feat: enable Azure subscription ID override

main.go

@@ -251,9 +251,9 @@ func main() {
 		}
 		p, err = awssd.NewAWSSDProvider(domainFilter, cfg.AWSZoneType, cfg.DryRun, cfg.AWSSDServiceCleanup, cfg.TXTOwnerID, sd.New(awsSession))
 	case "azure-dns", "azure":
-		p, err = azure.NewAzureProvider(cfg.AzureConfigFile, domainFilter, zoneNameFilter, zoneIDFilter, cfg.AzureResourceGroup, cfg.AzureUserAssignedIdentityClientID, cfg.DryRun)
+		p, err = azure.NewAzureProvider(cfg.AzureConfigFile, domainFilter, zoneNameFilter, zoneIDFilter, cfg.AzureSubscriptionID, cfg.AzureResourceGroup, cfg.AzureUserAssignedIdentityClientID, cfg.DryRun)
 	case "azure-private-dns":
-		p, err = azure.NewAzurePrivateDNSProvider(cfg.AzureConfigFile, domainFilter, zoneIDFilter, cfg.AzureResourceGroup, cfg.AzureUserAssignedIdentityClientID, cfg.DryRun)
+		p, err = azure.NewAzurePrivateDNSProvider(cfg.AzureConfigFile, domainFilter, zoneIDFilter, cfg.AzureSubscriptionID, cfg.AzureResourceGroup, cfg.AzureUserAssignedIdentityClientID, cfg.DryRun)
 	case "bluecat":
 		p, err = bluecat.NewBluecatProvider(cfg.BluecatConfigFile, cfg.BluecatDNSConfiguration, cfg.BluecatDNSServerName, cfg.BluecatDNSDeployType, cfg.BluecatDNSView, cfg.BluecatGatewayHost, cfg.BluecatRootZone, cfg.TXTPrefix, cfg.TXTSuffix, domainFilter, zoneIDFilter, cfg.DryRun, cfg.BluecatSkipTLSVerify)
 	case "vinyldns":

pkg/apis/externaldns/types.go

@@ -493,8 +493,8 @@ func (cfg *Config) ParseFlags(args []string) error {
 	app.Flag("aws-zone-match-parent", "Expand limit possible target by sub-domains (default: disabled)").BoolVar(&cfg.AWSZoneMatchParent)
 	app.Flag("aws-sd-service-cleanup", "When using the AWS CloudMap provider, delete empty Services without endpoints (default: disabled)").BoolVar(&cfg.AWSSDServiceCleanup)
 	app.Flag("azure-config-file", "When using the Azure provider, specify the Azure configuration file (required when --provider=azure)").Default(defaultConfig.AzureConfigFile).StringVar(&cfg.AzureConfigFile)
-	app.Flag("azure-resource-group", "When using the Azure provider, override the Azure resource group to use (required when --provider=azure-private-dns)").Default(defaultConfig.AzureResourceGroup).StringVar(&cfg.AzureResourceGroup)
+	app.Flag("azure-resource-group", "When using the Azure provider, override the Azure resource group to use (optional)").Default(defaultConfig.AzureResourceGroup).StringVar(&cfg.AzureResourceGroup)
-	app.Flag("azure-subscription-id", "When using the Azure provider, specify the Azure configuration file (required when --provider=azure-private-dns)").Default(defaultConfig.AzureSubscriptionID).StringVar(&cfg.AzureSubscriptionID)
+	app.Flag("azure-subscription-id", "When using the Azure provider, override the Azure subscription to use (optional)").Default(defaultConfig.AzureSubscriptionID).StringVar(&cfg.AzureSubscriptionID)
 	app.Flag("azure-user-assigned-identity-client-id", "When using the Azure provider, override the client id of user assigned identity in config file (optional)").Default("").StringVar(&cfg.AzureUserAssignedIdentityClientID)
 	app.Flag("tencent-cloud-config-file", "When using the Tencent Cloud provider, specify the Tencent Cloud configuration file (required when --provider=tencentcloud)").Default(defaultConfig.TencentCloudConfigFile).StringVar(&cfg.TencentCloudConfigFile)
 	app.Flag("tencent-cloud-zone-type", "When using the Tencent Cloud provider, filter for zones with visibility (optional, options: public, private)").Default(defaultConfig.TencentCloudZoneType).EnumVar(&cfg.TencentCloudZoneType, "", "public", "private")

