I have paly to copy the web server logs from remote machine to Ansible machine. At the end of the playbook, I want to find the file with pattern and remove it. in the task I have defined delegate_to: 127.0.0.1 but this task is running one of the remote machine.
How to make these task run on only localhost and run once:
- name: Finds files and folders
find:
paths: "/tmp/"
patterns: "access-*.tar.gz"
recurse: no
use_regex: yes
register: result
delegate_to: 127.0.0.1
run_once: true
tags:
- pulllogs
- name: display filename
debug:
msg: "{{ result }}"
delegate_to: 127.0.0.1
run_once: true
tags:
- pulllogs
Output:
TASK [operate : Finds files and folders] ***********************************************************************************************************************************************
ok: [host01]
TASK [operate : display filename] ******************************************************************************************************************************************************
ok: [host01] =>
msg:
changed: false
examined: 640
failed: false
files: []
matched: 0
msg: ''
In Ansible 2.10 the delegation works as expected. In the output, I can't see the delegation either. But both plays, running at localhost and at delegated localhost respectively, show the same results. For example, given the archive at localhost
shell> sudo find /tmp -name 'access-*.tar.gz'
/tmp/access-01.tar.gz
and no archives at the remote host
shell> ssh admin#test_11 sudo find /tmp -name 'access-*.tar.gz'
the playbook
- hosts: localhost
tasks:
- find:
paths: /tmp
patterns: "access-*.tar.gz"
recurse: false
use_regex: false
register: result
- debug:
msg: "{{ result.files|map(attribute='path')|list }}"
- hosts: test_11,test_12,test_13
tasks:
- block:
- find:
paths: /tmp
patterns: "access-*.tar.gz"
recurse: false
use_regex: false
register: result
- debug:
msg: "{{ result.files|map(attribute='path')|list }}"
delegate_to: 127.0.0.1
run_once: true
shows the same results at localhost and delegated localhost
PLAY [localhost] **********************************************************
TASK [find] ***************************************************************
ok: [localhost]
TASK [debug] **************************************************************
ok: [localhost] =>
msg:
- /tmp/access-01.tar.gz
PLAY [test_11,test_12,test_13] ********************************************
TASK [find] ***************************************************************
ok: [test_11]
TASK [debug] **************************************************************
ok: [test_11] =>
msg:
- /tmp/access-01.tar.gz
PLAY RECAP ****************************************************************
localhost : ok=2 changed=0 unreachable=0 failed=0 skipped=0 rescued=0 ignored=0
test_11 : ok=2 changed=0 unreachable=0 failed=0 skipped=0 rescued=0 ignored=0
Related
I have a script that will execute in two parts. First it will execute on localhost and query a database table to get a hostname. second part of the script should run on the host which was registered in the query before. I am not able to set the host with the set_fact I did in the first part of the code.
this is what iam trying to do:
- hosts: localhost
gather_facts: false
become: yes
become_user: oracle
vars_files:
- vars/main.yml
tasks:
- name: Get new hostname
tempfile:
state: file
register: tf
- name: create sql file
template:
src: get_hostname.sql.j2
dest:"{{ tf.path }}"
mode: 0775
- name: login
command:
argv:
- "sqlplus"
- -s
- "#{{ tf.path }}"
environment:
ORACLE_HOME: "oracle/home"
register: command_out
- set_fact:
NEW_HOST: "{{ command_out.stdout }}"
- hosts: "{{ NEW_HOST }}"
gather_facts: false
become: yes
become_user: oracle
vars_file:
- vars/main.yml
tasks:
- name: debug
command: hostname
register: new_host_out
- debug:
msg: "new host is {{ new_host_out.stdout }}"
Everything works fine in the first part of the code, but errors out at the second part saying it cannot find the NEW_HOST.
