Refactoring the XMLRPC::Client error-handling

I split it all into smaller, manageable chunks,
and used methods for each step, instead
of having one huge call.

Note that I made all of the tests first, then
refactored the code, so I'm confident there's no
behavior change.

I don't know that this is actually a lot cleaner,
but it seems that way to me.  I'm open to
skipping this, but I think it makes the whole thing
a lot cleaner.

Signed-off-by: Luke Kanies <luke@madstop.com>

2 files changed, 254 insertions, 60 deletions

diff --git a/lib/puppet/network/xmlrpc/client.rb b/lib/puppet/network/xmlrpc/client.rb
index 37ace2101..91bb03e1f 100644
--- a/lib/puppet/network/xmlrpc/client.rb
+++ b/lib/puppet/network/xmlrpc/client.rb
@@ -36,57 +36,7 @@ module Puppet::Network
             interface.methods.each { |ary|
                 method = ary[0]
                 newclient.send(:define_method,method) { |*args|
-                    Puppet.debug "Calling %s.%s" % [namespace, method]
-                    begin
-                        call("%s.%s" % [namespace, method.to_s],*args)
-                    rescue OpenSSL::SSL::SSLError => detail
-                        if detail.message =~ /bad write retry/
-                            Puppet.warning "Transient SSL write error; restarting connection and retrying"
-                            self.recycle_connection
-                            retry
-                        end
-                        ["certificate verify failed", "hostname was not match", "hostname not match"].each do |str|
-                            if detail.message.include?(str)
-                                Puppet.warning "Certificate validation failed; consider using the certname configuration option"
-                            end
-                        end 
-                        raise XMLRPCClientError,
-                            "Certificates were not trusted: %s" % detail
-                    rescue ::XMLRPC::FaultException => detail
-                        raise XMLRPCClientError, detail.faultString
-                    rescue Errno::ECONNREFUSED => detail
-                        msg = "Could not connect to %s on port %s" %
-                            [@host, @port]
-                        raise XMLRPCClientError, msg
-                    rescue SocketError => detail
-                        Puppet.err "Could not find server %s: %s" %
-                            [@host, detail.to_s]
-                        error = XMLRPCClientError.new(
-                            "Could not find server %s" % @host
-                        )
-                        error.set_backtrace detail.backtrace
-                        raise error
-                    rescue Errno::EPIPE, EOFError
-                        Puppet.warning "Other end went away; restarting connection and retrying"
-                        self.recycle_connection
-                        retry
-                    rescue Timeout::Error => detail
-                        Puppet.err "Connection timeout calling %s.%s: %s" %
-                            [namespace, method, detail.to_s]
-                        error = XMLRPCClientError.new("Connection Timeout")
-                        error.set_backtrace(detail.backtrace)
-                        raise error
-                    rescue => detail
-                        if detail.message =~ /^Wrong size\. Was \d+, should be \d+$/
-                            Puppet.warning "XMLRPC returned wrong size.  Retrying."
-                            retry
-                        end    
-                        Puppet.err "Could not call %s.%s: %s" %
-                            [namespace, method, detail.inspect]
-                        error = XMLRPCClientError.new(detail.to_s)
-                        error.set_backtrace detail.backtrace
-                        raise error
-                    end
+                    make_rpc_call(namespace, method, *args)
                 }
             }
 
@@ -97,13 +47,117 @@ module Puppet::Network
             @clients[handler] || self.mkclient(handler)
         end
 
