i have in the inventory host with own variables:
children:
webserver:
vars:
hosts:
web01.local:
function: live
location: lca
web02.local:
function: test
location: lcb
now i would like to create a playbook, which installs the snmpd service on each of the hosts (all) and stores the value "location" from the inventory.
How can I access this variable "location" in the playbook?
If your playbook is targeting the remote hosts, you can just refer to the location variable:
- hosts: webserver
tasks:
- debug:
msg: "value of location: {{ location }}"
Related
I'm trying to create a playbook which basically consists 2 hosts init; (don't ask why)
---
- hosts: all
tasks:
- name: get the hostname of machine and save it as a variable
shell: hostname
register: host_name
when: ansible_host == "x.x.x.x" *(will be filled by my application)*
- hosts: "{{ host_name.stdout }}"
tasks:
- name: use the variable as hostname
shell: whoami
I don't have any hostname information in my application so I need to trigger my playbook with an IP address, then i should get the hostname of that machine and save it to a variable to use in my other tasks to avoid "when" command for each task.
The problem is that I'm able to use "host_name" variable in all other fields except "hosts", it gives me an Error like this when i try to run;
ERROR! The field 'hosts' has an invalid value, which includes an undefined variable. The error was: 'host_name' is undefined
Screenshot of the error
By default, Ansible itself gathers some information about a host. This happens at the beginning of a playbook's execution right after PLAY in TASK [Gathering Facts].
This automatic gathering of information about a system can be turned off via gather_facts: no, by default this is active.
This collected information is called Ansible Facts. An example of the collected facts is shown in the Ansible Docs, for your host you can print out all Ansible Facts:
either in the playbook as a task:
- name: Print all available facts
debug:
var: ansible_facts
or via CLI as an adhoc command:
ansible <hostname> -m setup
The Ansible Facts contain values like: ansible_hostname, ansible_fqdn, ansible_domain or even ansible_all_ipv4_addresses. This is the simplest way to act with the hostname of the client.
If you want to output the hostname and IP addresses that Ansible has collected, you can do it with the following tasks for example:
- name: Print hostname
debug:
var: ansible_hostname
- name: Print IP addresses
debug:
var: ansible_all_ipv4_addresses
If you start your playbook for all hosts, you can check the IP address and also stop it directly for the "wrong" clients.
---
- hosts: all
tasks:
- name: terminate execution for wrong hosts
assert:
that: '"x.x.x.x" is in ansible_all_ipv4_addresses'
fail_msg: Terminating because IP did not match
success_msg: "Host matched. Hostname: {{ ansible_hostname }}"
# your task for desired host
I am trying to use ansible to modify the hostnames of a dozen newly created Virtual Machines, and I am failing to understand how to loop correctly.
Here is the playbook I've written:
---
- hosts: k8s_kvm_vms
tasks:
- name: "update hostnames"
hostname:
name: "{{ item }}"
with_items:
- centos01
- centos02
...
The result is that it updates each host with each hostname. So if I have 12 machines, each hostname would be "centos12" at the end of the playbook.
I expect this behavior to essentially produce the same result as:
num=0
for ip in ${list_of_ips[*]}; do
ssh $ip hostnamectl set-hostname centos${num}
num=$((num+1))
done
If I were to write it myself in bash
The answer on this page leads me to believe I would have to include all of the IP addresses in my playbook. In my opinion, the advantage of scripting would be that I could have the same hostnames even if their IP changes (I just have to copy the ip addresses into /etc/ansible/hosts) which I could reuse with other playbooks. I have read the ansible page on the hostname module, but their example leads me to believe I would, instead of using a loop, have to define a task for each individual IP address. If this is the case, why use ansible over a bash script?
ansible hostname module
You can create a new variable for each of the servers in the inventory like
[k8s_kvm_vms]
server1 new_hostname=centos1
server2 new_hostname=centos2
Playbook:
---
- hosts: k8s_kvm_vms
tasks:
- name: "update hostnames"
hostname:
name: "{{ new_hostname }}"
I think you need to sudo to change the hostname thus you should add "become: yes"
---
- hosts: k8s_kvm_vms
become: yes
tasks:
- name: "update hostnames"
hostname:
name: "{{ new_hostname }}"
how can I edit a remote cfg file or in my case
I must modify the "hostname" by the name of the remote machine,
knowing that it is for automated because aprre I will deploy it on +300 server
I must be able to get the remote hostname and put it in the cfg file with ansible
thanks
############# file for config host ############
---
- hosts: computer_user
remote_user: toto
tasks:
- name: "config zabbix agent"
lineinfile:
path: /etc/zabbix.cfg
regexp: '(.*)hostname_local(.*)'
line: '%hostname%'
########### file_cfg_on_computer_user #########
hostname_local: here_i_want_put_the_hostname_of_my_computer_user_with_a_like_%hostname%
I'm not really sure about what you really want, but if you want to get the hostname of the system where your playbook is running, then you have two possibility :
You can get the value of inventory_hostname : It is the name of the hostname as configured in Ansible’s inventory host file
Or you can get the value of the ansible fact ansible_hostname : this one is discovered during the gathering fact phase
You can find more info about hosts variables and facts here
Ansible defines many special variables at runtime.
