testscript: improve ssh() network diagnosis and logging

On-behalf-of: SAP philipp.schuster@sap.com
Signed-off-by: Philipp Schuster <philipp.schuster@cyberus-technology.de>

Author: phip1611

tests/testscript.py

@@ -2026,9 +2026,19 @@ def ssh(machine: Machine, cmd, user="root", password="root", ip="192.168.1.2"):
     :param ip: SSH host to log into
     :return: status and output
     """
+
+    # Sometimes we experienced test runs where the host lost IPs. We therefore
+    # check that early and always for better debuggability.
+    assert_ip_in_local_192_168_net24(machine, ip)
+
+    # Check VM is pingable
+    machine.succeed(f"ping -c 1 -W 1 {ip}")
+
+    # And here we check if the guest also responds via SSH.
     status, out = machine.execute(
         f"sshpass -p {password} ssh -o UserKnownHostsFile=/dev/null -o StrictHostKeyChecking=no {user}@{ip} {cmd}"
     )
+    # TODO, this could be refactored to raise an exception on error
     return status, out