make API host configurable

Author: pbusko

client.go

@@ -1,6 +1,7 @@
 package diego_logging_client
 
 import (
+	"cmp"
 	"fmt"
 	"time"
 
@@ -11,6 +12,7 @@ import (
 // Config is the shared configuration between v1 and v2 clients.
 type Config struct {
 	UseV2API      bool   `json:"loggregator_use_v2_api"`
+	APIHost       string `json:"loggregator_api_host"`
 	APIPort       int    `json:"loggregator_api_port"`
 	CACertPath    string `json:"loggregator_ca_path"`
 	CertPath      string `json:"loggregator_cert_path"`
@@ -29,6 +31,10 @@ type Config struct {
 	AppMetricExclusionFilter []string `json:"loggregator_app_metric_exclusion_filter"`
 }
 
+func (c Config) APIAddr() string {
+	return fmt.Sprintf("%s:%d", cmp.Or(c.APIHost, "127.0.0.1"), c.APIPort)
+}
+
 // A ContainerMetric records resource usage of an app in a container.
 type ContainerMetric struct {
 	ApplicationId            string //deprecated
@@ -107,7 +113,7 @@ func newV2IngressClient(config Config) (IngressClient, error) {
 	}
 
 	if config.APIPort != 0 {
-		opts = append(opts, loggregator.WithAddr(fmt.Sprintf("127.0.0.1:%d", config.APIPort)))
+		opts = append(opts, loggregator.WithAddr(config.APIAddr()))
 	}
 
 	//lint:ignore SA1019 - we can't use grpc.WithContextDial until loggregator is updated for grpc.DialContext

client_test.go

@@ -33,6 +33,22 @@ var _ = Describe("DiegoLoggingClient", func() {
 		metronClientKeyFile = filepath.Join(fixturesPath, "metron", "client.key")
 	})
 
+	Context("Config", func() {
+		It("returns the configured API address", func() {
+			config := client.Config{
+				APIHost: "api.example.com",
+				APIPort: 8080,
+			}
+			Expect(config.APIAddr()).To(Equal("api.example.com:8080"))
+		})
+		It("returns the default API address when no host is specified", func() {
+			config := client.Config{
+				APIPort: 8080,
+			}
+			Expect(config.APIAddr()).To(Equal("127.0.0.1:8080"))
+		})
+	})
+
 	Context("when the v2 api is used", func() {
 		var (
 			testIngressServer *testhelpers.TestIngressServer