How to access a programmatically constructed ansible variable? - ansible

I have constructed an ansible variable using two other defined ansible variables. The constructed variable is defined in the vars/main.yml and I want to access the defined value in vars/main.yml.
vars/main.yml
---
var1_var2: "some value"
Now, I construct the variable
---
- name: Construct and get the value
hosts: localhost
tasks:
- include_vars: "vars/main.yml"
- set_fact:
variable1: "var1"
variable2: "var2"
- set_fact:
final_variable: "{{ variable1 }}_{{ variable2 }}"
- set_fact:
ultimate_variable: "{{ final_variable }}"
If I run the playbook with -vvv flag, I can see that ultimate_variable sets to var1_var2 while I want to get the value defined in the vars/main.yml
i.e., some value
TASK [set_fact]
ok: [localhost] => {
"ansible_facts": {
"variable1": "var1",
"variable2": "var2"
},
"changed": false,
"failed": false
}
TASK [set_fact] task path: /home/ubuntu/test.yml:78
ok: [localhost] => {
"ansible_facts": {
"final_variable": "var1_var2"
},
"changed": false,
"failed": false
}
TASK [set_fact]
ok: [localhost] => {
"ansible_facts": {
"ultimate_variable": "var1_var2"
},
"changed": false,
"failed": false
}

updated answer:
use the lookup plugin to do the double replacement:
ultimate_variable: "{{ lookup('vars', '{{final_variable}}') }}"
playbook:
- include_vars: "vars/main.yml"
- set_fact:
variable1: "var1"
variable2: "var2"
- set_fact:
final_variable: "{{ variable1 }}_{{ variable2 }}"
- set_fact:
ultimate_variable: "{{ lookup('vars', '{{final_variable}}') }}"
- debug:
var: ultimate_variable
output:
PLAY [localhost] ****************************************************************************************************************************************************************************************************
TASK [include_vars] *************************************************************************************************************************************************************************************************
ok: [localhost]
TASK [set_fact] *****************************************************************************************************************************************************************************************************
ok: [localhost]
TASK [set_fact] *****************************************************************************************************************************************************************************************************
ok: [localhost]
TASK [set_fact] *****************************************************************************************************************************************************************************************************
ok: [localhost]
TASK [debug] ********************************************************************************************************************************************************************************************************
ok: [localhost] => {
"ultimate_variable": "some value"
}
PLAY RECAP **********************************************************************************************************************************************************************************************************
localhost : ok=5 changed=0 unreachable=0 failed=0
hope it helps.

You could also skip the intermediary variable definition:
- include_vars: "vars/main.yml"
- set_fact:
variable1: "var1"
variable2: "var2"
- set_fact:
ultimate_variable: "{{ lookup('vars', variable1 ~ '_' ~ variable2) }}"
- debug:
var: ultimate_variable

