feat(ssh-tunnelling): Setup SSH Tunneling Commands for Database Connections (#21912)

Co-authored-by: Antonio Rivero Martinez <38889534+Antonio-RiveroMartnez@users.noreply.github.com>
Co-authored-by: Elizabeth Thompson <eschutho@gmail.com>

superset/extensions/ssh.py

@@ -0,0 +1,88 @@
+# Licensed to the Apache Software Foundation (ASF) under one
+# or more contributor license agreements.  See the NOTICE file
+# distributed with this work for additional information
+# regarding copyright ownership.  The ASF licenses this file
+# to you under the Apache License, Version 2.0 (the
+# "License"); you may not use this file except in compliance
+# with the License.  You may obtain a copy of the License at
+#
+#   http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing,
+# software distributed under the License is distributed on an
+# "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+# KIND, either express or implied.  See the License for the
+# specific language governing permissions and limitations
+# under the License.
+
+import importlib
+from typing import TYPE_CHECKING
+
+from flask import Flask
+from sshtunnel import open_tunnel, SSHTunnelForwarder
+
+from superset.databases.utils import make_url_safe
+
+if TYPE_CHECKING:
+    from superset.databases.ssh_tunnel.models import SSHTunnel
+
+
+class SSHManager:
+    def __init__(self, app: Flask) -> None:
+        super().__init__()
+        self.local_bind_address = app.config["SSH_TUNNEL_LOCAL_BIND_ADDRESS"]
+
+    def build_sqla_url(  # pylint: disable=no-self-use
+        self, sqlalchemy_url: str, server: SSHTunnelForwarder
+    ) -> str:
+        # override any ssh tunnel configuration object
+        url = make_url_safe(sqlalchemy_url)
+        return url.set(
+            host=server.local_bind_address[0],
+            port=server.local_bind_port,
+        )
+
+    def create_tunnel(
+        self,
+        ssh_tunnel: "SSHTunnel",
+        sqlalchemy_database_uri: str,
+    ) -> SSHTunnelForwarder:
+        url = make_url_safe(sqlalchemy_database_uri)
+        params = {
+            "ssh_address_or_host": ssh_tunnel.server_address,
+            "ssh_port": ssh_tunnel.server_port,
+            "ssh_username": ssh_tunnel.username,
+            "remote_bind_address": (url.host, url.port),  # bind_port, bind_host
+            "local_bind_address": (self.local_bind_address,),
+        }
+
+        if ssh_tunnel.password:
+            params["ssh_password"] = ssh_tunnel.password
+        elif ssh_tunnel.private_key:
+            params["private_key"] = ssh_tunnel.private_key
+            params["private_key_password"] = ssh_tunnel.private_key_password
+
+        return open_tunnel(**params)
+
+
+class SSHManagerFactory:
+    def __init__(self) -> None:
+        self._ssh_manager = None
+
+    def init_app(self, app: Flask) -> None:
+        ssh_manager_fqclass = app.config["SSH_TUNNEL_MANAGER_CLASS"]
+        ssh_manager_classname = ssh_manager_fqclass[
+            ssh_manager_fqclass.rfind(".") + 1 :
+        ]
+        ssh_manager_module_name = ssh_manager_fqclass[
+            0 : ssh_manager_fqclass.rfind(".")
+        ]
+        ssh_manager_class = getattr(
+            importlib.import_module(ssh_manager_module_name), ssh_manager_classname
+        )
+
+        self._ssh_manager = ssh_manager_class(app)
+
+    @property
+    def instance(self) -> SSHManager:
+        return self._ssh_manager  # type: ignore