webapp.rb

require 'sinatra'
require 'elasticsearch'
require 'rest-client'

es_config = {host: ENV['ELASTICSEARCH_HOST']}
es = Elasticsearch::Client.new(es_config)

# Show welcome page
get "/" do

  # Get known cameras from Elasticsearch
  ts = Time.now.to_i
  @cameras = []
  response = es.search index: 'camera', type: 'camera_info', body: {query: {match_all: {}}, size: 100}
  response['hits']['hits'].each do |r|
    status = (ts - r['_source']['epoch_timestamp'].to_i < 120)
    @cameras << {:name => r['_source']['camera_name'], :ip => r['_id'], :online => status}
  end

  # Get 4 latest photos
  @photos = []
  response = es.search index: 'photo', type: 'info', body: {query: {match_all: {}}, size: 4, sort: [{timestamp: 'desc'}]}
  response['hits']['hits'].each do |r|
    @photos << {:url => r['_source']['url'], :camera_name => r['_source']['camera_name'], :timestamp => r['_source']['timestamp']}
  end

  haml :index
end

# Show take photo page
get "/take_photo/:camera_ip" do
  camera_ip = params[:camera_ip]
  response = RestClient::Request.execute(method: :post, url: "http://#{camera_ip}:8080/take_photo", timeout: 10)
  @image_url = response.body['url'].to_s
  @timestamp = response.body['timestamp'].to_s

  haml :show_photo
end