Ansible Module command
External
Internal
Overview
The command module takes the command name followed by a list of space-delimited arguments. A command will NOT be interpreted by a shell, so variables like $HOME and operations like "<", ">", "|", ";" and "&" will not work. Use the shelll module for that.
For a discussion on the interaction between command
, cmd
, argv
, etc. see command, argv and cmd below.
- name: A command example
command: some-command arg1 arg2 # the command can be specified here, or with 'cmd', or with 'argv'
argv: ... # Passes the command as a list rather than a string
cmd: ... # The command to run
chdir: ... # Change into this directory before running the command
stdin: ...
stdin_add_newline: ...
warn: ...
creates: ...
become: true
become_user: root
args:
chdir: /somedir/ # alternative way of specifying "command" configuration
register: variable_that_contains_results_of_execution
A variable that contains the result of the command execution can be set as usual for a task using the task's register
configuration element. After an execution, the variable references a map similar to:
cmd:
- "sh"
- "-l"
- "/tmp"
failed: false
stdout: "lrwxr-xr-x@ 1 root admin 11 Sep 21 2020 /tmp -> private/tmp"
stdout_lines:
- "lrwxr-xr-x@ 1 root admin 11 Sep 21 2020 /tmp -> private/tmp"
stderr: ""
stderr_lines: []
start: "2021-07-03 23:39:57.499748"
end: "2021-07-03 23:39:57.506848"
changed: false
delta: "0:00:00.007100"
rc: 0
The content of execution stdout and stderr can be accessed with variable_name.stdout
, variable_name.stderr
, the failure situation with variable_name.failed
, etc.
Playground
Examples
- name: Read requested Java version
command: "sh -c \"grep ^JAVA_VERSION {{ansible_env.HOME}}/config.txt | sed -e 's/.*=//'\""
register: java_version
changed_when: false
The task execution result can be referred to via a variable declared with the register:
keyword:
- name: Get Homebrew installation directory
command: "sh -c \"brew --prefix\""
register: brew_prefix_cmd
changed_when: false
The output of the command execution can then be set as a fact with set_fact
:
- name: Set a fact
set_fact:
pkg_manager_install_dir: "{{ brew_prefix_cmd.stdout }}"
command, argv and cmd
The command followed by the space-separated list of arguments can be specified immediately after the command:
keyword:
- name: some name
command: ls -l /tmp
Alternatively, the command provided as a list with argv
. Note that either command
or argv
can be used, but not both at the same time:
- name: some name
command:
argv:
- ls
- -l
- /tmp
The full command can be specified as a string with cmd
. Note that either command
or cmd
can be used, but not both at the same time:
- name: some name
command:
cmd: ls -l /tmp
Privilege Escalation
See: