fix constraints

Signed-off-by: Kristoffer Dalby <kristoffer@tailscale.com>

flake.nix

@@ -32,7 +32,7 @@
 
           # When updating go.mod or go.sum, a new sha will need to be calculated,
           # update this if you have a mismatch after doing a change to thos files.
-          vendorHash = "sha256-CMkYTRjmhvTTrB7JbLj0cj9VEyzpG0iUWXkaOagwYTk=";
+          vendorHash = "sha256-Qoqu2k4vvnbRFLmT/v8lI+HCEWqJsHFs8uZRfNmwQpo=";
 
           subPackages = ["cmd/headscale"];
 

hscontrol/db/db_test.go

@@ -1,6 +1,7 @@
 package db
 
 import (
+	"database/sql"
 	"fmt"
 	"io"
 	"net/netip"
@@ -16,6 +17,7 @@ import (
 	"github.com/juanfont/headscale/hscontrol/types"
 	"github.com/juanfont/headscale/hscontrol/util"
 	"github.com/stretchr/testify/assert"
+	"github.com/stretchr/testify/require"
 	"gorm.io/gorm"
 	"zgo.at/zcache/v2"
 )
@@ -256,3 +258,110 @@ func testCopyOfDatabase(src string) (string, error) {
 func emptyCache() *zcache.Cache[string, types.Node] {
 	return zcache.New[string, types.Node](time.Minute, time.Hour)
 }
+
+func TestConstraints(t *testing.T) {
+	tests := []struct {
+		name string
+		run  func(*testing.T, *gorm.DB)
+	}{
+		{
+			name: "no-duplicate-username-if-no-oidc",
+			run: func(t *testing.T, db *gorm.DB) {
+				_, err := CreateUser(db, "user1")
+				require.NoError(t, err)
+				_, err = CreateUser(db, "user1")
+				require.Error(t, err)
+				// assert.Contains(t, err.Error(), "UNIQUE constraint failed: users.username")
+				require.Contains(t, err.Error(), "user already exists")
+			},
+		},
+		{
+			name: "no-oidc-duplicate-username-and-id",
+			run: func(t *testing.T, db *gorm.DB) {
+				user := types.User{
+					Model: gorm.Model{ID: 1},
+					Name:  "user1",
+				}
+				user.ProviderIdentifier = sql.NullString{String: "http://test.com/user1", Valid: true}
+
+				err := db.Save(&user).Error
+				require.NoError(t, err)
+
+				user = types.User{
+					Model: gorm.Model{ID: 2},
+					Name:  "user1",
+				}
+				user.ProviderIdentifier = sql.NullString{String: "http://test.com/user1", Valid: true}
+
+				err = db.Save(&user).Error
+				require.Error(t, err)
+				require.Contains(t, err.Error(), "UNIQUE constraint failed: users.provider_identifier")
+			},
+		},
+		{
+			name: "no-oidc-duplicate-id",
+			run: func(t *testing.T, db *gorm.DB) {
+				user := types.User{
+					Model: gorm.Model{ID: 1},
+					Name:  "user1",
+				}
+				user.ProviderIdentifier = sql.NullString{String: "http://test.com/user1", Valid: true}
+
+				err := db.Save(&user).Error
+				require.NoError(t, err)
+
+				user = types.User{
+					Model: gorm.Model{ID: 2},
+					Name:  "user1.1",
+				}
+				user.ProviderIdentifier = sql.NullString{String: "http://test.com/user1", Valid: true}
+
+				err = db.Save(&user).Error
+				require.Error(t, err)
+				require.Contains(t, err.Error(), "UNIQUE constraint failed: users.provider_identifier")
+			},
+		},
+		{
+			name: "allow-duplicate-username-cli-then-oidc",
+			run: func(t *testing.T, db *gorm.DB) {
+				_, err := CreateUser(db, "user1") // Create CLI username
+				require.NoError(t, err)
+
+				user := types.User{
+					Name: "user1",
+				}
+				user.ProviderIdentifier.String = "http://test.com/user1"
+
+				err = db.Save(&user).Error
+				require.NoError(t, err)
+			},
+		},
+		{
+			name: "allow-duplicate-username-oidc-then-cli",
+			run: func(t *testing.T, db *gorm.DB) {
+				user := types.User{
+					Name: "user1",
+				}
+				user.ProviderIdentifier.String = "http://test.com/user1"
+
+				err := db.Save(&user).Error
+				require.NoError(t, err)
+
+				_, err = CreateUser(db, "user1") // Create CLI username
+				require.NoError(t, err)
+			},
+		},
+	}
+
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			db, err := newTestDB()
+			if err != nil {
+				t.Fatalf("creating database: %s", err)
+			}
+
+			tt.run(t, db.DB)
+		})
+
+	}
+}

