Prometheus fixes (#2433)

examples/Console/Program.cs

@@ -31,7 +31,7 @@ namespace Examples.Console
         /// dotnet run -p Examples.Console.csproj inmemory
         /// dotnet run -p Examples.Console.csproj zipkin -u http://localhost:9411/api/v2/spans
         /// dotnet run -p Examples.Console.csproj jaeger -h localhost -p 6831
-        /// dotnet run -p Examples.Console.csproj prometheus -i 15 -p 9184 -d 2
+        /// dotnet run -p Examples.Console.csproj prometheus -p 9184 -d 2
         /// dotnet run -p Examples.Console.csproj otlp -e "http://localhost:4317"
         /// dotnet run -p Examples.Console.csproj zpages
         /// dotnet run -p Examples.Console.csproj metrics --help

examples/Console/TestPrometheusExporter.cs

@@ -52,7 +52,7 @@ namespace Examples.Console
                 .AddPrometheusExporter(opt =>
                 {
                     opt.StartHttpListener = true;
-                    opt.HttpListenerPrefixes = new string[] { $"http://*:{port}/" };
+                    opt.HttpListenerPrefixes = new string[] { $"http://localhost:{port}/" };
                 })
                 .Build();
 

src/OpenTelemetry.Exporter.Prometheus/Implementation/PrometheusExporterMetricsHttpServer.cs

@@ -53,6 +53,11 @@ namespace OpenTelemetry.Exporter.Prometheus
                 path = $"/{path}";
             }
 
+            if (!path.EndsWith("/"))
+            {
+                path = $"{path}/";
+            }
+
             foreach (string prefix in exporter.Options.HttpListenerPrefixes)
             {
                 this.httpListener.Prefixes.Add($"{prefix.TrimEnd('/')}{path}");