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In docker-compose, how do I create an alias / link to localhost?

In my docker compose file, I need multiple containers to know the hostname of a particular container, including that particular container.

Links will not work as the container cannot reference itself.

Basically what I'm looking for is a way to create a localhost alias in docker-compose.

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3 answers


You should avoid using links. Instead, services on the same Docker network can find each other using service names as DNS names. Use this to refer to a specific container that you described, including when it references itself.

For example, in the following compiled Docker Compose, if there someservice

was a webserver serving port 80, the service anotherservice

could connect to it at the address http://someservice/

because they are on a shared network the_net

.



version: '3'

services:
  someservice:
    image: someserviceimage
    networks:
      - the_net

  anotherservice:
    image: anotherserviceimage
    networks:
      - the_net

networks:
  the_net:

someservice

can also reach itself in http://someservice/

.

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extra_hosts helped.

extra_hosts: - "hostname: 127.0.0.1"



From the docker-compose docs:

extra_hosts Add hostname mapping. Use the same values ​​as docker client --add-host.

extra_hosts: - "somehost: 162.242.195.82" - "otherhost: 50.31.209.229" An entry with IP address and hostname will be created in / etc / hosts inside containers for this service, for example:

162.242.195.82 somehost 50.31.209.229 otherhost

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I think the correct answer is from

Aliases can be defined as part of an online advertisement for a service. See the aliases in the Compose file link for more information on this. - King Chung Huang on April 24, 17 at 15:18

here is an example from the doc

version: '2'

services:
  web:
    build: ./web
    networks:
      - new

worker:
  build: ./worker
  networks:
    - legacy

db:
  image: mysql
  networks:
    new:
      aliases:
        - database
    legacy:
      aliases:
        - mysql

networks:
  new:
  legacy:

you can access db

in this docker-compose, also you can use mysql

to connect thisdb

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