hscontrol/db/users.go

@@ -28,11 +28,9 @@ func CreateUser(tx *gorm.DB, name string) (*types.User, error) {
 	if err != nil {
 		return nil, err
 	}
-	user := types.User{}
-	if err := tx.Where("name = ?", name).First(&user).Error; err == nil {
-		return nil, ErrUserExists
+	user := types.User{
+		Name: name,
 	}
-	user.Name = name
 	if err := tx.Create(&user).Error; err != nil {
 		return nil, fmt.Errorf("creating user: %w", err)
 	}
@@ -177,6 +175,10 @@ func (hsdb *HSDatabase) GetUserByName(name string) (*types.User, error) {
 		return nil, err
 	}
 
+	if len(users) == 0 {
+		return nil, ErrUserNotFound
+	}
+
 	if len(users) != 1 {
 		return nil, fmt.Errorf("expected exactly one user, found %d", len(users))
 	}

hscontrol/oidc.go

@@ -460,7 +460,7 @@ func (a *AuthProviderOIDC) createOrUpdateUserFromClaim(
 			// This is to prevent users that have already been migrated to the new OIDC format
 			// to be updated with the new OIDC identifier inexplicitly which might be the cause of an
 			// account takeover.
-			if user != nil && user.ProviderIdentifier != "" {
+			if user != nil && user.ProviderIdentifier.Valid {
 				log.Info().Str("username", claims.Username).Str("sub", claims.Sub).Msg("user found by username, but has provider identifier, creating new user.")
 				user = &types.User{}
 			}

hscontrol/types/users.go

@@ -2,6 +2,7 @@ package types
 
 import (
 	"cmp"
+	"database/sql"
 	"strconv"
 
 	v1 "github.com/juanfont/headscale/gen/go/headscale/v1"
@@ -26,7 +27,7 @@ type User struct {
 
 	// Username for the user, is used if email is empty
 	// Should not be used, please use Username().
-	Name string `gorm:"uniqueIndex:idx_name_provider_identifier,index"`
+	Name string `gorm:"uniqueIndex:idx_name_provider_identifier;index"`
 
 	// Typically the full name of the user
 	DisplayName string
@@ -38,7 +39,7 @@ type User struct {
 	// Unique identifier of the user from OIDC,
 	// comes from `sub` claim in the OIDC token
 	// and is used to lookup the user.
-	ProviderIdentifier string `gorm:"unique,index,uniqueIndex:idx_name_provider_identifier"`
+	ProviderIdentifier sql.NullString `gorm:"uniqueIndex:idx_name_provider_identifier;uniqueIndex:idx_provider_identifier"`
 
 	// Provider is the origin of the user account,
 	// same as RegistrationMethod, without authkey.
@@ -55,7 +56,7 @@ type User struct {
 // should be used throughout headscale, in information returned to the
 // user and the Policy engine.
 func (u *User) Username() string {
-	username := cmp.Or(u.Email, u.Name, u.ProviderIdentifier, strconv.FormatUint(uint64(u.ID), 10))
+	username := cmp.Or(u.Email, u.Name, u.ProviderIdentifier.String, strconv.FormatUint(uint64(u.ID), 10))
 
 	// TODO(kradalby): Wire up all of this for the future
 	// if !strings.Contains(username, "@") {
@@ -118,7 +119,7 @@ func (u *User) Proto() *v1.User {
 		CreatedAt:     timestamppb.New(u.CreatedAt),
 		DisplayName:   u.DisplayName,
 		Email:         u.Email,
-		ProviderId:    u.ProviderIdentifier,
+		ProviderId:    u.ProviderIdentifier.String,
 		Provider:      u.Provider,
 		ProfilePicUrl: u.ProfilePicURL,
 	}
@@ -145,7 +146,7 @@ func (c *OIDCClaims) Identifier() string {
 // FromClaim overrides a User from OIDC claims.
 // All fields will be updated, except for the ID.
 func (u *User) FromClaim(claims *OIDCClaims) {
-	u.ProviderIdentifier = claims.Identifier()
+	u.ProviderIdentifier = sql.NullString{String: claims.Identifier(), Valid: true}
 	u.DisplayName = claims.Name
 	if claims.EmailVerified {
 		u.Email = claims.Email

integration/auth_oidc_test.go

@@ -54,7 +54,7 @@ func TestOIDCAuthenticationPingAll(t *testing.T) {
 	scenario := AuthOIDCScenario{
 		Scenario: baseScenario,
 	}
-	defer scenario.ShutdownAssertNoPanics(t)
+	// defer scenario.ShutdownAssertNoPanics(t)
 
 	// Logins to MockOIDC is served by a queue with a strict order,
 	// if we use more than one node per user, the order of the logins