Merge pull request brentley#4 from brentley/sd

Sd

Gemfile.lock

@@ -36,10 +36,10 @@ GEM
       thread_safe (~> 0.3, >= 0.3.4)
       tzinfo (~> 1.1)
     arel (6.0.4)
-    binding_of_caller (0.7.3)
+    binding_of_caller (0.8.0)
       debug_inspector (>= 0.0.1)
     builder (3.2.3)
-    byebug (9.1.0)
+    byebug (10.0.2)
     coffee-rails (4.1.1)
       coffee-script (>= 2.2.0)
       railties (>= 4.0.0, < 5.1.x)
@@ -48,36 +48,38 @@ GEM
       execjs
     coffee-script-source (1.12.2)
     concurrent-ruby (1.0.5)
-    crass (1.0.3)
+    crass (1.0.4)
+    daemons (1.2.6)
     debug_inspector (0.0.3)
     erubis (2.7.0)
+    eventmachine (1.2.7)
     execjs (2.7.0)
-    ffi (1.9.18)
+    ffi (1.9.25)
     globalid (0.4.1)
       activesupport (>= 4.2.0)
-    i18n (0.9.1)
+    i18n (0.9.5)
       concurrent-ruby (~> 1.0)
     jbuilder (2.7.0)
       activesupport (>= 4.2.0)
       multi_json (>= 1.2)
-    jquery-rails (4.3.1)
+    jquery-rails (4.3.3)
       rails-dom-testing (>= 1, < 3)
       railties (>= 4.2.0)
       thor (>= 0.14, < 2.0)
     json (1.8.6)
-    libv8 (3.16.14.19-x86_64-linux)
-    loofah (2.1.1)
+    libv8 (3.16.14.19)
+    loofah (2.2.2)
       crass (~> 1.0.2)
       nokogiri (>= 1.5.9)
     mail (2.7.0)
       mini_mime (>= 0.1.1)
     mini_mime (1.0.0)
     mini_portile2 (2.3.0)
-    minitest (5.10.3)
-    multi_json (1.12.2)
-    nokogiri (1.8.1)
+    minitest (5.11.3)
+    multi_json (1.13.1)
+    nokogiri (1.8.4)
       mini_portile2 (~> 2.3.0)
-    rack (1.6.8)
+    rack (1.6.10)
     rack-test (0.6.3)
       rack (>= 1.0)
     rails (4.2.10)
@@ -97,20 +99,20 @@ GEM
       activesupport (>= 4.2.0, < 5.0)
       nokogiri (~> 1.6)
       rails-deprecated_sanitizer (>= 1.0.1)
-    rails-html-sanitizer (1.0.3)
-      loofah (~> 2.0)
+    rails-html-sanitizer (1.0.4)
+      loofah (~> 2.2, >= 2.2.2)
     railties (4.2.10)
       actionpack (= 4.2.10)
       activesupport (= 4.2.10)
       rake (>= 0.8.7)
       thor (>= 0.18.1, < 2.0)
-    rake (12.3.0)
-    rb-fsevent (0.10.2)
+    rake (12.3.1)
+    rb-fsevent (0.10.3)
     rb-inotify (0.9.10)
       ffi (>= 0.5.0, < 2)
     rdoc (4.3.0)
     ref (2.0.0)
-    sass (3.5.4)
+    sass (3.5.7)
       sass-listen (~> 4.0.0)
     sass-listen (4.0.0)
       rb-fsevent (~> 0.9, >= 0.9.4)
@@ -126,7 +128,7 @@ GEM
       rdoc (~> 4.0)
     spring (2.0.2)
       activesupport (>= 4.2)
-    sprockets (3.7.1)
+    sprockets (3.7.2)
       concurrent-ruby (~> 1.0)
       rack (> 1, < 3)
     sprockets-rails (3.2.1)
@@ -137,15 +139,19 @@ GEM
     therubyracer (0.12.3)
       libv8 (~> 3.16.14.15)
       ref
+    thin (1.7.2)
+      daemons (~> 1.0, >= 1.0.9)
+      eventmachine (~> 1.0, >= 1.0.4)
+      rack (>= 1, < 3)
     thor (0.20.0)
     thread_safe (0.3.6)
     tilt (2.0.8)
-    turbolinks (5.0.1)
-      turbolinks-source (~> 5)
-    turbolinks-source (5.0.3)
-    tzinfo (1.2.4)
+    turbolinks (5.1.1)
+      turbolinks-source (~> 5.1)
+    turbolinks-source (5.1.0)
+    tzinfo (1.2.5)
       thread_safe (~> 0.1)
-    uglifier (4.0.2)
+    uglifier (4.1.18)
       execjs (>= 0.3.0, < 3)
     web-console (2.3.0)
       activemodel (>= 4.0)
@@ -168,6 +174,7 @@ DEPENDENCIES
   spring
   sqlite3
   therubyracer
+  thin
   turbolinks
   uglifier (>= 1.3.0)
   web-console (~> 2.0)

