Added retrying

Gemfile

@@ -10,3 +10,5 @@ gem "rack-indifferent", "~> 1.2"
 gem "sinatra-router", "~> 0.2.4"
 
 gem "rest-client", "~> 2.0"
+
+gem "sinatra-contrib", "~> 2.0"

Gemfile.lock

@@ -1,14 +1,25 @@
 GEM
   remote: https://rubygems.org/
   specs:
+    activesupport (5.2.1)
+      concurrent-ruby (~> 1.0, >= 1.0.2)
+      i18n (>= 0.7, < 2)
+      minitest (~> 5.1)
+      tzinfo (~> 1.1)
+    backports (3.11.3)
+    concurrent-ruby (1.0.5)
     domain_name (0.5.20180417)
       unf (>= 0.0.5, < 1.0.0)
     dotenv (2.5.0)
     http-cookie (1.0.3)
       domain_name (~> 0.5)
+    i18n (1.1.0)
+      concurrent-ruby (~> 1.0)
     mime-types (3.1)
       mime-types-data (~> 3.2015)
     mime-types-data (3.2016.0521)
+    minitest (5.11.3)
+    multi_json (1.13.1)
     mustermann (1.0.2)
     netrc (0.11.0)
     rack (2.0.5)
@@ -26,9 +37,20 @@ GEM
       rack (~> 2.0)
       rack-protection (= 2.0.3)
       tilt (~> 2.0)
+    sinatra-contrib (2.0.3)
+      activesupport (>= 4.0.0)
+      backports (>= 2.8.2)
+      multi_json
+      mustermann (~> 1.0)
+      rack-protection (= 2.0.3)
+      sinatra (= 2.0.3)
+      tilt (>= 1.3, < 3)
     sinatra-router (0.2.4)
       sinatra (>= 1.4, < 3.0)
+    thread_safe (0.3.6)
     tilt (2.0.8)
+    tzinfo (1.2.5)
+      thread_safe (~> 0.1)
     unf (0.1.4)
       unf_ext
     unf_ext (0.0.7.5)
@@ -42,6 +64,7 @@ DEPENDENCIES
   rest-client (~> 2.0)
   retries (~> 0.0.5)
   sinatra (~> 2.0)
+  sinatra-contrib (~> 2.0)
   sinatra-router (~> 0.2.4)
 
 BUNDLED WITH

config.ru

@@ -1,15 +1,9 @@
 require 'bundler/setup'
 require 'dotenv/load'
 require 'rack/indifferent'
-require 'sinatra/router'
 
 require_relative 'lib/api/tree.rb'
 
-app = Sinatra::Router.new do
-  mount Pruning::API::Tree
-end
+run Pruning::API::Tree
 
-map '/' do
-  run app
-end
 

lib/api/app.rb

@@ -1,15 +1,32 @@
 require 'json'
 require 'sinatra/base'
+require 'sinatra/custom_logger'
 require_relative '../http/query'
+require_relative '../exceptions'
 
 module Pruning
   module API
     class App < Sinatra::Base
       before { content_type :json }
       after  { serialise_response }
+      set :show_exceptions, true
+      
+
+      error Pruning::Exceptions::UnexpectedError do 
+        status 500
+      end
+
+      error Pruning::Exceptions::OriginCannotFindTheResource do
+        status 404     
+      end
+
+
+      get '/' do
+        "Try /tree/:name"
+      end
+
 
       private
-
       def serialise_response
         return unless content_type == 'application/json'
         response.body = [JSON(response.body)]

lib/api/tree.rb

@@ -1,16 +1,18 @@
 require 'rest-client'
+require 'retries'
 require_relative 'app'
 require_relative '../repos/tree'
 require_relative '../pruner'
+require_relative '../exceptions'
 
 module Pruning
   module API
     class Tree < App
       get '/tree/:name' do
-        tree_repo = Pruning::Repos::Tree.new(RestClient, ENV['TREE_SOURCE_API_HOSTNAME'])
-        complete_tree = tree_repo.get(query.name)
-        pruner = Pruning::Processing::Pruner.new(complete_tree)
-        pruner.prune_tree(query.indicator_ids) 
+          tree_repo = Pruning::Repos::Tree.new(RestClient, ENV['TREE_SOURCE_API_HOSTNAME'])
+          complete_tree = tree_repo.get(query.name)
+          pruner = Pruning::Processing::Pruner.new(complete_tree)
+          pruner.prune_tree(query.indicator_ids) 
       end
     end
   end 

lib/exceptions.rb

@@ -0,0 +1,13 @@
+module Pruning
+  module Exceptions
+    class ServerErrorOnOrigin < StandardError
+    end
+
+    class OriginCannotFindTheResource < StandardError
+    end 
+
+    class UnexpectedError < StandardError
+    end
+  end
+end
+

lib/repos/tree.rb

@@ -1,6 +1,7 @@
 require 'rest-client'
 require 'retries'
 require 'json'
+require_relative '../exceptions'
 
 module Pruning
   module Repos
@@ -11,8 +12,19 @@ module Pruning
       end
 
       def get(name)
-        resp = @client.get(url(name))
-        JSON(resp.body)
+        with_retries(max_tries: 3, rescue: [Pruning::Exceptions::ServerErrorOnOrigin]) do
+          begin
+            resp = @client.get(url(name))
+          rescue RestClient::ExceptionWithResponse => e
+            if e.response.code != 404 
+              raise Pruning::Exceptions::ServerErrorOnOrigin
+            else 
+              raise Pruning::Exceptions::OriginCannotFindTheResource
+            end
+          end
+          return JSON(resp.body)
+        end
+        raise Pruning::Exceptions::UnexpectedError
       end
 
       private