Ansible: Set variable to file content

Question

I'm using the ec2 module with ansible-playbook I want to set a variable to the contents of a file. Here's how I'm currently doing it.

1. Var with the filename
2. shell task to cat the file
3. use the result of the cat to pass to the ec2 module.

Example contents of my playbook.

vars:   amazon_linux_ami: "ami-fb8e9292"   user_data_file: "base-ami-userdata.sh" tasks: - name: user_data_contents   shell: cat {{ user_data_file }}   register: user_data_action - name: launch ec2-instance   local_action: ...   user_data: "{{ user_data_action.stdout }}" 

I assume there's a much easier way to do this, but I couldn't find it while searching Ansible docs.

Answer 1

You can use lookups in Ansible in order to get the contents of a file, e.g.

user_data: "{{ lookup('file', user_data_file) }}" 

Caveat: This lookup will work with local files, not remote files.

Here's a complete example from the docs:

- hosts: all   vars:      contents: "{{ lookup('file', '/etc/foo.txt') }}"   tasks:      - debug: msg="the value of foo.txt is {{ contents }}" 

Answer 2

You can use the slurp module to fetch a file from the remote host: (Thanks to @mlissner for suggesting it)

vars:   amazon_linux_ami: "ami-fb8e9292"   user_data_file: "base-ami-userdata.sh" tasks: - name: Load data   slurp:     src: "{{ user_data_file }}"   register: slurped_user_data - name: Decode data and store as fact # You can skip this if you want to use the right hand side directly...   set_fact:     user_data: "{{ slurped_user_data.content | b64decode }}"