provider/azure/azure.go

@@ -65,8 +65,8 @@ type AzureProvider struct {
 // NewAzureProvider creates a new Azure provider.
 //
 // Returns the provider or an error if a provider could not be created.
-func NewAzureProvider(configFile string, domainFilter endpoint.DomainFilter, zoneNameFilter endpoint.DomainFilter, zoneIDFilter provider.ZoneIDFilter, resourceGroup string, userAssignedIdentityClientID string, dryRun bool) (*AzureProvider, error) {
+func NewAzureProvider(configFile string, domainFilter endpoint.DomainFilter, zoneNameFilter endpoint.DomainFilter, zoneIDFilter provider.ZoneIDFilter, subscriptionID string, resourceGroup string, userAssignedIdentityClientID string, dryRun bool) (*AzureProvider, error) {
-	cfg, err := getConfig(configFile, resourceGroup, userAssignedIdentityClientID)
+	cfg, err := getConfig(configFile, subscriptionID, resourceGroup, userAssignedIdentityClientID)
 	if err != nil {
 		return nil, fmt.Errorf("failed to read Azure config file '%s': %v", configFile, err)
 	}

provider/azure/azure_private_dns.go

@@ -59,8 +59,8 @@ type AzurePrivateDNSProvider struct {
 // NewAzurePrivateDNSProvider creates a new Azure Private DNS provider.
 //
 // Returns the provider or an error if a provider could not be created.
-func NewAzurePrivateDNSProvider(configFile string, domainFilter endpoint.DomainFilter, zoneIDFilter provider.ZoneIDFilter, resourceGroup, userAssignedIdentityClientID string, dryRun bool) (*AzurePrivateDNSProvider, error) {
+func NewAzurePrivateDNSProvider(configFile string, domainFilter endpoint.DomainFilter, zoneIDFilter provider.ZoneIDFilter, subscriptionID string, resourceGroup string, userAssignedIdentityClientID string, dryRun bool) (*AzurePrivateDNSProvider, error) {
-	cfg, err := getConfig(configFile, resourceGroup, userAssignedIdentityClientID)
+	cfg, err := getConfig(configFile, subscriptionID, resourceGroup, userAssignedIdentityClientID)
 	if err != nil {
 		return nil, fmt.Errorf("failed to read Azure config file '%s': %v", configFile, err)
 	}

provider/azure/config.go

@@ -43,7 +43,7 @@ type config struct {
 	UserAssignedIdentityID       string `json:"userAssignedIdentityID" yaml:"userAssignedIdentityID"`
 }
 
-func getConfig(configFile, resourceGroup, userAssignedIdentityClientID string) (*config, error) {
+func getConfig(configFile, subscriptionID, resourceGroup, userAssignedIdentityClientID string) (*config, error) {
 	contents, err := os.ReadFile(configFile)
 	if err != nil {
 		return nil, fmt.Errorf("failed to read Azure config file '%s': %v", configFile, err)
@@ -53,7 +53,10 @@ func getConfig(configFile, resourceGroup, userAssignedIdentityClientID string) (
 	if err != nil {
 		return nil, fmt.Errorf("failed to read Azure config file '%s': %v", configFile, err)
 	}
-
+	// If a subscription ID was given, override what was present in the config file
+	if subscriptionID != "" {
+		cfg.SubscriptionID = subscriptionID
+	}
 	// If a resource group was given, override what was present in the config file
 	if resourceGroup != "" {
 		cfg.ResourceGroup = resourceGroup

provider/azure/config_test.go

@@ -17,9 +17,12 @@ limitations under the License.
 package azure
 
 import (
+	"path"
+	"runtime"
 	"testing"
 
 	"github.com/Azure/azure-sdk-for-go/sdk/azcore/cloud"
+	"github.com/stretchr/testify/assert"
 )
 
 func TestGetCloudConfiguration(t *testing.T) {
@@ -44,3 +47,14 @@ func TestGetCloudConfiguration(t *testing.T) {
 		})
 	}
 }
+
+func TestOverrideConfiguration(t *testing.T) {
+	_, filename, _, _ := runtime.Caller(0)
+	configFile := path.Join(path.Dir(filename), "config_test.json")
+	cfg, err := getConfig(configFile, "subscription-override", "rg-override", "")
+	if err != nil {
+		t.Errorf("got unexpected err %v", err)
+	}
+	assert.Equal(t, cfg.SubscriptionID, "subscription-override")
+	assert.Equal(t, cfg.ResourceGroup, "rg-override")
+}

provider/azure/config_test.json

@@ -0,0 +1,7 @@
+{
+  "tenantId": "tenant",
+  "subscriptionId": "subscription",
+  "resourceGroup": "rg",
+  "aadClientId": "clientId",
+  "aadClientSecret": "clientSecret"
+}