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使用 DNS 解析器作为容器的 Docker 容器 DNS 速度较慢（约 4 秒）

tag-icon • tag-icon networking domain-name-system docker docker-compose unbound
使用 DNS 解析器作为容器的 Docker 容器 DNS 速度较慢（约 4 秒）

我所有 Docker 容器内的 DNS 解析始终很慢（略多于 4 秒）。从主机上看，DNS 查询很快，在我的网络的其余部分也是如此。

我必须承认，到目前为止我还没有尝试很多方法，因为谷歌搜索没有给我很多答案。正如您在下面看到的，许多 TCP 数据包都发送到例如172.18.0.12.domain或homeserver.my.tld.domain。我认为.domain后缀不正确，但我不知道如何处理该信息。

知道我的设置有什么问题吗？如果有人能给我指明正确的方向，或者给我一些关于如何定位我的问题的想法，我将不胜感激。

如果您需要任何其他信息，我很乐意提供我所能提供的一切。

编辑：当我将容器内的 /etc/resolve.conf 更改为：

search local
nameserver 172.18.0.1
options ndots:0

然后容器内的 DNS 查找又会很快了。但这当然意味着我无法再根据名称解析其他容器了。

我的设置是：

  • 我的华硕路由器运行 DHCP 并给出 DNS 服务器地址 192.168.1.12
  • 家庭网络为 192.168.1.0/24
  • 物理机“Homeserver”（192.168.1.12）是我的Docker主机
  • 未绑定容器作为 DNS 服务器（端口转发 53/TCP、53/UDP）
  • 多个其他容器都存在同样的问题
  • docker compose所有容器都通过（无额外networks部分）进行管理

附加信息：

家庭服务器的 IP

me@homeserver ~ » hostname -I
192.168.1.12 172.18.0.1 172.17.0.1

resolve.conf家庭服务器

me@homeserver ~ » cat /etc/resolv.conf
domain local
search local
nameserver 192.168.1.12
nameserver 192.168.1.1

dig来自家庭服务器（主机）

me@homeserver ~ » dig example.com

; <<>> DiG 9.16.42-Debian <<>> example.com
;; global options: +cmd
;; Got answer:
;; ->>HEADER<<- opcode: QUERY, status: NOERROR, id: 39605
;; flags: qr rd ra ad; QUERY: 1, ANSWER: 1, AUTHORITY: 0, ADDITIONAL: 1

;; OPT PSEUDOSECTION:
; EDNS: version: 0, flags:; udp: 1232
;; QUESTION SECTION:
;example.com.                   IN      A

;; ANSWER SECTION:
example.com.            84515   IN      A       93.184.216.34

;; Query time: 0 msec
;; SERVER: 192.168.1.12#53(192.168.1.12)
;; WHEN: Thu Jul 06 14:40:26 CEST 2023
;; MSG SIZE  rcvd: 56

容器的 IP（随机选择）

root@917745962ebd:/var/www/html# hostname -I
172.18.0.3

resolve.conf同一容器

root@917745962ebd:/var/www/html# cat /etc/resolv.conf 
search local
nameserver 127.0.0.11
options ndots:0

dig来自同一容器

root@917745962ebd:/var/www/html# dig example.com

; <<>> DiG 9.16.42-Debian <<>> example.com
;; global options: +cmd
;; Got answer:
;; ->>HEADER<<- opcode: QUERY, status: NOERROR, id: 56875
;; flags: qr rd ra; QUERY: 1, ANSWER: 1, AUTHORITY: 0, ADDITIONAL: 1

;; OPT PSEUDOSECTION:
; EDNS: version: 0, flags:; udp: 1280
;; QUESTION SECTION:
;example.com.                   IN      A

