How to change the network used by Docker?

By default, Docker virtualization system uses 172.17.0.0/12 networks for its operation. If your equipment uses addresses from these networks, you can change the Docker settings. This will prevent possible network conflicts.

Viewing the information about the networks used

To find out which networks are used by Docker:

1. Request the list of networks:

   docker network list

   An example of response

   NETWORK ID          NAME                          DRIVER              SCOPE
   14a38927e118        bridge                        bridge              local
   b91a38ed491b        dci_auth                      bridge              local
   7bdf76184b18        docker_ipmi_proxy_v2_bridge   bridge              local
   2d9237551d88        etc_default                   bridge              local
   f67c6099ef24        host                          host                local
   cbb6fb4096c5        none                          null                local

    In the response to the command, the NAME column will show the names of the networks used.

2. Request the information about the address space used:

   An example of commands with responses

   [root@dci ~]# docker network inspect etc_default | grep Subnet
   "Subnet": "172.19.0.0/16",
   [root@dci ~]# docker network inspect docker_ipmi_proxy_v2_bridge | grep Subnet
   "Subnet": "172.26.0.0/16",
   [root@dci ~]# docker network inspect bridge | grep Subnet
   "Subnet": "172.17.0.0/16",
   [root@dci ~]# docker network inspect dci_auth | grep Subnet
   "Subnet": "172.25.0.0/16",

Changing the network for Docker

To change the settings of networks used by Docker:

1. Edit or create the /etc/docker/daemon.json file:

   An example of file

   {
   	"live-restore": true,
   	"bip": "10.10.0.1/16",
   	"default-address-pools": [{
   		"base": "10.0.0.0/8",
   		"size": 16
   	}]
   }

    Comments to the file format

   live-restore — this parameter helps reduce container downtime when the system is shut down or rebooted.

   bip — IP address of Docker's bridge-interface in the format "address/network prefix". For example, to use the IP address 10.10.0.1 in a 10.10.0.0/16 network, specify "10.10.0.1/16".

   base — the range of IP addresses for creating Docker networks in the format "network/network prefix". E.g., "10.0.0.0/8".

   size — prefix of networks being created.

2.  Delete all running docker containers:

   docker rm -f `docker ps -q -a`

3. Delete all unused Docker objects:

   docker system prune

   docker network prune

4. Run DCImanager:

   dci start

5. Run the BMC proxy module's docker containers:

   docker-compose -f /opt/ispsystem/ipmi_proxy_service/etc/docker/ipmi_proxy_v2.yml up -d

6. Run docker containers for working with locations:

   docker-compose -f /opt/ispsystem/dci/etc/location.yaml up -d

7. Reboot the server with DCImanager:

   reboot

8. Check the network settings:

   Examples of commands with responses

   [root@dci6 ~]# docker network inspect bridge | grep Subnet
   "Subnet": "10.10.0.0/16",
   [root@dci6 ~]# docker network inspect dci_auth | grep Subnet
   "Subnet": "10.0.0.0/16",
   [root@dci6 ~]# docker network inspect docker_ipmi_proxy_v2_bridge | grep Subnet
   "Subnet": "10.1.0.0/16",
   [root@dci6 ~]# docker network inspect etc_default | grep Subnet
   "Subnet": "10.2.0.0/16",