Use hostvars to reference such a variable. Create a dummy host to keep this variable. For example, given the inventory
shell> cat hosts
dummy
[test]
test_11
test_12
test_13
The playbook creates the variable. See Delegated facts
shell> cat pb.yml
- hosts: localhost
tasks:
- set_fact:
NEW_HOST: test_12
delegate_to: dummy
delegate_facts: true
- debug:
var: hostvars.dummy.NEW_HOST
- hosts: "{{ hostvars.dummy.NEW_HOST }}"
gather_facts: false
tasks:
- debug:
var: inventory_hostname
gives
shell> ansible-playbook pb.yml
PLAY [localhost] ****************************************************************************
TASK [set_fact] *****************************************************************************
ok: [localhost -> dummy]
TASK [debug] ********************************************************************************
ok: [localhost] =>
hostvars.dummy.NEW_HOST: test_12
PLAY [test_12] ******************************************************************************
TASK [debug] ********************************************************************************
ok: [test_12] =>
inventory_hostname: test_12
PLAY RECAP **********************************************************************************
localhost: ok=2 changed=0 unreachable=0 failed=0 skipped=0 rescued=0 ignored=0
test_12 : ok=1 changed=0 unreachable=0 failed=0 skipped=0 rescued=0 ignored=0
You can use localhost for this purpose as well. The playbook below works as expected
- hosts: localhost
tasks:
- set_fact:
NEW_HOST: test_12
- hosts: "{{ hostvars.localhost.NEW_HOST }}"
gather_facts: false
tasks:
- debug:
var: inventory_hostname
I have following inventory file
$ cat hosts
[web]
server1.example.com
server2.example.com
I would like to fetch the hostname, without the part of domain (.example.com).
I tried with the following playbook, however, it is still fetching with the entire hostname..
$ playbook.yaml
- hosts: localhost
tasks:
- debug:
msg: "{{ groups['web'] }}"
Output
PLAY [localhost] *************************************************************************************************************************************************************
TASK [Gathering Facts] *******************************************************************************************************************************************************
ok: [localhost]
TASK [debug] *****************************************************************************************************************************************************************
ok: [localhost] => {
"msg": [
"server1.example.com"
"server2.example.com"
]
}
PLAY RECAP *******************************************************************************************************************************************************************
localhost : ok=2 changed=0 unreachable=0 failed=0 skipped=0 rescued=0 ignored=0
Expected output
PLAY [localhost] *************************************************************************************************************************************************************
TASK [Gathering Facts] *******************************************************************************************************************************************************
ok: [localhost]
TASK [debug] *****************************************************************************************************************************************************************
ok: [localhost] => {
"msg": [
"server1"
"server2"
]
}
PLAY RECAP *******************************************************************************************************************************************************************
localhost : ok=2 changed=0 unreachable=0 failed=0 skipped=0 rescued=0 ignored=0
You can get what you want from a magic variable called inventory_hostname_short which basically returns anything before the first . found in the inventory_hostname.
To get this in a normal play host loop, it's as easy as:
- hosts: all
tasks:
- name: show target short name
debug:
var: inventory_hostname_short
If you need to get that for hosts not in the host loop, you will have to go through hostvars. Here is an example to get all those names in a list for a given group running from localhost:
- hosts: localhost
gather_facts: false
tasks:
- name: show list of shortnames for group 'toto'
debug:
msg: "{{ groups['toto'] | map('extract', hostvars, 'inventory_hostname_short') }}"
An other example to get that name only for the first server in group 'toto'
- hosts: localhost
gather_facts: false
tasks:
- name: show shortnames for first server in group 'toto'
vars:
server_name: "{{ groups['toto'][0] }}"
debug:
msg: "{{ hostvars[server_name].inventory_hostname_short }}"
ansible version: 2.9.16 running on RHEL 7.9 python ver = 2.7.5 targeting windows 2016 servers. ( should behave the same for linux target servers too)
EDIT: Switched to using host specific variables in inventory to avoid confusion that Iam just trying to print hostnames of a group. Even here its a gross simplification. Pretend that var1 is obtained dynamically for each server instead of being declared in the inventory file.
My playbook has two plays. One targets 3 remote servers ( Note: serial: 0 i.e Concurrently ) and another just the localhost. In play1 I am trying to delegate facts obtained from each of these hosts to the localhost using delegate_facts and delegate_to. The intent is to have these facts delegated to a single host ( localhost ) so I can use it later in a play2 (using hostvars) that targets the localhost. But strangely thats not working. It only has information from the last host from Play1.
