internal/component => internal/dis/component

internal/dis/component/sql/provision.go

@@ -0,0 +1,120 @@
+package sql
+
+import (
+	"errors"
+
+	"github.com/FAU-CDI/wisski-distillery/internal/models"
+	"github.com/FAU-CDI/wisski-distillery/pkg/errorx"
+	"github.com/FAU-CDI/wisski-distillery/pkg/sqle"
+)
+
+var errProvisionInvalidDatabaseParams = errors.New("Provision: Invalid parameters")
+var errProvisionInvalidGrant = errors.New("Provision: Grant failed")
+
+// Provision provisions sql-specific resource for the given instance
+func (sql *SQL) Provision(instance models.Instance, domain string) error {
+	return sql.CreateDatabase(instance.SqlDatabase, instance.SqlUsername, instance.SqlPassword)
+}
+
+// Purge purges sql-specific resources for the given instance
+func (sql *SQL) Purge(instance models.Instance, domain string) error {
+	return errorx.First(
+		sql.PurgeDatabase(instance.SqlDatabase),
+		sql.PurgeUser(instance.SqlUsername),
+	)
+}
+
+// CreateDatabase creates a new database with the given name.
+// It then generates a new user, with the name 'user' and the password 'password', that is then granted access to this database.
+//
+// Provision internally waits for the database to become available.
+func (sql *SQL) CreateDatabase(name, user, password string) error {
+
+	// NOTE(twiesing): We shouldn't use string concat to build sql queries.
+	// But the driver doesn't support using query params for this particular query.
+	// Apparently it's a "feature", see https://github.com/go-sql-driver/mysql/issues/398#issuecomment-169951763.
+
+	// quick and dirty check to make sure that all the names won't sql inject.
+	if !sqle.IsSafeDatabaseLiteral(name) || !sqle.IsSafeDatabaseSingleQuote(user) || !sqle.IsSafeDatabaseSingleQuote(password) {
+		return errProvisionInvalidDatabaseParams
+	}
+
+	// We use the sql shell here, because not only can we not use query params, but the driver outright rejects queries.
+	// Queries of the form "CREATE USER 'test'@'%' IDENTIFIED BY 'test'; FLUSH PRIVILEGES;" return error 1064 when using driver, but are fine with the shell.
+	// This should be fixed eventually, but I have no idea how.
+
+	if err := sql.unsafeWaitShell(); err != nil {
+		return err
+	}
+
+	query := "CREATE DATABASE `" + name + "`;" +
+		"CREATE USER '" + user + "'@'%' IDENTIFIED BY '" + password + "';" +
+		"GRANT ALL PRIVILEGES ON `" + name + "`.* TO `" + user + "`@`%`; FLUSH PRIVILEGES;"
+	if !sql.unsafeQueryShell(query) {
+		return errProvisionInvalidGrant
+	}
+
+	return nil
+}
+
+var errCreateSuperuserGrant = errors.New("CreateSuperUser: Grant failed")
+
+// CreateSuperuser createsa new user, with the name 'user' and the password 'password'.
+// It then grants this user superuser status in the database.
+//
+// CreateSuperuser internally waits for the database to become available.
+func (sql *SQL) CreateSuperuser(user, password string, allowExisting bool) error {
+	// NOTE(twiesing): This function unsafely uses the shell directly to create a superuser.
+	// This is for two reasons:
+	// (1) this is used during bootstraping
+	// (2) The underlying driver doesn't support "GRANT ALL PRIVILEGES"
+	// See also [sql.Provision].
+
+	if !sqle.IsSafeDatabaseSingleQuote(user) || !sqle.IsSafeDatabaseSingleQuote(password) {
+		return errProvisionInvalidDatabaseParams
+	}
+
+	if err := sql.unsafeWaitShell(); err != nil {
+		return err
+	}
+
+	var IfNotExists string
+	if allowExisting {
+		IfNotExists = "IF NOT EXISTS"
+	}
+
+	query := "CREATE USER " + IfNotExists + " '" + user + "'@'%' IDENTIFIED BY '" + password + "';" +
+		"GRANT ALL PRIVILEGES ON *.* TO '" + user + "'@'%' WITH GRANT OPTION; FLUSH PRIVILEGES;"
+	if !sql.unsafeQueryShell(query) {
+		return errCreateSuperuserGrant
+	}
+
+	return nil
+}
+
+var errPurgeUser = errors.New("PurgeUser: Failed to drop user")
+
+// SQLPurgeUser deletes the specified user from the database
+func (sql *SQL) PurgeUser(user string) error {
+	if !sqle.IsSafeDatabaseSingleQuote(user) {
+		return errPurgeUser
+	}
+
+	query := "DROP USER IF EXISTS '" + user + "'@'%';" +
+		"FLUSH PRIVILEGES;"
+	if !sql.unsafeQueryShell(query) {
+		return errPurgeUser
+	}
+
+	return nil
+}
+
+var errSQLPurgeDB = errors.New("unable to drop database: unsafe database name")
+
+// SQLPurgeDatabase deletes the specified db from the database
+func (sql *SQL) PurgeDatabase(db string) error {
+	if !sqle.IsSafeDatabaseLiteral(db) {
+		return errSQLPurgeDB
+	}
+	return sql.Exec("DROP DATABASE IF EXISTS `" + db + "`")
+}