How do I set hostname in docker-compose

Question

In my docker-compose yml file  I have the following  However the container does not pick up the hostname value  Any ideas   dns    image  phensley docker-dns   hostname  affy   domainname  affy com   volumes      -  var run docker sock  docker sock   When I check the hostname in the container it does not pick up affy

User · Answer

The simplest way I have found is to just set the container name in the docker-compose.yml See container_name documentation. It is applicable to docker-compose v1+. It works for container to container, not from the host machine to container.

services:
  dns:
    image: phensley/docker-dns
    container_name: affy

Now you should be able to access affy from other containers using the container name. I had to do this for multiple redis servers in a development environment.

NOTE The solution works so long as you don't need to scale. Such as consistant individual developer environments.

User · Answer

As of docker-compose version 3 and later  you can just use the hostname key  version   3  services    dns      hostname   your-name

User · Answer

I found that the hostname was not visible to other containers when using docker run  This turns out to be a known issue  perhaps more a known feature   with part of the discussion being   We should probably add a warning to the docs about using hostname  I think it is rarely useful   The correct way of assigning a hostname - in terms of container networking - is to define an alias like so  services    some-service      networks        some-network          aliases            - alias1           - alias2  Unfortunately this still doesn t work with docker run  The workaround is to assign the container a name  docker-compose run --name alias1 some-service  And alias1 can then be pinged from the other containers  UPDATE  As  grilix points out  you should use docker-compose run --use-aliases to make the defined aliases available

User · Answer

This seems to work correctly   If I put your config into a file     cat  gt  compose yml  lt  lt EOF dns    image  phensley docker-dns   hostname  affy   domainname  affy com   volumes      -  var run docker sock  docker sock EOF   And then bring things up     docker-compose -f compose yml up Creating tmp dns 1    Attaching to tmp dns 1 dns 1   2015-04-28T17 47 45 423387  dockerdns  table add tmp dns 1 docker - gt  172 17 0 5   And then check the hostname inside the container  everything seems to be fine     docker exec -it stack dns 1 hostname affy affy com

User · Answer

Based on docker documentation  https   docs docker com compose compose-file   command  I simply put hostname   lt string gt  in my docker-compose file   E g           lb01    hostname  at-lb01   image  at-client-base v1          and container lb01 picks up at-lb01 as hostname

User · Answer

I needed to spin freeipa container to have a working kdc and had to give it a hostname otherwise it wouldn t run  What eventually did work for me is setting the HOSTNAME env variable in compose   version  2 services    freeipa      environment        - HOSTNAME ipa example test   Now its working   docker exec -it freeipa freeipa 1 hostname ipa example test

User · Answer

This issue is still open here  https   github com docker compose issues 2925 You can set hostname but it is not reachable from other containers   So it is mostly useless

User · Answer

For docker compose version   quot 3 4 quot  It works for me  services      my-service          hostname  my host name  Don t need to use dns  Just use hostname  Compose file version 3 reference

[docker] How do I set hostname in docker-compose?

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