Is it possible to run commands on the Ansible host?
My scenario is that I want to take a checkout from a git server that is hosted internally (and isn't accessible outside the company firewall). Then I want to upload the checkout (tarballed) to the production server (hosted externally).
At the moment, I'm looking at running a script that does the checkout, tarballs it, and then runs the deployment script - but if I could integrate this into Ansible that would be preferable.
This question is related to
deployment
ansible
From the Ansible documentation:
Delegation This isn’t actually rolling update specific but comes up frequently in those cases.
If you want to perform a task on one host with reference to other hosts, use the ‘delegate_to’ keyword on a task. This is ideal for placing nodes in a load balanced pool, or removing them. It is also very useful for controlling outage windows. Be aware that it does not make sense to delegate all tasks, debug, add_host, include, etc always get executed on the controller. Using this with the ‘serial’ keyword to control the number of hosts executing at one time is also a good idea:
---
- hosts: webservers
serial: 5
tasks:
- name: take out of load balancer pool
command: /usr/bin/take_out_of_pool {{ inventory_hostname }}
delegate_to: 127.0.0.1
- name: actual steps would go here
yum:
name: acme-web-stack
state: latest
- name: add back to load balancer pool
command: /usr/bin/add_back_to_pool {{ inventory_hostname }}
delegate_to: 127.0.0.1
These commands will run on 127.0.0.1, which is the machine running Ansible. There is also a shorthand syntax that you can use on a per-task basis: ‘local_action’. Here is the same playbook as above, but using the shorthand syntax for delegating to 127.0.0.1:
---
# ...
tasks:
- name: take out of load balancer pool
local_action: command /usr/bin/take_out_of_pool {{ inventory_hostname }}
# ...
- name: add back to load balancer pool
local_action: command /usr/bin/add_back_to_pool {{ inventory_hostname }}
A common pattern is to use a local action to call ‘rsync’ to recursively copy files to the managed servers. Here is an example:
---
# ...
tasks:
- name: recursively copy files from management server to target
local_action: command rsync -a /path/to/files {{ inventory_hostname }}:/path/to/target/
Note that you must have passphrase-less SSH keys or an ssh-agent configured for this to work, otherwise rsync will need to ask for a passphrase.
Expanding on the answer by @gordon, here's an example of readable syntax and argument passing with shell/command module (these differ from the git module in that there are required but free-form arguments, as noted by @ander)
- name: "release tarball is generated" local_action: module: shell _raw_params: git archive --format zip --output release.zip HEAD chdir: "files/clones/webhooks"
ansible your_server_name -i custom_inventory_file_name -m -a "uptime"
The default module is command module, hence command
keyword is not required.
If you need to issue any command with elevated privileges use -b
at the end of the same command.
ansible your_server_name -i custom_inventory_file_name -m -a "uptime" -b
You can use delegate_to
to run commands on your Ansible host (admin host), from where you are running your Ansible play. For example:
Delete a file if it already exists on Ansible host:
- name: Remove file if already exists
file:
path: /tmp/logfile.log
state: absent
mode: "u+rw,g-wx,o-rwx"
delegate_to: 127.0.0.1
Create a new file on Ansible host :
- name: Create log file
file:
path: /tmp/logfile.log
state: touch
mode: "u+rw,g-wx,o-rwx"
delegate_to: 127.0.0.1
you can try this way
I've found a couple other ways you can write these which are a bit more readable IMHO.
- name: check out a git repository
local_action:
module: git
repo: git://foosball.example.org/path/to/repo.git
dest: /local/path
OR
- name: check out a git repository
local_action: git
args:
repo: git://foosball.example.org/path/to/repo.git
dest: /local/path
I'd like to share that Ansible can be run on localhost via shell:
ansible all -i "localhost," -c local -m shell -a 'echo hello world'
This could be helpful for simple tasks or for some hands-on learning of Ansible.
The example of code is taken from this good article:
Source: Stackoverflow.com