Any help will be greatly appreciated.
my inventory file inventory/test.ini looks like this:
[my_servers]
svr1 var1='abc'
svr2 var1='xyz'
svr3 var1='pqr'
My Code:
## Play1
- name: Main play that runs against multiple remote servers and builds a list.
hosts: 'my_servers' # my inventory group that contains 3 servers svr1,svr2,svr3
any_errors_fatal: false
ignore_unreachable: true
gather_facts: true
serial: 0
tasks:
- name: initialize my_server_list as a list and delegate to localhost
set_fact:
my_server_list: []
delegate_facts: yes
delegate_to: localhost
- command: /root/complex_script.sh
register: result
- set_fact:
my_server_list: "{{ my_server_list + hostvars[inventory_hostname]['result.stdout'] }}"
# run_once: true ## Commented as I need to query the hostvars for each host where this executes.
delegate_to: localhost
delegate_facts: true
- name: "Print list - 1"
debug:
msg:
- "{{ hostvars['localhost']['my_server_list'] | default(['NotFound']) | to_nice_yaml }}"
# run_once: true
- name: "Print list - 2"
debug:
msg:
- "{{ my_server_list | default(['NA']) }}"
## Play2
- name: Print my_server_list which was built in Play1
hosts: localhost
gather_facts: true
serial: 0
tasks:
- name: "Print my_server_list without hostvars "
debug:
msg:
- "{{ my_server_list | to_nice_json }}"
# delegate_to: localhost
- name: "Print my_server_list using hostvars"
debug:
msg:
- "{{ hostvars['localhost']['my_server_list'] | to_nice_yaml }}"
# delegate_to: localhost
###Output###
$ ansible-playbook -i inventory/test.ini delegate_facts.yml
PLAY [Main playbook that runs against multiple remote servers and builds a list.] ***********************************************************************************************************
TASK [Gathering Facts] **********************************************************************************************************************************************************************
ok: [svr3]
ok: [svr1]
ok: [svr2]
TASK [initialize] ***************************************************************************************************************************************************************************
ok: [svr1]
ok: [svr2]
ok: [svr3]
TASK [Build a list of servers] **************************************************************************************************************************************************************
ok: [svr1]
ok: [svr2]
ok: [svr3]
TASK [Print list - 1] ***********************************************************************************************************************************************************************
ok: [svr1] =>
msg:
- |-
- pqr
ok: [svr2] =>
msg:
- |-
- pqr
ok: [svr3] =>
msg:
- |-
- pqr
TASK [Print list - 2] ***********************************************************************************************************************************************************************
ok: [svr1] =>
msg:
- - NA
ok: [svr2] =>
msg:
- - NA
ok: [svr3] =>
msg:
- - NA
PLAY [Print my_server_list] *****************************************************************************************************************************************************************
TASK [Gathering Facts] **********************************************************************************************************************************************************************
ok: [localhost]
TASK [Print my_server_list without hostvars] ************************************************************************************************************************************************
ok: [localhost] =>
msg:
- |-
[
"pqr"
]
TASK [Print my_server_list using hostvars] **************************************************************************************************************************************************
ok: [localhost] =>
msg:
- |-
- pqr
PLAY RECAP **********************************************************************************************************************************************************************************
localhost : ok=3 changed=0 unreachable=0 failed=0 skipped=0 rescued=0 ignored=0
svr1 : ok=5 changed=0 unreachable=0 failed=0 skipped=0 rescued=0 ignored=0
svr2 : ok=5 changed=0 unreachable=0 failed=0 skipped=0 rescued=0 ignored=0
svr3 : ok=5 changed=0 unreachable=0 failed=0 skipped=0 rescued=0 ignored=0
Playbook run took 0 days, 0 hours, 0 minutes, 13 seconds
###Expected Output###
I was expecting the last two debug statements in Play2 to contain the values of var1 for all the servers something like this:
TASK [Print my_server_list using hostvars] **************************************************************************************************************************************************
ok: [localhost] =>
msg:
- |-
- abc
- xyz
- pqr
Use Special Variables, e.g.
- hosts: all
gather_facts: false
tasks:
- set_fact:
my_server_list: "{{ ansible_play_hosts_all }}"
run_once: true
delegate_to: localhost
delegate_facts: true
- hosts: localhost
gather_facts: false
tasks:
- debug:
var: my_server_list
gives
ok: [localhost] =>
my_server_list:
- svr1
- svr2
- svr3
There are many other ways how to create the list, e.g.
- hosts: all
gather_facts: false
tasks:
- debug:
msg: "{{ groups.my_servers }}"
run_once: true
- hosts: all
gather_facts: false
tasks:
- debug:
msg: "{{ hostvars|json_query('*.inventory_hostname') }}"
run_once: true
Q: "Fill the list with outputs gathered by running complex commands."
