Though Ansible Shell module can be used to execute Shell scripts. Ansible has a dedicated module named Script which can be used to copy the Shell script from the control machine to the remote server and to execute. Based on your requirement you can use either Script or Shell module to execute your scripts.
Yes, you can run commands on the Ansible host. You can specify that all tasks in a play run on the Ansible host, or you can mark individual tasks to run on the Ansible host.
If you want to run an entire play on the Ansible host, then specify hosts: 127.0.0.1
and connection:local
in the play, for example:
- name: a play that runs entirely on the ansible host
hosts: 127.0.0.1
connection: local
tasks:
- name: check out a git repository
git: repo=git://foosball.example.org/path/to/repo.git dest=/local/path
See Local Playbooks in the Ansible documentation for more details.
If you just want to run a single task on your Ansible host, you can use local_action
to specify that a task should be run locally. For example:
- name: an example playbook
hosts: webservers
tasks:
- ...
- name: check out a git repository
local_action: git repo=git://foosball.example.org/path/to/repo.git dest=/local/path
See Controlling where tasks run: delegation and local actions in the Ansible documentation for more details.
Edit: You can avoid having to type connection: local
in your play by adding this to your inventory:
localhost ansible_connection=local
(Here you'd use "localhost" instead of "127.0.0.1" to refer to the play).
Edit: In newer versions of ansible, you no longer need to add the above line to your inventory, ansible assumes it's already there.
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:
Running ansible playbook in localhost
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
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"
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.
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