How to use configurations on FlowEngine

In the Onesait Platform, you have the possibility to create your own configurations. In this example, we will see how to create a custom configuration and how to use it in the FlowEngine. This allows you to have everything related to configuration centralized in a single point.

Instructions

1. Create a custom configuration:

   1. In the menu, go to “Dev Tools” → “Centralized configuration”.

      Open

      

       

   2. Create a custom configuration:

      Open

      

      
      and fill it with the values you need, following a yaml format:

       

2. Read the configuration from the FlowEngine: To read the configuration, use the Onesait Platform Management API. The FlowEngine already has a node that will facilitate the calls to that API, and you only have to select the operation that you want to execute. You are going to create a subflow that will be in charge of reloading the configuration to global variables within your flows.

   1. Create a subflow:
      
      

      This will open a new tab. If you double click on it, you can change the name to “Load Config”.
      
      After this, you are going to define an input and an output:

      These represent the input and output pins of your subflow node.
      
      

   2. Get a valid OAuth token: You are going to use an “http request” call to your IM to get it. For more information related to the Identity Manager, take a look at how to use OAuth2 tokens in Platform
      
      First, you need to set the request headers and body, using a “function” node like the following:
      
      

       

      Next, create an “http request” node with the call to the IM:

      In this specific case, you are using KeyCloak as IM. The username and password in the authentication are “onesaitplatform” in both cases.
      After this, you can parse the response into a “function" node and get your OAuth token ready to use in the next call:

       

   3. Get the configuration:
      
      Once you have the OAuth token, you can retrieve the configuration using your “onesaitplatform-management-Rest-API-invoker” node. Add this node from the palette to the subflow and double click on it to edit it:
      
      

      1. Select “Configuration management service“ as the API.
         
         

          

      2. Select “getByIdentificationUsingGET” as the operation.
         
         

          

      3. Fill in the required fields of the request. These parameters correspond to the values defined in the configuration that you created in step 1:
         
         

          

   4. The “onesaitplatform-management-Rest-API-invoker” node has several outputs. By hovering the cursor over each one, you will get a tooltip with the description of each one. For simplicity, the top output is the one that will contain the correct answer, and the rest are different types of errors.
      
      

      
      Add a “function” node in which you can process errors if necessary.
      
      

3. Load configuration into global variables.
   
   Now you are going to process the response from the API to convert it into an object that is easier to use. The management API invocation node will return the configuration in the message, specifically in the “msg.payload.yml" field. The next step is to parse the yaml intto a JSON object.
   To do this, add a “yaml" node to the subflow and indicate the field to parse:
   
   

   
   The parsed configuration should look like this:
   
   

   
   Finally, in a “function” node, read the configuration object and create the global variables you need:
   
   

    

4. Deploy the changes by clicking on the “deploy” button:
   
   
   

   
   
   

5. Use the subflow and test the results.
   Simply create a simple flow that executes the “Load Config” subflow and a “function” node that reads all the global variables to display them:

Related articles