improvement: don't save tailnet and don't signal change when nothing is updated

internal/domain/acl.go

@@ -8,6 +8,7 @@ import (
 	"gorm.io/gorm"
 	"gorm.io/gorm/schema"
 	"net/netip"
+	"reflect"
 	"slices"
 	"sort"
 	"strconv"
@@ -66,6 +67,16 @@ type Grant struct {
 	App tailcfg.PeerCapMap       `json:"app"`
 }
 
+func (a *ACLPolicy) Equal(x *ACLPolicy) bool {
+	if a == nil && x == nil {
+		return true
+	}
+	if (a == nil) != (x == nil) {
+		return false
+	}
+	return reflect.DeepEqual(a, x)
+}
+
 func (a ACLPolicy) FindAutoApprovedIPs(routableIPs []netip.Prefix, tags []string, u *User) []netip.Prefix {
 	if a.AutoApprovers == nil || len(routableIPs) == 0 {
 		return nil

internal/domain/dns_config.go

@@ -6,6 +6,7 @@ import (
 	"fmt"
 	"gorm.io/gorm"
 	"gorm.io/gorm/schema"
+	"reflect"
 )
 
 type DNSConfig struct {
@@ -17,6 +18,22 @@ type DNSConfig struct {
 	SearchDomains     []string            `json:"search_domains"`
 }
 
+func (i *DNSConfig) Equal(x *DNSConfig) bool {
+	if i == nil && x == nil {
+		return true
+	}
+	if (i == nil) != (x == nil) {
+		return false
+	}
+
+	return i.MagicDNS == x.MagicDNS &&
+		i.HttpsCertsEnabled == x.HttpsCertsEnabled &&
+		i.OverrideLocalDNS == x.OverrideLocalDNS &&
+		reflect.DeepEqual(i.Nameservers, x.Nameservers) &&
+		reflect.DeepEqual(i.Routes, x.Routes) &&
+		reflect.DeepEqual(i.SearchDomains, x.SearchDomains)
+}
+
 func (i *DNSConfig) Scan(destination interface{}) error {
 	switch value := destination.(type) {
 	case []byte:

internal/domain/iam.go

@@ -9,6 +9,7 @@ import (
 	"github.com/mitchellh/pointerstructure"
 	"gorm.io/gorm"
 	"gorm.io/gorm/schema"
+	"reflect"
 )
 
 type Identity struct {
@@ -68,6 +69,16 @@ func (i *IAMPolicy) EvaluatePolicy(identity *Identity) (bool, error) {
 	return false, nil
 }
 
+func (i *IAMPolicy) Equal(x *IAMPolicy) bool {
+	if i == nil && x == nil {
+		return true
+	}
+	if (i == nil) != (x == nil) {
+		return false
+	}
+	return reflect.DeepEqual(i, x)
+}
+
 func (i *IAMPolicy) Scan(destination interface{}) error {
 	switch value := destination.(type) {
 	case []byte:

internal/service/acl.go

@@ -45,12 +45,17 @@ func (s *Service) SetACLPolicy(ctx context.Context, req *connect.Request[api.Set
 		return nil, connect.NewError(connect.CodeNotFound, fmt.Errorf("tailnet does not exist"))
 	}
 
-	var policy domain.ACLPolicy
-	if err := mapping.CopyViaJson(req.Msg.Policy, &policy); err != nil {
+	oldPolicy := tailnet.ACLPolicy
+	var newPolicy domain.ACLPolicy
+	if err := mapping.CopyViaJson(req.Msg.Policy, &newPolicy); err != nil {
 		return nil, logError(err)
 	}
 
-	tailnet.ACLPolicy = policy
+	if oldPolicy.Equal(&newPolicy) {
+		return connect.NewResponse(&api.SetACLPolicyResponse{}), nil
+	}
+
+	tailnet.ACLPolicy = newPolicy
 	if err := s.repository.SaveTailnet(ctx, tailnet); err != nil {
 		return nil, logError(err)
 	}

internal/service/dns.go

@@ -54,23 +54,21 @@ func (s *Service) SetDNSConfig(ctx context.Context, req *connect.Request[api.Set
 		return nil, connect.NewError(connect.CodeNotFound, fmt.Errorf("tailnet not found"))
 	}
 
-	tailnet.DNSConfig = apiDNSConfigToDomainDNSConfig(req.Msg.Config)
+	oldConfig := tailnet.DNSConfig
+	newConfig := apiDNSConfigToDomainDNSConfig(req.Msg.Config)
 
+	if oldConfig.Equal(&newConfig) {
+		return connect.NewResponse(&api.SetDNSConfigResponse{Config: domainDNSConfigToApiDNSConfig(tailnet)}), nil
+	}
+
+	tailnet.DNSConfig = newConfig
 	if err := s.repository.SaveTailnet(ctx, tailnet); err != nil {
 		return nil, logError(err)
 	}
 
 	s.sessionManager.NotifyAll(tailnet.ID)
 
-	resp := &api.SetDNSConfigResponse{
-		Config: domainDNSConfigToApiDNSConfig(tailnet),
-	}
-
-	if dnsConfig.HttpsCerts && s.dnsProvider == nil {
-		resp.Message = "# HTTPS Certs cannot be enabled because a DNS provider is not properly configured"
-	}
-
-	return connect.NewResponse(resp), nil
+	return connect.NewResponse(&api.SetDNSConfigResponse{Config: domainDNSConfigToApiDNSConfig(tailnet)}), nil
 }
 
 func domainRoutesToApiRoutes(routes map[string][]string) map[string]*api.Routes {

internal/service/iam.go

@@ -50,13 +50,20 @@ func (s *Service) SetIAMPolicy(ctx context.Context, req *connect.Request[api.Set
 		return nil, connect.NewError(connect.CodeInvalidArgument, fmt.Errorf("invalid iam policy: %w", err))
 	}
 
-	tailnet.IAMPolicy = domain.IAMPolicy{
+	oldPolicy := tailnet.IAMPolicy
+	newPolicy := domain.IAMPolicy{
 		Subs:    req.Msg.Policy.Subs,
 		Emails:  req.Msg.Policy.Emails,
 		Filters: req.Msg.Policy.Filters,
 		Roles:   apiRolesMapToDomainRolesMap(req.Msg.Policy.Roles),
 	}
 
+	if oldPolicy.Equal(&newPolicy) {
+		return connect.NewResponse(&api.SetIAMPolicyResponse{}), nil
+	}
+
+	tailnet.IAMPolicy = newPolicy
+
 	if err := s.repository.SaveTailnet(ctx, tailnet); err != nil {
 		return nil, logError(err)
 	}