Run command on the Ansible host

问题:

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.

回答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.

回答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

回答3:

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

回答4:

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

回答5:

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"

回答6:

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