shell – Execute shell commands on targets

From Get docs
Ansible/docs/2.8/modules/shell module


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

  • no
  • yes

Whether to append a newline to stdin data.

warn

boolean

  • 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 Template:Var instead of just Template: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

If you notice any issues in this documentation you can edit this document to improve it.


© 2012–2018 Michael DeHaan
© 2018–2019 Red Hat, Inc.
Licensed under the GNU General Public License version 3.
https://docs.ansible.com/ansible/2.8/modules/shell_module.html