Try a data product

This tutorial uses Harbour observations: two fixed, synthetic measurements. You will run its API, read the records and validate a product description. The example does not connect to a real harbour sensor.

Before you start

Install Git, curl and Go at the version declared in the repository’s go.mod or newer. The first build downloads Go dependencies.

Run the example API

In a terminal:

git clone https://github.com/devantler-tech/data-product-controller.git
cd data-product-controller
go run ./cmd/demo-product --listen-address 127.0.0.1:8080

Keep this terminal open. The loopback address limits the example to your machine. If port 8080 is occupied, choose another port and update the requests below.

Read the observations

In a second terminal:

curl --fail http://127.0.0.1:8080/api/observations

The response has an items array with stations nordhavn and refshaleoen. Nordhavn has temperature 16.8 and salinity 14.2. These values are examples.

Request one station:

curl --fail 'http://127.0.0.1:8080/api/observations?station=nordhavn'
curl --fail http://127.0.0.1:8080/openapi.json

The first response contains only Nordhavn. The second is the API contract. The product also has its own page at http://127.0.0.1:8080/ui; consumer applications can use the API directly.

Check a product declaration

From the cloned repository in the second terminal:

PUBLISHER_PREFLIGHT_ENABLED=true go run ./cmd/product-check \
  --file website/public/examples/harbour-product.yaml

Expect Validated 1 product(s). This checks the declaration, including its placeholder HTTPS URLs. It does not request those URLs, publish the product or establish live readiness.

Stop and continue

Press Ctrl+C in the API terminal. The example writes no application data. Go retains its dependency and build caches.

You have exercised a product API and checked its metadata. Next, publish an independently running API or install the controller to make descriptions discoverable.