feat: [cxl-host] attempt to publish as avahi service for auto discovery

cmd/cxl-host/main.go

@@ -11,8 +11,11 @@ import (
 	"log"
 	"net/http"
 	"os"
+	"strconv"
 	"strings"
 
+	"github.com/godbus/dbus/v5"
+	"github.com/holoplot/go-avahi"
 	"k8s.io/klog/v2"
 )
 
@@ -53,9 +56,61 @@ func main() {
 	accounts.AccountsHandler().InitLogger(logger)
 	accounts.AccountsHandler().Restore()
 
+	// avahi publish
+	err = AvahiPublish(ctx, settings.Port)
+	if err != nil {
+		fmt.Printf("ERROR: avahi publish failed, err=%v\nContinue...\n", err)
+	}
 	DefaultApiService := cxl_host.NewCxlHostApiService()
 	DefaultApiController := redfishapi.NewDefaultAPIController(DefaultApiService)
 	OverrideAPIController := cxl_host.NewOverrideAPIController(DefaultApiService)
 	router := cxl_host.NewCxlHostRouter(ctx, OverrideAPIController, DefaultApiController)
 	log.Fatal(http.ListenAndServe(":"+settings.Port, router))
 }
+
+// AvahiPublish: Publish the service with avahi
+func AvahiPublish(ctx context.Context, port string) error {
+	txt := [][]byte{}
+	txt = append(txt, []byte("cxl-host=true"))
+
+	conn, err := dbus.SystemBus()
+	if err != nil {
+		return fmt.Errorf("avahi: Cannot get system bus: %v", err)
+	}
+
+	a, err := avahi.ServerNew(conn)
+	if err != nil {
+		return fmt.Errorf("avahi: Avahi new failed: %v", err)
+	}
+
+	eg, err := a.EntryGroupNew()
+	if err != nil {
+		return fmt.Errorf("avahi: EntryGroupNew() failed: %v", err)
+	}
+
+	hostname, err := a.GetHostName()
+	if err != nil {
+		return fmt.Errorf("avahi: GetHostName() failed: %v", err)
+	}
+
+	fqdn, err := a.GetHostNameFqdn()
+	if err != nil {
+		return fmt.Errorf("avahi: GetHostNameFqdn() failed: %v", err)
+	}
+
+	p, err := strconv.Atoi(port)
+	if err != nil {
+		return fmt.Errorf("avahi: Cannot convert port to Integer: %v", err)
+	}
+	err = eg.AddService(avahi.InterfaceUnspec, avahi.ProtoInet, 0, hostname, "_obmc_redfish._tcp", "local", fqdn, uint16(p), txt)
+	if err != nil {
+		return fmt.Errorf("avahi: AddService() failed: %v", err)
+	}
+
+	err = eg.Commit()
+	if err != nil {
+		return fmt.Errorf("avahi: Commit() failed: %v", err)
+	}
+
+	return nil
+}

go.mod

@@ -20,12 +20,15 @@ require (
 	k8s.io/klog/v2 v2.120.1
 )
 
+require github.com/godbus/dbus/v5 v5.0.4 // indirect
+
 require (
 	github.com/davecgh/go-spew v1.1.2-0.20180830191138-d8f796af33cc // indirect
 	github.com/fsnotify/fsnotify v1.7.0 // indirect
 	github.com/go-logr/logr v1.4.2 // indirect
 	github.com/google/go-cmp v0.6.0 // indirect
 	github.com/hashicorp/hcl v1.0.0 // indirect
+	github.com/holoplot/go-avahi v1.0.1
 	github.com/inconshreveable/mousetrap v1.1.0 // indirect
 	github.com/magiconair/properties v1.8.7 // indirect
 	github.com/mitchellh/mapstructure v1.5.0 // indirect

go.sum

@@ -13,6 +13,8 @@ github.com/fsnotify/fsnotify v1.7.0 h1:8JEhPFa5W2WU7YfeZzPNqzMP6Lwt7L2715Ggo0nos
 github.com/fsnotify/fsnotify v1.7.0/go.mod h1:40Bi/Hjc2AVfZrqy+aj+yEI+/bRxZnMJyTJwOpGvigM=
 github.com/go-logr/logr v1.4.2 h1:6pFjapn8bFcIbiKo3XT4j/BhANplGihG6tvd+8rYgrY=
 github.com/go-logr/logr v1.4.2/go.mod h1:9T104GzyrTigFIr8wt5mBrctHMim0Nb2HLGrmQ40KvY=
+github.com/godbus/dbus/v5 v5.0.4 h1:9349emZab16e7zQvpmsbtjc18ykshndd8y2PG3sgJbA=
+github.com/godbus/dbus/v5 v5.0.4/go.mod h1:xhWf0FNVPg57R7Z0UbKHbJfkEywrmjJnf7w5xrFpKfA=
 github.com/google/go-cmp v0.6.0 h1:ofyhxvXcZhMsU5ulbFiLKl/XBFqE1GSq7atu8tAmTRI=
 github.com/google/go-cmp v0.6.0/go.mod h1:17dUlkBOakJ0+DkrSSNjCkIjxS6bF9zb3elmeNGIjoY=
 github.com/google/uuid v1.6.0 h1:NIvaJDMOsjHA8n1jAhLSgzrAzy1Hgr+hNrb57e+94F0=
@@ -21,6 +23,8 @@ github.com/gorilla/mux v1.8.1 h1:TuBL49tXwgrFYWhqrNgrUNEY92u81SPhu7sTdzQEiWY=
 github.com/gorilla/mux v1.8.1/go.mod h1:AKf9I4AEqPTmMytcMc0KkNouC66V3BtZ4qD5fmWSiMQ=
 github.com/hashicorp/hcl v1.0.0 h1:0Anlzjpi4vEasTeNFn2mLJgTSwt0+6sfsiTG8qcWGx4=
 github.com/hashicorp/hcl v1.0.0/go.mod h1:E5yfLk+7swimpb2L/Alb/PJmXilQ/rhwaUYs4T20WEQ=
+github.com/holoplot/go-avahi v1.0.1 h1:XcqR2keL4qWRnlxHD5CAOdWpLFZJ+EOUK0vEuylfvvk=
+github.com/holoplot/go-avahi v1.0.1/go.mod h1:qH5psEKb0DK+BRplMfc+RY4VMOlbf6mqfxgpMy6aP0M=
 github.com/inconshreveable/mousetrap v1.1.0 h1:wN+x4NVGpMsO7ErUn/mUI3vEoE6Jt13X2s0bqwp9tc8=
 github.com/inconshreveable/mousetrap v1.1.0/go.mod h1:vpF70FUmC8bwa3OWnCshd2FqLfsEA9PFc4w1p2J65bw=
 github.com/kr/pretty v0.3.1 h1:flRD4NNwYAUpkphVc1HcthR4KEIFJ65n8Mw5qdRn3LE=