Related

Use variable with item in when condition in ansible task

I'm using the below playbook to capture the vmware datacenter information, which is working fine without any issues:
---
- hosts: localhost
vars_files: 1credentials.yml
tasks:
- name: Gather information about all datacenters
community.vmware.vmware_datacenter_info:
hostname: '{{ vcenter_hostname }}'
username: '{{ vcenter_username }}'
password: '{{ vcenter_password }}'
validate_certs: no
delegate_to: localhost
register: datacenter
- debug:
msg: "{{ item.name }}"
loop: "{{ datacenter.datacenter_info }}"
when:
- item.name is defined
- item.name == datacenter
below is the output:
PLAY [localhost] *******************************************************************************************************************************************************
TASK [Gathering Facts] *************************************************************************************************************************************************
ok: [localhost]
TASK [Gather information about all datacenters] ************************************************************************************************************************
ok: [localhost]
TASK [debug] ***********************************************************************************************************************************************************
skipping: [localhost] => (item={'name': 'Datacenter-Test', 'moid': 'datacenter-1247', 'config_status': 'gray', 'overall_status': 'gray'})
ok: [localhost] => (item={'name': 'opendc-rookie', 'moid': 'datacenter-2', 'config_status': 'gray', 'overall_status': 'gray'}) => {
"msg": "opendc-rookie"
}
PLAY RECAP *************************************************************************************************************************************************************
localhost : ok=3 changed=0 unreachable=0 failed=0 skipped=0 rescued=0 ignored=0
But when I try to use a var_prompt and ask for user input for the variable datacenter, as below:
---
- hosts: localhost
vars_files: 1credentials.yml
vars_prompt:
- name: datacenter
prompt: mention the datacenter name
private: no
tasks:
- name: Gather information about all datacenters
community.vmware.vmware_datacenter_info:
hostname: '{{ vcenter_hostname }}'
username: '{{ vcenter_username }}'
password: '{{ vcenter_password }}'
validate_certs: no
delegate_to: localhost
register: datacenter
- debug:
msg: "{{ item.name }}"
loop: "{{ datacenter.datacenter_info }}"
when:
- item.name is defined
- item.name == "datacenter"
It is skipping the debug task without substituting the datacenter variable's value which was the user's input in the when condition. Kindly suggest how can I incorporate the variable value with the when condition having item. Below is the output skipping the variable
mention the datacenter name: opendc-rookie
PLAY [localhost] *******************************************************************************************************************************************************
TASK [Gathering Facts] *************************************************************************************************************************************************
ok: [localhost]
TASK [Gather information about all datacenters] ************************************************************************************************************************
ok: [localhost]
TASK [debug] ***********************************************************************************************************************************************************
skipping: [localhost] => (item={'name': 'Datacenter-Test', 'moid': 'datacenter-1247', 'config_status': 'gray', 'overall_status': 'gray'})
skipping: [localhost] => (item={'name': 'opendc-rookie', 'moid': 'datacenter-2', 'config_status': 'gray', 'overall_status': 'gray'})
skipping: [localhost]
PLAY RECAP *************************************************************************************************************************************************************
localhost : ok=2 changed=0 unreachable=0 failed=0 skipped=1 rescued=0 ignored=0
i suggest you to rename your register value (same name than the prompt var)
- hosts: localhost
vars_files: 1credentials.yml
vars_prompt:
- name: datacenter
prompt: mention the datacenter name
private: no
tasks:
- name: Gather information about all datacenters
community.vmware.vmware_datacenter_info:
hostname: '{{ vcenter_hostname }}'
username: '{{ vcenter_username }}'
password: '{{ vcenter_password }}'
validate_certs: no
delegate_to: localhost
register: datacenterX
- debug:
msg: "{{ item.name }}"
loop: "{{ datacenterX.datacenter_info }}"
when:
- item.name is defined
- item.name == datacenter
