updating readme. more CRUD endpoints. refactor state to status

README.md

@@ -11,6 +11,8 @@ _ruby setup.rb_
 	Create Service entry for noah
 	Creating Application entry for 'noah'
 	Creating Configuration entry for 'noah'
+	Creating sample entries - Host and Service
+	Creating sample entries - Application and Configuration
 	Setup successful!
 
 ## Run it
@@ -45,14 +47,14 @@ _curl http://localhost:9292/s/_
 	 {
 	  "id":"1",
 	  "name":"redis",
-	  "state":true,
+	  "status":"up",
 	  "updated_at":"2011-01-17 14:12:43 UTC",
 	  "host":"localhost"
 	 },
 	 {
 	  "id":"2",
 	  "name":"noah",
-	  "state":true,
+	  "status":"up",
 	  "updated_at":"2011-01-17 14:12:43 UTC",
 	  "host":"localhost"
 	 }
@@ -65,20 +67,20 @@ _curl http://localhost:9292/h/_
 	 {
 	  "id":"1",
 	  "name":"localhost",
-	  "state":true,
+	  "status":"up",
 	  "updated_at":"2011-01-17 14:12:43 UTC",
 	  "services":[
 		      {
 		       "id":"1",
 		       "name":"redis",
-		       "state":true,
+		       "status":"up",
 		       "updated_at":"2011-01-17 14:12:43 UTC",
 		       "host":"localhost"
 		      },
 		      {
 		       "id":"2",
 		       "name":"noah",
-		       "state":true,
+		       "status":"up",
 		       "updated_at":"2011-01-17 14:12:43 UTC",
 		       "host":"localhost"
 		      }
@@ -99,8 +101,7 @@ _curl http://localhost:9292/a/_
 
 Most other combinations of endpoints work as well:
 
-* `http://localhost:9292/h/<hostname>/s/` - All service for `<hostname>`
-* `http://localhost:9292/h/<hostname>/s/<servicename>` - `<servicename>` on `<hostname>`
+* `http://localhost:9292/h/<hostname>/<servicename>` - `<servicename>` on `<hostname>`
 * `http://localhost:9292/a/<appname>/<configname>` - Configuration for `<appname>`
 * `http://localhost:9292/c/<appname>/<element>` - Specific configuration element for `<appname>`
 
@@ -114,7 +115,7 @@ Most other combinations of endpoints work as well:
 	}
 
 # Adding new entries
-I've not yet flushed out the put support for each route yet. I've been doing additions via `irb` for now:
+I've not yet flushed out all the put support for each route yet. I've been doing additions via `irb` for now:
 
 ## Adding a new application and configuration item
 
@@ -150,13 +151,37 @@ I've not yet flushed out the put support for each route yet. I've been doing add
 	  password: my super secret password
 
 # Hosts and Services/Applications and Configurations
-I'm still noodling out some things around Hosts and Services. There's a field called `state` that's a Boolean. The thought is that `state` set at `0` or `false` means that service or Host is unavailable. Services would, when they start up, send a put to Noah setting the flag to online. There's a bit of overlap between Applications and Services but I think the distinction is clear. Applications have configurations and Hosts have Services.
+Host/Services and Applications/Configurations are almost the same thing with a few exceptions. Here are some basic facts:
+
+* Hosts have many Services
+* Applications have many Configurations
+* Hosts and Services have a status - `up`,`down` or `pending`
+
+The intention of the `status` field for Hosts and Services is that a service might, when starting up, set the appropriate status. Same goes for said service shutting down. This also applies to hosts (i.e. a curl PUT is sent to Noah during the boot process).
+ 
+While an application might have different "configurations" based on environment (production, qa, dev), the Configuration object in Noah is intended to be more holistic i.e. these are the Configuration atoms (a yaml file, property X, property Y) that form the running configuration of an Application.
+
+Here's a holistic example using a tomcat application:
+
+* Host running tomcat comes up. It sets its status as "pending"
+* Each service on the box starts up and sets its status to "pending" and finally "up" (think steps in the init script for the service)
+* Tomcat (now in the role of `Application`) given a single property in a properties file called "bootstrap.url", grabs a list of `Configuration`atoms it needs to run. Let's say, by default, Tomcat starts up with all webapps disabled. Using the `Configuration` item `webapps`, it knows which ones to start up.
+* Each webapp (an application under a different context root) now has the role of `Application` and the role of `Service`. As an application, the webapp would grab things that would normally be stored in a .properties file. Maybe even the log4j.xml file. In the role of `Service`, a given webapp might be an API endpoint and so it would have a hostname (a virtual host maybe?) and services associated with it. Each of those, has a `status`.
+
+That might be confusing and it's a fairly overly-contrived example. A more comon use case would be the above where, instead of storing the database.yml on the server, the Rails application actually reads the file from Noah. Now that might not be too exciting but try this example:
+
+* Rails application with memcached as part of the stack.
+* Instead of a local configuration file, the list of memcached servers is a `Configuration` object belonging to the rails application's `Application` object.
+* As new memcached servers are brought online, your CM tool (puppet or chef) updates Noah
+* Your Rails application either via restarting (and thus rebootstrapping the list of memcached servers from Noah) or using the Watcher subsystem is instantly aware of those servers. You could fairly easily implement a custom Watcher that, when the list of memcached server changes, the Passenger restart file is written.
+
+Make sense?
 
