I'm trying to create a playbook that will first modify another playbook, then run that modified version of the playbook. But import_playbook pre-processes, so the original playbook, not the modified, is run. Is there any way to tell Ansible to re-read this playbook? Note I am changing more that the hosts, but using this simple example.
- name: Change the playbook
hosts: localhost
connection: local
gather_facts: False
tasks:
- name: Change the playbook
lineinfile:
path: "my_playbook.yml"
regexp: "- hosts: some_group_name"
line: "- hosts: some_other_group_name"
- name: Include the playbook that was modified
import_playbook: my_playbook.yml
With proper organized inventory, group_vars, variables, templating and add_host or dynamic inventory, there is no need for self-modifying code (SMC).
Regarding
But import_playbook pre-processes, so the original playbook ...
you may have a look into What's the difference between include_tasks and import_tasks?.
Furthermore, there is no dynamic include_playbook.
I have written a playbook which copies a file from source to destination on multiple hosts. The playbook works if all hosts are reachable but it doesn't fail if one of the host is unreachable.
ansible-playbook -i "10.11.12.13,10.11.12.14," -e "hostid=12345" test.yml
.e.g. if the host "10.11.12.13" is not reachable task execution skips the unreachable host and move onto the next host.
Sample playbook
- hosts: localhost
gather_facts: no
tasks:
- debug: msg="backup_restore.py file not found"
- name: Copy file
hosts: all
remote_user: test
gather_facts: no
vars:
srcFolder: "/home/test"
destFolder: "/opt/config"
tasks:
- block:
- name: Copy file to node
copy:
src: '{{srcFolder}}/self.config'
dest: '{{destFolder}}/self.config'
Is there a way to fail the task if the any of the hosts are not reachable. I am using ansible 2.6.1. Thank you in advance.
Brute force solution is any_errors_fatal
- name: Copy file
hosts: all
any_errors_fatal: true
Overview of other options is in Abort execution of remaining task if certain condition is failed.
I'm running an Ansible playbook for host_a. Some tasks I delegate to host_b.
Now I would like to use the synchronize module to copy a directory from localhost to host_b. But delegate_to is the wrong option here, since this results in copying from host_b to host_a.
Is there a possibility to do that?
- hosts: host_a
tasks:
- name: rsync directory from localhost to host_b
synchronize:
# files on localhost
src: files/directory
dest: /directory/on/host_b
# delegate_to does not work here
# delegate_to: host_b
The only solution I can think of is deleting the target directory and then using a recursive copy with the copy module.
I couldn't find anything in the module documentation.
(Using ansible 2.4.2.0)
Doing this task in its own play for host_b is also not really an option because the variables I need for this task depend on host_a.
The easiest solution in this case is to use rsync command with local_action, i.e
- hosts: cache1
tasks:
- name: rsync directory from localhost to host_b
local_action: command rsync -az "{{ playbook_dir }}/files/directory" "{{ hostvars['host_b']['ansible_host'] }}:/directory/on/host_b"
{{ playbook_dir }} helps by not hardcoding paths on local system.
I'm trying to look for a text pattern in a load balancer host from a worker host, using the following:
- name: A play
hosts: workers
tasks:
- name: Look for text pattern in delegated host
delegate_to: load-balancer-host
find:
paths: "$ENVIRONMENT_VARIABLE/subdir"
file_type: file
patterns: file.pattern
contains: 'text pattern'
register: aVariable
The problem is that I can't found any way to make $ENVIRONMENT_VARIABLE (this variable exists in the load-balancer-host) available for the play (it contains the directory, in load-balancer-host, from where I want to look for). ansible_env is only available for the workers but not for the load-balancer-host
I have tried...
- name: A play
hosts: workers
tasks:
- name: set fact
set_fact:
env_var: "{{ lookup('env', 'ENVIRONMENT_VARIABLE') }}"
delegate_to: load-balancer-host
- name: debug
debug:
msg: "{{ env_var }}"
... too, but it prints an empty string.
For users running Ansible 1.x, see kfreezy's answer.
For users running Ansible 2.x, I have found the following solution:
- hosts: workers
tasks:
- name: gather facts from lb
setup:
delegate_to: load-balancer-host
delegate_facts: false
This task will make $ENVIRONMENT_VARIABLE available in every worker ansible_env var. If you want to make $ENVIRONMENT_VARIABLE available in the load-balancer-host ansible_env, just set delegate_facts to True.
More info in ansible docs
Personally I would simplify your playbook by either adding the $ENVIRONMENT_VARIABLE as a variable in Ansible (probably in the host_vars for load-balancer-host) or running a play against load-balancer-host rather than use delegate_to. It might not make sense depending on what the other tasks are.
Here's a direct answer to your question though.
load-balancer-host's ansible_env will only be defined when the host is included in the playbook. You can add another play against the 'load-balancer-host' that will just gather facts. Then you can reference the facts from 'load-balancer-host' using hostvars in your subsequent plays against 'workers'. He's what it would look like.
- hosts: load-balancer-host
tasks:
- name: print debug message
debug:
msg: "this play is for gathering facts on the LB"
- name: A play
hosts: workers
tasks:
- name: Look for text pattern in delegated host
delegate_to: load-balancer-host
find:
paths: "{{ hostvars['load-balancer-host'].ansible_env.ENVIRONMENT_VARIABLE }}/subdir"
file_type: file
patterns: file.pattern
contains: 'text pattern'
register: aVariable
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 }}'