CODEWITHSUNDEEP
yamlip-addressjinja2ansible
user673906
user673906

Reputation: 847

Ansible: How to increment IP address?

I am passing a variable to Ansible with --extra-vars "lan=10.10.10.1".

I now need to increment this IPaddress so that the last octet is .2 so it will equal 10.10.10.2.

How would this be achieved in Ansible?

Upvotes: 4

Views: 9414

Answers (5)

Başar Söker
Başar Söker

Reputation: 726

This can be helpful, if you want to do this with a subnet.

- name: Give IP addresses sequentially from a subnet
  debug:
     msg: "{{ '10.10.1.48/28' | next_nth_usable(loop_index) }}" 
  loop: "{{ list }}"
  loop_control:
     index_var: loop_index

Please do not forget to install "netaddr" Python library before running the playbook via:

pip install netaddr

Lastly, please bear in mind that index_var starts from 0, so if you want to start it from the 1st IP address, switch the msg line with:

msg: "{{ '10.10.1.48/28' | next_nth_usable(loop_index |int + 1) }}"

Upvotes: 0

user1338062
user1338062

Reputation: 12745

Before Ansible 2.7

Using the ipaddr filter:

{{ ((lan | ipaddr('int')) + 1) | ipaddr }}

Be careful with the operator precedence of Jinja2, it's quite funky.

Ansible 2.7+

Use ipmath() filter. See the answer by Lars Francke.

Upvotes: 3

Lars Francke
Lars Francke

Reputation: 726

As of Ansible 2.7 this can be done using IP Math:

{{ lan | ipmath(1) }}

Upvotes: 11

tersmitten
tersmitten

Reputation: 1330

You might want to have a look at the ipaddr filter

Upvotes: 1

helloV
helloV

Reputation: 52393

In one line:

- set_fact: new_ip="{{ lan | regex_replace('(^.*\.).*$', '\\1') }}{{lan.split('.')[3] | int + 1 }}"

How does it work?

  tasks:
  - name: Echo the passed IP
    debug: var={{lan}}

  - name: Extract the last octet, increment it and store it
    set_fact: octet={{lan.split('.')[3] | int + 1 }}
  - debug: var=octet

  - name: Append the incremented octet to the first 3 octets
    set_fact: new_ip="{{ lan | regex_replace('(^.*\.).*$', '\\1') }}{{octet}}"
  - debug: var=new_ip

Output

TASK: [Echo the passed IP] ****************************************************
ok: [127.0.0.1] => {
    "127.0.0.1": "{{ 127.0.0.1 }}"
}
TASK: [Extract the last octet, increment it and store it] *********************
ok: [127.0.0.1] => {"ansible_facts": {"octet": "2"}}

TASK: [debug var=octet] *******************************************************
ok: [127.0.0.1] => {
    "octet": "2"
}
TASK: [Append the incremented octet to the first 3 octets] ********************
ok: [127.0.0.1] => {"ansible_facts": {"new_ip": "127.0.0.2"}}

TASK: [debug var=new_ip] ******************************************************
ok: [127.0.0.1] => {
    "new_ip": "127.0.0.2"
}

Upvotes: 3

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