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Learning Module - Level 1 [Beginner Track]

· 3 min read

  1. Install Godspeed if you have not. The updated and maintained version is available at Godspeed website.

  2. Start the service from a remote container Tip: Learn about dev containers in VS Code and its benefits.

We would prefer you to go through the getting started section for this.

  1. Once your service is in running status as mentioned in getting started section, Open the Swagger doc at
localhost:3000/api-docs

  1. Hit the Hello world API

  2. Export Swagger spec and import the same as Postman collection. From within

godspeed gen-api-docs

  1. Now come back to the project structure in VS Code. In order to study the basic parts of your project check here.

  2. Study about events (docs)

    • What is schema driven development?
    • Study how to define the schema of the event. FYI, Godspeed events use Swagger/JSON-schema specification.
    • Lets test the schema based validation of inputs by Godspeed. Go to Swagger and give a wrong input to your event. See how it rejects.
    • Now modify the hello world event schema in src/events/hello_world.yaml to add name in query section. Make it required: true.
    • Test the new schema through Swagger or Postman, by sending hit without name and then with a name.
    • The five kinds of inputs you receive from an HTTP event -> params (path), query, headers, body, files (in case of file upload)
    • The kind of inputs you receive from Kafka event - body (only)

  3. Studying workflows or functions in Godspeed world (docs)

      * Do read the documentation on the workflow structure and have some hands-on experience.
      * Open `src/functions/com/jfs/hello_world.yaml` in VS Code.
      * Study inline scripting within workflows (docs). Check config/default to see which is the primary language in your project, for inline scripting: js or coffee? For the time being keep it JS  (default). Here’s an example of Coffee Script in `src/functions/com/coffee/httpbin_anything_coffee.yaml` You can study that to check the coffee script flavor of programming. It is shorthand for JS. Let's come back to inline scripting with JS for now.
     * In the first and only task of hello world workflow, we will replace static string Hello World with Hello `<your_name_from_query>`
     * Replace the string ‘Hello World’ with `<% ”Hello ” + inputs.query.name %>.`
     * Go to Swagger and hit with your name. You should obtain the following response

    Hello <your_name>

  4. Calling pure JS/TS from within workflows In the previous section you had allowed for name parameters in the query.

    • Now, create a JS file called hello_world.js (or .ts) in the functions/com/biz directory. Write code like

      module.exports = function helloWorld (text) { return text; }

      Edit the hello_world.yaml to call fn: com.biz.hello_world and set args:

      <% ”Hello ” + inputs.query.name %>

    • Go to Swagger Hello World example, and hit with your name. You should see the response Hello <your_name>

  • Now read about the plugins on the documentation. The purpose of plugins is that you can invoke the functions defined in files in that directory, from within the inline JS or CS scripts that you write in the YAML. Test out the example from the documentation.

Congratulations! You have now successfully tested events and workflows basics.

Before you move to our next section, do inspect the src folder.

Feel free to play around by modifying the schema and workflow to your curiosity with everything you have learned so far.

See You in Level 2 Track