my playbook structure looks like:
- hosts: all
name: all
roles:
- roles1
- roles2
In tasks of roles1, I define such a variable
---
# tasks for roles1
- name: Get the zookeeper image tag # rel3.0
run_once: true
shell: echo '{{item.split(":")[-1]}}' # Here can get the string rel3.0 normally
with_items: "{{ret.stdout.split('\n')}}"
when: "'zookeeper' in item"
register: zk_tag
ret.stdout：
Loaded image: test/old/kafka:latest
Loaded image: test/new/mysql:v5.7
Loaded image: test/old/zookeeper:rel3.0
In tasks of roles2, I want to use the zk_tag variable
- name: Test if the variable zk_tag can be used in roles2
debug: var={{ zk_tag.stdout }}
Error :
The task includes an option with an undefined variable. The error was: 'dict object' has no attribute 'stdout'
I think I encountered the following 2 problems:
When registering a variable with register, when condition is added, this variable cannot be used in all groups. How to solve this problem? How to make this variable available to all groups?
is my title, How to use variables between different roles in ansible?
You're most likely starting a new playbook for a new host. Meaning all previous collected vars are lost.
What you can do is pass a var to another host with the add_host module.
- name: Pass variable from this play to the other host in the same play
add_host:
name: hostname2
var_in_play_2: "{{ var_in_play_1 }}"
--- EDIT ---
It's a bit unclear. Why do you use the when statement in the first place if you want every host in the play for it to be available?
You might want to use the group_vars/all.yml file to place vars in.
Also, using add_host should be the way to go as how I read it. Can you post your playbook, and the outcome of your playbook on a site, e.g. pastebin?
If there is any chance the var is not defined because of a when condition, you should use a default value to force the var to be defined when using it. While you are at it, use the debug module for your tests rather than echoing something in a shell
- name: Debug my var
debug:
msg: "{{ docker_exists | default(false) }}"
Related
In my playbook i have tasks that use the hostname of a server and extrapolate data to set location and environment based on that. But some servers have unique names and I'm not sure how to set variables on those. I'd prefer not to use ansible facts since i would like to share the playbook with a team. One way I was thinking is to do what's listed below but i'm running into issues. Could someone please guide me.
Create vars_file inventory
---
customservers
customhostname1:
env: test
location: hawaii
customhostname2:
env: prod
location: alaska
In Playbook.
---
task
tasks:
- name: set hostname
shell: echo "customhostname1"
register: my_hostname
- name: setting env var
set_fact:
env: "{{ item.value.env }}"
when: my_hostname == "{{ item.key }}"
with_dict: "{{ customservers }}"
- name: outputing env var
debug:
msg: the output is {{ env }}
Expected output should be test.
Thank you.
In my playbook i have tasks that use the hostname of a server and
extrapolate data to set location and environment based on that.
Bad Idea.
But some servers have unique names and I'm not sure how to set variables on those
And that is why.
The second Bad Idea is to have TEST and PROD in the same inventory. That's just begging for a disaster. They should be two completely separate inventories, though perhaps under the same parent directory:
inventories/
inventories/test/
inventories/test/hosts
inventories/test/host_vars/
inventories/test/host_vars/customhostname1.yml
inventories/prod/
inventories/prod/hosts
inventories/prod/host_vars/
inventories/prod/host_vars/customhostname2.yml
So inventories/prod/hosts could look like this (I prefer the ini format):
[customservers]
customhostname2 location=hawaii
Or:
[customservers]
customhostname2
[customhostname2:vars]
location=hawaii
But in any case, DO NOT combine test and prod inventories.
If you still need that env variable, you can either put it in group_vars/all.yml or right in the hosts file like so:
[all:vars]
env=prod
I have the following ansible playbook that writes the content of the variable "hello" as a message (I got this code from an example online). I tried modifying it so it would write this to a local file however I got an error. The modified code and error message are below:
original code (successful):
- hosts: all
vars:
hello: world
tasks:
- name: Ansible Basic Variable Example
debug:
msg: "{{ hello }}"
modified code (unsuccessful):
- hosts: all
vars:
hello: world
tasks:
- name: Ansible Basic Variable Example
- local_action: copy content={{hello}} dest=~/ansible_logfile
debug:
msg: "{{ hello }}"
error message:
ERROR! no action detected in task. This often indicates a misspelled module name, or incorrect module path.
The error appears to have been in '/space/mathewLewis/towerCodeDeploy/playBooks/test.yml': line 5, column 5, but may
be elsewhere in the file depending on the exact syntax problem.
The offending line appears to be:
tasks:
- name: Ansible Basic Variable Example
^ here
I would like to know how to write a variable to a file correctly
It's a simple syntax error.
A Task is an entry in the list of tasks, which in YAML is designated by a - (dash).
Task names are optional in Ansible.
