Passing Host's Hostname to Docker Container

There are two simple ways to pass hostname of the machine running docker daemon to the docker container using Ansible.

1. Using Environmental Variable

- name: Start application container
  docker:
    name: my_application
    image: my_username/my_application
    env:
        HOST_HOSTNAME: "{{ "{{ ansible_hostname " }} }}"

2. Setting the hostname of the docker container the same as of the host running it.

- name: Start application container
  docker:
    name: my_application
    image: my_username/my_application
    hostname: "{{ "{{ ansible_hostname " }} }}"