Hi,
On Ubuntu 20.04, I've docker installed with the default bridge network
mode. See the following for more information:
werner@X10DAi-01:~$ docker -v
Docker version 19.03.12, build 48a66213fe
werner@X10DAi-01:~$ ip a s
1: lo: <LOOPBACK,UP,LOWER_UP> mtu 65536 qdisc noqueue state UNKNOWN
group default qlen 1000
link/loopback 00:00:00:00:00:00 brd 00:00:00:00:00:00
inet 127.0.0.1/8 scope host lo
valid_lft forever preferred_lft forever
2: enp4s0: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc mq state
UP group default qlen 1000
link/ether 3c:ec:ef:00:f1:28 brd ff:ff:ff:ff:ff:ff
inet 192.168.0.3/24 brd 192.168.0.255 scope global dynamic enp4s0
valid_lft 3688sec preferred_lft 3688sec
inet6 fe80::3eec:efff:fe00:f128/64 scope link
valid_lft forever preferred_lft forever
3: enp5s0: <NO-CARRIER,BROADCAST,MULTICAST,UP> mtu 1500 qdisc mq state
DOWN group default qlen 1000
link/ether 3c:ec:ef:00:f1:29 brd ff:ff:ff:ff:ff:ff
4: docker0: <NO-CARRIER,BROADCAST,MULTICAST,UP> mtu 1500 qdisc noqueue
state DOWN group default
link/ether 02:42:fd:6f:8c:9b brd ff:ff:ff:ff:ff:ff
inet 172.17.0.1/16 brd 172.17.255.255 scope global docker0
valid_lft forever preferred_lft forever
At the same time, I use systemd-resolvd stub resolver on the host
network DNS server as shown following:
werner@X10DAi-01:~$ egrep -v '^[[:blank:]]*(#|$)' /etc/resolv.conf
nameserver 127.0.0.53
options edns0
werner@X10DAi-01:~$ realpath -e /etc/resolv.conf
/run/systemd/resolve/stub-resolv.conf
With the following settings, I can use the host network DNS server in
the docker container via setting 172.17.0.1 as the DNS server:
$ sudo sysctl -w net.ipv4.conf.docker0.route_localnet=1
$ sudo iptables -t nat -I PREROUTING -i docker0 -p udp --dport 53 -j
DNAT --to-destination 127.0.0.53
$ sudo iptables -t nat -I PREROUTING -i docker0 -p tcp --dport 53 -j
DNAT --to-destination 127.0.0.53
But I want to extend this method to use the host network
socks5/http servers in docker container, say, socks5 server on
127.0.0.1:18888 and http server on 127.0.0.1:8080, by setting the
following iptables rules:
$ sudo iptables -t nat -I PREROUTING -i docker0 -p tcp --dport 18888
-j DNAT --to-destination 127.0.0.1
$ sudo iptables -t nat -I PREROUTING -i docker0 -p tcp --dport 8080 -j
DNAT --to-destination 127.0.0.1
But, with the above settings, it doesn't get me to use the host
socks5/http servers in docker container with the following forms:
socks5 proxy server: 172.17.0.1:18888
http proxy server: 172.17.0.1:8080
Any hints for this problem will be highly appreciated.
Sincerely,
--
Assoc. Prof. Hongyi Zhao <hongyi.zhao@xxxxxxxxx>
Theory and Simulation of Materials
Hebei Polytechnic Vocational and Technical University
NO. 552 North Gangtie Road, Xingtai, China
