Task 2 - Using Kamelets

This example demonstrates how to create a simple Chuck Norris Kamelet source and how to integrate it with Telegram.
Our goal is to connect to a website containing Chuck Norris jokes via API, get a joke every few seconds and print it in the terminal first,
and then also send it to our Telegram channel. Architecture of this example is shown below:

What are Kamelets?

Kamelets are custom resources that hide the complexity of connecting to external systems behind a simple interface, which contains all the information needed to instantiate them, even for users who are not familiar with Camel. You can install kamelets on an OpenShift cluster and use then in Camel K integrations.

As kamelets look like any other Camel component, experienced developers will enjoy using them as much, and will quickly browse through all the already available, predefined Catalog Kamelets. It is of course possible to create your own kamelets too! You can define your own library of reusable kamelets for your organisation. And desirebly, contribute them to the Camel community.

Camel provides more than 300 components out of the box, therefore we can create a kamelet in a simple way, making use of one of the components already available. Most of the Kamelets available in the official catalog, are simple ones having only a remapping of the kamelet properties into Camel endpoint parameters.

Kamelets have two kinds of connectors, sources and sinks. Sources produce the data and sinks consume the data and optionally produce a response.

Let’s get started

☐ oc new-project kamelet-example - create a new project for the second example
☐ kamel init chuck-norris-source.kamelet.yaml - initiate a simple Kamelet template. this is the code you will see once you opened the newly created file:

You can also use kamel init xxxx-source.kamelet.yaml / xxxx-sink.kamelet.yaml to instantiate a kamelet template for creating your own custom kamelet of a given type.

☐ Modify your kamelet, or copy the entire kamelet code from: chuck-norris-source.kamelet.yaml
☐ oc apply -f chuck-norris-source.kamelet.yaml - use kamel CLI to create the chuck norris source kamelet on your OpenShift instance
☐ oc get kamelets - check if the chuck norris source is ready
☐ Create chuck-norris-example.groovy file:

☐ kamel run chuck-norris-example.groovy --dev- run the integration using chuck norris kamelet in the “dev” mode

You should see the jokes appearing in the terminal.

☐ Change the .to('log:info') to .to("telegram:bots?authorizationToken=XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX&chatID=XXXXXXXXXXXXX") - simply comment the line number 2 and uncomment the line number 3 in chuck-norris-example.groovy
☐ Provide your bot Authorization Token and chat ID in places marked by X characters.
☐ Save the file. After saving, your integration will reload automatically, because we are running it in “dev” mode.

Your Telegram bot should now be sending you Chuck Norris jokes!

☐ Verify that each 10 seconds you are getting a new joke.
☐ oc delete project chuck-norris - clean up the project