Flogo demo by Square IT Services - IoT application

Introduction

This repository is part of the Flogo Demo by Square IT Services.

• This Flogo application manages the screen display part.
• Another Flogo application is used to manage the interactions with end-users.

Currently, these two applications communicates very simply through a REST service.

Description

The application is running on a Raspberry Pi. Its goal is to display a smiley image on the display of the Raspberry Pi.

The smiley image is chosen using a REST API over HTTP. This API is described by the file swagger.yaml

Implementation

The application is built with Flogo and Square IT custom activities.

The flow is composed of:

• A REST trigger
• A log activity to print the input request
• A command activity to hide the previous smiley image displayed
• A command activity to display the new smiley image
• A return activity to reply to the client

The program fbi is used by the application to display the images.

The smiley images used come from the openmoji site.

Prerequisites

• a Raspberry Pi with a screen display, sudoer right and SSH access (using Raspbian with default user pi is advised)
• a system with Go & Flogo installed (for compilation only)

Usage

Prepare

1. configure your SSH config (considering the Raspberry Pi is reachable at 192.168.1.2)

mkdir -p ~/.ssh
touch ~/.ssh/config
export RPI_IP=192.168.1.2
cat <<EOF >> ~/.ssh/config
Host rpi
        HostName $RPI_IP
        User pi
EOF

2. copy the smileys to the Raspberry Pi

ssh rpi 'curl -fsSL https://github.com/hfg-gmuend/openmoji/releases/download/1.0.0/618x618-color.zip > /tmp/618x618-color.zip && rm -rf ~/emojis && unzip -q /tmp/618x618-color.zip -d ~/emojis'

3. install fbi

ssh rpi 'sudo apt-get update && sudo apt-get install -y fbi'

4. to enable OpenTracing, run a Zipkin collector (optional):

docker run --name zipkin -d -p 9411:9411 openzipkin/zipkin

For detailed instructions read OpenTracing collectors for Flogo.

Build from sources

1. clone this repository

git clone https://github.com/square-it/flogo-demo-iot.git
cd flogo-demo-iot

2. compile the application into a native executable

GOOS=linux GOARCH=arm GOARM=7 flogo build -e

Go language supports cross-compilation out-of-the-box.

Test

1. copy the executable to the Raspberry Pi

scp bin/linux_arm/flogo-demo-iot rpi:~

2. run the executable on the Raspberry Pi

ssh rpi 'sudo DEMO_IOT_EMOJIS_DIR=~/emojis/618x618-color ~/flogo-demo-iot'

To enable OpenTracing with a Zipkin HTTP collector listening on 192.168.1.1:9411, run instead

ssh rpi 'sudo DEMO_IOT_EMOJIS_DIR=~/emojis/618x618-color FLOGO_OPENTRACING_IMPLEMENTATION=zipkin FLOGO_OPENTRACING_TRANSPORT=http FLOGO_OPENTRACING_ENDPOINTS=http://192.168.1.1:9411/api/v1/spans ~/flogo-demo-iot'

3. test with a sample smiley

curl http://192.168.1.2:4445/v1/smiley/1F605

Development

1. run a Flogo Web UI

docker run --name flogo -it -d -p 3303:3303 -e FLOGO_NO_ENGINE_RECREATION=false flogo/flogo-docker:v0.5.8 eula-accept

2. install custom-made activities contributions

docker exec -it flogo sh -c 'cd /tmp/flogo-web/build/server/local/engines/flogo-web && flogo install github.com/square-it/flogo-contrib-activities/command'
docker exec -it flogo sh -c 'cd /tmp/flogo-web/build/server/local/engines/flogo-web && flogo install github.com/square-it/flogo-contrib-activities/copyfile'

3. restart the Flogo Web UI container

docker restart flogo

The Flogo Web UI is available at http://localhost:3303.

Import the application using the provided flogo.json.