We have lots of playbooks that we use to setup our remote instances. We would like to use those playbooks when bringing up our local environment for test purposes as well.
Is it possible to differentiate between a playbook running locally and remotely?
I'm looking for something like:
- name: install apache2
apt: name=apache2 update_cache=yes state=latest
when: ansible.connection_type == 'local'
Which means I only want to install apache when running ansible against my local environment.
I will then execute it with:
ansible-playbook -i /root/ansible-config/ec2.py -c local myplaybook.yml
Is it possible?
There is ansible_connection variable for every host.
Related
Use-Case:
Playbook 1
when we first connect to a remote host/s, the remote host will already have some python version installed - the auto-discovery feature will find it
now we install ansible-docker on the remote host
from this time on: the ansible-docker docs suggest to use ansible_python_interpreter=/usr/bin/env python-docker
Playbook 2
We connect to the same host/s again, but now we must use the /usr/bin/env python-docker python interpreter
What is the best way to do this?
Currently we set ansible_python_interpreter on the playbook level of Playbook 2:
---
- name: DaqMon app
vars:
- ansible_python_interpreter: "{{ '/usr/bin/env python-docker' }}"
This works, but this will also change the python interpreter of the local actions. And thus the local actions will fail, because (python-docker does not exist locally).
the current workaround is to explicitly specify the ansible_python_interpreter on every local-action which is tedious and error-prone
Questions:
the ideal solution is, if we could add '/usr/bin/env python-docker' as fallback to interpreter-python-fallback - but I think this is not possible
is there a way to set the python interpreter only for the remote hosts - and keep the default for the localhost?
or is it possible to explicitly override the python interpreter for the local host?
You should set the ansible_python_interpreter on the host level.
So yes, it's possible to explicitly set the interpreter for localhost in your inventory.
localhost ansible_connection=local ansible_python_interpreter=/usr/bin/python
And I assume that you could also use set_fact on hostvars[<host>].ansible_python_interpreter on your localhost or docker host.
There is a brillant article about set_fact on hostvars ! ;-P
Thanks to the other useful answers I found an easy solution:
on the playbook level we set the python interpreter to /usr/bin/env python-docker
then we use a set_fact task to override the interpreter for localhost only
we must also delegate the facts
we can use the magic ansible_playbook_python variable, which refers to the python interpreter that was used on the (local) Ansible host to start the playbook: see Ansible docs
Here are the important parts at the start of Playbook 2:
---
- name: Playbook 2
vars:
- ansible_python_interpreter: "{{ '/usr/bin/env python-docker' }}"
...
tasks:
- set_fact:
ansible_python_interpreter: '{{ ansible_playbook_python }}'
delegate_to: localhost
delegate_facts: true
Try to use set_fact for ansible_python_interpreter at host level in the first playbook.
Globally, use the interpreter_python key in the [defaults] section of the ansible.cfg file.
interpreter_python = auto_silent
I need to know if it's possible to call / execute ansible playbooks from the target machine. I think i saw a vendor do it or at least something similar. they downloaded a script and it did ran the playbook.
if this is possible how would it be done?
my goal is to run ansible as a centralized server in aws to perform tasks in mulitple environments. most are behind firewalls, any reccomendations/thoughts would be appreciated.
Sure. If your host will install Ansible on target and feed it with all the playbooks the you can run it as any other executable. Should you do that is another story but technically there's no obstacle.
You can run ansible and ansible playbook as you would any other binary on the target's $PATH, so any tool that facilitates running remote commands would work.
Because you are in AWS, one way might be to use AWS System's Manager.
If you wanted to use Ansible itself to do this you could use the shell or command modules:
- hosts: target
become: false
gather_facts: false
tasks:
- name: ansible in ansible
command: ansible --version
- name: ansible-playbook in ansible
command: ansible-playbook --version
Though, as with any situation where you reach for the shell or command modules, you have to be vigilant to maintain playbook idempotency yourself.
If you're requirement is just the ability to execute Ansible commands remotely, you might look into AWX which is the upstream project for Red Hat's Ansible Tower. It wraps ansible in a nice user interface to allow you to trigger Ansible playbooks remotely and with nice-to-haves like RBAC.
If you're ok with executing tasks remotely over ssh take a look at Sparrowdo it has out of the box facilities to run bash scripts ( read ansible executable ) remotely from one master host to another. Or you can even use it to install all the ansible dependencies or whatever you need to do for your scope.
I'm setting up an Ansible playbook to set up a couple servers. There are a couple of tasks that I only want to run if the current host is my local dev host, named "local" in my hosts file. How can I do this? I can't find it anywhere in the documentation.
I've tried this when statement, but it fails because ansible_hostname resolves to the host name generated when the machine is created, not the one you define in your hosts file.
- name: Install this only for local dev machine
pip:
name: pyramid
when: ansible_hostname == "local"
The necessary variable is inventory_hostname.
- name: Install this only for local dev machine
pip:
name: pyramid
when: inventory_hostname == "local"
It is somewhat hidden in the documentation at the bottom of this section.
You can limit the scope of a playbook by changing the hosts header in its plays without relying on your special host label ‘local’ in your inventory. Localhost does not need a special line in inventories.
- name: run on all except local
hosts: all:!local
This is an alternative:
- name: Install this only for local dev machine
pip: name=pyramid
delegate_to: localhost
I am trying to start a server using ansible shell module with ipmitools and then do configuration change on that server once its up.
Server with ansible installed also has ipmitools.
On server with ansible i need to execute ipmitools to start target server and then execute playbooks on it.
Is there a way to execute local ipmi commands on server running ansible to start target server through ansible and then execute all playbooks over ssh on target server.
You can run any command locally by providing the delegate_to parameter.
- shell: ipmitools ...
delegate_to: localhost
If ansible complains about connecting to localhost via ssh, you need to add an entry in your inventory like this:
localhost ansible_connection=local
or in host_vars/localhost:
ansible_connection: local
See behavioral parameters.
Next, you're going to need to wait until the server is booted and accessible though ssh. Here is an article from Ansible covering this topic and this is the task they have listed:
- name: Wait for Server to Restart
local_action:
wait_for
host={{ inventory_hostname }}
port=22
delay=15
timeout=300
sudo: false
If that doesn't work (since it is an older article and I think I previously had issues with this solution) you can look into the answers of this SO question.
I'm setting up an Ansible playbook to set up a couple servers. There are a couple of tasks that I only want to run if the current host is my local dev host, named "local" in my hosts file. How can I do this? I can't find it anywhere in the documentation.
I've tried this when statement, but it fails because ansible_hostname resolves to the host name generated when the machine is created, not the one you define in your hosts file.
- name: Install this only for local dev machine
pip:
name: pyramid
when: ansible_hostname == "local"
The necessary variable is inventory_hostname.
- name: Install this only for local dev machine
pip:
name: pyramid
when: inventory_hostname == "local"
It is somewhat hidden in the documentation at the bottom of this section.
You can limit the scope of a playbook by changing the hosts header in its plays without relying on your special host label ‘local’ in your inventory. Localhost does not need a special line in inventories.
- name: run on all except local
hosts: all:!local
This is an alternative:
- name: Install this only for local dev machine
pip: name=pyramid
delegate_to: localhost