I’ll tell you about my scenario. I have a host file with two servers and two playbooks.
I need to perform the following, first I have to run a playbook on server number 1 and if there is no errors, I need to run the second playbook on server number 2.
What condition should I use?
- name: Execute the First Play
import_playbook: first-playbook-to-run.yml
- name: Run the Second Playbook
import_playbook: second-playbook-to-run.yml
Any helps?
Regards,
Try the below
- name: Execute the First Play
import_playbook: first-playbook-to-run.yml
delegate_to: server1
run_once: true
- name: Run the Second Playbook
import_playbook: second-playbook-to-run.yml
delegate_to: server2
run_once: true
Scenario
I have a group A in my inventory, where A contains a1,a2,a3 hosts. It does mean that I can write in my playbook X.yml:
- hosts: A
roles:
- role:
name: r
The problem is about playbook X is started with limited number of hosts, namely launch of ansible-playbook X is limited to host a1. This playbook X invoke role r (which is executed on host a1). I wouldn't like to change this behaviour (in other words I would like to preserve this limitation, don't ask why please).
Question
Is it possible to write task in role r in such way that it will be executed on all hosts from group A even if playbook is limited to host a1? Please keep in mind that my inventory contains group A.
If not, could you suggest me another approach?
The one that I can do is:
- hosts: A
tasks:
- name: "This task"
I do not know for certain, but this might work:
- name: Run task on hosts in group A
some_random_module:
var1: value1
var2: value2
delegate_to: "{{ item }}"
with_items: "{{ groups['A'] }}"
No promises.
We have a "periodic" tag in our roles that is intended to be run at regular intervals by our Ansible box for file assurance, etc. Would it be possible to have a playbook for periodic runs that calls the other playbooks with the appropriate host groups and tags?
The only way to execute an Ansible playbook "with the appropriate host groups and tags" is to run ansible-playbook executable. This is the only case in which all the data structures starting from the inventory would be created in isolation from the currently running playbook.
You can simply call the executable using command module on the control machine:
- hosts: localhost
tasks:
- command: ansible-playbook {{ playbook }} --tags {{ tags }}
You can also use local_action or delegate_to.
It might be that you want to include plays, or use roles, however given the problem description in the question, it's impossible to tell.
Here is what we ended up with: It turns out that tags and variables passed on the command-line are inherited all the way down the line. This allowed us to pass this on the command line:
ansible-playbook -t periodic periodic.yml
Which calls a playbook like this:
---
- name: This playbook must be called with the "periodic" tag.
hosts: 127.0.0.1
any_errors_fatal: True
tasks:
- fail:
when: periodic not True
- name: Begin periodic runs for type 1 servers
include: type1-server.yml
vars:
servers:
- host_group1
- host_group2
- ...
- name: Begin periodic runs for type 2 servers
...
Our 'real' playbooks have - hosts: "{{ servers }}" so that they can be inherited from the parent. The tasks in our roles are tagged with "periodic" for things that need to be run on a schedule. We then use SystemD to schedule the runs. You can use cron, but SystemD is better IMHO. Examples can be provided upon request.
- name: "API"
hosts: api
vars:
platform: "{{ application.api }}"
vars_files:
- vars/application-vars.yml
tasks:
- include: tasks/application-install.yml
- name: "JOBS"
hosts: jobs
vars:
platform: "{{ application.jobs }}"
vars_files:
- vars/application-vars.yml
tasks:
- include: tasks/application-install.yml
playbook like before described, can I execute this difference tasks on difference hosts in the same time as parallel way?
No sure what do you actually want, but I'd combine it into single play:
- hosts: api:jobs
tasks:
- include: tasks/application-install.yml
And add group vars to inventory:
[api:vars]
platform="{{ application.api }}"
[jobs:vars]
platform="{{ application.jobs }}"
This way you can run your playbook on all hosts at once, and also you can use --limit option to choose api or jobs group only.
you can run more playbooks using "ansible-playbook [OPTIONS] *.yml" command. This will execute all the playbooks NOT IN PARALLEL WAY, but in serial way, so first one playbook and after the execution, another playbook. This command can be helpful if you have many playbooks.
I don't know a way to execute more playbooks in parallel.
This is a fragment of a playbook that I'm using (server.yml):
- name: Determine Remote User
hosts: web
gather_facts: false
roles:
- { role: remote-user, tags: [remote-user, always] }
My hosts file has different groups of servers, e.g.
[web]
x.x.x.x
[droplets]
x.x.x.x
Now I want to execute ansible-playbook -i hosts/<env> server.yml and override hosts: web from server.yml to run this playbook for [droplets].
Can I just override as a one time off thing, without editing server.yml directly?
Thanks.
I don't think Ansible provides this feature, which it should. Here's something that you can do:
hosts: "{{ variable_host | default('web') }}"
and you can pass variable_host from either command-line or from a vars file, e.g.:
ansible-playbook server.yml --extra-vars "variable_host=newtarget(s)"
For anyone who might come looking for the solution.
