Make docker use IPv4 for port binding
UbuntuDockerPortIpv6Ubuntu Problem Overview
I have docker host and inside I have one container.
The docker host is binding the port on IPv6 interface only, not on IPv4.
This is the output
tcp 0 0 0.0.0.0:22 0.0.0.0:* LISTEN -
tcp 0 0 0.0.0.0:55082 0.0.0.0:* LISTEN -
tcp 0 0 0.0.0.0:111 0.0.0.0:* LISTEN -
tcp6 0 0 :::80 :::* LISTEN -
tcp6 0 0 :::22 :::* LISTEN -
tcp6 0 0 :::40280 :::* LISTEN -
tcp6 0 0 :::5432 :::* LISTEN -
tcp6 0 0 :::40122 :::* LISTEN -
tcp6 0 0 :::36378 :::* LISTEN -
tcp6 0 0 :::40543 :::* LISTEN -
tcp6 0 0 :::111 :::* LISTEN -
Now I have 40122 port on host to link with port 22 on container.
I want to SSH into that container but I am not able to as its only bound to IPv6
This is my docker version Docker version 1.5.0, build a8a31ef
docker ps
201bde6c839a myapp:latest "supervisord -n" 3 weeks ago Up 2 hours 0.0.0.0:40122->22/tcp, 0.0.0.0:40280->80/tcp, 0.0.0.0:40543->443/tcp myapp
I ran using docker run -d -P -p 40122:22
netstat -tlna
tcp 0 0 0.0.0.0:80 0.0.0.0:* LISTEN
tcp 0 0 0.0.0.0:22 0.0.0.0:* LISTEN
tcp 0 0 127.0.0.1:3031 0.0.0.0:* LISTEN
tcp 0 0 0.0.0.0:6379 0.0.0.0:* LISTEN
tcp6 0 0 :::22 :::* LISTEN
tcp6 0 0 :::6379 :::* LISTEN
ps aux
root 1 0.0 0.8 52440 16668 ? Ss 00:53 0:03 /usr/bin/python /usr/bin/supervisord -n
root 49 0.0 0.1 17980 3048 ? S 01:32 0:00 bash
root 64 0.0 0.1 46632 2712 ? S 01:32 0:00 su -l vagrant
vagrant 65 0.0 0.1 21308 3760 ? S 01:32 0:00 -su
root 288 0.0 0.1 17980 3088 ? S 02:01 0:00 bash
root 304 0.0 0.1 46632 2720 ? S 02:01 0:00 su -l vagrant
vagrant 305 0.0 0.1 21304 3804 ? S 02:01 0:00 -su
vagrant 308 0.0 3.7 429616 75840 ? Sl+ 02:01 0:05 python ./manage.py shell_plus
root 654 0.0 0.4 47596 9848 ? S 03:12 0:01 /usr/local/bin/uwsgi --die-on-term --ini /var/www/conf/uwsgi.ini
root 655 0.0 0.3 90280 7732 ? S 03:12 0:00 nginx: master process /usr/sbin/nginx
www-data 656 0.0 0.1 90600 3624 ? S 03:12 0:00 nginx: worker process
www-data 657 0.0 0.1 90600 3624 ? S 03:12 0:00 nginx: worker process
www-data 658 0.0 0.1 90600 3624 ? S 03:12 0:00 nginx: worker process
www-data 659 0.0 0.2 90940 4500 ? S 03:12 0:00 nginx: worker process
root 660 0.0 0.2 61372 5332 ? S 03:12 0:00 /usr/sbin/sshd -D
root 669 0.0 0.4 37004 8892 ? Sl 03:12 0:01 redis-server *:6379
root 856 8.0 2.8 388720 57792 ? Sl 04:07 0:18 /usr/local/bin/uwsgi --die-on-term --ini /var/www/conf/uwsgi.ini
root 857 8.0 2.8 388720 57792 ? Sl 04:07 0:18 /usr/local/bin/uwsgi --die-on-term --ini /var/www/conf/uwsgi.ini
root 858 8.0 2.8 388720 57792 ? Sl 04:07 0:18 /usr/local/bin/uwsgi --die-on-term --ini /var/www/conf/uwsgi.ini
root 859 8.0 2.8 388720 57792 ? Sl 04:07 0:18 /usr/local/bin/uwsgi --die-on-term --ini /var/www/conf/uwsgi.ini
vagrant 889 0.0 0.1 18692 2508 ? R+ 04:11 0:00 ps aux
Ubuntu Solutions
Solution 1 - Ubuntu
As @daniel-t points out in the comment: github.com/docker/docker/issues/2174 is about showing binding only to IPv6 in netstat, but that is not an issue. As that github issues states:
> When setting up the proxy, Docker requests the loopback address '127.0.0.1', Linux realises this is an address that exists in IPv6 (as ::0) and opens on both (but it is formally an IPv6 socket). When you run netstat it sees this and tells you it is an IPv6 - but it is still listening on IPv4. If you have played with your settings a little, you may have disabled this trick Linux does - by setting net.ipv6.bindv6only = 1.
