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Asked: 2019-02-08 10:36:19 +0800 CST

How to read a line from a file into an ansible variable

  • 772

I'm trying to read the database password on a remote host from the file /etc/mysql/debian.cnf. Format of the file is below. Is there a way to parse out the password field so I can drop a mysql user via Ansible?

# Automatically generated for Debian scripts. DO NOT TOUCH!
[client]
host     = localhost
user     = root
password = 5unnyv4l3
socket   = /var/run/mysqld/mysqld.sock
[mysql_upgrade]
host     = localhost
user     = root
password = 5unnyv4l3
socket   = /var/run/mysqld/mysqld.sock
basedir  = /usr
ansible

3 Answers

  1. It looks like the 'slurp' module will work for your requirements: https://docs.ansible.com/ansible/latest/modules/slurp_module.html

    - name: extract password from file
  slurp:
    src: /etc/mysql/debian.cnf
register: mypasswordfile

- name: Set User Password
  user: name=newUser
    password="{{ passwordfile['content'] | b64decode | regex_findall('password = \"(.+)\"') | first }}"

    Edited after testing and fixing.

    • 12

  2. If the file is local to the ansible system you can use the ini lookup which will read in values from a ini style file. If your file is remote you can use fetch/slurp to pull a copy to the local system.

    I would guess the lookup would be something like

    - debug: msg="Password is {{ lookup('ini', 'password section=client file=my.cnf') }}"
    • 4

  3. You can use the command or shell module and do it with awk/sed, someting like:

    - name: get the value in the block on the file
  command: >
         awk -F ' *= *' '{ if ($1 ~ /^\[/) section=$1;
         else if ($1 ~ /^password/ && section ~ /^\[client\]$/ ) print $2 }'
         "{{ file_path }}"
  register: password_value

    In this case to handle a comment in the same line you can do

    - name: setting the password without comments
  set_fact:
    password: "{{ password_value.stdout.split('#')[0] }}"
    • 0