Both copy and debug are modules, which are supposed to be a task's "action".
What the error message is telling you is that the task with name: Ansible Basic Variable Example does not have an action, which is because your local_action is a separate task, indicated by a -.
Fixing your example with appropriate names for the tasks:
- name: Write variable to file
local_action: copy content="{{hello}}" dest=~/ansible_logfile
- name: Output the variable
debug:
msg: "{{ hello }}"
Thomas Hirsh's answer is correct. However, I found this representation less confusing (I'm a newbie to ansible):
- name: "Controller"
hosts: "controller.jeff.ddns.net"
tasks:
- name: "Register a variable to be shared with the clients"
set_fact: shared_fact="Brother"
- name: "Client"
hosts: "client.jeff.ddns.net"
tasks:
- name: "writing to hostvars.json"
local_action: copy content="{{hostvars | to_json(indent=4) }}" dest="hostvars.json"
This example has two plays. The controller play only sets a variable. The client is what actually writes to the file. In this case, hostvars has a complicated structure, so I used the to_json(indent=4) filter to convert to a good .json file, suitable for use with jq .
How can I declare global variable within Ansible playbook. I have searched in google and found the below solution, but its not working as expected.
- hosts: all
vars:
prod-servers:
- x.x.x.x
- x.x.x.x
- hosts: "{{prod-servers}}"
tasks:
- name: ping
action: ping
When I'm trying the above code, it says variable prod-servers is undefined.
You cannot define a variable accessible on a playbook level (global variable) from within a play.
Variable Scopes
Ansible has 3 main scopes:
Global: this is set by config, environment variables and the command line
Play: each play and contained structures, vars entries (vars; vars_files; vars_prompt), role defaults and vars.
Host: variables directly associated to a host, like inventory, include_vars, facts or registered task outputs
Anything you declare inside a play can thus only be either a play variable, or a (host) fact.
To define a variable, which you can use in the hosts declaration:
run ansible-playbook with --extra-vars option and pass the value in the argument;
or to achieve the same functionality (decide which hosts to run a play on, from within a preceding play):
define an in-memory inventory and run the subsequent play against that inventory.
what you seem to want is an inventory (http://docs.ansible.com/ansible/latest/intro_inventory.html), it looks like you have an static list of IP's that may be prod servers (or dev, or whatever), therefore you can create an static inventory.
In your second play you want to use the list of IP's as hosts to run the tasks, that's not what Ansible expects. After the "hosts" keyword in a play declaration, Ansible expects a group name from the inventory.
If, on the opossite, your prod servers change from time to time, you may need to create a dynamic inventory. You can have a look at examples in https://github.com/ansible/ansible/tree/devel/contrib/inventory (for instance, there are examples of dynamic inventory based on EC2 from Amazon or vsphere)
regards
well, this can be done using
set_fact.
I don't know the best practice for this but this works for me
Here's my playbook example
- hosts: all
gather_facts: false
tasks:
- set_fact: host='hostname'
- hosts: host-name1
gather_facts: false
tasks:
- name: CheckHostName
shell: "{{ host }}"
register: output
- debug: msg="{{ output }}"
- hosts: host-name2
gather_facts: false
tasks:
- name: CheckHostName
shell: "{{ host }}"
register: output
- debug: msg="{{ output }}"
I am trying to craft a list of environment variables to use in tasks that may have slightly different path on each host due to version differences.
For example, /some/common/path/v_123/rest/of/path
I created a list of these variables in variables.yml file that gets imported via roles.
roles/somerole/varables/main.yml contains the following
somename:
somevar: 'coolvar'
env:
SOME_LIB_PATH: /some/common/path/{{ unique_part.stdout }}/rest/of/path
I then have a task that runs something like this
- name: Get unique path part
shell: 'ls /some/common/path/'
register: unique_part
tags: workflow
- name: Perform some actions that need some paths
shell: 'binary argument argument'
environment: somename.env
But I get some Ansible errors about variables not being defined.
Alternatively I tried to predefine the unique_part.stdout in hopes of register overwriting predefined variable, but then I got other ansible errors - failure to template.
Is there another way to craft these variables based on command returns?
You can also use facts:
http://docs.ansible.com/set_fact_module.html
# Prepare unique variables
- hosts: myservers
tasks:
- name: Get unique path part
shell: 'ls /some/common/path/'
register: unique_part
tags: workflow
- name: Add as Fact per for each hosts
set_fact:
library_path: "{{ unique_part.stdout }}"
# launch roles that use those unique variables
- hosts: myservers
roles:
- somerole
This way you can dynamicaly add variable to your hosts before using them.
