[receiver/loki] Use component.UseLocalHostAsDefaultHost feature gate

Fixes open-telemetry#30819

.chloggen/mx-psi_internal-localhostgate.yaml

@@ -17,7 +17,7 @@ issues: [30702]
 # Use pipe (|) for multiline entries.
 subtext: | 
   This change affects the following components:
-    - TBF
+    - receiver/loki
 
 # If your change doesn't affect end users or the exported elements of any package,
 # you should instead start your pull request title with [chore] or use the "Skip Changelog" label.

receiver/lokireceiver/README.md

@@ -22,7 +22,7 @@ This receiver runs HTTP and GRPC servers to ingest log entries in Loki format.
 
 The settings are:
 
-- `endpoint` (required, default = 0.0.0.0:3500 for HTTP protocol, 0.0.0.0:3600 gRPC protocol): host:port to which the receiver is going to receive data.
+- `endpoint` (required, default = 0.0.0.0:3500 for HTTP protocol, 0.0.0.0:3600 gRPC protocol): host:port to which the receiver is going to receive data. The `component.UseLocalHostAsDefaultHost` feature gate changes these to localhost:3500 and localhost:3600. These will become the default in a future release.
 - `use_incoming_timestamp` (optional, default = false) if set `true` the timestamp from Loki log entry is used
 
 Example:

receiver/lokireceiver/factory.go

@@ -15,10 +15,13 @@ import (
 	"go.opentelemetry.io/collector/consumer"
 	"go.opentelemetry.io/collector/receiver"
 
+	"github.com/open-telemetry/opentelemetry-collector-contrib/internal/common/localhostgate"
 	"github.com/open-telemetry/opentelemetry-collector-contrib/receiver/lokireceiver/internal/metadata"
 )
 
 const (
+	defaultGRPCPort         = 3600
+	defaultHTTPPort         = 3500
 	defaultGRPCBindEndpoint = "0.0.0.0:3600"
 	defaultHTTPBindEndpoint = "0.0.0.0:3500"
 )
@@ -36,12 +39,12 @@ func createDefaultConfig() component.Config {
 		Protocols: Protocols{
 			GRPC: &configgrpc.GRPCServerSettings{
 				NetAddr: confignet.NetAddr{
-					Endpoint:  defaultGRPCBindEndpoint,
+					Endpoint:  localhostgate.EndpointForPort(defaultGRPCPort),
 					Transport: "tcp",
 				},
 			},
 			HTTP: &confighttp.HTTPServerSettings{
-				Endpoint: defaultHTTPBindEndpoint,
+				Endpoint: localhostgate.EndpointForPort(defaultHTTPPort),
 			},
 		},
 	}