Playbooks¶
The ThreatConnect ™ TcEx App Framework provides common helper methods to write a Playbooks App. The TcExPlaybook module provides all required methods to communicate with upstream and downstream Apps.
Understanding Playbooks¶
A Playbook App is a single component of a Playbook. These Apps are intended to be reusable standalone components with minimum functionality to solve a single purpose. Multiple Playbook Apps will make up a Playbook that solves a use case. For more information on Playbook methodology and functionality refer to the Playbooks documentation.
Playbook Flow¶
As a Playbook starts execution each App will have input and output variables. The input variables can be user provided data or output from an upstream App. The Apps input and output variables are defined in the Install JSON file of the App. A downstream App has access to all output variables from any upstream Apps.
Note
Upstream Apps are app that have completed execution previous to the current Apps execution.
Input Variables¶
Inputs to an App can be static user data or dynamic output variables from a trigger or upstream App. The TcExPlaybook module provides the read method for pulling dynamic data from an upstream App. The read method will automatically determine the variable type for the App developer. If user data was passed instead of the output variable the read will return the unaltered string.
Tip
The read method will also handle mixed type data by automatically calling the read_embedded method when a mixed type variable is identified.
Output Variables¶
Playbook Apps write output variables for downstream Apps. The TcExPlaybook module provides the create method for writing output variables. However, output variables should only be written when requested by a downstream App. The requested variables are passed in the args.tc_playbook_out_variables argument as a CSV string. The TcExPlaybook module provides the create_output method that will validate that a downstream App requested the output variable before writing.
Hint
In most cases the create_output method is the best way to write output variables.
Variable Types¶
When output variables are passed to the input of an App the variable type is defined. In some cases it is useful to know the type of variable passed. The TcExPlaybook module provides the variable_type method that will return the variable type.
- Binary
- BinaryArray
- KeyValue
- KeyValueArray
- String
- StringArray
- TCEntity
- TCEntityArray
Note
For more information on Playbook variable types or updated type please see the Playbooks documentation.