;; ANSWER SECTION:
example.com.            6393    IN      A       93.184.216.34

;; Query time: 4000 msec
;; SERVER: 127.0.0.11#53(127.0.0.11)
;; WHEN: Thu Jul 06 12:38:09 UTC 2023
;; MSG SIZE  rcvd: 56

tcpdumpdig（在主机上）在容器上方运行时 我将下面的域名重命名为，my.tld并将我的公共 IP 重命名为redacted.correct.ip.address

me@homeserver ~ » sudo tcpdump -n -t -i any -w dns.dump port 53

14:38:04.838058 veth93caf60 P   IP 172.18.0.15.37644 > homeserver.my.tld.domain: 60373+ A? subdomain-a.my.tld. (43)
14:38:04.838058 br-27dccdedb325 In  IP 172.18.0.15.37644 > homeserver.my.tld.domain: 60373+ A? subdomain-a.my.tld. (43)
14:38:04.838288 br-27dccdedb325 Out IP 172.18.0.1.53289 > 172.18.0.12.domain: 60373+ A? subdomain-a.my.tld. (43)
14:38:04.838293 veth777c9f6 Out IP 172.18.0.1.53289 > 172.18.0.12.domain: 60373+ A? subdomain-a.my.tld. (43)
14:38:04.838369 veth777c9f6 P   IP 172.18.0.12.domain > 172.18.0.1.53289: 60373* 1/0/0 A 192.168.1.12 (59)
14:38:04.838369 br-27dccdedb325 In  IP 172.18.0.12.domain > 172.18.0.1.53289: 60373* 1/0/0 A 192.168.1.12 (59)
14:38:04.838424 br-27dccdedb325 Out IP 172.18.0.1.domain > 172.18.0.15.37644: 60373* 1/0/0 A 192.168.1.12 (59)
14:38:04.838429 veth93caf60 Out IP 172.18.0.1.domain > 172.18.0.15.37644: 60373* 1/0/0 A 192.168.1.12 (59)
14:38:05.173253 vethba9d77c P   IP 172.18.0.3.38698 > homeserver.my.tld.domain: 56875+ [1au] A? example.com. (52)
14:38:05.173253 br-27dccdedb325 In  IP 172.18.0.3.38698 > homeserver.my.tld.domain: 56875+ [1au] A? example.com. (52)
14:38:05.173414 br-27dccdedb325 Out IP 172.18.0.1.56291 > 172.18.0.12.domain: 56875+ [1au] A? example.com. (52)
14:38:05.173421 veth777c9f6 Out IP 172.18.0.1.56291 > 172.18.0.12.domain: 56875+ [1au] A? example.com. (52)
14:38:05.173522 veth777c9f6 P   IP 172.18.0.12.domain > 172.18.0.1.56291: 56875$ 1/0/1 A 93.184.216.34 (56)
14:38:05.173522 br-27dccdedb325 In  IP 172.18.0.12.domain > 172.18.0.1.56291: 56875$ 1/0/1 A 93.184.216.34 (56)
14:38:05.173613 br-27dccdedb325 Out IP 172.18.0.1.domain > 172.18.0.3.38698: 56875$ 1/0/1 A 93.184.216.34 (56)
14:38:05.173617 vethba9d77c Out IP 172.18.0.1.domain > 172.18.0.3.38698: 56875$ 1/0/1 A 93.184.216.34 (56)
14:38:06.834972 veth93caf60 P   IP 172.18.0.15.47468 > 192.168.1.1.domain: 10696+ A? subdomain-b.my.tld. (35)
14:38:06.834972 br-27dccdedb325 In  IP 172.18.0.15.47468 > 192.168.1.1.domain: 10696+ A? subdomain-b.my.tld. (35)
14:38:06.835010 eno1  Out IP homeserver.my.tld.47468 > 192.168.1.1.domain: 10696+ A? subdomain-b.my.tld. (35)
14:38:06.835852 eno1  In  IP 192.168.1.1.domain > homeserver.my.tld.47468: 10696 2/0/0 CNAME subdomain-c.my.tld., A redacted.correct.ip.address (91)
