support empty password

lib/logstash/outputs/elasticsearch/http_client.rb

@@ -171,7 +171,7 @@ def close
       @pool.close
     end
 
-    def calculate_property(uris, property, default, sniff_check)
+    def calculate_property(uris, property, default, sniff_check, allow_empty_string = false)
       values = uris.map(&property).uniq
 
       if sniff_check && values.size > 1
@@ -180,8 +180,8 @@ def calculate_property(uris, property, default, sniff_check)
 
       uri_value = values.first
 
-      default = nil if default.is_a?(String) && default.empty? # Blanks are as good as nil
-      uri_value = nil if uri_value.is_a?(String) && uri_value.empty?
+      default = nil if !allow_empty_string && default.is_a?(String) && default.empty? # Blanks are as good as nil
+      uri_value = nil if !allow_empty_string && uri_value.is_a?(String) && uri_value.empty?
 
       if default && uri_value && (default != uri_value)
         raise LogStash::ConfigurationError, "Explicit value for '#{property}' was declared, but it is different in one of the URLs given! Please make sure your URLs are inline with explicit values. The URLs have the property set to '#{uri_value}', but it was also set to '#{default}' explicitly"
@@ -199,7 +199,7 @@ def user
     end
 
     def password
-      calculate_property(uris, :password, @options[:password], sniffing)
+      calculate_property(uris, :password, @options[:password], sniffing, true)
     end
 
     def path

spec/unit/outputs/elasticsearch/http_client_spec.rb

@@ -4,6 +4,7 @@
 
 describe LogStash::Outputs::ElasticSearch::HttpClient do
   let(:ssl) { nil }
+  let(:hosts) { [::LogStash::Util::SafeURI.new("127.0.0.1")] }
   let(:base_options) do
     opts = {
       :hosts => [::LogStash::Util::SafeURI.new("127.0.0.1")],
@@ -124,6 +125,25 @@
     end
   end
 
+  describe "#password" do
+    subject { described_class.new(base_options) }
+    context "when using empty password" do
+      context "with password option" do
+        let(:base_options) { super.merge(:password => "", :user => "hello") }
+        it "returns empty string" do
+          expect(subject.password).to eq("")
+        end
+      end
+      context "with password in hosts option" do
+        let(:uri) { LogStash::Util::SafeURI.new("http://hello:@localhost:9200") }
+        let(:base_options) { super.merge(:hosts => [uri]) }
+        it "returns empty string" do
+          expect(subject.password).to eq("")
+        end
+      end
+    end
+  end
+
   describe "get" do
     subject { described_class.new(base_options) }
     let(:body) { "foobar" }