In the trace we can see that the debug task is iterating over 2 dict items with the keys (or property) name = "Datacenter-Test" and name = "opendc-rookie".
Since you have a condition on item.name == "datacenter", the condition will only be true for items having the property `name = "datacenter". Which is not what you want to achieve.
how can I add the list values "Datacenter-Test" and "opendc-rookie" as variable in the when condition
Here are two options to filter the list of datacenters in order to retain the two selected names.
"simple condition": use a simple or in the when condition.
"list condition": filter directly the list to iterate over the items defined in the list wanted_datacenters. This option works with an input ansible-playbook loop.yml --extra-vars='{"wanted_datacenters": ["opendc-rookie", "Datacenter-Test"]}'
- hosts: localhost
vars:
datacenter:
- name: opendc-rookie
- name: Datacenter-Test
wanted_datacenters:
- opendc-rookie
- Datacenter-Test
tasks:
- name: "simple condition"
debug:
msg: "{{ item.name }}"
loop: "{{ datacenter }}"
when: item.name == "Datacenter-Test" or item.name == "opendc-rookie"
- name: "list condition"
debug:
msg: "{{ item.name }}"
loop: "{{ datacenter|selectattr('name', 'in', wanted_datacenters)|list }}"
Use json_query. This filter doesn't fail when an attribute is missing. For example,
shell> cat pb.yml
- hosts: localhost
vars:
datacenter:
datacenter_info:
- config_status: gray
moid: datacenter-1247
name: Datacenter-Test
overall_status: gray
- config_status: gray
moid: datacenter-2
name: opendc-rookie
overall_status: gray
tasks:
- debug:
msg: "{{ _item }}"
vars:
_item: "{{ datacenter.datacenter_info|json_query(_query) }}"
_query: '[?name == `{{ dc_name|d("") }}`]'
gives
shell> ansible-playbook pb.yml -e dc_name=Datacenter-Test
PLAY [localhost] *****************************************************************************
TASK [debug] *********************************************************************************
ok: [localhost] =>
msg:
- config_status: gray
moid: datacenter-1247
name: Datacenter-Test
overall_status: gray
shell> ansible-playbook pb.yml
PLAY [localhost] *****************************************************************************
TASK [debug] *********************************************************************************
ok: [localhost] =>
msg: []
You can iterate the list. For example,
- debug:
msg: "{{ item.name }}"
loop: "{{ datacenter.datacenter_info|json_query(_query) }}"
vars:
_query: '[?name == `{{ dc_name|d("") }}`]'
If you want to test the name is in a list create an intersect. For example,
shell> cat pb.yml
- hosts: localhost
vars:
datacenter:
datacenter_info:
- config_status: gray
moid: datacenter-1247
name: Datacenter-Test
overall_status: gray
- config_status: gray
moid: datacenter-2
name: opendc-rookie
overall_status: gray
names: "{{ datacenter.datacenter_info|json_query('[].name') }}"
dc_names: ''
names_selected: "{{ names|intersect(dc_names.split(',')) }}"
tasks:
- debug:
msg: "{{ item.name }}"
loop: "{{ datacenter.datacenter_info }}"
when: item.name|d('') in names_selected
gives
shell> ansible-playbook pb.yml -e dc_names=Datacenter-Test,opendc-rookie
PLAY [localhost] *****************************************************************************
TASK [debug] *********************************************************************************
ok: [localhost] => (item={'config_status': 'gray', 'moid': 'datacenter-1247', 'name': 'Datacenter-Test', 'overall_status': 'gray'}) =>
msg: Datacenter-Test
ok: [localhost] => (item={'config_status': 'gray', 'moid': 'datacenter-2', 'name': 'opendc-rookie', 'overall_status': 'gray'}) =>
msg: opendc-rookie
shell> ansible-playbook pb.yml -e dc_names=opendc-rookie
PLAY [localhost] *****************************************************************************
TASK [debug] *********************************************************************************
skipping: [localhost] => (item={'config_status': 'gray', 'moid': 'datacenter-1247', 'name': 'Datacenter-Test', 'overall_status': 'gray'})
ok: [localhost] => (item={'config_status': 'gray', 'moid': 'datacenter-2', 'name': 'opendc-rookie', 'overall_status': 'gray'}) =>
msg: opendc-rookie
shell> ansible-playbook
PLAY [localhost] *****************************************************************************
TASK [debug] *********************************************************************************
skipping: [localhost] => (item={'config_status': 'gray', 'moid': 'datacenter-1247', 'name': 'Datacenter-Test', 'overall_status': 'gray'})
skipping: [localhost] => (item={'config_status': 'gray', 'moid': 'datacenter-2', 'name': 'opendc-rookie', 'overall_status': 'gray'})
skipping: [localhost]

