Merge "Wait for iperf3 server before starting client POD"

tobiko/podified/_openshift.py

@@ -764,8 +764,12 @@ def start_iperf3(
         **kwargs):  # noqa; pylint: disable=W0613
 
     if iperf3_server_ssh_client:
-        iperf3.start_iperf3_server(
-            port, protocol, iperf3_server_ssh_client)
+        # Wait until the server is listening before starting the client
+        # POD. Otherwise iperf3 exits with "Connection refused" and the
+        # POD (restartPolicy: Never) goes to Error/Failed.
+        iperf3.ensure_iperf3_server(
+            port=port, protocol=protocol,
+            ssh_client=iperf3_server_ssh_client)
 
     parameters = iperf3.iperf3_client_parameters(
         address=address, bitrate=bitrate,

tobiko/shell/iperf3/__init__.py

@@ -29,6 +29,7 @@ get_iperf3_logs_filepath = _execute.get_iperf3_logs_filepath
 iperf3_client_alive = _execute.iperf3_client_alive
 stop_iperf3_client = _execute.stop_iperf3_client
 start_iperf3_server = _execute.start_iperf3_server
+ensure_iperf3_server = _execute.ensure_iperf3_server
 parse_json_stream_output = _execute.parse_json_stream_output
 
 get_iperf3_client_command = _interface.get_iperf3_client_command

tobiko/shell/iperf3/_execute.py

@@ -140,22 +140,9 @@ def execute_iperf3_client_in_background(
     # failure in the previous run, it may report that is still "busy" thus
     # iperf3 client will not start properly
     if iperf3_server_ssh_client:
-        _stop_iperf3_server(
+        ensure_iperf3_server(
             port=port, protocol=protocol,
             ssh_client=iperf3_server_ssh_client)
-        start_iperf3_server(
-            port=port, protocol=protocol,
-            ssh_client=iperf3_server_ssh_client)
-
-        # if iperf3 server does not start properly, fail the test
-        for attempt in tobiko.retry(count=5, sleep_time=.5):
-            if _iperf3_server_alive(
-                    port=port, protocol=protocol,
-                    ssh_client=iperf3_server_ssh_client):
-                break
-            elif attempt.is_last:
-                tobiko.fail('iperf3 server did not start properly '
-                            f'on the server {iperf3_server_ssh_client}')
 
     # Now, finally iperf3 client should be ready to start
     execute_iperf3_client(
@@ -334,6 +321,29 @@ def start_iperf3_server(
     process.execute()
 
 
+def ensure_iperf3_server(
+        port: typing.Union[int, None],
+        protocol: typing.Union[str, None],
+        ssh_client: ssh.SSHClientType):
+    """Stop any existing server, start a fresh one, wait until it is alive.
+
+    Used by both the SSH-backed and pod-backed iperf3 client paths so the
+    client does not race ahead of the server listen socket (connection
+    refused).
+    """
+    _stop_iperf3_server(
+        port=port, protocol=protocol, ssh_client=ssh_client)
+    start_iperf3_server(
+        port=port, protocol=protocol, ssh_client=ssh_client)
+    for attempt in tobiko.retry(count=5, sleep_time=.5):
+        if _iperf3_server_alive(
+                port=port, protocol=protocol, ssh_client=ssh_client):
+            return
+        elif attempt.is_last:
+            tobiko.fail('iperf3 server did not start properly '
+                        f'on the server {ssh_client}')
+
+
 def _iperf3_server_alive(
         port: typing.Union[int, None],
         protocol: typing.Union[str, None],