Use NSM_IPV6_PREFIX variable in case of IPv6 CIDR only (no IPv4) #12

Signed-off-by: Laszlo Kiraly <laszlo.kiraly@est.tech>
networkservicemesh · Feb 23, 2022 · b255453 · b255453
1 parent 1af5210
commit b255453
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Showing 2 changed files with 52 additions and 26 deletions.
diff --git a/internal/pkg/config/config.go b/internal/pkg/config/config.go
@@ -38,16 +38,15 @@ const (
 
 // Config holds configuration parameters from environment variables
 type Config struct {
-	Name                  string        `default:"vlan-server" desc:"Name of the endpoint"`
-	ConnectTo             url.URL       `default:"nsm-registry-svc:5002" desc:"url of registry service to connect to" split_words:"true"`
-	MaxTokenLifetime      time.Duration `default:"24h" desc:"maximum lifetime of tokens" split_words:"true"`
-	CidrPrefix            string        `default:"169.254.0.0/16" desc:"CIDR Prefix to assign IPs from" split_words:"true"`
-	Ipv6Prefix            string        `default:"" desc:"Ipv6 Prefix for dual-stack" split_words:"true"`
-	RegisterService       bool          `default:"true" desc:"if true then registers network service on startup" split_words:"true"`
-	ListenOn              url.URL       `default:"tcp://:5003" desc:"tcp:// url to be listen on. It will be used as public to register NSM" split_words:"true"`
-	OpenTelemetryEndpoint string        `default:"otel-collector.observability.svc.cluster.local:4317" desc:"OpenTelemetry Collector Endpoint"`
-
-	Services []ServiceConfig `default:"" desc:"list of supported services"`
+	Name                  string          `default:"vlan-server" desc:"Name of the endpoint"`
+	ConnectTo             url.URL         `default:"nsm-registry-svc:5002" desc:"url of registry service to connect to" split_words:"true"`
+	MaxTokenLifetime      time.Duration   `default:"24h" desc:"maximum lifetime of tokens" split_words:"true"`
+	CidrPrefix            string          `default:"169.254.0.0/16" desc:"IPv4 CIDR Prefix to assign IPs from" split_words:"true"`
+	Ipv6Prefix            string          `default:"" desc:"IPv6 CIDR Prefix to assign IPs from" split_words:"true"`
+	RegisterService       bool            `default:"true" desc:"if true then registers network service on startup" split_words:"true"`
+	ListenOn              url.URL         `default:"tcp://:5003" desc:"tcp:// url to be listen on. It will be used as public to register NSM" split_words:"true"`
+	OpenTelemetryEndpoint string          `default:"otel-collector.observability.svc.cluster.local:4317" desc:"OpenTelemetry Collector Endpoint"`
+	Services              []ServiceConfig `default:"" desc:"list of supported services"`
 }
 
 // Process prints and processes env to config

diff --git a/main.go b/main.go
@@ -26,10 +26,12 @@ import (
 	"net"
 	"net/url"
 	"os"
+	"strings"
 	"time"
 
 	nested "github.com/antonfisher/nested-logrus-formatter"
 	"github.com/edwarnicke/grpcfd"
+	"github.com/pkg/errors"
 	"github.com/sirupsen/logrus"
 	"github.com/spiffe/go-spiffe/v2/spiffetls/tlsconfig"
 	"github.com/spiffe/go-spiffe/v2/workloadapi"
@@ -135,25 +137,12 @@ func main() {
 	log.FromContext(ctx).Infof("executing phase 3: parsing network prefixes for ipam")
 	// ********************************************************************************
 
-	_, ipNet1, err := net.ParseCIDR(cfg.CidrPrefix)
+	ipamChain, err := getIPAMChain(cfg.CidrPrefix, cfg.Ipv6Prefix)
 	if err != nil {
-		logrus.Fatalf("Could not parse cidr %s; %+v", cfg.CidrPrefix, err)
+		logger.Fatalf("error parsing CIDR from config: %v", err.Error())
 	}
+	log.FromContext(ctx).Infof("network prefixes parsed successfully")
 
-	var ipamChain networkservice.NetworkServiceServer
-
-	if cfg.Ipv6Prefix != "" {
-		_, ipNet2, parseErr := net.ParseCIDR(cfg.Ipv6Prefix)
-		if parseErr != nil {
-			log.FromContext(ctx).Fatalf("error parsing cidr: %+v", err)
-		}
-		ipamChain = chain.NewNetworkServiceServer(
-			singlepointipam.NewServer(ipNet1),
-			singlepointipam.NewServer(ipNet2),
-		)
-	} else {
-		ipamChain = chain.NewNetworkServiceServer(singlepointipam.NewServer(ipNet1))
-	}
 	// ********************************************************************************
 	logger.Infof("executing phase 4: create network service endpoint")
 	// ********************************************************************************
@@ -306,3 +295,41 @@ func getNseEndpoint(listenOn *url.URL, cfg *config.Config) *registryapi.NetworkS
 	}
 	return nse
 }
+
+func getIPAMChain(ip4CIDR, ip6CIDR string) (networkservice.NetworkServiceServer, error) {
+	var ipNet1 *net.IPNet
+	var ipNet2 *net.IPNet
+
+	if ip4CIDR != "" {
+		var parseErr error
+		_, ipNet1, parseErr = net.ParseCIDR(ip4CIDR)
+		if parseErr != nil {
+			logrus.Fatalf("Could not parse IPv4 CIDR %s; %+v", ip4CIDR, parseErr)
+		}
+		// accept IPv6 address also for backward compatibility reason
+	}
+	if ip6CIDR != "" {
+		var parseErr error
+		_, ipNet2, parseErr = net.ParseCIDR(ip6CIDR)
+		if parseErr != nil {
+			logrus.Fatalf("Could not parse IPv6 CIDR: %s; %+v", ip6CIDR, parseErr)
+		}
+		if !strings.Contains(ip6CIDR, ":") {
+			return nil, errors.New("not ipv6 address is set")
+		}
+	}
+
+	switch {
+	case ipNet1 != nil && ipNet2 != nil:
+		return chain.NewNetworkServiceServer(
+			singlepointipam.NewServer(ipNet1),
+			singlepointipam.NewServer(ipNet2),
+		), nil
+	case ipNet2 != nil:
+		return chain.NewNetworkServiceServer(singlepointipam.NewServer(ipNet2)), nil
+	case ipNet1 != nil:
+		return chain.NewNetworkServiceServer(singlepointipam.NewServer(ipNet1)), nil
+	default:
+		return nil, errors.New("can not set CIDR")
+	}
+}