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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.out = []
    validation.invalid = []
    validation.valid = []

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.