README.md

@@ -1,3 +1,3 @@
-# Amazon ECS Workshop
+# Amazon Containers Workshop
 
-This is part of an Amazon ECS workshop at https://ecsworkshop.com
+This is part of an Amazon Containers workshop at https://ecsworkshop.com or https://eksworkshop.com

app/controllers/application_controller.rb

@@ -1,4 +1,6 @@
 require 'net/http'
+require 'resolv'
+require 'uri'
 
 class ApplicationController < ActionController::Base
   # Prevent CSRF attacks by raising an exception.
@@ -8,9 +10,8 @@ class ApplicationController < ActionController::Base
   # Example endpoint that calls the backend nodejs api
   def index
     begin
-      url = URI.parse(backend_addr)
-      req = Net::HTTP::Get.new(url.to_s)
-      res = Net::HTTP.start(url.host, url.port) {|http|
+      req = Net::HTTP::Get.new(nodejs_uri.to_s)
+      res = Net::HTTP.start(nodejs_uri.host, nodejs_uri.port) {|http|
         http.request(req)
       }
 
@@ -20,9 +21,15 @@ def index
         @text = "no backend found"
       end
 
-      crystalurl = URI.parse(crystal_addr)
-      crystalreq = Net::HTTP::Get.new(crystalurl.to_s)
-      crystalres = Net::HTTP.start(crystalurl.host, crystalurl.port) {|http|
+    rescue => e
+      logger.error e.message
+      logger.error e.backtrace.join("\n")
+      @text = "no backend found"
+    end
+
+    begin
+      crystalreq = Net::HTTP::Get.new(crystal_uri.to_s)
+      crystalres = Net::HTTP.start(crystal_uri.host, crystal_uri.port) {|http|
         http.request(crystalreq)
       }
 
@@ -32,8 +39,9 @@ def index
         @crystal = "no backend found"
       end
 
-    rescue
-      @text = "no backend found"
+    rescue => e
+      logger.error e.message
+      logger.error e.backtrace.join("\n")
       @crystal = "no backend found"
     end
   end
@@ -43,16 +51,34 @@ def health
     render plain: "OK"
   end
 
-  def crystal_addr
-    crystal_addr = ENV["BACKEND_API"]
-    # The address will be of the form, http://172.17.0.5:5432, so we add a trailing slash
-    crystal_addr.sub(/^http:/, 'http:') + "/crystal"
+  def crystal_uri
+    expand_url ENV["CRYSTAL_URL"]
+  end
+
+  def nodejs_uri
+    expand_url ENV["NODEJS_URL"]
   end
 
-  def backend_addr
-    backend_addr = ENV["BACKEND_API"]
-    # The address will be of the form, http://172.17.0.5:5432, so we add a trailing slash
-    backend_addr.sub(/^http:/, 'http:') + "/"
+  # Resolve the SRV records for the hostname in the URL
+  def expand_url(url)
+    uri = URI(url)
+    resolver = Resolv::DNS.new()
+
+    # if host is relative, append the service discovery name
+    host = uri.host.count('.') > 0 ? uri.host : "#{uri.host}.#{ENV["_SERVICE_DISCOVERY_NAME"]}"
+
+    # lookup the SRV record and use if found
+    begin
+      srv = resolver.getresource(host, Resolv::DNS::Resource::IN::SRV)
+      uri.host = srv.target.to_s
+      uri.port = srv.port.to_s
+    rescue => e
+      logger.error e.message
+      logger.error e.backtrace.join("\n")
+    end
+
+    logger.info "expanded #{url} to #{uri}"
+    uri
   end
 
   before_action :discover_availability_zone

mu.yml

@@ -5,6 +5,7 @@ service:
   port: 3000
   pathPatterns:
   - /*
-  networkMode: awsvpc
+  discoveryTTL: 5
   environment:
-    BACKEND_API: "http://api.internal.service:80"
+    CRYSTAL_URL: "http://ecsdemo-crystal/crystal"
+    NODEJS_URL: "http://ecsdemo-nodejs/"