Merge branch 'feature/deal-with-network-failures' into 'master'

Feature/deal with network failures

Also activates the new nicknym lookup.

See merge request !5

3 files changed, 69 insertions, 8 deletions

diff --git a/lib/nickserver/dispatcher.rb b/lib/nickserver/dispatcher.rb
index 7a584e5..869f721 100644
--- a/lib/nickserver/dispatcher.rb
+++ b/lib/nickserver/dispatcher.rb
@@ -14,14 +14,17 @@
 #
 
 require 'nickserver/request'
+require 'nickserver/handler_chain'
 require 'nickserver/request_handlers/invalid_email_handler'
 require 'nickserver/request_handlers/local_email_handler'
+require 'nickserver/request_handlers/leap_email_handler'
 require 'nickserver/request_handlers/hkp_email_handler'
 require 'nickserver/request_handlers/fingerprint_handler'
 
 module Nickserver
   class Dispatcher
 
+
     def initialize(responder)
       @responder = responder
     end
@@ -35,10 +38,7 @@ module Nickserver
     protected
 
     def handle(request)
-      handler_chain.each do |handler|
-        response = handler.call request
-        return response if response
-      end
+      handler_chain.handle request
     rescue RuntimeError => exc
       puts "Error: #{exc}"
       puts exc.backtrace
@@ -46,13 +46,26 @@ module Nickserver
     end
 
     def handler_chain
-      [
-        RequestHandlers::InvalidEmailHandler,
+      @handler_chain ||= init_handler_chain
+    end
+
+    def init_handler_chain
+      chain = HandlerChain.new RequestHandlers::InvalidEmailHandler,
         RequestHandlers::LocalEmailHandler,
+        RequestHandlers::LeapEmailHandler,
         RequestHandlers::HkpEmailHandler,
         RequestHandlers::FingerprintHandler,
+        Proc.new {|_req| proxy_error_response },
         Proc.new { Nickserver::Response.new(404, "404 Not Found\n") }
-      ]
+      chain.continue_on HTTP::ConnectionError
+      return chain
+    end
+
+    def proxy_error_response
+      exception = handler_chain.rescued_exceptions.first
+      if exception
+        Nickserver::Response.new(502, exception.to_s)
+      end
     end
 
     def send_response(response)
diff --git a/lib/nickserver/handler_chain.rb b/lib/nickserver/handler_chain.rb
new file mode 100644
index 0000000..afc24a5
--- /dev/null
+++ b/lib/nickserver/handler_chain.rb
@@ -0,0 +1,48 @@
+#
+# Handler Chain
+#
+# A chain of handlers that respond to call. Invoking handle(*args) on the chain
+# will call the handlers with the given args until one of them returns a result
+# that is truethy (i.e. not false or nil).
+#
+# You can specify exception classes to rescue with
+#   handler_chain.continue_on ErrorClass1, ErrorClass2
+# These exceptions will be rescued and tracked. The chain will proceed even if
+# one handler raised the given exception. Afterwards you can inspect them with
+#   handler_chain.rescued_exceptions
+#
+
+module Nickserver
+  class HandlerChain
+
+    def initialize(*handlers)
+      @handlers = handlers
+      @exceptions_to_rescue = []
+      @rescued_exceptions = []
+    end
+
+    def continue_on(*exceptions)
+      self.exceptions_to_rescue += exceptions
+    end
+
+    def handle(*args)
+      result = nil
+      _handled_by = @handlers.find{|h| result = try_handler(h, *args)}
+      result
+    end
+
+    attr_reader :rescued_exceptions
+
+    protected
+
+    attr_writer :rescued_exceptions
+    attr_accessor :exceptions_to_rescue
+
+    def try_handler(handler, *args)
+      result = handler.call(*args)
+    rescue *exceptions_to_rescue
+      self.rescued_exceptions << $!
+      result = false
+    end
+  end
+end
diff --git a/lib/nickserver/hkp/source.rb b/lib/nickserver/hkp/source.rb
index e104aa8..82c94a0 100644
--- a/lib/nickserver/hkp/source.rb
+++ b/lib/nickserver/hkp/source.rb
@@ -19,7 +19,7 @@ module Nickserver; module Hkp
       if status == 200
         best = pick_best_key(response)
         get_key_by_fingerprint(best.keyid, nick)
-      else
+      elsif status != 404    # 404 means no key found and we proceed
         Nickserver::Response.new(status, response)
       end
     end