Play Book
- hosts: '{{ host }}'
tasks:
- debug: msg="Host is {{ ansible_fqdn }}"
Inventory
[web]
x.x.x.x
[droplets]
x.x.x.x
Command: ansible-playbook deplyment.yml -i hosts --extra-vars "host=droplets"
So you can specify the group name in the extra-vars
We use a simple fail task to force the user to specify the Ansible limit option, so that we don't execute on all hosts by default/accident.
The easiest way I found is this:
---
- name: Force limit
# 'all' is okay here, because the fail task will force the user to specify a limit on the command line, using -l or --limit
hosts: 'all'
tasks:
- name: checking limit arg
fail:
msg: "you must use -l or --limit - when you really want to use all hosts, use -l 'all'"
when: ansible_limit is not defined
run_once: true
Now we must use the -l (= --limit option) when we run the playbook, e.g.
ansible-playbook playbook.yml -l www.example.com
Limit option docs:
Limit to one or more hosts This is required when one wants to run a
playbook against a host group, but only against one or more members of
that group.
Limit to one host
ansible-playbook playbooks/PLAYBOOK_NAME.yml --limit "host1"
Limit to multiple hosts
ansible-playbook playbooks/PLAYBOOK_NAME.yml --limit "host1,host2"
Negated limit.
NOTE: Single quotes MUST be used to prevent bash
interpolation.
ansible-playbook playbooks/PLAYBOOK_NAME.yml --limit 'all:!host1'
Limit to host group
ansible-playbook playbooks/PLAYBOOK_NAME.yml --limit 'group1'
This is a bit late, but I think you could use the --limit or -l command to limit the pattern to more specific hosts. (version 2.3.2.0)
You could have
- hosts: all (or group)
tasks:
- some_task
and then ansible-playbook playbook.yml -l some_more_strict_host_or_pattern
and use the --list-hosts flag to see on which hosts this configuration would be applied.
An other solution is to use the special variable ansible_limit which is the contents of the --limit CLI option for the current execution of Ansible.
- hosts: "{{ ansible_limit | default(omit) }}"
If the --limit option is omitted, then Ansible issues a warning, but does nothing since no host matched.
[WARNING]: Could not match supplied host pattern, ignoring: None
PLAY ****************************************************************
skipping: no hosts matched
I'm using another approach that doesn't need any inventory and works with this simple command:
ansible-playbook site.yml -e working_host=myhost
To perform that, you need a playbook with two plays:
first play runs on localhost and add a host (from given variable) in a known group in inmemory inventory
second play runs on this known group
A working example (copy it and runs it with previous command):
- hosts: localhost
connection: local
tasks:
- add_host:
name: "{{ working_host }}"
groups: working_group
changed_when: false
- hosts: working_group
gather_facts: false
tasks:
- debug:
msg: "I'm on {{ ansible_host }}"
I'm using ansible 2.4.3 and 2.3.3
I changed mine to default to no host and have a check to catch it. That way the user or cron is forced to provide a single host or group etc. I like the logic from the comment from #wallydrag. The empty_group contains no hosts in the inventory.
- hosts: "{{ variable_host | default('empty_group') }}"
Then add the check in tasks:
tasks:
- name: Fail script if required variable_host parameter is missing
fail:
msg: "You have to add the --extra-vars='variable_host='"
when: (variable_host is not defined) or (variable_host == "")
Just came across this googling for a solution. Actually, there is one in Ansible 2.5. You can specify your inventory file with --inventory, like this: ansible --inventory configs/hosts --list-hosts all
If you want to run a task that's associated with a host, but on different host, you should try delegate_to.
In your case, you should delegate to your localhost (ansible master) and calling ansible-playbook command
I am using ansible 2.5 (2.5.3 exactly), and it seems that the vars file is loaded before the hosts param is executed. So you can set the host in a vars.yml file and just write hosts: {{ host_var }} in your playbook
For example, in my playbook.yml:
---
- hosts: "{{ host_name }}"
become: yes
vars_files:
- vars/project.yml
tasks:
...
And inside vars/project.yml:
---
# general
host_name: your-fancy-host-name
Here's a cool solution I came up to safely specify hosts via the --limit option. In this example, the play will end if the playbook was executed without any hosts specified via the --limit option.
This was tested on Ansible version 2.7.10
---
- name: Playbook will fail if hosts not specified via --limit option.
# Hosts must be set via limit.
hosts: "{{ play_hosts }}"
connection: local
gather_facts: false
tasks:
- set_fact:
inventory_hosts: []
- set_fact:
inventory_hosts: "{{inventory_hosts + [item]}}"
with_items: "{{hostvars.keys()|list}}"
- meta: end_play
when: "(play_hosts|length) == (inventory_hosts|length)"
- debug:
msg: "About to execute tasks/roles for {{inventory_hostname}}"
This worked for me as I am using Azure devops to deploy an application using CICD pipelines. I had to make this hosts (in yml file) more dynamic so in release pipeline I can add it's value, for example:
--extra-vars "host=$(target_host)"
pipeline_variable
My ansible playbook looks like this
- name: Apply configuration to test nodes
hosts: '{{ host }}'