Is there a variable or a method allowing one to list all the roles applied to a group of ansible hosts?
For example:
- hosts: webservers
gather_facts: true
roles:
- nginx
- php-fpm
tasks:
- debug:
msg: {{ item }} installed
with_items: ansible_roles
or perhaps another way to achieve this?
It depends on what applied means in your question.
The variable role_names holds all roles of the current play, so it would be an array: [nginx, php-fpm].
- debug:
msg: {{ item }} installed
with_items: role_names
But these roles not necessarily have been applied to the hosts, if you mean by that they have been processed. There is no such thing that will update once a role has been run on a host.
If that is what you're looking for you could implement it yourself with a callback plugin. AFAIK there is no callback for starting/completing a role itself. But since the names of the roles are present in the task names you could simply use the playbook_on_task_start, extract the role name from the task name and store it in some way. I have not yet looked into callback plugins in Ansible 2 where the API changed, but I expect you have access to the global variable list and can manipulate it.
Related
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) }}"
I'm working on putting together a playbook that will deploy local facts scripts to various groups in my Ansible inventory, and I would to be able to utilize the group name being worked on as a variable in the tasks themselves. Assume for this example that I have the traditional Ansible roles directory structure on my Ansible machine, and I have subdirectories under the "files" directory called "apache", "web", and "db". I'll now illustrate by example, ...
---
- hosts: apache:web:db
tasks:
- name: Set facts for facts directories
set_fact:
facts_dir_local: "files/{{ group_name }}"
facts_dir_remote: "/etc/ansible/facts.d"
- name: Deploy local facts
copy:
src: "{{ item }}"
dest: "{{ facts_dir_remote }}"
owner: ansible
group: ansible
mode: 0750
with_fileglob:
- "{{ facts_dir_local }}/*.fact"
The goal is to have {{ group_name }} above take on the value of "apache" for the hosts in the apache group, "web" for the hosts in the web group, and "db" for the hosts in the db group. This way I don't have to copy and paste this task and assign custom variables for each group. Any suggestions for how to accomplish this would be greatly appreciated.
While there is no group_name variable in ansible, there is a group_names (plural). That is because any host may be part of one or more groups.
It is described in the official documentation as
group_names
List of groups the current host is part of
In the most common case each host would only be part of one group and so you could simply say group_names[0] to get what you want.
TLDR;
Use group_names[0].
You can use group variables to achieve this, either specified in the inventory file or in separate group_vars/<group> files - see https://docs.ansible.com/ansible/latest/user_guide/intro_inventory.html
Note though that these group variables are squashed into host variables when you run the playbook. Hosts that are listed in multiple groups will end up with variables based on a precedence order
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'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}}" }
I'm adding few hosts in the hosts inventory file through playbook. Now I'm using those newly added hosts in the same playbook. But those newly added hosts are not readble by the same playbook in the same run it seems, because I get -
skipping: no hosts matched
When I run it separately, i.e. I update hosts file through one playbook and use the updated hosts in it through another playbook, it works fine.
I wanted to do something like this recently, using ansible 1.8.4. I found that add_host needs to use a group name, or the play will be skipped with "no hosts matched". At the same time I wanted play #2 to use facts discovered in play #1. Variables and facts normally remain scoped to each host, so this requires using the magic variables hostvars and groups.
Here's what I came up with. It works, but it's a bit ugly. I'd love to see a cleaner alternative.
# test.yml
#
# The name of the active CFN stack is provided on the command line,
# or is set in the environment variable AWS_STACK_NAME.
# Any host in the active CFN stack can tell us what we need to know.
# In real life the selection is random.
# For a simpler demo, just use the first one.
- hosts:
tag_aws_cloudformation_stack-name_{{ stack
|default(lookup('env','AWS_STACK_NAME')) }}[0]
gather_facts: no
tasks:
# Get some facts about the instance.
- action: ec2_facts
# In real life we might have more facts from various sources.
- set_fact: fubar='baz'
# This could be any hostname.
- set_fact: hostname_next='localhost'
# It's too late for variables set in this play to affect host matching
# in the next play, but we can add a new host to temporary inventory.
# Use a well-known group name, so we can set the hosts for the next play.
# It shouldn't matter if another playbook uses the same name,
# because this entry is exclusive to the running playbook.
- name: add new hostname to temporary inventory
connection: local
add_host: group=temp_inventory name='{{ hostname_next }}'
# Now proceed with the real work on the designated host.
- hosts: temp_inventory
gather_facts: no
tasks:
# The host has changed, so the facts from play #1 are out of scope.
# We can still get to them through hostvars, but it isn't easy.
# In real life we don't know which host ran play #1,
# so we have to check all of them.
- set_fact:
stack='{{ stack|default(lookup("env","AWS_STACK_NAME")) }}'
- set_fact:
group_name='{{ "tag_aws_cloudformation_stack-name_" + stack }}'
- set_fact:
fubar='{% for h in groups[group_name] %} {{
hostvars[h]["fubar"]|default("") }} {% endfor %}'
- set_fact:
instance_id='{% for h in groups[group_name] %} {{
hostvars[h]["ansible_ec2_instance_id"]|default("") }} {% endfor %}'
# Trim extra leading and trailing whitespace.
- set_fact: fubar='{{ fubar|replace(" ", "") }}'
- set_fact: instance_id='{{ instance_id|replace(" ", "") }}'
# Now we can use the variables instance_id and fubar.
- debug: var='{{ fubar }}'
- debug: var='{{ instance_id }}'
# end
It's not entirely clear what you're doing - but from what I gather, you're using the add_host module in a play.
It seems logical that you cannot limit that same play to those hosts, because they don't exist yet... so this can never work:
- name: Play - add a host
hosts: new_host
tasks:
- name: add new host
add_host: name=new_host
But you're free to add multiple plays to a single plabook file (which you also seem to have figured out):
- name: Play 1 - add a host
hosts: a_single_host
tasks:
- name: add new host
add_host: name=new_host
- name: Play 2 - do stuff
hosts: new_host
tasks:
- name: do stuff
It sounds like you are modifying the Ansible inventory file with your playbook, and then wanting to use the new contents of the file. Just modifying the contents of the file on disk, however, won't cause the inventory that Ansible is working with to be updated. The way Ansible works is that it reads that file (and any other inventory source you have) when it first begins and puts the host names it finds into memory. From then on it works only with the inventory that it has stored in memory, the stuff that existed when it first started running. It has no knowledge of any subsequent changes to the file.
But there are ways to do what you want! One option you could use is to add the new host into the inventory file, and also load it into memory using the add_host module. That's two separate steps: 1) add the new host to the file's inventory, and then 2) add the same new host to in-memory inventory using the add_host module:
- name: add a host to in-memory inventory
add_host:
name: "{{ new_host_name }}"
groups: "{{ group_name }}"
A second option is to tell Ansible to refresh the in-memory inventory from the file. But you have to explicitly tell it to do that. Using this option, you have two related steps: 1) add the new host to the file's inventory, like you already did, and then 2) use the meta module:
- name: Refresh inventory to ensure new instances exist in inventory
meta: refresh_inventory