如何在没有端口映射的情况下将docker容器的ip和端口暴露给外部docker主机？

Question

When i started two docker containers for a same web image on one docker host.

• two docker containers listened on the same port 5000
• port 5000 of the two containers were mapped to different ports of docker host: 49155 , 49156
• to access the two containers from outside docker host need to be by accessing the docker host ip and port 49155 or 49156

Is there a solution to access a docker container from outside docker host by its ip and port, xxxx:5000 , without port mapping?

All docker containers on different dock hosts can access each other directly.

Answer 1

You can accomplish this with IP aliasing on the host.

First, add a virtual interface on the host that has a different IP address than the primary interface. We'll call the primary interface eth0 with IP 10.0.0.10 , and the virtual interface eth0:1 with IP address 10.0.0.11 .

 ifconfig eth0:1 10.0.0.11 netmask 255.255.255.0 up 

Now run the containers and map port 5000 to the corresponding interface. For example:

docker run -p 10.0.0.10:5000:5000 -name container1 <someimage> <somecommand>
docker run -p 10.0.0.11:5000:5000 -name container2 <someimage> <somecommand>

Now you can access each container on port 5000 using different IP addresses externally.

Answer 2

When creating a VM make sure that the following are selected under networking

Attached to:        Bridged NetworkManager
Adapter Type:       PCnet-Fast III (Am 79C973)
Promiscious Mode    Allow All

RHEL 6.5 / Fedora 20

Install docker, libvrt

Make sure the following are done using root

# chkconfig NetworkManager off
# chkconfig network on  
# service NetworkManager stop
# service network start

Create file ifcfg-xxxxx in /etc/sysconfig/network-scripts

DEVICE=xxxxx
TYPE=Bridge
BOOTPROTO=dhcp
ONBOOT=yes
DELAY=0

and append to ifcfg-p2p1 / ifcfg-eth0 at the end of the file BRIDGE=xxxx

Restart the VM

run

brctl show 

to make sure the bridged connected has an adapter either p2p1 or eth0 eg

# brctl show
bridge name     bridge id               STP enabled     interfaces
gsbr01          8000.080027595649       no              eth0
virbr0          8000.5254004c1564       yes             virbr0-nic

now before starting docker we have to use our bridge and not docker0 to do that, run docker as docker -d -b=gsbr01

$ echo 'DOCKER_OPTS="-b=gsbr01"' >> /etc/sysconfig/docker
$ sudo service docker start

Check the result:

# brctl show
bridge name     bridge id               STP enabled     interfaces
gsbr01          8000.080027595649       no              eth0
                                                        veth5806f27
                                                        vethb3e33da
virbr0          8000.5254004c1564       yes             virbr0-nic

docker -d -b=gsbr01