services

OpenFaaS Services

Overview

• db-inserter

  Reads an MQTT message and inserts it into a Postgres table

  The following connects the function to the MQTT topic via the Emitter broker:

      annotations:
      topic: "drone-position/"

  # Delivering candles to the Peterborough Cathedral
  curl 127.0.0.1:8080/function/db-inserter \
  --data '{"name": "Halo", "tempCelsius": 8.5, "location": {"lat":  52.5724835, "lon": -0.2392101}, "destination": {"lat":  52.5724835, "lon": -0.2392101}, "batteryPercent": 80}' \
  -H "Content-Type: application/json"
  
  # Delivering cucumbers to the market
  curl 127.0.0.1:8080/function/db-inserter \
  --data '{"name": "Market-watch", "tempCelsius": 8.5, "location": {"lat":  52.5736589, "lon": -0.2400627}, "destination": {"lat":  52.5724835, "lon": -0.2392101}, "batteryPercent": 80}' \
  -H "Content-Type: application/json"
  
  # Dropping off ice-cream to the outdoor pool
  curl 127.0.0.1:8080/function/db-inserter \
  --data '{"name": "Pool-watch", "tempCelsius": 8.5, "location": {"lat":  52.5700276, "lon": -0.2384085}, "destination": {"lat":  52.5724835, "lon": -0.2392101}, "batteryPercent": 80}' \
  -H "Content-Type: application/json"

• db-reader

  Reads positions and events of the drones ingested so far

  GET /events - read the drone_event table in JSON

  curl -s 127.0.0.1:8080/function/db-reader/events

  GET /positions - read the drone_position table in JSON

  curl -s 127.0.0.1:8080/function/db-reader/positions

  GET /positions-geojson - return geoJSON to be used with a feed or external API

  curl -s 127.0.0.1:8080/function/db-reader/positions-geojson
  

  {
      "type": "FeatureCollection",
      "features": [
          {
              "type": "Feature",
              "geometry": {
                  "type": "Point",
                  "coordinates": [
                  -0.2392101,
                  52.5724835
                  ]
              },
              "properties": {
                  "title": "Halo",
                  "icon": "airfield"
              }
          },
          {
              "type": "Feature",
              "geometry": {
                  "type": "Point",
                  "coordinates": [
                  -0.2400627,
                  52.5736589
                  ]
              },
              "properties": {
                  "title": "Market-watch",
                  "icon": "airfield"
              }
          },
      ]
  }

• mqtt-publisher

  Broadcasts a POST body as an MQTT message on the control-event/ channel. Content of the message is left up to the publishers and consumers - the example below references the cancel control event.

  # Send all drones servicing the NE Vegas warehouse back to the hangar 
  curl 127.0.0.1:8080/function/mqtt-publisher \
  --data '{"type": "cancel", "filter": {"warehouse":  "NE Vegas"}, "data": {}}' \
  -H "Content-Type: application/json"

• render-map

  Static webpage assets generated from a webpack build. The webpage is written in React and renders locations from the db-reader endpoint using GeoJSON.

  Find out more about Mapbox GL JS + React

  See also: render-map README

Deployment

• You will need to create a secret for Postgres with the login information:

  export USER="postgres"
  export HOST="postgresql.default.svc.cluster.local"
  # export POSTGRES_PASSWORD=""  # Set this value or take it from the earlier step
  
  kubectl create secret generic -n openfaas-fn db \
    --from-literal db-username="$USER" \
    --from-literal db-password="$POSTGRES_PASSWORD" \
    --from-literal db-host="$HOST"

• Create the schema

  Use the psql command you got in the Postgres installation step to create the database schema held in the openfaas/services/schema.sql file.

• Deploy the stack

  cd openfaas/services
  
  faas-cli deploy

  Use --filter NAME to deploy only one function at a time

• Rebuild the stack if you want (optional)

  Use an environment variable to specify your own Docker Hub Account as per the docs

  export DOCKER_USER="some-user"
  
  faas-cli up

  You can build a single service at a time with --filter

  faas-cli up --filter db-inserter

• Debug

  Did the version not change? Alter latest to a version like 0.1.1 for each change.

  Are you not sure what went wrong? Try faas-cli logs NAME

  Want to add print statements? Try adding: console.log("Got here..")