14:38:06.835874 br-27dccdedb325 Out IP 192.168.1.1.domain > 172.18.0.15.47468: 10696 2/0/0 CNAME subdomain-c.my.tld., A redacted.correct.ip.address (91)
14:38:06.835879 veth93caf60 Out IP 192.168.1.1.domain > 172.18.0.15.47468: 10696 2/0/0 CNAME subdomain-c.my.tld., A redacted.correct.ip.address (91)
14:38:07.340717 veth93caf60 P   IP 172.18.0.15.52538 > homeserver.my.tld.domain: 60373+ A? subdomain-a.my.tld. (43)
14:38:07.340717 br-27dccdedb325 In  IP 172.18.0.15.52538 > homeserver.my.tld.domain: 60373+ A? subdomain-a.my.tld. (43)
14:38:07.340908 br-27dccdedb325 Out IP 172.18.0.1.55468 > 172.18.0.12.domain: 60373+ A? subdomain-a.my.tld. (43)
14:38:07.340916 veth777c9f6 Out IP 172.18.0.1.55468 > 172.18.0.12.domain: 60373+ A? subdomain-a.my.tld. (43)
14:38:07.341003 veth777c9f6 P   IP 172.18.0.12.domain > 172.18.0.1.55468: 60373* 1/0/0 A 192.168.1.12 (59)
14:38:07.341003 br-27dccdedb325 In  IP 172.18.0.12.domain > 172.18.0.1.55468: 60373* 1/0/0 A 192.168.1.12 (59)
14:38:07.341070 br-27dccdedb325 Out IP 172.18.0.1.domain > 172.18.0.15.52538: 60373* 1/0/0 A 192.168.1.12 (59)
14:38:07.341076 veth93caf60 Out IP 172.18.0.1.domain > 172.18.0.15.52538: 60373* 1/0/0 A 192.168.1.12 (59)
14:38:08.839315 veth93caf60 P   IP 172.18.0.15.56280 > 192.168.1.1.domain: 60373+ A? subdomain-a.my.tld. (43)
14:38:08.839315 br-27dccdedb325 In  IP 172.18.0.15.56280 > 192.168.1.1.domain: 60373+ A? subdomain-a.my.tld. (43)
14:38:08.839366 eno1  Out IP homeserver.my.tld.56280 > 192.168.1.1.domain: 60373+ A? subdomain-a.my.tld. (43)
14:38:08.840220 eno1  In  IP 192.168.1.1.domain > homeserver.my.tld.56280: 60373 2/0/0 CNAME subdomain-c.my.tld., A redacted.correct.ip.address (99)
14:38:08.840244 br-27dccdedb325 Out IP 192.168.1.1.domain > 172.18.0.15.56280: 60373 2/0/0 CNAME subdomain-c.my.tld., A redacted.correct.ip.address (99)
14:38:08.840250 veth93caf60 Out IP 192.168.1.1.domain > 172.18.0.15.56280: 60373 2/0/0 CNAME subdomain-c.my.tld., A redacted.correct.ip.address (99)
14:38:09.173904 vethba9d77c P   IP 172.18.0.3.43473 > 192.168.1.1.domain: 56875+ [1au] A? example.com. (52)
14:38:09.173904 br-27dccdedb325 In  IP 172.18.0.3.43473 > 192.168.1.1.domain: 56875+ [1au] A? example.com. (52)
14:38:09.173952 eno1  Out IP homeserver.my.tld.43473 > 192.168.1.1.domain: 56875+ [1au] A? example.com. (52)
14:38:09.174908 eno1  In  IP 192.168.1.1.domain > homeserver.my.tld.43473: 56875 1/0/1 A 93.184.216.34 (56)
14:38:09.174932 br-27dccdedb325 Out IP 192.168.1.1.domain > 172.18.0.3.43473: 56875 1/0/1 A 93.184.216.34 (56)
14:38:09.174939 vethba9d77c Out IP 192.168.1.1.domain > 172.18.0.3.43473: 56875 1/0/1 A 93.184.216.34 (56)

