Add mysql.get_version_string() convenience function

rattail_fabric2/mysql.py

@@ -24,6 +24,8 @@
 Fabric Library for MySQL
 """
 
+import re
+
 from rattail_fabric2 import apt, make_deploy, sed
 
 
@@ -38,6 +40,18 @@ def install(c):
     apt.install(c, 'default-mysql-server')
 
 
+def get_version_string(c):
+    """
+    Fetch the version of MySQL running on the target system
+    """
+    result = c.sudo('mysql --version', warn=True)
+    if not result.failed:
+        # match = re.match(r'^mysql .*?(\d+\.\d+\.\d+)-MariaDB', result.stdout)
+        match = re.match(r'^mysql +Ver +(\d+\.\d+\.\d+)-.*', result.stdout)
+        if match:
+            return match.group(1)
+
+
 def set_bind_address(c, address):
     """
     Configure the 'bind-address' setting with the given value.