In other words, just because you see it as IPv6 only, it is still able to communicate on IPv4 unless you have IPv6 set to only bind on IPv6 with the net.ipv6.bindv6only setting. To be clear, net.ipv6.bindv6only should be 0 - you can run sysctl net.ipv6.bindv6only to verify.
Solution 2 - Ubuntu
2021 Update:
Currently docker binds to both IPv4 and IPv6 by default.
If you want to explicitly "Make docker use IPv4 for port binding" (as in, have it only bind on the IPv4 port) add 0.0.0.0: before the ports in the -p/--publish option(s), like so:
$ docker run --publish "0.0.0.0:80:80" --publish "0.0.0.0:443:443" --detach nginx
The result will look like this when you're done:
$ docker ps
CONTAINER ID IMAGE COMMAND CREATED STATUS PORTS NAMES
2459bd225751 nginx "/docker-entrypoint.…" 4 seconds ago Up 2 seconds 0.0.0.0:80->80/tcp, 0.0.0.0:443->443/tcp jovial_yonath
The netstat results will look like this:
$ sudo netstat -tulnp
Active Internet connections (only servers)
Proto Recv-Q Send-Q Local Address Foreign Address State PID/Program name
tcp 0 0 0.0.0.0:443 0.0.0.0:* LISTEN 22676/docker-proxy
tcp 0 0 0.0.0.0:80 0.0.0.0:* LISTEN 22698/docker-proxy
You can browse or curl to the device to make sure it works, of course.
If you don't add the "0.0.0.0", it will bind on both IP versions, and the PORTS will read 0.0.0.0:80->80/tcp, :::80->80/tcp, 0.0.0.0:443->443/tcp, :::443->443/tcp, which may not be desirable for security, console spam or predictability reasons.
Solution 3 - Ubuntu
Setting net.ipv6.conf.all.forwarding=1 will fix the issue.
This can be done on a live system using
sudo sysctl -w net.ipv6.conf.all.forwarding=1
Solution 4 - Ubuntu
ISSUE RESOVLED:
USE docker run -it -p 80:80 --name nginx --net=host -d nginx
that's issue we face with VM some time instead of bridge network try with host that will work for you
> > tcp 0 0 0.0.0.0:80 0.0.0.0:* LISTEN - > tcp6 0 0 :::80 :::* LISTEN - >
Solution 5 - Ubuntu
By default, docker uses AF_INET6 sockets which can be used for both IPv4 and IPv6 connections. This causes netstat to report an IPv6 address for the listening address.
From RedHat https://access.redhat.com/solutions/3114021
Solution 6 - Ubuntu
If you want your container ports to bind on your ipv4 address, just :
- find the settings file
- /etc/sysconfig/docker-network on RedHat alike
- /etc/default/docker-network on Debian ans alike
- edit the network settings
- add DOCKER_NETWORK_OPTIONS=-ip=xx.xx.xx.xx
- xx.xx.xx.xx being your real ipv4 (and not 0.0.0.0)
- restart docker deamon
works for me on docker 1.9.1
Solution 7 - Ubuntu
For CentOS users,
I've got same issue on CentOS7 and setting net.ipv4.ip_forward to 1 solves the issue. Please, refer to https://stackoverflow.com/questions/41453263/docker-networking-disabled-warning-ipv4-forwarding-is-disabled-networking-wil for more details.
Solution 8 - Ubuntu
Try to remove --attachable flag for created networks
Doesn't work
docker network create --attachable --driver overlay --subnet=10.0.3.0/24 --gateway=10.0.3.1 dev
It works, but listeness IPv4 ports still not seeing when you check with sudo netstat -tulnp4
docker network create --attachable --driver overlay --subnet=10.0.3.0/24 --gateway=10.0.3.1 dev