W3cubDocs

/Ansible

shell - Execute commands in nodes.

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.

Options

parameter required default choices comments
chdir
 no
cd into this directory before running the command
creates
 no
a filename, when it already exists, this step will not be run.
executable
 no
change the shell used to execute the command. Should be an absolute path to the executable.
free_form
 yes
The shell module takes a free form command to run, as a string. There's not an actual option named "free form". See the examples!
removes
 no
a filename, when it does not exist, this step will not be run.
stdin
(added in 2.4)
 no
Set the stdin of the command directly to the specified value.
warn
(added in 1.8)
 no True
if command warnings are on in ansible.cfg, do not warn about this particular line if set to no/false.

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

Return Values

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

name description returned type sample
end
The command execution end time
 always string 2016-02-25 09:18:26.755339
stdout
The command standard output
 always string Clustering node rabbit@slave1 with rabbit@master ...
cmd
The command executed by the task
 always string rabbitmqctl join_cluster rabbit@master
start
The command execution start time
 always string 2016-02-25 09:18:26.429568
delta
The command execution delta time
 always string 0:00:00.325771
stderr
The command standard error
 always string ls: cannot access foo: No such file or directory
rc
The command return code (0 means success)
 always int 0
msg
changed
 always boolean True
stdout_lines
The command standard output split in lines
 always list ["u'Clustering node rabbit@slave1 with rabbit@master ...'"]

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.
  • To sanitize any variables passed to the shell module, you should use “{{ var | quote }}” instead of just “{{ var }}” to make sure they don’t include evil things like semicolons.
  • For Windows targets, use the win_shell module instead.

Status

This module is flagged as stableinterface which means that the maintainers for this module guarantee that no backward incompatible interface changes will be made.

Maintenance Info

For more information about Red Hat’s this support of this module, please refer to this knowledge base article<https://access.redhat.com/articles/rhel-top-support-policies>

For help in developing on modules, should you be so inclined, please read Community Information & Contributing, Testing Ansible and Developing Modules.

© 2012–2017 Michael DeHaan
© 2017 Red Hat, Inc.
Licensed under the GNU General Public License version 3.
https://docs.ansible.com/ansible/latest/shell_module.html