Skip to main content

Step 2: Make a Change

Now let's modify the pipeline to see how quickly you can iterate.

Update the Pipeline​

Stop the current pipeline (Ctrl+C) and update hello.yaml:

input:
  generate:
    interval: 1s
    mapping: |
      root.message = "Hello, World!"
      root.timestamp = now()
      root.count = counter()

output:
  stdout: {}

Run it again:

expanso-edge run --config hello.yaml

Now you see:

{"count":1,"message":"Hello, World!","timestamp":"2024-12-26T10:00:00.123Z"}
{"count":2,"message":"Hello, World!","timestamp":"2024-12-26T10:00:01.456Z"}
{"count":3,"message":"Hello, World!","timestamp":"2024-12-26T10:00:02.789Z"}

What Changed?​

  • now() - A Bloblang function that returns the current timestamp
  • counter() - A function that increments with each message

Try changing the message text or interval and re-run. The feedback loop is instant!

What's Next?​

👉 Step 3: Data Transformation