Ansible: Get all the IP addresses of a group - jinja2

Question

Let's imagine an inventory file like this:
node-01 ansible_ssh_host=192.168.100.101
node-02 ansible_ssh_host=192.168.100.102
node-03 ansible_ssh_host=192.168.100.103
node-04 ansible_ssh_host=192.168.100.104
node-05 ansible_ssh_host=192.168.100.105
[mainnodes]
node-[01:04]
In my playbook I now want to create some variables containing the IP addresses of the group mainnodes:
vars:
main_nodes_ips: "192.168.100.101,192.168.100.102,192.168.100.103,192.168.100.104"
main_nodes_ips_with_port: "192.168.100.101:3000,192.168.100.102:3000,192.168.100.103:3000,192.168.100.104:3000"
This is what I got so far:
vars:
main_nodes_ips: "{{groups['mainnodes']|join(',')}}"
main_nodes_ips_with_port: "{{groups['mainnodes']|join(':3000,')}}"
but that would use the host names instead of the IP addresses.
Any ideas how this could be done?
Update:
looking at the docs for a while, I think this would allow me to loop through all the ip adresses:
{% for host in groups['mainnodes'] %}
{{hostvars[host]['ansible_ssh_host']}}
{% endfor %}
But I just can't figure out how to create an array that holds all these IPs. So that I can use the |join() command on them.
Update2:
I just thought I had figured it out... but it turns out that you cannot use the {% %} syntax in the playbook... or can I?
Well in the vars section it didn't. :/
vars:
{% set main_nodes_ip_arr=[] %}
{% for host in groups['mesos-slave'] %}
{% if main_nodes_ip_arr.insert(loop.index,hostvars[host]['ansible_ssh_host']) %} {% endif %}
{% endfor %}
main_nodes_ips: "{{main_nodes_ip_arr|join(',')}}"
main_nodes_ips_with_port: "{{main_nodes_ip_arr|join(':3000,')}}"

Answer 1

I find the magic map extract here.
main_nodes_ips: "{{ groups['mainnodes'] | map('extract', hostvars, ['ansible_host']) | join(',') }}"
main_nodes_ips_with_port: "{{ groups['mainnodes'] | map('extract', hostvars, ['ansible_host']) | join(':3000,') }}:3000"
An alternative(idea comes from here):
main_nodes_ips: "{{ groups['mainnodes'] | map('extract', hostvars, ['ansible_eth0', 'ipv4', 'address']) | join(',') }}"
(Suppose the interface is eth0)

Answer 2

i came across this problem a while back and this is what i came up with (not optimal, but it works)
---
# playbook.yml
- hosts: localhost
connection: local
tasks:
- name: create deploy template
template:
src: iplist.txt
dest: /tmp/iplist.txt
- include_vars: /tmp/iplist.txt
- debug: var=ip
and the template file is
ip:
{% for h in groups['webservers'] %}
- {{ hostvars[h].ansible_ssh_host }}
{% endfor %}

Answer 3

This do the trick for me. Not relying on the interface name
- main_nodes_ips: "{{ groups['mainnodes'] | map('extract', hostvars, ['ansible_default_ipv4', 'address']) | join(',') }}"

Answer 4

- name: Create List of nodes to be added into Cluster
set_fact: nodelist={%for host in groups['mygroup']%}"{{hostvars[host].ansible_eth0.ipv4.address}}"{% if not loop.last %},{% endif %}{% endfor %}
- debug: msg=[{{nodelist}}]
- name: Set Cluster node list in config file
lineinfile:
path: "/etc/myfonfig.cfg"
line: "hosts: [{{ nodelist }}]"
as results you will have the following line in config file:
hosts: ["192.168.126.38","192.168.126.39","192.168.126.40"]

Answer 5

I got it to work on my own now. I'm not too happy about the solution, but it will do:
main_nodes_ips: "{% set IP_ARR=[] %}{% for host in groups['mainnodes'] %}{% if IP_ARR.insert(loop.index,hostvars[host]['ansible_ssh_host']) %}{% endif %}{% endfor %}{{IP_ARR|join(',')}}"
main_nodes_ips_with_port: "{% set IP_ARR=[] %}{% for host in groups['mainnodes'] %}{% if IP_ARR.insert(loop.index,hostvars[host]['ansible_ssh_host']) %}{% endif %}{% endfor %}{{IP_ARR|join(':3000,')}

Answer 6

I've done this by using ansible facts in a playbook.
This playbook takes ansible_all_ipv4_addresses list and ansible_nodename (which is actually fully qualified domain name), iterates through all hosts and saves the data in localpath_to_save_ips file on your localhost. You can change localpath_to_save_ips to the absolute path on your localhost.
---
- hosts: all
become: yes
gather_facts: yes
tasks:
- name: get ip
local_action: shell echo {{ ansible_all_ipv4_addresses }} {{ ansible_nodename }} >> localpath_to_save_ips

Answer 7

I found the "only way" to acceess other group's ip's, when any of the following is true:
some members are not bootstrapped by ansible yet
using serial
group is not part of playbook
Is as follows:
{% set ips=[] %}{% for host in groups['othergroup'] %}{% if ips.append(lookup('dig', host)) %}{% endif %}{% endfor %}{{ ips }}
Requires dnspython on the machine running ansible, install via
sudo apt-get install python-dnspython
If anyone knows a better way given the conditions, I'd love to get rid of this abomination.

Answer 8

this is what I did in order to not be relied on eth0 (thanks to ADV-IT's answer):
- name: gathering facts
hosts: mainnodes
gather_facts: true
- hosts: mainnodes
tasks:
- name: Create List of nodes
set_fact: nodelist={%for host in groups['mainnodes']%}"{{hostvars[host]['ansible_env'].SSH_CONNECTION.split(' ')[2]}}"{% if not loop.last %},{% endif %}{% endfor %}

Answer 9

I ran into a similar problem getting the IP address of a node in another group.
Using a construct like:
the_ip: "{{ hostvars[groups['master'][0]]['ansible_default_ipv4'].address }}"
works only when running the group master, which was not part of my playbook (I was running on localhost).
I have overcome the problem by adding an extra play to playbook, like:
- hosts: master
gather_facts: yes
become: no
vars:
- the_master_ip: "{{ hostvars[groups['master'][0]]['ansible_default_ipv4'].address }}"
tasks:
- debug: var=the_master_ip
- set_fact: the_ip={{ the_master_ip }}
After which I can use the the_ip in the next play of the playbook.
This may also solve the abomination mentioned by #Petroldrake ?

Answer 10

##Just fetch Ip's using -ansible_default_ipv4.address- & redirect to a local file & then use it
name: gathering_facts
hosts: hosts
gather_facts: true
tasks:
name: Rediret to the file
shell: echo "{{ansible_default_ipv4.address}}" >>ipss.txt
delegate_to: localhost