Ansible variables

I'm a real Ansible beginner.
Is there any way to reconstruct a variable from another ansible variable?
For example, this playbook :
- hosts: servers
vars:
ex_server1: First
ex_server2: Second
ex_server3: Third
toto: ex_
tasks:
- debug:
msg: "{{ toto+ansible_hostname }}"
It print :
ok: [server2] => {
"msg": "ex_server2"
}
ok: [server3] => {
"msg": "ex_server3"
}
ok: [server1] => {
"msg": "ex_server1"
}
Instead of "First", "Second" and "Third".
Is there a way to print variable content instead of variable name in this situation or in a jinja template ?
Use lookup vars plugin
- debug:
msg: "{{ lookup('vars', toto + ansible_hostname) }}"
gives
TASK [debug] ***********************************************************
ok: [server1] =>
msg: First
ok: [server2] =>
msg: Second
ok: [server3] =>
msg: Third
The details about the plugin are available from the command-line
shell> ansible-doc -t lookup vars

How can I filter certain element in a string

playbook.yml
---
hosts: local_host
connection: local
gather_facts: False
tasks:
- name: set-details
set_fact:
filter: "{{ lookup('file', 'tmp/task2.yml') | from_json }}"
- set_fact:
result: "{{ filter['msg'] }}"
- debug:
var: result
task2.yml
{
"ansible_loop_var": "item",
"_ansible_no_log": false,
"invocation": {
"module_args": {
"wait_for_task": true,
"policy_package": "Mills07_Simplified",
"version": null,
"wait_for_task_timeout": 30
}
},
"item": "Mills07_Simplified",
"changed": false,
"msg": "Task Verify policy operation with task id 01234567-89ab-cdef-928b-bef7e174fc7a failed. Look at the logs for more details",
"_ansible_item_label": "Mills07_Simplified"
}
debug message
TASK [debug] *****************************************************************************************************************************************************************************
ok: [localhost] => {
"result": "Task Verify policy operation with task id 01234567-89ab-cdef-928b-bef7e174fc7a failed. Look at the logs for more details"
}
When I did the following,
- set_fact:
task_id: "{{ result |
select('regex', my_regex)|
first|
regex_replace(my_regex, my_replace) }}"
vars:
my_regex: '^Task Verify policy operation with task id (.*)$'
my_replace: '\1'
- debug:
var: task_id
I got an error message
fatal: [localhost]: FAILED! => {"msg": "The task includes an option with an undefined variable. The error was: 'my_regex' is undefined\n\nThe error appears to be in
Goal: I want to get the task-id "01234567-89ab-cdef-928b-bef7e174fc7a"
How can I get this string 01234567-89ab-cdef-928b-bef7e174fc7a
Since you are looking for a universally unique identifier (or UUID) which has a defined format of 8-4-4-4-12 characters for a total of 36 characters (32 hexadecimal characters and 4 hyphens) source, you can use a simple regex to extract it.
It can be handled with the following regex:
[0-9a-f]{8}-(?:[0-9a-f]{4}-){3}[0-9a-f]{12}
You can test it there: https://regex101.com/r/4Hs7il/1
So, in a set_fact:
- set_fact:
uuid: >-
{{ filter.msg
| regex_search(
'([0-9a-f]{8}-(?:[0-9a-f]{4}-){3}[0-9a-f]{12})',
'\1',
ignorecase=True
)
| first
}}
As an example:
- hosts: localhost
gather_facts: no
tasks:
- set_fact:
uuid: >-
{{ filter.msg
| regex_search(
'([0-9a-f]{8}-(?:[0-9a-f]{4}-){3}[0-9a-f]{12})',
'\1',
ignorecase=True
)
| first
}}
vars:
filter:
msg: "Task Verify policy operation with task id 01234567-89ab-cdef-928b-bef7e174fc7a failed. Look at the logs for more details"
- debug:
var: uuid
Would yield the recap:
PLAY [localhost] ***************************************************************
TASK [set_fact] ****************************************************************
ok: [localhost]
TASK [debug] *******************************************************************
ok: [localhost] =>
uuid: 01234567-89ab-cdef-928b-bef7e174fc7a
PLAY RECAP *********************************************************************
localhost : ok=2 changed=0 unreachable=0 failed=0 skipped=0 rescued=0 ignored=0

Iterating via nested loops

The packages.yml file defined as:
---
- packages:
- name: Some description 1,
packageList:
- package1,
- package2,
- package3
- name: Some description 2,
package: package4
The first item contains a field packageList, the 2nd item does not have it, but only package field.
Playbook:
---
- hosts: all
become: yes
vars_files:
- packages.yml
How to iterate via all packageList items of the packages list only if this packageList is defined for an item.
Here is how I can iterate through items which contain package field:
- name: iteration
debug:
msg: "name: {{ item.package }}"
when: item.package is defined
with_items: "{{ packages }}"
As noted in my comment, if you simply want to install multiple yum/apt packages, it is usually more efficient to simply pass the list to the apt/yum/package module. As the docs state:
"When used with a loop: each package will be processed individually, it is much more efficient to pass the list directly to the name option."
However, if you really need a loop, here is a possible solution:
playbook.yml:
---
- hosts: all
gather_facts: false
vars_files:
- packages.yml
tasks:
- name: iteration over single items
debug:
msg: "name: {{ item.package }}"
when: item.package is defined
with_items: "{{ packages }}"
- name: iteration over lists
debug:
msg: "name: {{ item.packageList }}"
when: item.packageList is defined
with_items: "{{ packages }}"
- name: Do something with individual packages in the list
include_tasks: process_list.yml
vars:
mylist: "{{outer.packageList}}"
when: outer.packageList is defined
loop: "{{ packages }}"
loop_control:
loop_var: outer
process_list.yml:
- name: See what we have received
debug:
var: item
loop: "{{mylist}}"
result:
PLAY [all] *******************************************************************************************************************************
TASK [iteration over single items] *******************************************************************************************************
skipping: [localhost] => (item={u'packageList': [u'package1,', u'package2,', u'package3'], u'name': u'Some description 1,'})
ok: [localhost] => (item={u'name': u'Some description 2,', u'package': u'package4'}) => {
"msg": "name: package4"
}
TASK [iteration over lists] **************************************************************************************************************
ok: [localhost] => (item={u'packageList': [u'package1,', u'package2,', u'package3'], u'name': u'Some description 1,'}) => {
"msg": "name: [u'package1,', u'package2,', u'package3']"
}
skipping: [localhost] => (item={u'name': u'Some description 2,', u'package': u'package4'})
TASK [Do something with individual packages in the list] *********************************************************************************
skipping: [localhost] => (item={u'name': u'Some description 2,', u'package': u'package4'})
included: /root/tmp/process_list.yml for localhost
TASK [See what we have received] *********************************************************************************************************
ok: [localhost] => (item=package1,) => {
"ansible_loop_var": "item",
"item": "package1,"
}
ok: [localhost] => (item=package2,) => {
"ansible_loop_var": "item",
"item": "package2,"
}
ok: [localhost] => (item=package3) => {
"ansible_loop_var": "item",
"item": "package3"
}
PLAY RECAP *******************************************************************************************************************************
localhost : ok=4 changed=0 unreachable=0 failed=0 skipped=0 rescued=0 ignored=0
The loop_control/loop_var part is used because otherwise both the outer and inner loop will use {{item}} as the loop variable - and this will cause... interesting results :)
You can define a default value with an empty list for the cases, where the packageList is undefined.
{{ item.packageList | default ([]) }}
If the packageList is undefined, the job iterates over an empty list, which means, it does not do anything.
You can use default, as #ceving mentioned:
---
- hosts: localhost
connection: local
vars_files:
- packages.yml
tasks:
- name: iteration
debug:
msg: "name: {{ item.packageList | default([item.package]) }}"
with_items: "{{ packages }}"
If packageList exists, it will use that, else package put into a single-element array to match the form of packageList:
PLAY [localhost] **********************************************************************************************
TASK [Gathering Facts] ****************************************************************************************
ok: [localhost]
TASK [iteration] **********************************************************************************************
ok: [localhost] => (item=None) => {
"msg": "name: [u'package1,', u'package2,', u'package3']"
}
ok: [localhost] => (item=None) => {
"msg": "name: [u'package4']"
}
PLAY RECAP ****************************************************************************************************
localhost : ok=2 changed=0 unreachable=0 failed=0

