Alpine Linux docker set hostname

Question

I'm using lwieske/java-8:server-jre-8u121-slim with Alpine Linux

I'd like to set hostname from a text file to be seen globally (for all shells)

/ # env
HOSTNAME=2fa4a43a975c

/ # cat /etc/afile
something

/ # hostname -F /etc/afile
hostname: sethostname: Operation not permitted

everything running as a service in swarm

i want every node to have unique hostname based on container id.

Answer 1

You can provide the --hostname flag to docker run as well:

docker run -d --net mynet --ip 162.18.1.1 --hostname mynodename

Answer 2

As for workaround, can use docker-compose to assign the hostnames for multiple containers.

Here is the example docker-compose.yml:

version: '3'
services:
  ubuntu01:
    image: ubuntu
    hostname: ubuntu01
  ubuntu02:
    image: ubuntu
    hostname: ubuntu02
  ubuntu03:
    image: ubuntu
    hostname: ubuntu03
  ubuntu04:
    image: ubuntu
    hostname: ubuntu04

To make it dynamic, you can generatedocker-compose.yml from the script.

Then run with: docker-compose up.