Today I noticed that Ansible won't merge vars.
For example when I have something like
---
lvm_roles:
postgresql:
size: '10g'
path: '/var/lib/postgresql'
And in another place I have for example
---
lvm_roles:
sonarqube:
size: '10g'
path: '/opt/sonarqube'
Ansible won't merge these facts. I am not sure about precedence but I think the first one wins. Without errors or warnings. IMHO a dangerous feature for a configuration management tool.
Are there any vars that Ansible can merge? Lists and hash won't work. Is there a workaround of some sort for this?
This is a significant shortcoming of Ansible. Because "facts" can be dependent on what you are provisioning. The inability to merge "facts" make it necessary to hard code and duplicate the stuff that you wan't to be configurable.
For example when I create one file with
lvm_roles:
postgresql:
size: '10g'
path: '{{ postgresql_home }}'
sonarqube:
size: '10g'
path: '{{ sonar_home }}'
This will not work because sonar_home is not defined on de postgresql node. On the the sonarqube node, postgresql_home is not defined. The ability to flexibly use vars is greatly impacted if merging is not possible.
Extract of a default ansible.cfg file:
# if inventory variables overlap, does the higher precedence one win
# or are hash values merged together? The default is 'replace' but
# this can also be set to 'merge'.
#hash_behaviour = replace
You can therefore change this behavior by setting hash_behaviour = merge.
I would not change that on a system wide basis as it might break other projects/roles that would rely on a default behavior. You can distribute the ansible.cfg at the root of your specific project that really needs this.
Meanwhile, as #dgw pointed out with a specific example, I've always been able to keep the default behavior by carefully choosing where to place my variables (group or host in inventory, included file, playbook...) and eventually merge them myself if needed.
Related
I’m working on a ansible playbook to deploy some configuration of services to different region, and I have initial vars imported by include_vars as the following:
common: [...]
us_local: [...]
uk_local: [...]
us_global: [...]
uk_global: [...]
Basically, I want to generate the configuration by including vars from common, all the global configs as well as the local config of that region, using {{ site }} variable which is defined in hosts.yaml.
For example, if the deployed host is us, then I want to use common, us_local, us_global, uk_global.
I will use a jinja2 template to generate the final config, and from my understanding, the easiest way is to create another variable called current_site_local and copy everything from {{ site }}_local into it, so that later on I could directly reference it inside the template. However, I’m having trouble making it work through set_facts.
Any help would be appreciated.
UPDATE:
I used the following syntax and it works:
- name: generate curr_site_local
set_fact:
current_site_local: '{{ vars[site + "_local"] }}'
Try using the combine filter.
- name: Set site config '{{ site }}'
set_fact:
current_site_local: '{{ common
| combine(vars[site + "_global"])
| combine(vars[site + "_local"]) }}'
In this case, the order of precedence is that the local config will override the global, and that will override the common.
Not sure if that is what you wanted, but that is the order you gave in your question, but the <other>_global is not included now.
If you want common to have highest precedence, just reverse the order.
See docs for combine.
Updated my answer with suggestion from Matthew L Daniel.
I have the following Ansible role which simply does the following:
Create a temporary directory.
Download Goss, a server testing tool, into that temporary directory.
Upload a main Goss YAML file for the tests.
Upload additional directories for additional included tests.
Here are a couple places where I'm using it:
naftulikay.python-dev
naftulikay.ruby-dev
Specifically, these playbooks upload a local file adjacent to the playbook named goss.yml and a directory goss.d again adjacent to the playbook.
Unfortunately, it seems that Ansible logic has changed recently, causing my tests to not work as expected. My role ships with a default goss.yml, and it appears that when I set goss_file: goss.yml within my playbook, it uploads degoss/files/goss.yml instead of the Goss file adjacent to my playbook.
If I'm passing the name of a file to a role, is there a way to specify that Ansible should look up the file in the context of the playbook or the current working directory?
The actual role logic that is no longer working is this:
# deploy test files including the main and additional test files
- name: deploy test files
copy: src={{ item }} dest={{ degoss_test_root }} mode=0644 directory_mode=0755 setype=user_tmp_t
with_items: "{{ [goss_file] + goss_addtl_files + goss_addtl_dirs }}"
changed_when: degoss_changed_when
I am on Ansible 2.3.2.0 and I can reproduce this across distributions (namely CentOS 7, Ubuntu 14.04, and Ubuntu 16.04).
Ansible searches for relative paths in role's scope first, then in playbook's scope.
