 3 步：修改远程 DNS 服务器（在 Docker 网络上）上的 dnsmasq 配置文件，并将域配置分离为独立的配置文件，灵感来自：
    在 Docker /etc/dnsmasq.conf 中运行 dnsmasq：

    port=53
domain-needed
bogus-priv
no-hosts
keep-in-foreground
bind-interfaces
no-resolv
expand-hosts
server=8.8.8.8
server=8.8.4.4

# changed domain from .docker to .dev.home
domain=dev.home 

#log all dns queries
log-queries

conf-dir=/etc/dnsmasq.d

    /etc/dnsmasq/dnsmasq.d/1.whoami.conf: 

    address=/whoami.dev.home/172.18.0.4
txt-record=txt.whoami.dev.home,txt-whoami.whoami.dev.home

    第 4 步： 向 UFW ( /etc/ufw/after.rules ) 添加额外的规则以允许 Docker 内部网络正常，然后是在不禁用 Iptables 的情况下修复 Docker 和 UFW 安全漏洞

    • 0

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