[management] prevent dangling group refs in agent-network ACLs. (#7060)

Block deleting a group referenced as a source group by an agent network
   policy, and drop unresolvable groups from synthesised private-service
ACLs. A deleted group survived in agent_network_policies.source_groups
   and was carried into the injected in-memory policy, where network-map
   assembly resolved it to a nil group and panicked on every proxy peer
   sync.

management/server/group.go

@@ -6,6 +6,7 @@ import (
 	"fmt"
 	"slices"
 
+	agentNetworkTypes "github.com/netbirdio/netbird/management/internals/modules/agentnetwork/types"
 	"github.com/rs/xid"
 	log "github.com/sirupsen/logrus"
 
@@ -744,6 +745,10 @@ func validateDeleteGroup(ctx context.Context, transaction store.Store, group *ty
 		return &GroupLinkError{"network router", linkedRouter.ID}
 	}
 
+	if isLinked, linkedPolicy := isGroupLinkedToAgentNetworkPolicy(ctx, transaction, group.AccountID, group.ID); isLinked {
+		return &GroupLinkError{"agent network policy", linkedPolicy.Name}
+	}
+
 	return checkGroupLinkedToSettings(ctx, transaction, group)
 }
 
@@ -875,6 +880,26 @@ func isGroupLinkedToNetworkRouter(ctx context.Context, transaction store.Store,
 	return false, nil
 }
 
+// isGroupLinkedToAgentNetworkPolicy checks if a group is used as a source group by any
+// agent network policy in the account.
+func isGroupLinkedToAgentNetworkPolicy(ctx context.Context, transaction store.Store, accountID string, groupID string) (bool, *agentNetworkTypes.Policy) {
+	policies, err := transaction.GetAccountAgentNetworkPolicies(ctx, store.LockingStrengthNone, accountID)
+	if err != nil {
+		log.WithContext(ctx).Errorf("error retrieving agent network policies while checking group linkage: %v", err)
+		return false, nil
+	}
+
+	for _, policy := range policies {
+		if policy == nil {
+			continue
+		}
+		if slices.Contains(policy.SourceGroups, groupID) {
+			return true, policy
+		}
+	}
+	return false, nil
+}
+
 // areGroupChangesAffectPeers checks if any changes to the specified groups will affect peers.
 // It fetches each collection once and checks all groupIDs against them in memory.
 func areGroupChangesAffectPeers(ctx context.Context, transaction store.Store, accountID string, groupIDs []string) (bool, error) {

management/server/group_test.go

@@ -18,6 +18,7 @@ import (
 	"golang.org/x/exp/maps"
 
 	nbdns "github.com/netbirdio/netbird/dns"
+	agentNetworkTypes "github.com/netbirdio/netbird/management/internals/modules/agentnetwork/types"
 	"github.com/netbirdio/netbird/management/server/groups"
 	"github.com/netbirdio/netbird/management/server/networks"
 	"github.com/netbirdio/netbird/management/server/networks/resources"
@@ -125,6 +126,11 @@ func TestDefaultAccountManager_DeleteGroup(t *testing.T) {
 			"grp-for-integration",
 			"only service users with admin power can delete integration group",
 		},
+		{
+			"agent network policy",
+			"grp-for-agent-network-policy",
+			"agent network policy",
+		},
 	}
 
 	for _, testCase := range testCases {
@@ -218,6 +224,11 @@ func TestDefaultAccountManager_DeleteGroups(t *testing.T) {
 			groupIDs:        []string{"grp-for-integration"},
 			expectedReasons: []string{"only service users with admin power can delete integration group"},
 		},
+		{
+			name:            "agent network policy",
+			groupIDs:        []string{"grp-for-agent-network-policy"},
+			expectedReasons: []string{"agent network policy"},
+		},
 		{
 			name:            "successfully delete multiple groups",
 			groupIDs:        []string{"group-1", "group-2"},
@@ -406,6 +417,14 @@ func initTestGroupAccount(am *DefaultAccountManager) (*DefaultAccountManager, *t
 		Peers:     make([]string, 0),
 	}
 
+	groupForAgentNetworkPolicy := &types.Group{
+		ID:        "grp-for-agent-network-policy",
+		AccountID: "account-id",
+		Name:      "Group for agent network policies",
+		Issued:    types.GroupIssuedAPI,
+		Peers:     make([]string, 0),
+	}
+
 	routeResource := &route.Route{
 		ID:     "example route",
 		Groups: []string{groupForRoute.ID},
@@ -461,6 +480,18 @@ func initTestGroupAccount(am *DefaultAccountManager) (*DefaultAccountManager, *t
 	_ = am.CreateGroup(context.Background(), accountID, groupAdminUserID, groupForSetupKeys)
 	_ = am.CreateGroup(context.Background(), accountID, groupAdminUserID, groupForUsers)
 	_ = am.CreateGroup(context.Background(), accountID, groupAdminUserID, groupForIntegration)
+	_ = am.CreateGroup(context.Background(), accountID, groupAdminUserID, groupForAgentNetworkPolicy)
+
+	agentNetworkPolicy := &agentNetworkTypes.Policy{
+		ID:           "example agent network policy",
+		AccountID:    accountID,
+		Name:         "Example agent network policy",
+		Enabled:      true,
+		SourceGroups: []string{groupForAgentNetworkPolicy.ID},
+	}
+	if err := am.Store.SaveAgentNetworkPolicy(context.Background(), agentNetworkPolicy); err != nil {
+		return nil, nil, err
+	}
 
 	acc, err := am.Store.GetAccount(context.Background(), account.Id)
 	if err != nil {

management/server/types/account.go

@@ -1707,14 +1707,34 @@ func (a *Account) injectPrivateServicePolicies(svc *service.Service, proxyPeers
 	if len(proxyPeers) == 0 {
 		return
 	}
+	// A service's AccessGroups can name groups that no longer exist — persisted
+	// services and the agent-network synthesiser both carry the ids verbatim from
+	// their own state. An unresolvable source authorises nothing, so drop it here
+	// rather than let the network-map assembly resolve it to a nil group.
+	sources := a.existingGroupIDs(svc.AccessGroups)
+	if len(sources) == 0 {
+		return
+	}
 	for _, proxyPeer := range proxyPeers {
-		a.Policies = append(a.Policies, a.createPrivateServicePolicy(svc, proxyPeer))
+		a.Policies = append(a.Policies, a.createPrivateServicePolicy(svc, proxyPeer, sources))
 	}
 }
 
-func (a *Account) createPrivateServicePolicy(svc *service.Service, proxyPeer *nbpeer.Peer) *Policy {
+// existingGroupIDs returns the subset of groupIDs that resolve to a group in the account,
+// preserving the input order.
+func (a *Account) existingGroupIDs(groupIDs []string) []string {
+	out := make([]string, 0, len(groupIDs))
+	for _, groupID := range groupIDs {
+		if _, ok := a.Groups[groupID]; ok {
+			out = append(out, groupID)
+		}
+	}
+	return out
+}
+
+func (a *Account) createPrivateServicePolicy(svc *service.Service, proxyPeer *nbpeer.Peer, accessGroups []string) *Policy {
 	policyID := fmt.Sprintf("private-access-%s-%s", svc.ID, proxyPeer.ID)
-	sources := append([]string(nil), svc.AccessGroups...)
+	sources := append([]string(nil), accessGroups...)
 	return &Policy{
 		ID:      policyID,
 		Name:    fmt.Sprintf("Private Access to %s", svc.Name),