For example if you want to copy file test.txt in role r1, search order is this:
/path/to/playbook/roles/r1/files/test.txt
/path/to/playbook/roles/r1/test.txt
/path/to/playbook/roles/r1/tasks/files/test.txt
/path/to/playbook/roles/r1/tasks/test.txt
/path/to/playbook/files/test.txt
/path/to/playbook/test.txt
You can inspect your search_path order by calling ansible with ANSIBLE_DEBUG=1.
To answer your question, you have to options:
Use filename that doesn't exist within role's scope. Like:
goss_file: local_goss.yml
Supply absolute path. For example, you can use:
goss_file: '{{ playbook_dir }}/goss.yml'
Ansible doesn't apply search logic if the path is absolute.
So one thing we've encountered in our project is that we do not want to store our large files in our git repo for our ansible roles because it slows down cloning (and git limits files to 100 mb anyways).
What we've done is store our files in a separate internal location, where our files can sit statically and have no size restrictions. Our roles are written so that they first pull these static files to their local files folder and then continue like normal.
i.e.
roles/foo/tasks/main.yml
- name: Create role's files directory
file:
path: "{{roles_files_directory}}"
state: directory
- name: Copy static foo to local
get_url:
url: "{{foo_static_gz}}"
dest: "{{roles_files_directory}}/{{foo_gz}}"
#....Do rest of the tasks...
roles/foo/vars/main.yml
roles_files_directory: "/some/path/roles/foo/files"
foo_static_gz: "https://internal.foo.tar.gz"
foo_gz: "foo.tar.gz"
The main thing I don't find really sound is the hard coded path to the role's files directory. I preferably would like to dynamically look up the path when running ansible, but I haven't been able to find documentation on that. The issue can arise because different users may check roles to a different root paths. Does anyone know how to dynamically know the role path, or have some other pattern that solves the overall problem?
Edit:
I discovered there's actually a {{playbook_dir}} variable that would return "/some/path", which might be dynamic enough in this case. Still isn't safe against the situation where the role name might change, but that's a way rarer occurrence and can be handled through version control.
What about passing values from the command line?
---
- hosts: '{{ hosts }}'
remote_user: '{{ user }}'
tasks:
- ...
ansible-playbook release.yml --extra-vars "hosts=vipers user=starbuck"
http://docs.ansible.com/playbooks_variables.html#passing-variables-on-the-command-line
I just want to add another possible solution: you can try to add custom "facter".
Here is a link to official documentation: http://docs.ansible.com/setup_module.html
And I found this article that might be useful: http://serverascode.com/2015/01/27/ansible-custom-facts.html
I am using the zzet.rbenv role on my playbook. It has a files/default-gems file that it copies to the provisioned system.
I need my playbook to check for a myplaybook/files/default-gems and use it if it exists, using the zzet.rbenv/files/default-gems if otherwise.
How can I do that?
After some research and trial/error. I found out that Ansible is not capable of checking if files exist between roles. This is due to the way role dependencies (which roles themselves) will get expanded into the one requiring it, making it part of the playbook. There are no tasks that will let you differentiate my_role/files/my_file.txt from required_role/files/my_file.txt.
One approach to the problem (the one I found the easiest and cleanest) was to:
Add a variable to the my_role with the path to the file I want to use (overriding the default one)
Add a task (identical to the one that uses the default file) that checks if the above variable is defined and run the task using it
Example
required_role
# Existing task
- name: some task
copy: src=roles_file.txt dest=some/directory/file.txt
when: my_file_path is not defined
# My custom task
- name: my custom task (an alteration of the above task)
copy: src={{ my_file_path }} dest=/some/directory/file.txt
when: my_file_path is defined
my_role
#... existing code
my_file_path: "path/to/my/file"
As mentioned by Ramon de la Fuente: this solution was accepted into the zzet.rbenv repo :)
I have the following problem. I'm keeping two separate Ansible project directories for two different technologies. Imagine you have a nice Ansible setup and want to pull an Ansible project and use some of your established structure without integrating it completely.
The first statement does what I want. It gives a fq path.
debug: msg="{{lynx_ansible}}/roles/centos_common/centos_{{jdk_provider}}.yml"
include: "{{lynx_ansible}}/roles/centos_common/centos_{{jdk_provider}}.yml"
The include adds a path to the ansible-project root dir and doesn't expand the variables. Is there a way to do this?
Try $lynx_ansible rather than {{ lynx_ansible }}. Include doesn't seem to support jinja2 syntax.