docker network inspect smarthome_default

[

    {
        "Name": "smarthome_default",
        "Id": "27dccdedb3252ccb0967d8b1f552d3262aecbdaf5bd709088241e648acab1cc2",
        "Created": "2022-11-04T13:27:46.22785411+01:00",
        "Scope": "local",
        "Driver": "bridge",
        "EnableIPv6": false,
        "IPAM": {
            "Driver": "default",
            "Options": null,
            "Config": [
                {
                    "Subnet": "172.18.0.0/16",
                    "Gateway": "172.18.0.1"
                }
            ]
        },
        "Internal": false,
        "Attachable": false,
        "Ingress": false,
        "ConfigFrom": {
            "Network": ""
        },
        "ConfigOnly": false,
        "Containers": {
            "18cd21a56368b62752dfb99042ee6305fb680e6dceb5ab79f499ce78fffff053": {
                "Name": "smarthome-unbound-1",
                "EndpointID": "ca5169a1a1244d03756919a78d48b5b6a54a20d898f1293bbcecb9bfb1ea1435",
                "MacAddress": "02:42:ac:12:00:0c",
                "IPv4Address": "172.18.0.12/16",
                "IPv6Address": ""
            },
            "e70f22c6c4581d751061b7353cd32e8ae187f130a0811c3e259d379de9fb3b8b": {
                "Name": "smarthome-other-container-1",
                "EndpointID": "668b6ffa63d2a529ef5f257c763c3ca1731cdf1671c0115c405192b8c89f3ee9",
                "MacAddress": "02:42:ac:12:00:0a",
                "IPv4Address": "172.18.0.10/16",
                "IPv6Address": ""
            },
            // ...
        },
        "Options": {},
        "Labels": {
            "com.docker.compose.network": "default",
            "com.docker.compose.project": "smarthome",
            "com.docker.compose.version": "2.12.2"
        }
    }
]

答案1

解决了：

根本问题是这样的：

root@917745962ebd:/var/www/html# dig @192.168.1.12 example.com   
 
;; reply from unexpected source: 172.18.0.1#53, expected 192.168.1.12#53

当我使用上面命令输出中建议的 IP 地址时：

root@917745962ebd:/var/www/html# dig @172.18.0.1 example.com

; <<>> DiG 9.16.42-Debian <<>> @172.18.0.1 example.com
; (1 server found)
;; global options: +cmd
;; Got answer:
;; ->>HEADER<<- opcode: QUERY, status: NOERROR, id: 9462
;; flags: qr rd ra ad; QUERY: 1, ANSWER: 1, AUTHORITY: 0, ADDITIONAL: 1

;; OPT PSEUDOSECTION:
; EDNS: version: 0, flags:; udp: 1232
;; QUESTION SECTION:
;example.com.                   IN      A

;; ANSWER SECTION:
example.com.            85486   IN      A       93.184.216.34

;; Query time: 0 msec
;; SERVER: 172.18.0.1#53(172.18.0.1)
;; WHEN: Mon Jul 10 08:28:06 UTC 2023
;; MSG SIZE  rcvd: 56

因此解决方案是将此 IP 地址添加到我的/etc/resolv.conf（在主机上）作为第一个条目：

domain local
search local
nameserver 172.18.0.1
nameserver 192.168.1.12
nameserver 192.168.1.1

幸运的是，这不会导致主机上出现任何 DNS 问题：

me@homeserver ~ » dig example.com

; <<>> DiG 9.16.42-Debian <<>> example.com
;; global options: +cmd
;; Got answer:
;; ->>HEADER<<- opcode: QUERY, status: NOERROR, id: 7276
;; flags: qr rd ra ad; QUERY: 1, ANSWER: 1, AUTHORITY: 0, ADDITIONAL: 1

;; OPT PSEUDOSECTION:
; EDNS: version: 0, flags:; udp: 1232
;; QUESTION SECTION:
;example.com.                   IN      A

;; ANSWER SECTION:
example.com.            85272   IN      A       93.184.216.34

;; Query time: 0 msec
;; SERVER: 172.18.0.1#53(172.18.0.1)
;; WHEN: Mon Jul 10 10:31:40 CEST 2023
;; MSG SIZE  rcvd: 56

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