Addressed comments

Signed-off-by: Athishpranav2003 <athishanna@gmail.com>

lib/fluent/plugin/in_prometheus.rb

@@ -188,7 +188,7 @@ def start_webrick
     end
 
     def all_metrics
-      response_headers(::Prometheus::Client::Formats::Text.marshal(@registry))
+      response(::Prometheus::Client::Formats::Text.marshal(@registry))
     rescue => e
       [500, { 'Content-Type' => 'text/plain' }, e.to_s]
     end
@@ -201,7 +201,7 @@ def all_workers_metrics
           full_result.add_metrics(resp.body)
         end
       end
-      response_headers(full_result.get_metrics)
+      response(full_result.get_metrics)
     rescue => e
       [500, { 'Content-Type' => 'text/plain' }, e.to_s]
     end
@@ -230,7 +230,7 @@ def do_request(host:, port:, secure:)
       end
     end
 
-    def response_headers(metrics)
+    def response(metrics)
       body = nil
       case @content_encoding
       when :gzip

spec/fluent/plugin/in_prometheus_spec.rb

@@ -3,6 +3,7 @@
 require 'fluent/test/driver/input'
 
 require 'net/http'
+require 'zlib'
 
 describe Fluent::Plugin::PrometheusInput do
   CONFIG = %[
@@ -226,6 +227,7 @@
           registry.counter(:test,docstring: "Testing metrics") unless registry.exist?(:test)
           Net::HTTP.start("127.0.0.1", port) do |http|
             req = Net::HTTP::Get.new("/metrics")
+            req['accept-encoding'] = nil
             res = http.request(req)
             expect(res.body).to include("test Testing metrics")
           end
@@ -243,8 +245,10 @@
           registry.counter(:test,docstring: "Testing metrics") unless registry.exist?(:test)
           Net::HTTP.start("127.0.0.1", port) do |http|
             req = Net::HTTP::Get.new("/metrics")
+            req['accept-encoding'] = nil
             res = http.request(req)
-            expect(res.body).to include("test Testing metrics")
+            gzip = Zlib::GzipReader.new(StringIO.new(res.body.to_s))
+            expect(gzip.read).to include("test Testing metrics")
           end
         end
       end