Using variables for file name and file contents in lineinfile module

Question

I am trying to read the contents of a file, store these in a variable and then insert them into another file if they don't already exist.

So, how I'm attempting to go about this is as follows:

# Create a variable that represents the path to the file that you want to read from
ssh_public_key_file: '../../jenkins_master/files/{{ hostvars[inventory_hostname]["environment"] }}/id_rsa.pub'

# Create a variable that represents the contents of this file:
ssh_public_key: "{{ lookup('file', '{{ ssh_public_key_file }}') }}"

I then use these variables in my Ansible playbook as follows:

- name: Install SSH authorized key
  lineinfile: create=yes dest=~/.ssh/authorized_keys line=" {{ ssh_public_key }}" mode=0644

However, when I try and run the playbook, I get the following error message:

could not locate file in lookup: {{ ssh_public_key_file }}

Can anyone recommend a solution or suggest what I may have done wrong?

Thanks,

Seán

Answer 1

You have to change the line to:

# Create a variable that represents the contents of this file:
ssh_public_key: "{{ lookup('file', ssh_public_key_file) }}"

If you need to concatenate variables and strings you can do it like this:

# Example with two variables
ssh_public_key: "{{ lookup('file', var_1+var_2) }}"

# Example with string and variable
ssh_public_key: "{{ lookup('file', '~/config/'+var_1) }}"

. .