ansible.builtin.command module – Execute commands on targets

Note

This module is part of ansible-core and included in all Ansible installations. In most cases, you can use the short module name command even without specifying the collections: keyword. However, we recommend you use the FQCN for easy linking to the module documentation and to avoid conflicting with other collections that may have the same module name.

Synopsis

  • The command module takes the command name followed by a list of space-delimited arguments.

  • The given command will be executed on all selected nodes.

  • The command(s) will not be processed through the shell, so variables like $HOSTNAME and operations like "*", "<", ">", "|", ";" and "&" will not work. Use the ansible.builtin.shell module if you need these features.

  • To create command tasks that are easier to read than the ones using space-delimited arguments, pass parameters using the args task keyword or use cmd parameter.

  • Either a free form command or cmd parameter is required, see the examples.

  • For Windows targets, use the ansible.windows.win_command module instead.

Note

This module has a corresponding action plugin.

Parameters

Parameter

Comments

argv

list / elements=string

added in 2.6 of ansible.builtin

Passes the command as a list rather than a string.

Use argv to avoid quoting values that would otherwise be interpreted incorrectly (for example “user name”).

Only the string (free form) or the list (argv) form can be provided, not both. One or the other must be provided.

chdir

path

added in 0.6 of ansible.builtin

Change into this directory before running the command.

cmd

string

The command to run.

creates

path

A filename or (since 2.0) glob pattern. If a matching file already exists, this step will not be run.

This is checked before removes is checked.

free_form

string

The command module takes a free form string as a command to run.

There is no actual parameter named ‘free form’.

removes

path

added in 0.8 of ansible.builtin

A filename or (since 2.0) glob pattern. If a matching file exists, this step will be run.

This is checked after creates is checked.

stdin

string

added in 2.4 of ansible.builtin

Set the stdin of the command directly to the specified value.

stdin_add_newline

boolean

added in 2.8 of ansible.builtin

If set to yes, append a newline to stdin data.

Choices:

  • no

  • yes ← (default)

strip_empty_ends

boolean

added in 2.8 of ansible.builtin

Strip empty lines from the end of stdout/stderr in result.

Choices:

  • no

  • yes ← (default)

Attributes

Attribute

Support

Description

check_mode

Support: partial

while the command itself is arbitrary and cannot be subject to the check mode semantics it adds creates/removes options as a workaround

Can run in check_mode and return changed status prediction without modifying target

diff_mode

Support: none

Will return details on what has changed (or possibly needs changing in check_mode), when in diff mode

platform

Platform: posix

Target OS/families that can be operated against

raw

Support: full

Indicates if an action takes a ‘raw’ or ‘free form’ string as an option and has it’s own special parsing of it

Notes

Note

  • If you want to run a command through the shell (say you are using <, >, |, and so on), you actually want the ansible.builtin.shell module instead. Parsing shell metacharacters can lead to unexpected commands being executed if quoting is not done correctly so it is more secure to use the command module when possible.

  • creates, removes, and chdir can be specified after the command. For instance, if you only want to run a command if a certain file does not exist, use this.

  • Check mode is supported when passing creates or removes. If running in check mode and either of these are specified, the module will check for the existence of the file and report the correct changed status. If these are not supplied, the task will be skipped.

  • The executable parameter is removed since version 2.4. If you have a need for this parameter, use the ansible.builtin.shell module instead.

  • For Windows targets, use the ansible.windows.win_command module instead.

  • For rebooting systems, use the ansible.builtin.reboot or ansible.windows.win_reboot module.

See Also

See also

ansible.builtin.raw

The official documentation on the ansible.builtin.raw module.

ansible.builtin.script

The official documentation on the ansible.builtin.script module.

ansible.builtin.shell

The official documentation on the ansible.builtin.shell module.

ansible.windows.win_command

The official documentation on the ansible.windows.win_command module.

Examples

- name: Return motd to registered var
  ansible.builtin.command: cat /etc/motd
  register: mymotd

# free-form (string) arguments, all arguments on one line
- name: Run command if /path/to/database does not exist (without 'args')
  ansible.builtin.command: /usr/bin/make_database.sh db_user db_name creates=/path/to/database

# free-form (string) arguments, some arguments on separate lines with the 'args' keyword
# 'args' is a task keyword, passed at the same level as the module
- name: Run command if /path/to/database does not exist (with 'args' keyword)
  ansible.builtin.command: /usr/bin/make_database.sh db_user db_name
  args:
    creates: /path/to/database

# 'cmd' is module parameter
- name: Run command if /path/to/database does not exist (with 'cmd' parameter)
  ansible.builtin.command:
    cmd: /usr/bin/make_database.sh db_user db_name
    creates: /path/to/database

- name: Change the working directory to somedir/ and run the command as db_owner if /path/to/database does not exist
  ansible.builtin.command: /usr/bin/make_database.sh db_user db_name
  become: yes
  become_user: db_owner
  args:
    chdir: somedir/
    creates: /path/to/database

# argv (list) arguments, each argument on a separate line, 'args' keyword not necessary
# 'argv' is a parameter, indented one level from the module
- name: Use 'argv' to send a command as a list - leave 'command' empty
  ansible.builtin.command:
    argv:
      - /usr/bin/make_database.sh
      - Username with whitespace
      - dbname with whitespace
    creates: /path/to/database

- name: Safely use templated variable to run command. Always use the quote filter to avoid injection issues
  ansible.builtin.command: cat {{ myfile|quote }}
  register: myoutput

Return Values

Common return values are documented here, the following are the fields unique to this module:

Key

Description

cmd

list / elements=string

The command executed by the task.

Returned: always

Sample: [“echo”, “hello”]

delta

string

The command execution delta time.

Returned: always

Sample: “0:00:00.001529”

end

string

The command execution end time.

Returned: always

Sample: “2017-09-29 22:03:48.084657”

msg

boolean

changed

Returned: always

Sample: true

rc

integer

The command return code (0 means success).

Returned: always

Sample: 0

start

string

The command execution start time.

Returned: always

Sample: “2017-09-29 22:03:48.083128”

stderr

string

The command standard error.

Returned: always

Sample: “ls cannot access foo: No such file or directory”

stderr_lines

list / elements=string

The command standard error split in lines.

Returned: always

Sample: [{“u\u0027ls cannot access foo”: “No such file or directory\u0027”}, “u\u0027ls \u2026\u0027”]

stdout

string

The command standard output.

Returned: always

Sample: “Clustering node rabbit@slave1 with rabbit@master \u2026”

stdout_lines

list / elements=string

The command standard output split in lines.

Returned: always

Sample: [“u\u0027Clustering node rabbit@slave1 with rabbit@master \u2026\u0027”]

Authors

  • Ansible Core Team

  • Michael DeHaan