Implement the third assignment in ruby

[refs #f34238344b71]

developing/examples/webapp/ruby/Dockerfile

@@ -2,7 +2,8 @@ FROM ruby:2.4.3-alpine
 
 WORKDIR /app
 
-RUN gem install sinatra
+RUN apk update && apk add build-base postgresql-dev
+RUN gem install sinatra pg
 
 COPY app.rb .
 

developing/examples/webapp/ruby/app.rb

@@ -1,15 +1,14 @@
 require 'sinatra'
+require 'pg'
 
 set :bind, '0.0.0.0'
 set :port, 9494
 
 get '/' do
-  File.open('/tmp/requests.txt', 'a') do |file|
-    file.puts "IP: #{request.ip}"
-    file.puts "Hostname: #{Socket.gethostname}"
-    file.puts "Path: #{request.path}"
-    file.puts "Timestamp: #{Time.now}"
-    file.puts '------------'
-  end
-  'Hello World!'
+  conn = PG::Connection.open(ENV['POSTGRES_HOST'], 5432, '', '', ENV['POSTGRES_DB'], 
+                             ENV['POSTGRES_USER'], ENV['POSTGRES_PASSWORD'])
+  sql = "INSERT INTO requests (ip, path, host, requested_at) VALUES ($1, $2, $3, $4)"
+  res  = conn.exec(sql, [request.ip, '/', Socket.gethostname, Time.now])
+  conn.finish
+  'Hello, World!'
 end

developing/examples/webapp/ruby/docker-compose.yml

@@ -2,10 +2,32 @@ version: '3.3'
 
 services:
   app:
-    image: jfahrer/webapp-ruby:v2
+    image: jfahrer/webapp-ruby:v3
     build:
       context: .
+    environment:
+      - POSTGRES_USER=demo
+      - POSTGRES_PASSWORD=secret
+      - POSTGRES_DB=demo
+      - POSTGRES_HOST=pg
     volumes:
       - .:/app
     ports:
       - 9494:9494
+
+  pg:
+    image: postgres:9.6-alpine
+    environment:
+      - POSTGRES_USER=demo
+      - POSTGRES_PASSWORD=secret
+      - POSTGRES_DB=demo
+    volumes:
+      - ./sql/create_table.sql:/docker-entrypoint-initdb.d/create_table.sql
+
+  client:
+    image: jfahrer/checker-u-dev-a3:latest
+    environment:
+      - POSTGRES_USER=demo
+      - POSTGRES_PASSWORD=secret
+      - POSTGRES_DB=demo
+      - POSTGRES_HOST=pg

developing/examples/webapp/ruby/sql/create_table.sql

@@ -0,0 +1,7 @@
+CREATE TABLE IF NOT EXISTS requests (
+  id serial primary key,
+  requested_at character varying,
+  ip character varying,
+  host character varying,
+  path character varying
+);