discovery: use interface CIDR for auto-generated subnet, tests (#1452)

* fix subnet for different nodes overwriting each other

* set automatic subnet cidr based on interface

* add option to wait for subnet discovery

* use local api

* use ip as identifier

* use correct cidr

* migrate discovery simple

* convert dhcp

* convert dns forward and backwards

Author: BeryJu

api/api/openapi.yaml

@@ -857,6 +857,13 @@ paths:
         schema:
           type: string
         style: form
+      - explode: true
+        in: query
+        name: wait
+        required: true
+        schema:
+          type: boolean
+        style: form
       responses:
         "204":
           description: No Content

api/api_roles_discovery.go

@@ -519,7 +519,7 @@ No authorization required
 
 ## DiscoverySubnetStart
 
-> DiscoverySubnetStart(ctx).Identifier(identifier).Execute()
+> DiscoverySubnetStart(ctx).Identifier(identifier).Wait(wait).Execute()
 
 Discovery Subnets
 
@@ -537,10 +537,11 @@ import (
 
 func main() {
     identifier := "identifier_example" // string | 
+    wait := true // bool | 
 
     configuration := openapiclient.NewConfiguration()
     apiClient := openapiclient.NewAPIClient(configuration)
-    r, err := apiClient.RolesDiscoveryApi.DiscoverySubnetStart(context.Background()).Identifier(identifier).Execute()
+    r, err := apiClient.RolesDiscoveryApi.DiscoverySubnetStart(context.Background()).Identifier(identifier).Wait(wait).Execute()
     if err != nil {
         fmt.Fprintf(os.Stderr, "Error when calling `RolesDiscoveryApi.DiscoverySubnetStart``: %v\n", err)
         fmt.Fprintf(os.Stderr, "Full HTTP response: %v\n", r)
@@ -560,6 +561,7 @@ Other parameters are passed through a pointer to a apiDiscoverySubnetStartReques
 Name | Type | Description  | Notes
 ------------- | ------------- | ------------- | -------------
  **identifier** | **string** |  | 
+ **wait** | **bool** |  | 
 
 ### Return type
 

api/docs/RolesDiscoveryApi.md

@@ -63,7 +63,7 @@ func (e *ExtConfig) GetInterfaceForIP(forIp net.IP) (*net.Interface, error) {
 			}
 		}
 	}
-	return nil, fmt.Errorf("faild to find interface for %s", forIp.String())
+	return nil, fmt.Errorf("failed to find interface for %s", forIp.String())
 }
 
 func (e *ExtConfig) GetIP() (net.IP, error) {

pkg/extconfig/ip.go

@@ -14,6 +14,7 @@ import (
 func generateHW() net.HardwareAddr {
 	return net.HardwareAddr(securecookie.GenerateRandomKey(6))
 }
+
 func RoleConfig() []byte {
 	return []byte(tests.MustJSON(dhcp.RoleConfig{
 		Port: 0,

pkg/roles/dhcp/role_test.go

@@ -87,6 +87,7 @@ func (r *Role) APISubnetsPut() usecase.Interactor {
 
 type APISubnetsStartInput struct {
 	Name string `query:"identifier" required:"true"`
+	Wait bool   `query:"wait" required:"true"`
 }
 
 func (r *Role) APISubnetsStart() usecase.Interactor {
@@ -107,7 +108,11 @@ func (r *Role) APISubnetsStart() usecase.Interactor {
 			r.log.Warn("failed to parse subnet from KV", zap.Error(err))
 			return status.Wrap(err, status.Internal)
 		}
-		go s.RunDiscovery(context.Background())
+		if input.Wait {
+			s.RunDiscovery(context.Background())
+		} else {
+			go s.RunDiscovery(context.Background())
+		}
 		return nil
 	})
 	u.SetName("discovery.subnet_start")

pkg/roles/discovery/api_subnets.go

@@ -10,7 +10,6 @@ import (
 	dhcptypes "beryju.io/gravity/pkg/roles/dhcp/types"
 	"beryju.io/gravity/pkg/roles/discovery/types"
 	dnstypes "beryju.io/gravity/pkg/roles/dns/types"
-	"github.com/google/uuid"
 	"go.etcd.io/etcd/api/v3/mvccpb"
 	clientv3 "go.etcd.io/etcd/client/v3"
 	"go.uber.org/zap"
@@ -27,8 +26,7 @@ type Device struct {
 
 func (r *Role) newDevice() *Device {
 	return &Device{
-		Identifier: uuid.New().String(),
-		inst:       r.i,
+		inst: r.i,
 	}
 }
 

pkg/roles/discovery/device.go

@@ -2,7 +2,9 @@ package discovery
 
 import (
 	"context"
-	"net/netip"
+	"errors"
+	"fmt"
+	"net"
 
 	"beryju.io/gravity/pkg/extconfig"
 	instanceTypes "beryju.io/gravity/pkg/instance/types"
@@ -63,14 +65,14 @@ func New(instance roles.Instance) *Role {
 	})
 	r.i.AddEventListener(instanceTypes.EventTopicInstanceFirstStart, func(ev *roles.Event) {
 		// On first start create a subnet based on the instance IP
-		subnet := r.NewSubnet("default-instance-subnet")
-		ip := netip.MustParseAddr(extconfig.Get().Instance.IP)
-		prefix, err := ip.Prefix(24)
+		subnet := r.NewSubnet(fmt.Sprintf("instance-subnet-%s", extconfig.Get().Instance.Identifier))
+
+		cidr, err := GetCIDRFromIP()
 		if err != nil {
 			r.log.Warn("failed to get prefix", zap.Error(err))
 			return
 		}
-		subnet.CIDR = prefix.String()
+		subnet.CIDR = cidr
 		subnet.DNSResolver = extconfig.Get().FallbackDNS
 		subnet.DiscoveryTTL = 86400
 		err = subnet.put(ev.Context)
@@ -83,6 +85,28 @@ func New(instance roles.Instance) *Role {
 	return r
 }
 
+func GetCIDRFromIP() (string, error) {
+	ip := net.ParseIP(extconfig.Get().Instance.IP)
+	intf, err := extconfig.Get().GetInterfaceForIP(ip)
+	if err != nil {
+		return "", err
+	}
+	addrs, err := intf.Addrs()
+	if err != nil {
+		return "", err
+	}
+	for _, addr := range addrs {
+		iip, net, err := net.ParseCIDR(addr.String())
+		if err != nil {
+			continue
+		}
+		if ip.Equal(iip) {
+			return net.String(), nil
+		}
+	}
+	return "", errors.New("no CIDR found")
+}
+
 func (r *Role) Start(ctx context.Context, config []byte) error {
 	r.cfg = r.decodeRoleConfig(config)
 	if !r.cfg.Enabled || extconfig.Get().ListenOnlyMode {

pkg/roles/discovery/role.go

@@ -125,8 +125,12 @@ func (s *Subnet) RunDiscovery(ctx context.Context) []Device {
 				dev.MAC = addr.Addr
 			} else {
 				dev.IP = addr.Addr
+				dev.Identifier = addr.Addr
 			}
 		}
+		if dev.Identifier == "" {
+			continue
+		}
 		devices = append(devices, *dev)
 		err := dev.put(tr.Context(), int64(s.DiscoveryTTL))
 		if err != nil {