Persist sessions using a consistent session secret and memcached

Fixes #79

docker-compose.yml

@@ -2,6 +2,18 @@
 version: '3'
 services:
   webapp:
-    image: 'rtyler/codevalet-webapp:latest'
+    image: 'codevalet/webapp:latest'
     ports:
       - 9292:9292
+    links:
+      - cache
+    environment:
+      - USE_MEMCACHED=true
+      - SESSION_SECRET=fiddlesticks
+      - WARDEN_GITHUB_VERIFIER_SECRET=fiddlesticks
+
+  cache:
+    image: 'memcached:alpine'
+    command: '-v'
+    ports:
+      - 11211:11211

webapp/Gemfile

@@ -1,12 +1,28 @@
 source 'https://rubygems.org'
 
+# Web framework, yey
 gem 'sinatra'
-gem 'haml'
-gem 'warden-github'
-gem 'kramdown'
-gem 'sentry-raven'
+
+# The actual webserver
 gem 'puma'
 
+# For rendering all the views
+gem 'haml'
+
+# Provides some semblance of github-based authentication and authorization
+# within the rack app
+gem 'warden-github'
+
+# Responsible for markdown parsing in the webapp views
+gem 'kramdown'
+
+# Send exceptions into Sentry from the app
+gem 'sentry-raven'
+
+# For memcached access
+gem 'dalli'
+gem 'rack-cache'
+
 group :test do
   gem 'rspec'
 end

webapp/Gemfile.lock

@@ -9,6 +9,7 @@ GEM
     addressable (2.5.1)
       public_suffix (~> 2.0, >= 2.0.2)
     concurrent-ruby (1.0.5)
+    dalli (2.7.6)
     diff-lcs (1.3)
     faraday (0.12.2)
       multipart-post (>= 1.2, < 3)
@@ -25,6 +26,8 @@ GEM
     public_suffix (2.0.5)
     puma (3.10.0)
     rack (2.0.3)
+    rack-cache (1.7.1)
+      rack (>= 0.4)
     rack-protection (2.0.0)
       rack
     rspec (3.6.0)
@@ -66,13 +69,15 @@ PLATFORMS
   ruby
 
 DEPENDENCIES
+  dalli
   haml
   kramdown
   puma
+  rack-cache
   rspec
   sentry-raven
   sinatra
   warden-github
 
 BUNDLED WITH
-   1.15.3
+   1.16.0

webapp/app.rb

@@ -1,9 +1,13 @@
 #!/usr/bin/env ruby
 
+require 'securerandom'
+require 'yaml'
+
+require 'dalli'
 require 'haml'
+require 'rack/session/dalli'
 require 'sinatra/base'
 require 'warden/github'
-require 'yaml'
 
 Haml::TempleEngine.disable_option_validator!
 
@@ -24,11 +28,24 @@ module CodeValet
     include Warden::GitHub::SSO
 
     enable  :sessions
+    set :session_secret, ENV.fetch('SESSION_SECRET') { SecureRandom.hex(64) }
+
     enable  :raise_errors
-    disable :show_exceptions
+
+    if ENV['PRODUCTION']
+      disable :show_exceptions
+    end
 
     set :public_folder, File.dirname(__FILE__) + '/assets'
 
+    configure do
+      if ENV['PRODUCTION'] || ENV['USE_MEMCACHED']
+        use Rack::Session::Dalli,
+          :namespace => 'webapp.sessions',
+          :cache => Dalli::Client.new(ENV.fetch('MEMCACHED_SERVER') { 'cache:11211' })
+      end
+    end
+
     use Warden::Manager do |config|
       config.failure_app = AuthFailre
       config.default_strategies :github