First process
As a first step, we'll demonstrate basic orchestration layer work and set up a first simple process.
Prerequisites
Creating a process topology
The definition of a process is called a topology. To create a new topology, use the plus button in the left Admin bar. Topologies can be organized in folders and in addition to creating a new topology, we also have the option to import a ready-made topology. All of this will come in handy in the future, but for now, we'll just create a topology in the project root.
Select "New topology" from the action menu and name the topology.
Now the detail of the topology has opened up. We will describe its environment continuously. But first, let's open the editor and set up our first process. We open the editor with the pencil icon button in the action menu in the upper right corner of the screen.
In the left part of the editor we can see the toolbar. The circular elements in the toolbar are events. We use these as the default elements of topologies. You can find here 3 types of events - timer, webhook and start. We'll choose start and drag it onto the canvas.
The Start event creates an access point of the given topology. It provides a URL for sending data to be processed by the process. The URL is generated when the topology is saved. Then, the start event URL can be found in the right sidebar of the editor when the element is selected.
The next section of the tool editor is actions. For our topology, we'll select user task and drag it to the canvas. Click on start event to display its tools. Then use the arrows to connect the two elements of the topology.
Thus, we built the first sample topology using the user task action.
The User task action is useful for manually editing data using the user interface, but it can also be used very easily for stepping data when building topologies. Below we will show how.
Publishing a topology
Now save the prepared topology using the Save button in the action menu and close the editor using the Back button. This saves the changes. The topology is still in the Draft state. To run the prepared topology, we still need to publish it using the Publish button.
By publishing the topology, Orchesty creates a container with a control service and queues between process nodes.
Enable/disable process
The newly published process is in the inactive state. That is, it does not receive any start event signals. As soon as we switch the process to the enable state, it starts receiving requests for the start event URL.
Disable of a topology closes its entry points. The topology receives no signals and timers do not start scheduled processes. All running process instances continue processing.
Manually starting a process
If we have prepared a topology, we can also start the process manually by using the Run button in the action menu. In the window that opens, we can select the desired start event if the topology has more than one. In the body of the message we will insert the required data in JSON format.
Now start the process and move to the User tasks tab in the topology details. In this tab we can see all the messages of all the user tasks of the topology. When we click on our message, we can see its headers and data in the detail. The data can be edited before sending.
So if you see your first message in the user tasks overview, you have successfully started your first process. Use the Approve button to complete the process.
In the next chapter, we will show how to register a worker to the orchestration layer. In the worker, we can create our scripts and connectors using the SDK.