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.
Parameters
Parameter | Choices/Defaults | Comments |
---|---|---|
chdir | Default: None | cd into this directory before running the command |
creates | Default: None | a filename, when it already exists, this step will not be run. |
executable | Default: None | change the shell used to execute the command. Should be an absolute path to the executable. |
free_form required | Default: None | 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 | Default: None | a filename, when it does not exist, this step will not be run. |
stdin (added in 2.4) | Default: None | Set the stdin of the command directly to the specified value. |
warn (added in 1.8) | Default: yes | if command warnings are on in ansible.cfg, do not warn about this particular line if set to no/false. |
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.
- Rather than using here documents to create multi-line scripts inside playbooks, use the script module instead.
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, 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 int | 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
This module is flagged as stableinterface which means that the maintainers for this module guarantee that no backward incompatible interface changes will be made.
Support
For more information about Red Hat’s support of this module, please refer to this Knowledge Base article
Author
- 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/2.5/modules/shell_module.html