Kristoffer Dalby 83769ba715
Replace database locks with transactions (#1701)
This commits removes the locks used to guard data integrity for the
database and replaces them with Transactions, turns out that SQL had
a way to deal with this all along.

This reduces the complexity we had with multiple locks that might stack
or recurse (database, nofitifer, mapper). All notifications and state
updates are now triggered _after_ a database change.


Signed-off-by: Kristoffer Dalby <kristoffer@tailscale.com>
2024-02-08 17:28:19 +01:00

199 lines
4.4 KiB
Go

package db
import (
"errors"
"github.com/juanfont/headscale/hscontrol/types"
"github.com/juanfont/headscale/hscontrol/util"
"github.com/rs/zerolog/log"
"gorm.io/gorm"
)
var (
ErrUserExists = errors.New("user already exists")
ErrUserNotFound = errors.New("user not found")
ErrUserStillHasNodes = errors.New("user not empty: node(s) found")
)
func (hsdb *HSDatabase) CreateUser(name string) (*types.User, error) {
return Write(hsdb.DB, func(tx *gorm.DB) (*types.User, error) {
return CreateUser(tx, name)
})
}
// CreateUser creates a new User. Returns error if could not be created
// or another user already exists.
func CreateUser(tx *gorm.DB, name string) (*types.User, error) {
err := util.CheckForFQDNRules(name)
if err != nil {
return nil, err
}
user := types.User{}
if err := tx.Where("name = ?", name).First(&user).Error; err == nil {
return nil, ErrUserExists
}
user.Name = name
if err := tx.Create(&user).Error; err != nil {
log.Error().
Str("func", "CreateUser").
Err(err).
Msg("Could not create row")
return nil, err
}
return &user, nil
}
func (hsdb *HSDatabase) DestroyUser(name string) error {
return hsdb.Write(func(tx *gorm.DB) error {
return DestroyUser(tx, name)
})
}
// DestroyUser destroys a User. Returns error if the User does
// not exist or if there are nodes associated with it.
func DestroyUser(tx *gorm.DB, name string) error {
user, err := GetUser(tx, name)
if err != nil {
return ErrUserNotFound
}
nodes, err := ListNodesByUser(tx, name)
if err != nil {
return err
}
if len(nodes) > 0 {
return ErrUserStillHasNodes
}
keys, err := ListPreAuthKeys(tx, name)
if err != nil {
return err
}
for _, key := range keys {
err = DestroyPreAuthKey(tx, key)
if err != nil {
return err
}
}
if result := tx.Unscoped().Delete(&user); result.Error != nil {
return result.Error
}
return nil
}
func (hsdb *HSDatabase) RenameUser(oldName, newName string) error {
return hsdb.Write(func(tx *gorm.DB) error {
return RenameUser(tx, oldName, newName)
})
}
// RenameUser renames a User. Returns error if the User does
// not exist or if another User exists with the new name.
func RenameUser(tx *gorm.DB, oldName, newName string) error {
var err error
oldUser, err := GetUser(tx, oldName)
if err != nil {
return err
}
err = util.CheckForFQDNRules(newName)
if err != nil {
return err
}
_, err = GetUser(tx, newName)
if err == nil {
return ErrUserExists
}
if !errors.Is(err, ErrUserNotFound) {
return err
}
oldUser.Name = newName
if result := tx.Save(&oldUser); result.Error != nil {
return result.Error
}
return nil
}
func (hsdb *HSDatabase) GetUser(name string) (*types.User, error) {
return Read(hsdb.DB, func(rx *gorm.DB) (*types.User, error) {
return GetUser(rx, name)
})
}
func GetUser(tx *gorm.DB, name string) (*types.User, error) {
user := types.User{}
if result := tx.First(&user, "name = ?", name); errors.Is(
result.Error,
gorm.ErrRecordNotFound,
) {
return nil, ErrUserNotFound
}
return &user, nil
}
func (hsdb *HSDatabase) ListUsers() ([]types.User, error) {
return Read(hsdb.DB, func(rx *gorm.DB) ([]types.User, error) {
return ListUsers(rx)
})
}
// ListUsers gets all the existing users.
func ListUsers(tx *gorm.DB) ([]types.User, error) {
users := []types.User{}
if err := tx.Find(&users).Error; err != nil {
return nil, err
}
return users, nil
}
// ListNodesByUser gets all the nodes in a given user.
func ListNodesByUser(tx *gorm.DB, name string) (types.Nodes, error) {
err := util.CheckForFQDNRules(name)
if err != nil {
return nil, err
}
user, err := GetUser(tx, name)
if err != nil {
return nil, err
}
nodes := types.Nodes{}
if err := tx.Preload("AuthKey").Preload("AuthKey.User").Preload("User").Where(&types.Node{UserID: user.ID}).Find(&nodes).Error; err != nil {
return nil, err
}
return nodes, nil
}
func (hsdb *HSDatabase) AssignNodeToUser(node *types.Node, username string) error {
return hsdb.Write(func(tx *gorm.DB) error {
return AssignNodeToUser(tx, node, username)
})
}
// AssignNodeToUser assigns a Node to a user.
func AssignNodeToUser(tx *gorm.DB, node *types.Node, username string) error {
err := util.CheckForFQDNRules(username)
if err != nil {
return err
}
user, err := GetUser(tx, username)
if err != nil {
return err
}
node.User = *user
if result := tx.Save(&node); result.Error != nil {
return result.Error
}
return nil
}