How to split strings and join them in A​nsibl​e

Posted on by Ansible admin

Split commands are useful when you need to divide a large line or a block of lines into a list. The dividing character will be specified in the command itself. So we can split when every ‘space’ character occurs, semicolon appears, a digit occurs etc.

Join command is useful when you want values in a list or dictionary to be joined or concatenated together. You can specify the joining character also.

Split Lines in Ansible

You can use the ‘split()’ function to divide a line into smaller parts. The output will be a list or dictionary. This is a Python function and not a Jinja2 filter.

For example, in the below example, I am splitting the variable ‘split_value’ whenever a space character is seen. The default split character is ‘space’.  So I am not giving any argument for the same. It is similar to the python split operation.

- hosts: all
  vars:
    test: "This single line should be split based on white space"
  tasks:
  - debug:
      msg: "{{ test.split() }}"

output
------
ok: [localhost] => {
    "msg": [
        "This", 
        "single", 
        "line", 
        "should", 
        "be", 
        "split", 
        "based", 
        "on", 
        "white", 
        "space"
    ]
}

If you need to split based on any other characters, you can input that in the split command.

In the below example, I am splitting an IPv4 address based on the character ‘.’. As you can see the output contains 4 values in the list.

 

- hosts: all
  vars:
    ip: "192.168.14.21"
  tasks:
  - debug:
      msg: "{{ ip.split('.') }}"

output
------
    "msg": [
        "192", 
        "168", 
        "14", 
        "21"
    ]

Joining multiple strings in Ansible

Jinja2 provides a filter for this purpose. It will return a string which is the result of concatenating all the string in the list.

For example, to join 4 values in the previous example, you can do the following.

- hosts: all
  vars:
    test: ['192','168','14','21']
  tasks:
  - debug:
      msg: "{{ test | join('.') }}"

output
------
ok: [localhost] => {
    "msg": "192.168.14.21"
}
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