Creating file via ansible directly in container - docker

Question

I want to create a file, directly in a container directory.
I created a directory before:
- name: create private in container
ansible.builtin.file:
path: playcontainer:/etc/ssl/private/
state: directory
mode: 0755
But it doesn´t let me create a file in that directory
- name: openssl key
openssl_privatekey:
path: playcontainer:/etc/ssl/private/playkey.key
size: "{{ key_size }}"
type: "{{ key_type }}"`
What am I missing?

Answer 1

From scratch full example to interact with a container from ansible.
Please note that this is not always what you want to do. In this specific case, unless if testing an ansible role for example, the key should be written inside the image at build time when running your Dockerfile, or bind mounted from host at container start. You should not mess with the container filesystem once started on production.
First we create a container for our test:
docker run -d --rm --name so_example python:latest sleep infinity
Now we need an inventory to target that container (inventories/default/main.yml)
---
all:
vars:
ansible_connection: docker
hosts:
so_example:
Finally a test playbook.yml to achieve your goal:
---
- hosts: all
gather_facts: false
vars:
key_path: /etc/ssl/private
key_size: 4096
key_type: RSA
tasks:
- name: Make sure package requirements are met
apt:
name: python3-pip
state: present
- name: Make sure python requirements are met
pip:
name: cryptography
state: present
- name: Create private directory
file:
path: "{{ key_path }}"
state: directory
owner: root
group: root
mode: 0750
- name: Create a key
openssl_privatekey:
path: "{{ key_path }}/playkey.key"
size: "{{ key_size }}"
type: "{{ key_type }}"
Running the playbook gives:
$ ansible-playbook -i inventories/default/ playbook.yml
PLAY [all] *****************************************************************************************************************************************************************************************
TASK [Make sure package requirements are met] ******************************************************************************************************************************************************
changed: [so_example]
TASK [Make sure python requirements are met] *******************************************************************************************************************************************************
changed: [so_example]
TASK [Create private directory] ********************************************************************************************************************************************************************
changed: [so_example]
TASK [Create a key] ********************************************************************************************************************************************************************************
changed: [so_example]
PLAY RECAP *****************************************************************************************************************************************************************************************
so_example : ok=4 changed=4 unreachable=0 failed=0 skipped=0 rescued=0 ignored=0
We can now check that the file is there
$ docker exec so_example ls -l /etc/ssl/private
total 5
-rw------- 1 root root 3243 Sep 15 13:28 playkey.key
$ docker exec so_example head -2 /etc/ssl/private/playkey.key
-----BEGIN RSA PRIVATE KEY-----
MIIJKQIBAAKCAgEA6xrz5kQuXbd59Bq0fqnwJ+dhkcHWCMh4sZO6UNCfodve7JP0
Clean-up:
docker stop so_example