An action runner is the execution environment for user-implemented actions. |st2| comes with pre-canned action runners such as a remote runner and shell runner which provide for user-implemented actions to be run remotely (via SSH) and locally. The objective is to allow the Action author to concentrate only on the implementation of the action itself rather than setting up the environment.
Normally the exit code of a runner is defined by the exit code of the script or command executed. All runners return timeout exit code (-9) if the command or script did not complete its execution within the specified timeout.
This is the local runner. This runner executes a Linux command on the host where |st2| is running.
Note
stdout and stderr attributes in the runner result object have the last \n or \r
or \r\n characters removed if present. This is done so you can re-use the result of common
commands that include a trailing line break of carriage return, such as uptime, whoami,
etc., in other actions and workflows. If you have an action which requires a trailing line
break character to be present, you can add it explicitly to the result, e.g.
echo -e 'test\n' (this will result into two line break characters and only one of
them will be stripped/removed from the result).
This is the local runner. Actions are implemented as scripts. They are executed on the host where
|st2| is running. The last newline character is stripped from stdout and stderr fields in
the output.
This is a remote runner. This runner executes a Linux command on one or more remote hosts provided
by the user. The last newline character is stripped from stdout and stderr fields in the
output.
Note
By default |st2| uses paswordless sudo for system user which is used to execute commands on
local and remote systems. In addition to paswordless sudo, local and remote runners also support
password protected sudo via sudo_password runner parameter. With the remote runner, sudo
password is passed to the sudo command as a command line argument which means it has some
security implications - if bash history is enabled for the system user under which |st2|
remote commands run, this command which includes sudo password will be saved in bash history
and any system user which access to that user bash history file will be able to view it.
This is a remote runner. Actions are implemented as scripts. They run on one or
more remote hosts provided by the user. The last newline character is stripped
from stdout and stderr fields in the output.
The Windows command runner allows you to run the command-line interpreter (cmd) and PowerShell
commands on Windows hosts.
For more information on enabling and setting up the Windows runner, please see the following section - :doc:`/install/config/windows_runners`.
Windows script runner allows you to run PowerShell scripts on Windows hosts.
For more information on enabling and setting up the Windows runner, please see the following section - :doc:`/install/config/windows_runners`.
HTTP runner works by performing HTTP request to the provided URL.
Keep in mind that other parameters such as body, method, headers, etc. are defined
as part of the core.http action.
The result object from this runner contains the following keys:
status_code(integer) - Response status code (e.g. 200, 404, etc.)body(string/object) - Response body. If the response body contains JSON and the responseContent-Typeheader isapplication/json, the body will be automatically parsed as JSON.parsed(boolean) - Flag which indicates if the response body has been parsed.headers- Response headers.
This is a Python runner. Actions are implemented as Python classes with a run method. They run
locally on the machine where st2actionrunner is running.
Python runner actions return an execution status (success, failure) by returning a tuple
from the Python action class run() method. The first item in this tuple is a boolean
flag indicating success/failure and the second one is the result. However, execution status is
optional i.e. the return value from action runner can either be a tuple of success status
and result or just the result object.
The return value from this action runner is a tuple consisting of a boolean flag indicating success/failure and the second one is the result:
status(boolean) - Flag indicating action's success, i.e. Succeeded status is True/False. Note: This is an optional flag.result(object) - result returned by the action based on success or failure.
The status flag allows users to return a result from a failing action. When the status flag is not used the only way for action to be considered as failed is to throw an exception or exit with a non-zero exit code.
ActionChain is a no-frills linear workflow, providing a simple chain of action invocations. For more information, please refer to the :doc:`Workflows </workflows>` and :doc:`ActionChain </actionchain>` section of documentation.
This runner is built on top of the Mistral OpenStack project and supports executing complex workflows. For more information, please refer to the :doc:`Workflows </workflows>` and :doc:`Mistral </mistral>` sections of the documentation.
This runner is built on top of the CloudSlang project and supports executing complex workflows. For more information, please refer to the :doc:`Workflows </workflows>` and :doc:`CloudSlang </cloudslang>` sections of the documentation.
Note: This runner is currently in an experimental phase which means that there might be bugs and the external user-facing API might change.