shell – Execute shell commands on targets

Synopsis

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

  • It is almost exactly like the command module but runs the command through a shell (/bin/sh) on the remote node.

  • For Windows targets, use the win_shell module instead.

Parameters

Parameter Choices/Defaults Comments
chdir
path
Change into this directory before running the command.
creates
path
A filename, when it already exists, this step will not be run.
executable
path
Change the shell used to execute the command.
This expects an absolute path to the executable.
free_form
string / required
The shell module takes a free form command to run, as a string.
There is no actual parameter named 'free form'.
See the examples on how to use this module.
removes
path
A filename, when it does not exist, this step will not be run.
stdin
string
added in 2.4
Set the stdin of the command directly to the specified value.
stdin_add_newline
boolean
added in 2.8
    Choices:
  • no
  • yes ←
Whether to append a newline to stdin data.
warn
boolean
    Choices:
  • no
  • yes ←
Whether to enable task warnings.

Notes

Note

  • If you want to execute a command securely and predictably, it may be better to use the command module instead. Best practices when writing playbooks will follow the trend of using command unless the shell module is explicitly required. When running ad-hoc commands, use your best judgement.

  • 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.

  • To sanitize any variables passed to the shell module, you should use {{ var | quote }} instead of just {{ var }} to make sure they do not include evil things like semicolons.

  • An alternative to using inline shell scripts with this module is to use the script module possibly together with the template module.

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

See Also

See also

command – Execute commands on targets

The official documentation on the command module.

raw – Executes a low-down and dirty command

The official documentation on the raw module.

script – Runs a local script on a remote node after transferring it

The official documentation on the script module.

win_shell – Execute shell commands on target hosts

The official documentation on the win_shell module.

Examples

- name: Execute the command in remote shell; stdout goes to the specified file on the remote.
  shell: somescript.sh >> somelog.txt

- name: Change the working directory to somedir/ before executing the command.
  shell: somescript.sh >> somelog.txt
  args:
    chdir: somedir/

# You can also use the 'args' form to provide the options.
- name: This command will change the working directory to somedir/ and will only run when somedir/somelog.txt doesn't exist.
  shell: somescript.sh >> somelog.txt
  args:
    chdir: somedir/
    creates: somelog.txt

- name: Run a command that uses non-posix shell-isms (in this example /bin/sh doesn't handle redirection and wildcards together but bash does)
  shell: cat < /tmp/*txt
  args:
    executable: /bin/bash

- name: Run a command using a templated variable (always use quote filter to avoid injection)
  shell: cat {{ myfile|quote }}

# You can use shell to run other executables to perform actions inline
- name: Run expect to wait for a successful PXE boot via out-of-band CIMC
  shell: |
    set timeout 300
    spawn ssh admin@{{ cimc_host }}

    expect "password:"
    send "{{ cimc_password }}\n"

    expect "\n{{ cimc_name }}"
    send "connect host\n"

    expect "pxeboot.n12"
    send "\n"

    exit 0
  args:
    executable: /usr/bin/expect
  delegate_to: localhost

# Disabling warnings
- name: Using curl to connect to a host via SOCKS proxy (unsupported in uri). Ordinarily this would throw a warning.
  shell: curl --socks5 localhost:9000 http://www.ansible.com
  args:
    warn: no

Return Values

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

Key Returned Description
cmd
string
 always
The command executed by the task

Sample:
rabbitmqctl join_cluster rabbit@master
delta
string
 always
The command execution delta time

Sample:
0:00:00.325771
end
string
 always
The command execution end time

Sample:
2016-02-25 09:18:26.755339
msg
boolean
 always
changed

Sample:
True
rc
integer
 always
The command return code (0 means success)
start
string
 always
The command execution start time

Sample:
2016-02-25 09:18:26.429568
stderr
string
 always
The command standard error

Sample:
ls: cannot access foo: No such file or directory
stdout
string
 always
The command standard output

Sample:
Clustering node rabbit@slave1 with rabbit@master ...
stdout_lines
list
 always
The command standard output split in lines

Sample:
["u'Clustering node rabbit@slave1 with rabbit@master ...'"]


Status

Red Hat Support

More information about Red Hat’s support of this module is available from this Red Hat Knowledge Base article.

Authors

  • Ansible Core Team

  • Michael DeHaan

Hint

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