+        class ErrorHandler
+            def initialize(&block)
+                metaclass.define_method(:execute, &block)
+            end
+        end
+
+        # Use a class variable so all subclasses have access to it.
+        @@error_handlers = {}
+
+        def self.error_handler(exception)
+            if handler = @@error_handlers[exception.class]
+                return handler
+            else
+                return @@error_handlers[:default]
+            end
+        end
+
+        def self.handle_error(*exceptions, &block)
+            handler = ErrorHandler.new(&block)
+
+            exceptions.each do |exception|
+                @@error_handlers[exception] = handler
+            end
+        end
+
+        handle_error(OpenSSL::SSL::SSLError) do |client, detail, namespace, method|
+            if detail.message =~ /bad write retry/
+                Puppet.warning "Transient SSL write error; restarting connection and retrying"
+                client.recycle_connection
+                return :retry
+            end
+            ["certificate verify failed", "hostname was not match", "hostname not match"].each do |str|
+                if detail.message.include?(str)
+                    Puppet.warning "Certificate validation failed; consider using the certname configuration option"
+                end
+            end 
+            raise XMLRPCClientError, "Certificates were not trusted: %s" % detail
+        end
+
+        handle_error(:default) do |client, detail, namespace, method|
+            if detail.message.to_s =~ /^Wrong size\. Was \d+, should be \d+$/
+                Puppet.warning "XMLRPC returned wrong size.  Retrying."
+                return :retry
+            end    
+            Puppet.err "Could not call %s.%s: %s" % [namespace, method, detail.inspect]
+            error = XMLRPCClientError.new(detail.to_s)
+            error.set_backtrace detail.backtrace
+            raise error
+        end
+
+        handle_error(OpenSSL::SSL::SSLError) do |client, detail, namespace, method|
+            if detail.message =~ /bad write retry/
+                Puppet.warning "Transient SSL write error; restarting connection and retrying"
+                client.recycle_connection
+                return :retry
+            end
+            ["certificate verify failed", "hostname was not match", "hostname not match"].each do |str|
+                if detail.message.include?(str)
+                    Puppet.warning "Certificate validation failed; consider using the certname configuration option"
+                end
+            end 
+            raise XMLRPCClientError, "Certificates were not trusted: %s" % detail
+        end
+
+        handle_error(::XMLRPC::FaultException) do |client, detail, namespace, method|
+            raise XMLRPCClientError, detail.faultString
+        end
+
+        handle_error(Errno::ECONNREFUSED) do |client, detail, namespace, method|
+            msg = "Could not connect to %s on port %s" % [client.host, client.port]
+            raise XMLRPCClientError, msg
+        end
+
+        handle_error(SocketError) do |client, detail, namespace, method|
+            Puppet.err "Could not find server %s: %s" % [@host, detail.to_s]
+            error = XMLRPCClientError.new("Could not find server %s" % client.host)
+            error.set_backtrace detail.backtrace
+            raise error
+        end
+
+        handle_error(Errno::EPIPE, EOFError) do |client, detail, namespace, method|
+            Puppet.warning "Other end went away; restarting connection and retrying"
+            client.recycle_connection
+            return :retry
+        end
+
+        handle_error(Timeout::Error) do |client, detail, namespace, method|
+            Puppet.err "Connection timeout calling %s.%s: %s" % [namespace, method, detail.to_s]
+            error = XMLRPCClientError.new("Connection Timeout")
+            error.set_backtrace(detail.backtrace)
+            raise error
+        end
+
+        def make_rpc_call(namespace, method, *args)
+            Puppet.debug "Calling %s.%s" % [namespace, method]
+            begin
+                call("%s.%s" % [namespace, method.to_s],*args)
+            rescue Exception => detail
+                retry if self.class.error_handler(detail).execute(self, detail, namespace, method) == :retry
+            end
+        end
+
         def http
             unless @http
-                @http = Puppet::Network::HttpPool.http_instance(@host, @port, true)
+                @http = Puppet::Network::HttpPool.http_instance(host, port, true)
             end
             @http
         end
 
+        attr_reader :host, :port
+
         def initialize(hash = {})
             hash[:Path] ||= "/RPC2"
             hash[:Server] ||= Puppet[:server]
@@ -135,7 +189,11 @@ module Puppet::Network
         # or we've just downloaded certs and we need to create new http instances
         # with the certs added.
         def recycle_connection
-            @http = Puppet::Network::HttpPool.http_instance(@host, @port, true) # reset the instance
+            if http.started?
+                http.finish
+            end
+            @http = nil
+            self.http # force a new one
         end
         
         def start
diff --git a/spec/unit/network/xmlrpc/client.rb b/spec/unit/network/xmlrpc/client.rb
index a0a2e77fb..76ef5c799 100755
--- a/spec/unit/network/xmlrpc/client.rb
+++ b/spec/unit/network/xmlrpc/client.rb
@@ -2,12 +2,148 @@
 
 Dir.chdir(File.dirname(__FILE__)) { (s = lambda { |f| File.exist?(f) ? require(f) : Dir.chdir("..") { s.call(f) } }).call("spec/spec_helper.rb") }
 
