Workflow Builder

Workflow Builder is the graphical interface inside UniConfig UI to create, modify and manage workflows.

Creating new workflow

To create a new workflow click on the New button in the Workflows -> Definition tab and fill in workflow general parameters. Then you can proceed with adding tasks.

Note

Parameter name is required and must be unique. Keep in mind that the name cannot be changed later. Other parameters are optional and can be changed anytime.

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Editing existing workflow

To edit an already existing workflow, find the workflow in the Definitions tab, click on it and then click on the Edit button. A diagram of the workflow will be rendered on the canvas. Now you can restructure the workflow, add new tasks, remove tasks or edit the workflow information and parameters.

Adding tasks

To add new task on canvas, find the task in the left menu, drag and drop the task on canvas.

To remove one task, select the task by clicking on it once and pressing the Delete button on the keyboard. To remove multiple tasks, hold Shift and left click on the respective tasks, then press the Delete button on keyboard.

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Task parameters

To edit or add task parameters, double-click on the task that is placed on the canvas.

Input parameters can be declared as:

  • Input provided by user, e.g.:

${workflow.input.<name>}

  • Variable provided by other task, e.g.:

${<taskRefName>.output.result}

  • Statically defined, e.g.:

https://example.com/api/user

For full documentation of tasks see: https://netflix.github.io/conductor/configuration/taskdef/.

System tasks

Fork & Join

The ‘Fork’ function is used to schedule a parallel set of tasks.

Note

A Join task MUST follow Fork task.

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Decision

A decision task is similar to an if…else statement in a programming language. The task takes 2 parameters:

  • name of the parameter in the task input whose value will be evaluated (default is param)

  • value that will be compared with param (or other specified input variable)

If param and is equal to are evaluated as equal, the workflow will continue to If branch, otherwise the workflow will continue in else branch.

Note

Else branch is optional and can be empty.

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Lambda

Lambda Task helps execute ad hoc logic at Workflow run-time, using javax & Nashorn Javascript evaluator engine.

This is particularly helpful in running simple evaluations in the Conductor server, instead of creating Workers.

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The task output can then be referenced in downstream tasks like: ${lambda_test.output.result.testvalue}

HTTP

An HTTP system task is used to make calls to another microservice over HTTP.

You can use GET, PUT, POST, DELETE Methods and also you can set your custom header.

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TERMINATE

Task that can terminate a workflow with a given status and modify the workflow’s output with a given parameter. It can act as a “return” statement for conditions where you simply want to terminate your workflow.

For example, if you have a decision where the first condition is met, you want to execute some tasks, otherwise you want to finish your workflow.

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description

notes

terminationStatus

can only accept “COMPLETED” or “FAILED”

task cannot be optional

workflowOutput

Expected workflow output

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EVENT

Event task provides ability to publish an event (message) to either Conductor or an external eventing system like SQS. Event tasks are useful for creating event based dependencies for workflows and tasks.

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When producing an event with Conductor as sink, the event name follows the structure: conductor:<workflow_name>:<task_reference_name>

WAIT

A wait task is implemented as a gate that remains in IN_PROGRESS state unless marked as COMPLETED or FAILED by an external trigger. To use a wait task, set the task type as WAIT

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Subworkflows

Subworkflows acts as a regular task inside a parent workflow. Subworkflows can be unbundled into its respective tasks (or other nested subworkflows) by selecting it and then by clicking on Expand in the upper right-hand corner.

Note

Simple tasks differs in color shade from Subworkflow tasks and cannot be expanded.

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You can expand unbundled tasks/subworkflows further or you can simply delete, edit, restructure or add new tasks.

Note

Un-bundling and editing a subworkflow (as a part of other workflow) will not change the original definition of subworkflow.

Linking tasks

To connect tasks or subworkflows into execution flow, drag and drop respective Out and In endpoints on nodes, like this: Out —> In

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To remove the link, hold Shift and left click on the link, then press Delete on the keyboard.

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Adding workflow information

To provide additional workflow information, click on Edit general in the upper right-hand corner.

Output parameters

We can specify custom output parameters of a workflow, by using JSON templates to generate the output of the workflow. If not specified, the output is defined as the output of the last executed task.

Let’s say we have a task with taskReferenceName: task1 which returns summary and we want output of the worklow to be output of this specific task only. The outputParameter value named e.g. finalResult will be: ${task1.output.summary}

For full documentation of workflow parameters and definition read https://netflix.github.io/conductor/configuration/workflowdef/.

Defaults & Description

Here, we can define default values and descriptions for workflow inputs. Each input value declared as ${workflow.input...} will appear in a dropdown list of available input parameters.

Save and execute workflow

To Save workflow, click on the Save button in the upper left corner. Then you can find the workflow in the Workflows -> Definitions tab.

To Execute workflow directly from the builder, click on the Execute button in the upper right corner. You will be prompted to provide input parameters.

Note

Executing workflow will also save the workflow.

Import and export of workflow

To import a workflow on to the canvas, click on Import in the upper left corner and select the valid JSON definition of the workflow.

Note

Imported workflow will not be saved until you click on Save or Execute

To export and save the workflow in JSON format into your filesystem, click on Export in the upper left corner.

Note

In order to choose a location to which you want to export the workflow, you have to have it enabled in your browser settings. Default location is Downloads folder.

Creating custom workflow subsets

In order to create new custom subset containing workflows, assign a label with prefix CUSTOM_ to the workflow and it will appear as a new group in left side menu.

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