我找到了有关此问题的帖子。但是，我所做的只是使我的安装崩溃。
我的问题的根源：无法从容器内访问在主机上侦听 127.0.0.1:3306 的 mysql。
环境：Centos8, docker-ce / Docker version 20.10.5, build 55c4c88
我之前尝试 ping/traceroute 到 google - ifconfig：
docker0: flags=4163<UP,BROADCAST,RUNNING,MULTICAST> mtu 1500
inet 172.17.0.1 netmask 255.255.0.0 broadcast 172.17.255.255
inet6 fe80::42:7dff:fe3a:1d23 prefixlen 64 scopeid 0x20<link>
ether 02:42:7d:3a:1d:23 txqueuelen 0 (Ethernet)
RX packets 152 bytes 9114 (8.9 KiB)
RX errors 0 dropped 0 overruns 0 frame 0
TX packets 32 bytes 2132 (2.0 KiB)
TX errors 0 dropped 0 overruns 0 carrier 0 collisions 0
lo: flags=73<UP,LOOPBACK,RUNNING> mtu 65536
inet 127.0.0.1 netmask 255.0.0.0
inet6 ::1 prefixlen 128 scopeid 0x10<host>
loop txqueuelen 1000 (Lokale Schleife)
RX packets 8 bytes 400 (400.0 B)
RX errors 0 dropped 0 overruns 0 frame 0
TX packets 8 bytes 400 (400.0 B)
TX errors 0 dropped 0 overruns 0 carrier 0 collisions 0
venet0: flags=211<UP,BROADCAST,POINTOPOINT,RUNNING,NOARP> mtu 1500
inet 127.0.0.1 netmask 255.255.255.255 broadcast 0.0.0.0 destination 127.0.0.1
unspec 00-00-00-00-00-00-00-00-00-00-00-00-00-00-00-00 txqueuelen 0 (UNSPEC)
RX packets 20275 bytes 48492440 (46.2 MiB)
RX errors 0 dropped 0 overruns 0 frame 0
TX packets 7901 bytes 1118291 (1.0 MiB)
TX errors 0 dropped 125 overruns 0 carrier 0 collisions 0
venet0:0: flags=211<UP,BROADCAST,POINTOPOINT,RUNNING,NOARP> mtu 1500
inet 85.214.171.64 netmask 255.255.255.255 broadcast 85.214.171.64 destination 85.214.171.64
unspec 00-00-00-00-00-00-00-00-00-00-00-00-00-00-00-00 txqueuelen 0 (UNSPEC)
veth182b7de: flags=4163<UP,BROADCAST,RUNNING,MULTICAST> mtu 1500
inet6 fe80::b463:b4ff:fecd:8989 prefixlen 64 scopeid 0x20<link>
ether b6:63:b4:cd:89:89 txqueuelen 0 (Ethernet)
RX packets 0 bytes 0 (0.0 B)
RX errors 0 dropped 0 overruns 0 frame 0
TX packets 13 bytes 866 (866.0 B)
TX errors 0 dropped 0 overruns 0 carrier 0 collisions 0
veth2bbb74a: flags=4163<UP,BROADCAST,RUNNING,MULTICAST> mtu 1500
inet6 fe80::2415:b4ff:fe28:e625 prefixlen 64 scopeid 0x20<link>
ether 26:15:b4:28:e6:25 txqueuelen 0 (Ethernet)
RX packets 99 bytes 7654 (7.4 KiB)
RX errors 0 dropped 0 overruns 0 frame 0
TX packets 18 bytes 1076 (1.0 KiB)
TX errors 0 dropped 0 overruns 0 carrier 0 collisions 0
发行后
docker run -it --rm alpine traceroute -m 5 172.217.168.227
traceroute to 172.217.168.227 (172.217.168.227), 5 hops max, 46 byte packets
1 172.17.0.1 (172.17.0.1) 0.020 ms 0.012 ms 0.009 ms
2 * * *
（限制为 2 跳，因为与默认的 30 跳没有区别）
ifconfig 输出：
docker0: flags=4163<UP,BROADCAST,RUNNING,MULTICAST> mtu 1500
inet 172.17.0.1 netmask 255.255.0.0 broadcast 172.17.255.255
inet6 fe80::42:7dff:fe3a:1d23 prefixlen 64 scopeid 0x20<link>
ether 02:42:7d:3a:1d:23 txqueuelen 0 (Ethernet)
RX packets 166 bytes 9860 (9.6 KiB)
RX errors 0 dropped 0 overruns 0 frame 0
TX packets 37 bytes 2480 (2.4 KiB)
TX errors 0 dropped 0 overruns 0 carrier 0 collisions 0
lo: flags=73<UP,LOOPBACK,RUNNING> mtu 65536
inet 127.0.0.1 netmask 255.0.0.0
inet6 ::1 prefixlen 128 scopeid 0x10<host>
loop txqueuelen 1000 (Lokale Schleife)
RX packets 8 bytes 400 (400.0 B)
RX errors 0 dropped 0 overruns 0 frame 0
TX packets 8 bytes 400 (400.0 B)
TX errors 0 dropped 0 overruns 0 carrier 0 collisions 0
venet0: flags=211<UP,BROADCAST,POINTOPOINT,RUNNING,NOARP> mtu 1500
inet 127.0.0.1 netmask 255.255.255.255 broadcast 0.0.0.0 destination 127.0.0.1
unspec 00-00-00-00-00-00-00-00-00-00-00-00-00-00-00-00 txqueuelen 0 (UNSPEC)
RX packets 20326 bytes 48495436 (46.2 MiB)
RX errors 0 dropped 0 overruns 0 frame 0
TX packets 7936 bytes 1124283 (1.0 MiB)
TX errors 0 dropped 134 overruns 0 carrier 0 collisions 0
venet0:0: flags=211<UP,BROADCAST,POINTOPOINT,RUNNING,NOARP> mtu 1500
inet 85.214.171.64 netmask 255.255.255.255 broadcast 85.214.171.64 destination 85.214.171.64
unspec 00-00-00-00-00-00-00-00-00-00-00-00-00-00-00-00 txqueuelen 0 (UNSPEC)
veth182b7de: flags=4163<UP,BROADCAST,RUNNING,MULTICAST> mtu 1500
inet6 fe80::b463:b4ff:fecd:8989 prefixlen 64 scopeid 0x20<link>
ether b6:63:b4:cd:89:89 txqueuelen 0 (Ethernet)
RX packets 0 bytes 0 (0.0 B)
RX errors 0 dropped 0 overruns 0 frame 0
TX packets 14 bytes 908 (908.0 B)
TX errors 0 dropped 0 overruns 0 carrier 0 collisions 0
veth2bbb74a: flags=4163<UP,BROADCAST,RUNNING,MULTICAST> mtu 1500
inet6 fe80::2415:b4ff:fe28:e625 prefixlen 64 scopeid 0x20<link>
ether 26:15:b4:28:e6:25 txqueuelen 0 (Ethernet)
RX packets 99 bytes 7654 (7.4 KiB)
RX errors 0 dropped 0 overruns 0 frame 0
TX packets 19 bytes 1118 (1.0 KiB)
TX errors 0 dropped 0 overruns 0 carrier 0 collisions 0
显然数据包在 venet0 上被丢弃了。
我需要配置什么才能连接到容器外部（包括 127.0.0.1）？