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) }}'
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 am trying to setup a playbook which will run the command to check status of the service installed in the target machine. The command will only work only if the .env file executed. The command to execute the .env file is .<space>./.env_file_name and the file contains list of environment variables like export JAVA_HOME=/optware/java/jdk/1.2.
I tried to execute the environment file before running the command with the below playbook, but it is not working.
- hosts: name
tasks:
- name: `execute env file`
command: . ./.env_file_name
register: result
Is there any playbook to run the executable environment file to set the environments present on the target machine and then run our command??
First, the . ./.env_file_name syntax is a shell syntax and cannot work with the command module, you need to use the shell module.
Secondly, the shell environment context is reset at every task as each is an ssh command round-trip (so a new shell session), and loading the environment variables in one task will not not make them available for next tasks.
Depending on your context, you have some options:
1. Inventory environment variables
The best option is to have the environment at your inventory side in a variable with different value for each group/host through group_vars/host_vars, then to use it for the environment keyword
# host_vars/my_host.yml
---
env_vars:
VAR1: key1
VAR2: key2
- hosts: my_host
tasks:
- name: Display environment variables
command: env
environment: "{{ env_vars }}"
Pros:
full ansible solution
will work for environment of every module
Cons:
need to know the environment variables at ansible side
2. Loading environment variables for every tasks
If your tasks are all shell/command (which I don't advise, as it's better to use appropriate ansible module whenever possible), you can simply load the env file every time with shell module
- hosts: my_host
tasks:
- name: Display environment variables
shell: |
. ./.env_file_name && env
- name: Do another action
shell: |
. ./.env_file_name && do_something_else
Pros:
no need to know the environment variables at ansible side
Cons:
limited to tasks with shell module
3. Load environment variables from env_file into ansible fact
This option is to parse the env file once and for all and load it in an ansible fact to use with the environment keyword.
- hosts: my_host
tasks:
- name: Get env file content
slurp:
src: ./.env_file_name
register: env_file_content
- name: Parse environment
set_fact:
env_vars: "{{ ('{' + (env_file_content.content | b64decode).split('\n') | select | map('regex_replace', '([^=]*)=(.*)', '\"\\1\": \"\\2\"') | join(',') + '}') | from_json }}"
- name: Display environment variables
command: env
environment: "{{ env_vars }}"
Or, if the env file need to be executed instead of directly parsed:
- hosts: my_host
tasks:
- name: Get env file content
shell: . ./.env_file_name && env
register: env_file_result
- name: Parse environment
set_fact:
env_vars: "{{ ('{' + env_file_result.stdout_lines | map('regex_replace', '([^=]*)=(.*)', '\"\\1\": \"\\2\"') | join(',') + '}') | from_json }}"
- name: Display environment variables
command: env
environment: "{{ env_vars }}"
Pros:
will work for environment of every module
no need to know the environment variables at ansible side
Cons:
could fail on bad formatting of file
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 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 .
My playbook (/home/user/Ansible/dist/playbooks/test.yml):
- hosts: regional_clients
tasks:
- shell: /export/home/user/ansible_scripts/test.sh
register: shellout
- debug: var=shellout
- hosts: web_clients
tasks:
- shell: /var/www/html/webstart/release/ansible_scripts/test.sh
register: shellout
- debug: var=shellout
- command: echo catalina.sh start
register: output
- debug: var=output
The [regional_clients] group is specified in /home/user/Ansible/webproj/hosts and the [web_clients] group is specified in /home/user/Ansible/regions/hosts.
Is there a way I could make the above work? Currently, running the playbook will fail since neither [regional_clients] or [web_clients] are defined in the default inventory file /home/user/Ansible/dist/hosts.
Yes, you can write a simple shell script:
#!/bin/sh
cat /home/user/Ansible/webproj/hosts /home/user/Ansible/regions/hosts
and call it as a dynamic inventory in Ansible:
ansible-playbook -i my_script test.yml
This question, however, looks to me like a problem with your organisation, not a technical one. If your environment is so complex and maintained by different parties, then use some kind of configuration database (and a dynamic inventory in Ansible which would retrieve the data), instead of individual files in user's paths.