You can use {{ inventory_hostname }} to returns the inventory name for the ‘current’ host being iterated over in the play.
Or you can execute a remote command and use result in next task :
---
- hosts: computer_user
remote_user: toto
tasks:
- name: "get hostname from remote host"
shell: hostname
register: result_hostname
- name: "config zabbix agent"
lineinfile:
path: /etc/zabbix.cfg
regexp: '(.*)hostname_local(.*)'
line: '{{ result_hostname.stdout }}'
I want to write a bootstrapper playbook for new machines in Ansible which will reconfigure the network settings. At the time of the first execution target machines will have DHCP-assigned address.
The user who is supposed to execute the playbook knows the assigned IP address of a new machine. I would like to prompt the user for is value.
vars_prompt module allows getting input from the user, however it is defined under hosts section effectively preventing host address as the required value.
Is it possible without using a wrapper script modifying inventory file?
The right way to do this is to create a dynamic host with add_host and place it in a new group, then start a new play that targets that group. That way, if you have other connection vars that need to be set ahead of time (credentials/keys/etc) you could set them on an empty group in inventory, then add the host to it dynamically. For example:
- hosts: localhost
gather_facts: no
vars_prompt:
- name: target_host
prompt: please enter the target host IP
private: no
tasks:
- add_host:
name: "{{ target_host }}"
groups: dynamically_created_hosts
- hosts: dynamically_created_hosts
tasks:
- debug: msg="do things on target host here"
You could pass it with extra-vars instead.
Simply make your hosts section a variable such as {{ hosts_prompt }} and then pass the host on the command line like so:
ansible-playbook -i inventory/environment playbook.yml --extra-vars "hosts_prompt=192.168.1.10"
Or if you are using the default inventory file location of /etc/ansible/hosts you could simply use:
ansible-playbook playbook.yml --extra-vars "hosts_prompt=192.168.1.10"
Adding to Matt's answer for multiple hosts.
input example would be 192.0.2.10,192.0.2.11
- hosts: localhost
gather_facts: no
vars_prompt:
- name: target_host
prompt: please enter the target host IP
private: no
tasks:
- add_host:
name: "{{ item }}"
groups: dynamically_created_hosts
with_items: "{{ target_host.split(',') }}"
- hosts: dynamically_created_hosts
tasks:
- debug: msg="do things on target host here"
Disclaimer: The accepted answer offers the best solution to the problem. While this one is working it is based on a hack and I leave it as a reference.
I found out it was possible use a currently undocumented hack (credit to Bruce P for pointing me to the post) that turns the value of -i / --inventory parameter into an ad hoc list of hosts (reference). With just the hostname/ip address and a trailing space (like below) it refers to a single host without the need for the inventory file to exist.
Command:
ansible-playbook -i "192.168.1.21," playbook.yml
And accordingly playbook.yml can be run against all hosts (which in the above example will be equal to a single host 192.168.1.21):
- hosts: all
The list might contain more than one ip address -i "192.168.1.21,192.168.1.22"
Adding to Jacob's and Matt's examples, with the inclusion of a username and password prompt:
---
- hosts: localhost
pre_tasks:
- name: verify_ansible_version
assert:
that: "ansible_version.full is version_compare('2.10.7', '>=')"
msg: "Error: You must update Ansible to at least version 2.10.7 to run this playbook..."
vars_prompt:
- name: target_hosts
prompt: |
Enter Target Host IP[s] or Hostname[s] (comma separated)
(example: 1.1.1.1,myhost.example.com)
private: false
- name: username
prompt: Enter Target Host[s] Login Username
private: false
- name: password
prompt: Enter Target Host[s] Login Password
private: true
tasks:
- add_host:
name: "{{ item }}"
groups: host_groups
with_items:
- "{{ target_hosts.split(',') }}"
- add_host:
name: login
username: "{{ username }}"
password: "{{ password }}"
- hosts: host_groups
remote_user: "{{ hostvars['login']['username'] }}"
vars:
ansible_password: "{{ hostvars['login']['password'] }}"
ansible_become: yes
ansible_become_method: sudo
ansible_become_pass: "{{ hostvars['login']['password'] }}"
roles:
- my_role
Helllo, what is the best way to make an included playbook run on the same hosts as the playbook that called him?
I've tried declaring a variable in the parent playbook with the host name and then passing it to the included playbook, but I get an error telling me that the variable is undefined.
Below is my playbook:
---
# Main staging configuration playbook
- vars:
host_name: "stage_ansible"
hosts: "{{ host_name }}"
remote_user: ubuntu
tasks:
- name: test connection
ping:
remote_user: ubuntu
- include: NginxDefinitions.yml
vars:
service_name: "interaction.qmerce.com"
env_name: "stage4"
host_name_pass: "{{ host_name }}"
...
and the error I'm receiving:
`ERROR! 'host_name' is undefined
If you want to define the hosts runtime and avoid hard coding them on the playbook, you can pass the hosts as extra variables on the command line.
To do so, remove vars definition from your first play and add the following to the ansible-playbook command line:
--extra-vars host_name=localhost
or when you have multiple hosts:
--extra-vars '{"host_name":["host1","host2","host3"]}'