Run command on the Ansible host

Question

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

Answer 1

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 Delegation 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.

Answer 2

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

Answer 3

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.

Answer 4

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

Answer 5

you can try this way

• git: repo: 'https://foosball.example.org/path/to/repo.git' dest: /srv/checkout version: release-0.2 delegate_to: localhost
• name: perform some command next yum: name=ntp state=latest

Answer 6

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"