 # Constraints
 You can view all the constraints inside `models.rb` but here they are for now:
 
-* A new host must have at least `name` and `state` set.
-* A new service must have at least `name` and `state` set.
+* A new host must have at least `name` and `status` set.
+* A new service must have at least `name` and `status` set.
 * Each Host `name` must be unique
 * Each Service `name` per Host must be unique
 * Each Application `name` must exist and be unique

app.rb

@@ -21,16 +21,10 @@ end
 
 namespace "/h" do
 
-  get '/:hostname/s/:servicename/?' do |hostname, servicename|
+  get '/:hostname/:servicename/?' do |hostname, servicename|
     host_service(hostname, servicename).to_json
   end
 
-  get '/:hostname/s/?' do |hostname|
-    hs = host_services(hostname)
-    hs.map! {|x| x.to_hash} 
-    hs.to_json
-  end
-
   get '/:hostname/?' do |hostname|
     host(:name => hostname).to_json
   end
@@ -40,11 +34,32 @@ namespace "/h" do
     hosts.to_json
   end
 
+  put '/?' do
+    begin
+      required_params = ["name", "status"]
+      data = JSON.parse(request.body.read)
+      data.keys.sort == required_params.sort  ? (host = Host.find_or_create(:name => data['name'], :status => data['status'])) : (raise "Missing Parameters")
+      if host.valid?
+        status 200
+        r = {"result" => "success","id" => "#{host.id}","status" => "#{host.status}", "name" => "#{host.name}"}
+        r.to_json
+      else
+        status 500
+        r = {"result" => "failure","error" => "#{app.errors}"}
+        r.to_json
+      end
+    rescue Exception => e
+      status 500
+      r = {"result" => "failure","error" => "#{e.message}"}
+      r.to_json
+    end
+  end
+
 end
 
 namespace "/s" do
 
-  get '/:servicename/h/:hostname/?' do |servicename, hostname|
+  get '/:servicename/:hostname/?' do |servicename, hostname|
     host_service(hostname, servicename).to_json
   end
 
@@ -155,10 +170,10 @@ namespace '/c' do
     "#{configs.to_json}"
   end
 
-  put '/:appname/:element?' do |appname, item|
+  put '/:appname/:element?' do |appname, element|
     begin
       app = Application.find_or_create(:name => appname)
-      config = Configuration.find_or_create(:name => item, :application_id => app.id)
+      config = Configuration.find_or_create(:name => element, :application_id => app.id)
       required_params = ["format", "body"]
       data = JSON.parse(request.body.read)
       data.keys.sort == required_params.sort  ? (config.format = data["format"]; config.body = data["body"]) : (raise "Missing Parameters")
@@ -179,23 +194,28 @@ namespace '/c' do
     end
   end
 
-end
-
-# A route for adding a new host
-put '/h/:hostname' do
-  host = params[:hostname]
-  data = JSON.parse(request.body.read)
-  begin
-    h = Host.find(:name => host).first
-    h.state = 1
-  rescue
-    # If we have to register the host, we mark it as inactive
-    # Feels like the right thing to do in case of accidental creation
-    # from mispelling
-    h = Host.create(:name => params[:hostname], :state => 0)
-  end
-  if h.save
-    data['services'].each {|x| h.services << Service.create(:name=> x['name'], :state => x['state'], :host => h)} if data['services']
-    {"msg" => "success"}.to_json
+  delete '/:appname/:element?' do |appname, element|
+    begin
+      app = Application.find(:name => appname).first
+      if app
+        config = Configuration.find(:name=> element, :application_id => app.id).first
+        if config
+          config.delete
+          status 200
+          r = {"result" => "success", "id" => "#{config.id}", "item" => "#{appname}/#{element}"}
+          r.to_json
+        else
+          r = {"result" => "failure","error" => "Configuration element not found"}
+          halt 404, r.to_json
+        end
+      else
+        r = {"result" => "failure","error" => "Application not found"}
+        halt 404, r.to_json
+      end
+    rescue Exception => e
+      r = {"result" => "failure", "error" => "#{e.message}"}
+      halt 500, r.to_json
+    end
   end
+
 end

