Allow overriding the broker API endpoint URL

In some setups, the broker URL determined from the kubeconfig context
isn't usable from the clusters which will be joined. For these setups,
the broker URL needs to be overridden, and this implements that by
adding a --broker-url option to the following subctl sub-commands:

* deploy-broker, to override the URL stored in the generated
  broker-info.subm file
* recover-broker-info, for the same reason
* join, to override the URL retrieved from the broker-info.subm file

Thus when the user knows ahead of time that the broker URL needs to be
manually specified, they can provide the correct setting to
deploy-broker, and join works as before. If they didn't know when
deploy-broker was run, they can specify the correct URL when joining
clusters. This also handles setups where each joining cluster might
need a different URL to reach the broker.

Signed-off-by: Stephen Kitt <[email protected]>

cmd/subctl/deploybroker.go

@@ -85,6 +85,9 @@ func addDeployBrokerFlags(flags *pflag.FlagSet) {
 	flags.StringVar(&deployflags.ImageVersion, "version", "", "image version")
 
 	flags.BoolVar(&deployflags.OperatorDebug, "operator-debug", false, "enable operator debugging (verbose logging)")
+
+	flags.StringVar(&deployflags.BrokerURL, "broker-url", "",
+		"broker API endpoint URL (stored in the broker information file, defaults to the context URL)")
 }
 
 func deployBrokerInContext(clusterInfo *cluster.Info, namespace string, status reporter.Interface) error {
@@ -114,6 +117,6 @@ func deployBrokerInContext(clusterInfo *cluster.Info, namespace string, status r
 	}
 
 	return broker.WriteInfoToFile( //nolint:wrapcheck // No need to wrap errors here.
-		clusterInfo.RestConfig, namespace, ipsecPSK,
+		clusterInfo.RestConfig, namespace, deployflags.BrokerURL, ipsecPSK,
 		set.New(deployflags.BrokerSpec.Components...), deployflags.BrokerSpec.DefaultCustomDomains, status)
 }

cmd/subctl/join.go

@@ -60,6 +60,11 @@ var joinCmd = &cobra.Command{
 		exit.OnError(status.Error(err, "Error loading the broker information from the given file"))
 		status.Success("%s indicates broker is at %s", args[0], brokerInfo.BrokerURL)
 
+		if joinFlags.BrokerURL != "" {
+			status.Success("Overriding broker URL using %s", joinFlags.BrokerURL)
+			brokerInfo.BrokerURL = joinFlags.BrokerURL
+		}
+
 		exit.OnError(joinRestConfigProducer.RunOnSelectedContext(
 			func(clusterInfo *cluster.Info, namespace string, status reporter.Interface) error {
 				return joinInContext(brokerInfo, clusterInfo, status)
@@ -127,6 +132,8 @@ func addJoinFlags(cmd *cobra.Command) {
 
 	cmd.Flags().BoolVar(&joinFlags.BrokerK8sSecure, "check-broker-certificate", true,
 		"check the broker certificate (disable this to allow \"insecure\" connections)")
+	cmd.Flags().StringVar(&joinFlags.BrokerURL, "broker-url", "",
+		"URL of the broker API endpoint (overrides the URL stored in the broker information file)")
 }
 
 func joinInContext(brokerInfo *broker.Info, clusterInfo *cluster.Info, status reporter.Interface) error {

cmd/subctl/recover_broker_info.go

@@ -34,6 +34,7 @@ import (
 )
 
 var recoverRestConfigProducer = restconfig.NewProducer()
+var recoverBrokerURL string
 
 // recoverBrokerInfo represents the reconstruct command.
 var recoverBrokerInfo = &cobra.Command{
@@ -48,6 +49,8 @@ var recoverBrokerInfo = &cobra.Command{
 
 func init() {
 	recoverRestConfigProducer.SetupFlags(recoverBrokerInfo.Flags())
+	recoverBrokerInfo.Flags().StringVar(&recoverBrokerURL, "broker-url", "",
+		"broker API endpoint URL (stored in the broker information file, defaults to the context URL)")
 	rootCmd.AddCommand(recoverBrokerInfo)
 }
 
@@ -84,5 +87,5 @@ func recoverBrokerInfoFromSubm(submCluster *cluster.Info, _ string, status repor
 	}
 
 	//nolint:wrapcheck // No need to wrap errors here.
-	return broker.RecoverData(submCluster, brokerObj, brokerNamespace, brokerRestConfig, status)
+	return broker.RecoverData(submCluster, brokerObj, brokerNamespace, recoverBrokerURL, brokerRestConfig, status)
 }

pkg/broker/file.go

@@ -39,7 +39,7 @@ import (
 
 const InfoFileName = "broker-info.subm"
 
-func WriteInfoToFile(restConfig *rest.Config, brokerNamespace string, ipsecPSK []byte, components set.Set[string],
+func WriteInfoToFile(restConfig *rest.Config, brokerNamespace, brokerURL string, ipsecPSK []byte, components set.Set[string],
 	customDomains []string, status reporter.Interface,
 ) error {
 	status.Start("Saving broker info to file %q", InfoFileName)
@@ -70,6 +70,10 @@ func WriteInfoToFile(restConfig *rest.Config, brokerNamespace string, ipsecPSK [
 
 	data.BrokerURL = restConfig.Host + restConfig.APIPath
 
+	if brokerURL != "" {
+		data.BrokerURL = brokerURL
+	}
+
 	data.ServiceDiscovery = components.Has(component.ServiceDiscovery)
 	data.Components = components.UnsortedList()
 	sort.Strings(data.Components)

pkg/broker/recover_broker_info.go

@@ -28,7 +28,7 @@ import (
 	"k8s.io/utils/set"
 )
 
-func RecoverData(submCluster *cluster.Info, broker *v1alpha1.Broker, brokerNamespace string,
+func RecoverData(submCluster *cluster.Info, broker *v1alpha1.Broker, brokerNamespace, brokerURL string,
 	brokerRestConfig *rest.Config, status reporter.Interface,
 ) error {
 	status.Start("Retrieving data to reconstruct broker-info.subm")
@@ -43,7 +43,7 @@ func RecoverData(submCluster *cluster.Info, broker *v1alpha1.Broker, brokerNames
 
 	status.Success("Successfully retrieved the data. Writing it to broker-info.subm")
 
-	err = WriteInfoToFile(brokerRestConfig, brokerNamespace, decodedPSKSecret,
+	err = WriteInfoToFile(brokerRestConfig, brokerNamespace, brokerURL, decodedPSKSecret,
 		set.New(broker.Spec.Components...), broker.Spec.DefaultCustomDomains, status)
 
 	return status.Error(err, "error reconstructing broker-info.subm")

pkg/deploy/broker.go

@@ -41,6 +41,7 @@ type BrokerOptions struct {
 	Repository      string
 	ImageVersion    string
 	BrokerNamespace string
+	BrokerURL       string
 	BrokerSpec      operatorv1alpha1.BrokerSpec
 }
 

pkg/join/options.go

@@ -43,6 +43,7 @@ type Options struct {
 	ImageVersion                  string
 	CableDriver                   string
 	CoreDNSCustomConfigMap        string
+	BrokerURL                     string
 	CustomDomains                 []string
 	ImageOverrideArr              []string
 }