How to develop a custom connector for IoT Project Flogo? This video demonstrates how build a custom Flogo Adapter / Connector quickly and easily for any kind of technology or interface. In Flogo terms, this is either a Trigger (to initiate and start a new Flogo flow from an interface) or an Activity (to send a message to an interface). This video shows how to use Golang to build a Flogo Activity to send messages to Apache Kafka. Note that building a Trigger can be done with the same procedure as described here. The source code can be found here: https://github.com/kwaehner/flogo/tree/master/activity/kafka (I will also contribute it to the Flogo project, of course). Any feedback or questions are highly appreciated. Please use the Flogo Community Q&A to ask questions or discuss concepts or use cases for Flogo: https://community.tibco.com/products/project-flogo A video recording with live demo can be found here: https://youtu.be/NScV3v8A6Mk

1. Kai Wähner
Technology Evangelist
kontakt@kai-waehner.de
LinkedIn
@KaiWaehner
www.kai-waehner.de
January 2017
Development of a Custom Flogo Connector
(using Apache Kafka as example)

2. © Copyright 2000-2016 TIBCO Software Inc.
This is not an introduction to Open Source IoT Project Flogo
www.flogo.io
https://community.tibco.com/wiki/flogo-
introduction-slides-and-videos

3. © Copyright 2000-2016 TIBCO Software Inc.
• is very easy, fast and lightweight
• can be done without much experience in Go programming language
• is best done by using other Flogo connectors (and unit tests) as template
• should be contributed to the Flogo open source community (not a must, of course!)
Key Takeaways
Building custom Flogo connectors…

4. Flogo Concepts
Trigger
Flow
Activity
Error Handler
Flogo App
One or more Flows
Flows
Activities + Transitions +
Optional error handler
Triggers
Starts those flows

5. Flogo Repositories on Github
flogo-lib
Core libraries.
flogo-services
Backing services required by Flogo for flow
and state management.
flogo-contrib
Flogo extensions available out of the box, like
triggers or activities.
flogo-cli
A command line tool to build Flogo apps.
https://github.com/TIBCOSoftware/flogo
(very permissive open source BSD license)
This projects includes
Triggers and Activities
go get github.com/TIBCOSoftware/flogo-contrib/...

6. © Copyright 2000-2016 TIBCO Software Inc.
Apache Kafka
https://kafka.apache.org/
“Kafka is used for building real-time
data pipelines and streaming apps. It
is horizontally scalable, fault-tolerant,
wicked fast, and runs in production in
thousands of companies.”

7. © Copyright 2000-2016 TIBCO Software Inc.
• Get Access to a technology which you want to integrate
• For Kafka, this could be a locally installed broker, or a remote connection
• Find, install and use a corresponding Go library
• Various Golang APIs are available for Apache Kafka
• I chose the Kafka API from optiopay because it is very simply and easy to use – depending on requirements
regarding functionality, performance or maturity, other options might be better (I did not do more research)
• Install the library into your Go workspace (command ‘go install’)
• Run an “hello world“ example (optiopay delivers a very nice simple demo where you send and consume messages
from command line)
• Duplicate an existing Flogo Activity
• Choose a similar Flogo Activity (e.g. Kafka is similar to MQTT, you connect to a broker and send messages)
• The folder includes implementation, test, runtime config and UI config
• Use the existing folder as template and re-write / update / replace / enhance the code + config + test
• Run “go test” to validate correctness of the new connector
• In my Kafka test, I see that the test sends a new message to Kafka (verified in a Kafka consumer running on the
command line)
• Deploy and test the new connector in the Flogo Web UI
• The web UI allows to install a new activity (or trigger) via URL Link (you need to publish your connector on Github)
• Github Pull Request to contribute your code back to the Flogo community
• (optional step, but highly recommended J)
Steps to develop a custom connector

8. © Copyright 2000-2016 TIBCO Software Inc.
Live Demo
Development of a Flogo Activity for Apache Kafka

9. © Copyright 2000-2016 TIBCO Software Inc.
• is very easy, fast and lightweight
• can be done without much experience in Go programming language
• is best done by using other Flogo connectors (and unit tests) as template
• should be contributed to the Flogo open source community (not a must, of course!)
Key Takeaways
Building custom Flogo connectors…

10. Questions? Please contact me!
Kai Wähner
Technology Evangelist
kontakt@kai-waehner.de
@KaiWaehner
www.kai-waehner.de
LinkedIn
Ask questions on the Flogo community:
https://community.tibco.com/products/project-flogo