Create method to find currently connected network interface

Create method to find currently connected network interface

sssd_test_framework/utils/tools.py

@@ -515,6 +515,46 @@ def grep(self, pattern: str, paths: str | list[str], args: list[str] | None = No
 
         return command.rc == 0
 
+    def connected_interface(self) -> str:
+        """
+        Test to retrieve and validate the default network interface from the system's routing table.
+
+        This test executes the `ip route show default` command on the host and parses the output
+        using `jc.parse` to extract routing information. It ensures the output is in the expected format,
+        validates the presence of a single default interface, and extracts the interface name.
+
+        Raises:
+            ValueError: If the output from `jc.parse` is not in the expected format (a list of dictionaries),
+                       if there is no default interface or multiple default interfaces are found,
+                       or if the default interface is not set.
+
+        Returns:
+            str: The name of the default network interface.
+
+        Example:
+            >>> client.tools.connected_interface()
+            eth0
+        """
+        result = self.host.conn.exec(["ip", "route", "show", "default"])
+        output = jc.parse("ip_route", result.stdout)
+
+        # Ensure output is a list
+        if isinstance(output, dict):
+            output = [output]  # Convert single dictionary to a list of one dictionary
+        elif not isinstance(output, list):
+            raise ValueError("Unexpected output format from jc.parse")
+
+        # Validate the output
+        if not output or len(output) != 1:
+            raise ValueError("Unexpected number of default interfaces")
+
+        # Extract the interface
+        interface = output[0].get("dev")
+        if not interface:
+            raise ValueError("Default interface is not set")
+
+        return interface
+
     def tcpdump(self, pcap_path: str, args: list[Any] | None = None) -> SSHKillableProcess:
         """
         Run tcpdump. The packets are captured in ``pcap_path``.