Creating the blueprint

The blueprint declares which streamlets join together to form our pipeline. Create blueprint.conf in src/main/blueprint to specify the connection as follows:

blueprint {
  streamlets {
    http-ingress = sensordata.SensorDataHttpIngress
    metrics = sensordata.SensorDataToMetrics
    validation = sensordata.MetricsValidation
    valid-logger = sensordata.ValidMetricLogger
    invalid-logger = sensordata.InvalidMetricLogger
  }

  connections {
    http-ingress.out = [metrics.in]
    metrics.out = [validation.in]
    validation.invalid = [invalid-logger.in]
    validation.valid = [valid-logger.in]
  }
}

Commit your changes

Next, commit your changes:

  1. Change directories to the parent directory of your project.

  2. Use the git add command to add all of the files you created.

    git add *
  3. Use the git commit command to commit your changes:

    git commit -m "my first Cloudflow app"

What’s next

With the streamlets implemented and the blueprint ready, let’s try running Hello World in a development sandbox.