[1/1] support/testing: add mariadb runtime test

diff --git a/DEVELOPERS b/DEVELOPERS
index 0d12c3abcb..cf6e4c51d4 100644
--- a/DEVELOPERS
+++ b/DEVELOPERS
@@ -1814,6 +1814,7 @@  F:	support/testing/tests/package/test_lzip.py
 F:	support/testing/tests/package/test_lsof.py
 F:	support/testing/tests/package/test_lz4.py
 F:	support/testing/tests/package/test_lzop.py
+F:	support/testing/tests/package/test_mariadb.py
 F:	support/testing/tests/package/test_mdadm.py
 F:	support/testing/tests/package/test_mdadm/
 F:	support/testing/tests/package/test_micropython.py
diff --git a/support/testing/tests/package/test_mariadb.py b/support/testing/tests/package/test_mariadb.py
new file mode 100644
index 0000000000..523f075db1
--- /dev/null
+++ b/support/testing/tests/package/test_mariadb.py
@@ -0,0 +1,195 @@ 
+import os
+
+import infra.basetest
+
+
+class TestMariaDB(infra.basetest.BRTest):
+    # We use a specific configuration for:
+    # - using Aarch64, to have more than 256MB memory,
+    # - to have an ext4 rootfs image exposed as a virtio storage
+    #   (rather than cpio initrd). This will save some memory, as the
+    #   rootfs image is big.
+    config = \
+        """
+        BR2_aarch64=y
+        BR2_TOOLCHAIN_EXTERNAL=y
+        BR2_TARGET_GENERIC_GETTY_PORT="ttyAMA0"
+        BR2_LINUX_KERNEL=y
+        BR2_LINUX_KERNEL_CUSTOM_VERSION=y
+        BR2_LINUX_KERNEL_CUSTOM_VERSION_VALUE="6.1.78"
+        BR2_LINUX_KERNEL_USE_CUSTOM_CONFIG=y
+        BR2_LINUX_KERNEL_CUSTOM_CONFIG_FILE="board/qemu/aarch64-virt/linux.config"
+        BR2_PACKAGE_MYSQL=y
+        BR2_PACKAGE_MARIADB=y
+        BR2_PACKAGE_MARIADB_SERVER=y
+        BR2_TARGET_ROOTFS_EXT2=y
+        BR2_TARGET_ROOTFS_EXT2_4=y
+        BR2_TARGET_ROOTFS_EXT2_SIZE="512M"
+        # BR2_TARGET_ROOTFS_TAR is not set
+        """
+
+    # Configuration for the test
+    db_adminuser = "root"
+    db_admin = "mysql"
+    db_user = "br_user"
+    db_name = "br_database"
+    backup_file = "dump.sql"
+
+    def run_user_db_query(self, user, database, query, opts=None):
+        cmd = f"mariadb --user={user} --database={database}"
+        cmd += f' --execute="{query}"'
+        if opts is not None:
+            cmd += " " + opts
+        self.assertRunOk(cmd)
+
+    def run_admin_sql_query(self, query, opts=None):
+        self.run_user_db_query(self.db_adminuser, self.db_admin, query, opts)
+
+    def run_sql_query(self, query, opts=None):
+        self.run_user_db_query(self.db_user, self.db_name, query, opts)
+
+    def cleanup_database(self):
+        # This cleanup is useful when run-test -k is used. It makes
+        # this test idempotent. Since the drive storage is preserved
+        # between reboots, this cleanup will prevent errors during the
+        # user/db creation.
+
+        # Drop the test database, if it exists.
+        sql_query = f"DROP USER IF EXISTS {self.db_user}@localhost;"
+        self.run_admin_sql_query(sql_query)
+
+        # Drop the test user, if it exists.