The vars files gets evaluated when it is read by Ansible. Your only chance would be to include a placeholder which you then later have to replace yourself, like this:
somename:
somevar: 'coolvar'
env:
SOME_LIB_PATH: '/some/common/path/[[ unique_part.stdout ]]/rest/of/path'
And then later in your playbook you can replace that placeholder:
- name: Perform some actions that need some paths
shell: 'binary argument argument'
environment: '{{ somename.env | replace("[[ unique_part.stdout ]]", unique_part.stdout) }}'
I've registered a variable in a play.
---
- hosts: 127.0.0.1
gather_facts: no
connection: local
sudo: no
vars_files:
- vars.yml
tasks:
- name: build load balancer
os_load_balancer: net=mc_net ext_net=vlan3320 name=load_balancer protocol=HTTPS port=80
register: my_lb
I can access that variable fine, until I make the request inside a role.
For example, in a separate role in the same run, I want to access that registered variable:
- debug: var=my_lb
I get the following output:
{'msg': "AnsibleUndefinedVariable: One or more undefined variables: 'my_lb' is undefined", 'failed': True}
How can I access variables registered in a separate role, within the same play?
Edit for clarity of how things piece together:
Top Play
-includes:
- Sub play 1
- registers variable foo
- Sub play 2
-includes:
- sub play A
- role 1
- role 2
- role 3
- references variable foo in template
- Sub play B
- Sub play 3
NB: This was written referring to Ansible 1.X. I suspect variable parsing and scoping has changed considerably with Ansible 2.0, so bear that in mind. I'll try to update the answer if I get time (or maybe someone else will answer for v2.0!)
There are two options here. The simplest is to define the variables in your top-level playbook, then propagate them down into your various roles. You can either set these as simple vars, or use pre_tasks to lookup / calculate values dynamically, e.g.
vars:
foo_static: "value_bar"
pre_tasks:
- set_fact:
foo_ncpu: "{{ ansible_processor_vcpus }}"
roles:
- {role: role1, role1_var1: "{{foo_static}}", role1_var2: "{{foo_ncpu}}" }
- {role: role2, role2_var1: "{{foo_static}}", role2_var2: "{{foo_ncpu}}" }
The second option requires that you add a task to whichever role you need to extract a variable from (though since all ansible roles are open-source, that should be easy enough). The trick is to use set_fact to export a variable as a 'host_fact', e.g.
- name: Export role1_varfoo to a 'host-fact' type variable
set_fact:
role1_varfoo: "{{ role1_varfoo }}"
Which can then be accessed later like so:
vars:
role2_varfoo: "{{ hostvars['myhost']['role1_varfoo']}}"
As described in this bit of the ansible docs.
Note that if you always want to lookup the hostvars of the current machine you're running commands on (without knowing what it's actually called in the ansible hosts file), you can use the variable inventory_hostname like so:
vars:
role2_varfoo: "{{ hostvars[inventory_hostname]['role1_varfoo']}}"
(Note lack of quote-marks, since it's a variable, not a string-literal.)
Slightly awkward, but those combinations have met all my needs so far.
Try moving your variable declarations into a pre_task block. Variables set here should be available within and following roles.
https://docs.ansible.com/playbooks_roles.html#roles
e.g.
pre_tasks:
- name: build load balancer
os_load_balancer: net=mc_net ext_net=vlan3320 name=load_balancer protocol=HTTPS port=80
register: my_lb
roles:
- { role: some_role }
Update: To access the variable using the hostvars syntax use the appropriate host GROUP variable rather than the host that executed the set_fact:
hostvars[inventory_hostname]['variable']
To broaden the accepted question.
1.-You can define ANOTHER role where you register the variable and then set it there then refer that variable from multiple roles. AS LONG as the roles are in the same play.
Docu here:
http://docs.ansible.com/ansible/playbooks_variables.html#variable-examples
Generally speaking, variables set in one role are available to others. This means if you have a roles/common/vars/main.yml you can set variables in there and make use of them in other roles and elsewhere in your playbook
Edit: Clarification, this applies for REGISTERED and set variables in Ansible 2.x in my experience.
2.-As far as using hostvars goes, I tried it myself and failed with this error:
fatal: [localhost]: FAILED! => {"failed": true, "msg": "'dict object' has no attribute 'ec2_instance_id'"}
I my case I was doing the following.
- hosts: localhost
gather_facts: yes
roles:
- { role: role_1 }
post_tasks:
- name: Check instance variables within localhost
debug: var={{ hostvars['localhost']['ec2_instance_id'] }}
On role 1 I had:
- name: register instance_id
set_fact: ec2_instance_id="{{ item.id }}"
with_items: "{{ ec2_instance.instances }}"
Although according to this old thread, the hostvar approach should work:
https://github.com/ansible/ansible/issues/1934
How abt passing it as parameter to role. I'm assuming such (register) variables aren't passed implicitly (like hotvars are).
- { role: my_role, my_lb: "{{my_lb}}" }