-describe Puppet::Network do
-    it "should raise an XMLRPCClientError if a generated class raises a Timeout::Error" do
-        http = mock 'http'
-        Puppet::Network::HttpPool.stubs(:http_instance).returns http
-        file = Puppet::Network::Client.file.new({:Server => "foo.com"})
-        http.stubs(:post2).raises Timeout::Error
-        lambda { file.retrieve }.should raise_error(Puppet::Network::XMLRPCClientError)
+describe Puppet::Network::XMLRPCClient do
+    describe "when performing the rpc call" do
+        before do
+            @client = Puppet::Network::Client.report.xmlrpc_client.new
+            @client.stubs(:call).returns "foo"
+
+        end
+
+        it "should call the specified namespace and method, with the specified arguments" do
+            @client.expects(:call).with("puppetreports.report", "eh").returns "foo"
+            @client.report("eh")
+        end
+
+        it "should return the results from the call" do
+            @client.expects(:call).returns "foo"
+            @client.report("eh").should == "foo"
+        end
+
+        describe "when returning the http instance" do
+            it "should use the http pool to create the instance" do
+                @client.instance_variable_set("@http", nil)
+                @client.expects(:host).returns "myhost"
+                @client.expects(:port).returns "myport"
+                Puppet::Network::HttpPool.expects(:http_instance).with("myhost", "myport", true).returns "http"
+
+                @client.http.should == "http"
+            end
+
+            it "should reuse existing instances" do
+                @client.http.should equal(@client.http)
+            end
+        end
+
+        describe "when recycling the connection" do
+            it "should close the existing instance if it's open" do
+                http = mock 'http'
+                @client.stubs(:http).returns http
+
+                http.expects(:started?).returns true
+                http.expects(:finish)
+
+                @client.recycle_connection
+            end
+
+            it "should force creation of a new instance" do
+                Puppet::Network::HttpPool.expects(:http_instance).returns "second_http"
+
+                @client.recycle_connection
+
+                @client.http.should == "second_http"
+            end
+        end
+
+        describe "and an exception is raised" do
+            it "should raise XMLRPCClientError if XMLRPC::FaultException is raised" do
+                error = XMLRPC::FaultException.new("foo", "bar")
+
+                @client.expects(:call).raises(error)
+
+                lambda { @client.report("eh") }.should raise_error(Puppet::Network::XMLRPCClientError)
+            end
+
+            it "should raise XMLRPCClientError if Errno::ECONNREFUSED is raised" do
+                @client.expects(:call).raises(Errno::ECONNREFUSED)
+
+                lambda { @client.report("eh") }.should raise_error(Puppet::Network::XMLRPCClientError)
+            end
+
+            it "should log and raise XMLRPCClientError if Timeout::Error is raised" do
+                Puppet.expects(:err)
+                @client.expects(:call).raises(Timeout::Error)
+
+                lambda { @client.report("eh") }.should raise_error(Puppet::Network::XMLRPCClientError)
+            end
+
+            it "should log and raise XMLRPCClientError if SocketError is raised" do
+                Puppet.expects(:err)
+                @client.expects(:call).raises(SocketError)
+
+                lambda { @client.report("eh") }.should raise_error(Puppet::Network::XMLRPCClientError)
+            end
+
+            it "should log, recycle the connection, and retry if Errno::EPIPE is raised" do
+                @client.expects(:call).times(2).raises(Errno::EPIPE).then.returns "eh"
+
+                Puppet.expects(:warning)
+                @client.expects(:recycle_connection)
+
+                @client.report("eh")
+            end
+
+            it "should log, recycle the connection, and retry if EOFError is raised" do
+                @client.expects(:call).times(2).raises(EOFError).then.returns "eh"
+
+                Puppet.expects(:warning)
+                @client.expects(:recycle_connection)
+
+                @client.report("eh")
+            end
+
+            it "should log and retry if an exception containing 'Wrong size' is raised" do
+                error = RuntimeError.new("Wrong size. Was 15, should be 30")
+                @client.expects(:call).times(2).raises(error).then.returns "eh"
+
+                Puppet.expects(:warning)
+
+                @client.report("eh")
+            end
+
+            it "should raise XMLRPCClientError if OpenSSL::SSL::SSLError is raised" do
+                @client.expects(:call).raises(OpenSSL::SSL::SSLError)
+
+                lambda { @client.report("eh") }.should raise_error(Puppet::Network::XMLRPCClientError)
+            end
+
+            it "should log and raise XMLRPCClientError if OpenSSL::SSL::SSLError is raised with certificate issues" do
+                error = OpenSSL::SSL::SSLError.new("hostname was not match")
+                @client.expects(:call).raises(error)
+
+                Puppet.expects(:warning)
+
+                lambda { @client.report("eh") }.should raise_error(Puppet::Network::XMLRPCClientError)
+            end
+
+            it "should log, recycle the connection, and retry if OpenSSL::SSL::SSLError is raised containing 'bad write retry'" do
+                error = OpenSSL::SSL::SSLError.new("bad write retry")
+                @client.expects(:call).times(2).raises(error).then.returns "eh"
+
+                @client.expects(:recycle_connection)
+
+                Puppet.expects(:warning)
+
+                @client.report("eh")
+            end
+
+            it "should log and raise XMLRPCClientError if any other exception is raised" do
+                @client.expects(:call).raises(RuntimeError)
+
+                Puppet.expects(:err)
+
+                lambda { @client.report("eh") }.should raise_error(Puppet::Network::XMLRPCClientError)
+            end
+        end
     end
 end