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Steffen S.'s questions

Martin Hope
Steffen S.
Asked: 2020-08-23 06:03:39 +0800 CST
  • 5

Espero que você esteja bem.

Estou lutando há 2 dias com um problema de conexão entre o sistema host e o contêiner. Parece que perdi pacotes aleatoriamente em 'trânsito' para o contêiner (47 em 100).

Posso ver os pacotes 'saindo' da interface do host docker0, mas às vezes eles nunca chegam ao contêiner. Isso é reproduzível independentemente da imagem usada (software diferente, não versão).

Estou muito grato por qualquer indicação, já que estou sem noção agora. Obrigado pelo seu tempo!

Recipiente

host tcpdump 172.17.0.6 e icmp

tcpdump: verbose output suppressed, use -v or -vv for full protocol decode
listening on eth0, link-type EN10MB (Ethernet), capture size 262144 bytes
13:34:22.406364 IP 172.17.0.1 > files.bit-in: ICMP echo request, id 19794, seq 1, length 64
13:34:22.406397 IP files.bit-in > 172.17.0.1: ICMP echo reply, id 19794, seq 1, length 64
>> missing seq# 2 <<
13:34:24.451683 IP 172.17.0.1 > files.bit-in: ICMP echo request, id 19794, seq 3, length 64
13:34:24.451721 IP files.bit-in > 172.17.0.1: ICMP echo reply, id 19794, seq 3, length 64
^C
4 packets captured
4 packets received by filter
0 packets dropped by kernel

Hospedeiro

Debian GNU/Linux 10 (buster)
Kernel 4.19.0-10-amd64 (Debian 4.19.132-1)
Docker version 19.03.12, build 48a66213fe

ping 172.17.0.6 -c3

PING 172.17.0.6 (172.17.0.6) 56(84) bytes of data.
64 bytes from 172.17.0.6: icmp_seq=1 ttl=64 time=0.111 ms
>> missing seq# 2 <<
64 bytes from 172.17.0.6: icmp_seq=3 ttl=64 time=0.097 ms

--- 172.17.0.6 ping statistics ---
3 packets transmitted, 2 received, 33.3333% packet loss, time 47ms
rtt min/avg/max/mdev = 0.097/0.104/0.111/0.007 ms

tcpdump -i docker0 host 172.17.0.6 e icmp

tcpdump: verbose output suppressed, use -v or -vv for full protocol decode
listening on docker0, link-type EN10MB (Ethernet), capture size 262144 bytes
15:34:22.406332 IP 172.17.0.1 > 172.17.0.6: ICMP echo request, id 19794, seq 1, length 64
15:34:22.406401 IP 172.17.0.6 > 172.17.0.1: ICMP echo reply, id 19794, seq 1, length 64
15:34:23.427549 IP 172.17.0.1 > 172.17.0.6: ICMP echo request, id 19794, seq 2, length 64
15:34:24.451657 IP 172.17.0.1 > 172.17.0.6: ICMP echo request, id 19794, seq 3, length 64
15:34:24.451725 IP 172.17.0.6 > 172.17.0.1: ICMP echo reply, id 19794, seq 3, length 64
^C
5 packets captured
5 packets received by filter
0 packets dropped by kernel

rede docker inspecionar ponte

[
    {
        "Name": "bridge",
        "Id": "fbd2aea6a1c634c95ea3e0ac628daf0c266f77cdda63edc573d978d142c57ed8",
        "Created": "2020-08-21T22:13:41.905418474+02:00",
        "Scope": "local",
        "Driver": "bridge",
        "EnableIPv6": false,
        "IPAM": {
            "Driver": "default",
            "Options": null,
            "Config": [
                {
                    "Subnet": "172.17.0.0/16",
                    "Gateway": "172.17.0.1"
                }
            ]
        },
        "Internal": false,
        "Attachable": false,
        "Ingress": false,
        "ConfigFrom": {
            "Network": ""
        },
        "ConfigOnly": false,
        "Containers": {
            "90f16aa06342932ae2bb258c0f1b67a833db3de8142336dbec1cda4468ddf76e": {
                "Name": "container-test",
                "EndpointID": "6e3b17d55b1836d6a1a12219011ceb31950c0fc421fb17923a983eea3c2d559a",
                "MacAddress": "02:42:ac:11:00:07",
                "IPv4Address": "172.17.0.6/16",
                "IPv6Address": ""
            }
        },
        "Options": {
            "com.docker.network.bridge.default_bridge": "true",
            "com.docker.network.bridge.enable_icc": "true",
            "com.docker.network.bridge.enable_ip_masquerade": "true",
            "com.docker.network.bridge.host_binding_ipv4": "0.0.0.0",
            "com.docker.network.bridge.name": "docker0",
            "com.docker.network.driver.mtu": "1500"
        },
        "Labels": {}
    }
]

Atualização 1

Criei uma nova rede bridge com o mínimo de opções e o problema parece estar resolvido para containers rodando na nova rede.

docker network create --subnet=172.20.0.0/24 --gateway=172.20.0.1 docker20

A única diferença parece ser as opções associadas. Enquanto o novo não tem nada, o antigo tem:

        "Options": {
            "com.docker.network.bridge.default_bridge": "true",
            "com.docker.network.bridge.enable_icc": "true",
            "com.docker.network.bridge.enable_ip_masquerade": "true",
            "com.docker.network.bridge.host_binding_ipv4": "0.0.0.0",
            "com.docker.network.bridge.name": "docker0",
            "com.docker.network.driver.mtu": "1500"
        },

Farei mais algumas investigações.

linux networking