models.rb

@@ -4,23 +4,44 @@ class Host < Ohm::Model
   include Ohm::Typecast
   include Ohm::Timestamping
   include Ohm::Callbacks
+  include Ohm::ExtraValidations
 
   attribute :name
-  attribute :state, Boolean
+  attribute :status
   collection :services, Service
 
   index :name
-  index :state
+  index :status
 
   def validate
-    assert_present :name, :state
+    assert_present :name, :status
     assert_unique :name
+    assert_member :status, ["up","down","pending"]
   end
 
   def to_hash
     arr = []
     services.sort.each {|s| arr << s.to_hash}
-    super.merge(:name => name, :state => state, :updated_at => updated_at, :services => arr)
+    super.merge(:name => name, :status => status, :updated_at => updated_at, :services => arr)
+  end
+
+  class << self
+  def find_or_create(opts = {})
+    begin
+      # exclude requested status from lookup
+      h = find(opts.reject{|key,value| key == :status}).first
+      host = h.nil? ? create(opts) : h
+      host.status = opts[:status]
+      if host.valid?
+        host.save
+        host 
+      else
+        raise host.errors
+      end
+    rescue Exception => e
+      e.message
+    end
+  end
   end
 end
 
@@ -28,21 +49,23 @@ class Service < Ohm::Model
   include Ohm::Typecast
   include Ohm::Timestamping
   include Ohm::Callbacks
+  include Ohm::ExtraValidations
 
   attribute :name
-  attribute :state, Boolean
+  attribute :status
   reference :host, Host
 
   index :name
-  index :state
+  index :status
 
   def validate
-    assert_present :name, :state
+    assert_present :name, :status
     assert_unique [:name, :host_id]
+    assert_member :status, ["up", "down", "pending"]
   end
 
   def to_hash
-    super.merge(:name => name, :state => state, :updated_at => updated_at, :host => Host[host_id].name)
+    super.merge(:name => name, :status => status, :updated_at => updated_at, :host => Host[host_id].name)
   end
 end
 
@@ -50,6 +73,7 @@ class Configuration < Ohm::Model
   include Ohm::Typecast
   include Ohm::Timestamping
   include Ohm::Callbacks
+  include Ohm::ExtraValidations
 
   attribute :name
   attribute :format
@@ -84,6 +108,7 @@ class Application < Ohm::Model
   include Ohm::Typecast
   include Ohm::Timestamping
   include Ohm::Callbacks
+  include Ohm::ExtraValidations
 
   attribute :name
   collection :configurations, Configuration

setup.rb

@@ -8,11 +8,11 @@ require File.join(File.dirname(__FILE__), 'models')
 Ohm.redis.flushdb
 # Add an entry for my localhost
 puts "Creating Host entry for 'localhost'"
-h = Host.create(:name => 'localhost', :state => 1)
+h = Host.create(:name => 'localhost', :status => "up")
 if h.save
   %w[redis noah].each do |service|
     puts "Create Service entry for #{service}"
-    s = Service.create(:name => service, :state => 1, :host => h)
+    s = Service.create(:name => service, :status => "up", :host => h)
     h.services << s
   end
 end
@@ -31,10 +31,10 @@ end
 
 puts "Creating sample entries - Host and Service"
 %w[host1.domain.com host2.domain.com host3.domain.com].each do |host|
-  h = Host.create(:name => host, :state => 0)
+  h = Host.create(:name => host, :status => "up")
   if h.save
     %w[http https smtp mysql].each do |service|
-      s = Service.create(:name => service, :state =>0, :host => h)
+      s = Service.create(:name => service, :status => "pending", :host => h)
       h.services << s
     end
   end

views/index.haml

@@ -12,18 +12,16 @@
                 %li 
                     %a{:href => "/h/localhost"} localhost (this server)
                 %li
-                    %a{:href => "/h/localhost/s"} localhost services
-                %li
-                    %a{:href => "/h/localhost/s/noah"} localhost noah service
+                    %a{:href => "/h/localhost/noah"} localhost noah service
         #header
             %h2 Services
             %ul
                 %li 
                     %a{:href => "/s/"} All registered Services
-                %li 
-                    %a{:href => "/s/noah/h/localhost"} localhost noah service
                 %li
                     %a{:href => "/s/http"} All hosts providing 'http'
+                %li 
+                    %a{:href => "/s/noah/localhost"} localhost noah service
         #header
             %h2 Applications
             %ul