In Ansible, how can I iterate over stdout with an array?

Ansible v2.6.3
I have the simple task, which gets the AWS ARNs in my jenkins ECS cluster
tasks:
- command: aws ecs list-container-instances --cluster jenkins
register: jenkins_ecs_containers
- debug: var=jenkins_ecs_containers.stdout
and has the following output
TASK [debug] *******************************************************************
ok: [localhost] => {
"jenkins_ecs_containers.stdout": {
"containerInstanceArns": [
"arn:aws:ecs:us-east-1:arn0",
"arn:aws:ecs:us-east-1:arn1"
]
}
}
How can I iterate over the ARNs? I tried
- debug: var=item
with_items: jenkins_ecs_containers.stdout.containerInstanceArns
gives
TASK [debug] *******************************************************************
ok: [localhost] => (item=jenkins_ecs_containers.stdout.containerInstanceArns) => {
"item": "jenkins_ecs_containers.stdout.containerInstanceArns"
}
or
- debug: var=item
with_items: "{{ jenkins_ecs_containers.stdout.containerInstanceArns }}"
gives
TASK [debug] *******************************************************************
fatal: [localhost]: FAILED! => {"msg": "'ansible.utils.unsafe_proxy.AnsibleUnsafeText object' has no attribute 'containerInstanceArns'"}
to retry, use: --limit #/Users/cfouts/git-repos/ansible/playbooks/loop.retry
Thanks!
I created a file with your output. So I used set_fact. Otherwise, it's just a string, not a JSON object:
tasks:
- command: cat files/stdout.txt
register: result
- debug: var=result.stdout
- set_fact:
jenkins_ecs_containers: "{{ result.stdout }}"
- debug:
msg: "{{ item }}"
with_items: "{{ jenkins_ecs_containers.containerInstanceArns }}"
This gave me the following output:
PLAY [localhost] ***************************************************************
TASK [Gathering Facts] *********************************************************
ok: [localhost]
TASK [command] *****************************************************************
changed: [localhost]
TASK [debug] *******************************************************************
ok: [localhost] => {
"result.stdout": {
"containerInstanceArns": [
"arn:aws:ecs:us-east-1:arn0",
"arn:aws:ecs:us-east-1:arn1"
]
}
}
TASK [set_fact] ****************************************************************
ok: [localhost]
TASK [debug] *******************************************************************
ok: [localhost] => (item=None) => {
"msg": "arn:aws:ecs:us-east-1:arn0"
}
ok: [localhost] => (item=None) => {
"msg": "arn:aws:ecs:us-east-1:arn1"
}
PLAY RECAP *********************************************************************
localhost : ok=5 changed=1 unreachable=0 failed=0
You can iterate over like this:
- debug:
msg: "{{ item[1] }}"
with_subelements:
- "{{ jenkins_ecs_containers }}"
- containerInstanceArns
Go through this link, it will make it clearer.

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