fix: Set default port attribute for Database classes

db.default_port wil be available as a class attribute to hold defaults
for DB types.

Usage: frappe.conf.db_port or frappe.db.default_port
Why: I couldn't run the mariadb command because the defaults aren't set
for my system. server is remote / containerized. Setting port in
equivalent mysql command fixes this.

frappe/commands/utils.py

@@ -523,22 +523,24 @@ def postgres(context):
 
 
 def _mariadb():
+	from frappe.database.mariadb.database import MariaDBDatabase
+
 	mysql = find_executable("mysql")
-	os.execv(
+	command = [
 		mysql,
-		[
-			mysql,
-			"-u",
-			frappe.conf.db_name,
-			"-p" + frappe.conf.db_password,
-			frappe.conf.db_name,
-			"-h",
-			frappe.conf.db_host or "localhost",
-			"--pager=less -SFX",
-			"--safe-updates",
-			"-A",
-		],
-	)
+		"--port",
+		frappe.conf.db_port or MariaDBDatabase.default_port,
+		"-u",
+		frappe.conf.db_name,
+		f"-p{frappe.conf.db_password}",
+		frappe.conf.db_name,
+		"-h",
+		frappe.conf.db_host or "localhost",
+		"--pager=less -SFX",
+		"--safe-updates",
+		"-A",
+	]
+	os.execv(mysql, command)
 
 
 def _psql():

frappe/database/mariadb/database.py

@@ -143,6 +143,7 @@ class MariaDBDatabase(MariaDBConnectionUtil, MariaDBExceptionUtil, Database):
 		FIELD_TYPE.DATETIME: get_datetime,
 		UnicodeWithAttrs: escape_string,
 	}
+	default_port = "3306"
 
 	def setup_type_map(self):
 		self.db_type = "mariadb"

frappe/database/postgres/database.py

@@ -108,6 +108,7 @@ class PostgresDatabase(PostgresExceptionUtil, Database):
 	# to the next non-cached value hence not using cache in postgres.
 	# ref: https://stackoverflow.com/questions/21356375/postgres-9-0-4-sequence-skipping-numbers
 	SEQUENCE_CACHE = 0
+	default_port = "5432"
 
 	def setup_type_map(self):
 		self.db_type = "postgres"

frappe/tests/test_db.py

@@ -97,7 +97,6 @@ class TestDB(unittest.TestCase):
 		)
 
 	def test_get_value_limits(self):
-
 		# check both dict and list style filters
 		filters = [{"enabled": 1}, [["enabled", "=", 1]]]
 		for filter in filters:

frappe/utils/backups.py

@@ -73,11 +73,7 @@ class BackupGenerator:
 		if not self.db_type:
 			self.db_type = "mariadb"
 
-		if not self.db_port:
-			if self.db_type == "mariadb":
-				self.db_port = 3306
-			if self.db_type == "postgres":
-				self.db_port = 5432
+		self.db_port = self.db_port or frappe.db.default_port
 
 		site = frappe.local.site or frappe.generate_hash(length=8)
 		self.site_slug = site.replace(".", "_")