A: Last example above shows how to create a list from hostvars. Register the result from the complex command, e.g.
shell> ssh admin#srv1 cat /root/complex_script.sh
#!/bin/sh
ifconfig wlan0 | grep inet | cut -w -f3
The playbook
- hosts: all
gather_facts: false
tasks:
- command: /root/complex_script.sh
register: result
- set_fact:
my_server_list: "{{ hostvars|json_query('*.result.stdout') }}"
run_once: true
delegate_to: localhost
delegate_facts: true
- hosts: localhost
gather_facts: false
tasks:
- debug:
var: my_server_list
gives
my_server_list:
- 10.1.0.61
- 10.1.0.62
- 10.1.0.63
Q: "Why the logic of delegating facts to localhost and keep appending them to that list does not work?"
A: The code below (simplified) can't work because the right-hand-side msl value still comes from the hostvars of the inventory_host despite the fact delegate_facts: true. This merely puts the created variable msl into the localhost's hostvars
- hosts: my_servers
tasks:
- set_fact:
msl: "{{ msl|default([]) + [inventory_hostname] }}"
delegate_to: localhost
delegate_facts: true
Quoting from Delegating facts
To assign gathered facts to the delegated host instead of the current host, set delegate_facts to true
As a result of such code, the variable msl will keep the last assigned value only.
I have this URL string server https://test.example.com:6443. I need to extract only hostname test from it using Ansible task.
came up with this playbook, Is there a better way of doing this with-out using sed?
- hosts: localhost
connection: local
gather_facts: no
tasks:
- name: get the URL
shell: echo 'server https://test.example.com:6443' |sed -e 's/^.*https...//' -e 's/\..*$//'
register: result
- name: Print the var
debug:
msg: "{{ result.stdout }}"
Output
PLAY [localhost] *********************************************************************************************************************
TASK [get the URL] *******************************************************************************************************************
changed: [localhost]
TASK [Print the var] *****************************************************************************************************************
ok: [localhost] => {
"msg": "test"
}
PLAY RECAP ***************************************************************************************************************************
localhost : ok=2 changed=1 unreachable=0 failed=0 skipped=0 rescued=0 ignored=0
You can use split on the URL name and get the desired value, Ideally hostname should be test.example.com in your case. However, you can customize the split function based on your need also as below.
- hosts: localhost
connection: local
gather_facts: no
vars:
url: "https://test.example.com:6443"
tasks:
- name: Print the hostname var
debug:
msg: "{{ url.split(':')[1].split('//')[1] }}"
- name: Print the subdomain prefix
debug:
msg: "{{ url.split(':')[1].split('//')[1].split('.')[0] }}"
In ansible what i require is to check for a file is available on two hosts. But if the file is available on even one host i need to cancel the task on other host and move onto the next task. The reason why i require this is because a the next task can only be done if that particular file is available and that file can be randomly written to any of the hosts.
The following play does exactly what you want:
---
- hosts:
- server1
- server2
gather_facts: False
vars:
file_name: 'foo.bar'
tasks:
- name: wait for file
wait_for:
path: '{{ file_name }}'
state: present
timeout: 30
ignore_errors: True
- name: stat
stat:
path: '{{ file_name }}'
register: result
- name: next
debug:
msg: "File {{ file_name }} available on {{ ansible_host }}"
when: result.stat.isreg is defined and result.stat.isreg
The output is:
PLAY [server1,server2] *********************************************************
TASK [wait for file] ***********************************************************
ok: [server1]
fatal: [server2]: FAILED! => {"changed": false, "elapsed": 3, "msg": "Timeout when waiting for file foo.bar"}
...ignoring
TASK [stat] ********************************************************************
ok: [server1]
ok: [server2]
TASK [next] ********************************************************************
skipping: [server2]
ok: [server1] => {
"msg": "File foo.bar available on server1"
}
PLAY RECAP *********************************************************************
server1 : ok=3 changed=0 unreachable=0 failed=0
server2 : ok=0 changed=0 unreachable=0 failed=0
You can use the stat module to check the status like below and for also you can add the serial:1 below hosts: in your playbook
stat:
path: /path/to/something
register: p
debug:
msg: "Path exists and is a directory"
when: p.stat.isdir is defined and p.stat.isdir
https://docs.ansible.com/ansible/latest/modules/stat_module.html for more details