+        sql_query = f"DROP DATABASE IF EXISTS {self.db_name};"
+        self.run_admin_sql_query(sql_query)
+
+    def create_tables(self):
+        sql_query = "CREATE TABLE fruits ("
+        sql_query += "id integer PRIMARY KEY, name varchar(16) NOT NULL);"
+        self.run_sql_query(sql_query)
+
+        sql_query = "CREATE TABLE colors ("
+        sql_query += "id integer PRIMARY KEY, name varchar(16) NOT NULL);"
+        self.run_sql_query(sql_query)
+
+        sql_query = "CREATE TABLE fruit_colors ("
+        sql_query += "fruit_id integer REFERENCES fruits(id), "
+        sql_query += "color_id integer REFERENCES colors(id), "
+        sql_query += "UNIQUE (fruit_id, color_id));"
+        self.run_sql_query(sql_query)
+
+    def insert_data(self):
+        fruits = ["Banana", "Blueberry", "Orange", "Raspberry"]
+        fruit_id = 1
+        for fruit in fruits:
+            sql_query = "INSERT INTO fruits (id, name) "
+            sql_query += f"VALUES ({fruit_id}, '{fruit}');"
+            self.run_sql_query(sql_query)
+            fruit_id += 1
+
+        colors = ["Blue", "Orange", "Red", "Yellow"]
+        color_id = 1
+        for color in colors:
+            sql_query = "INSERT INTO colors (id, name) "
+            sql_query += f"VALUES ({color_id}, '{color}');"
+            self.run_sql_query(sql_query)
+            color_id += 1
+
+        fruit_colors = [(1, 4), (2, 1), (3, 2), (4, 3)]
+        for fruit_color in fruit_colors:
+            fruit_id, color_id = fruit_color
+            sql_query = "INSERT INTO fruit_colors (fruit_id, color_id) "
+            sql_query += f"VALUES ({fruit_id}, {color_id});"
+            self.run_sql_query(sql_query)
+
+    def query_database(self):
+        sql_query = "SELECT "
+        sql_query += "fruits.name AS fruit, colors.name AS color "
+        sql_query += "FROM fruits, colors, fruit_colors "
+        sql_query += "WHERE fruits.id = fruit_colors.fruit_id "
+        sql_query += "AND colors.id = fruit_colors.color_id "
+        sql_query += "ORDER BY fruit;"
+        self.run_sql_query(sql_query)
+
+    def test_run(self):
+        drive = os.path.join(self.builddir, "images", "rootfs.ext4")
+        kern = os.path.join(self.builddir, "images", "Image")
+        self.emulator.boot(arch="aarch64",
+                           kernel=kern,
+                           kernel_cmdline=["root=/dev/vda console=ttyAMA0"],
+                           options=["-M", "virt",
+                                    "-cpu", "cortex-a57",
+                                    "-m", "2G",
+                                    "-smp", "2",
+                                    "-drive", f"file={drive},if=virtio,format=raw"])
+        self.emulator.login()
+
+        # Check the server binary can execute.
+        self.assertRunOk("mariadbd --version")
+
+        # Check the client binary can execute.
+        self.assertRunOk("mariadb --version")
+
+        # Check the server is ready.
+        self.assertRunOk("mariadb-admin ping")
+
+        # Query the server version from the client.
+        sql_query = "SELECT version();"
+        self.run_admin_sql_query(sql_query, opts="-N -s")
+
+        self.cleanup_database()
+
+        # Create a new user.
+        sql_query = f"CREATE USER {self.db_user}@localhost;"
+        self.run_admin_sql_query(sql_query)
+
+        # Create a new database.
+        sql_query = f"CREATE DATABASE {self.db_name}"
+        sql_query += " COMMENT = 'Test Database for Buildroot Test';"
+        self.run_admin_sql_query(sql_query)
+
+        # Grant all permission on this new database to our test user.
+        sql_query = "GRANT ALL PRIVILEGES"
+        sql_query += f" ON {self.db_name}.*"
+        sql_query += f" TO {self.db_user}@localhost;"
+        self.run_admin_sql_query(sql_query)
+
+        self.create_tables()
+
+        self.insert_data()
+
+        self.query_database()
+
+        # Update a table.
+        sql_query = "UPDATE fruits SET name = 'Lemon' WHERE id = 1;"
+        self.run_sql_query(sql_query)
+
+        # Backup the test database.
+        cmd = f"mariadb-dump --user={self.db_user}"
+        cmd += f" {self.db_name} > {self.backup_file}"
+        self.assertRunOk(cmd)
+
+        # Drop all the tables.
+        sql_query = "DROP TABLE fruit_colors, fruits, colors;"
+        self.run_sql_query(sql_query)
+
+        # Query the server status.
+        self.assertRunOk("mariadb-admin status")
+
+        # Stop the server.
+        self.assertRunOk("/etc/init.d/S97mysqld stop")
+
+        # Check the server is stopped.
+        _, exit_code = self.emulator.run("mariadb-admin ping")
+        self.assertNotEqual(exit_code, 0)
+
+        # Restart the server.
+        self.assertRunOk("/etc/init.d/S97mysqld start")
+
+        # Restore the backup.
+        cmd = f"mariadb --user={self.db_user} --database={self.db_name}"
+        cmd += f" < {self.backup_file}"
+        self.assertRunOk(cmd)
+
+        # Query one last time our data, to check the backup
+        # restoration succeeded.
+        self.query_database()