[RFC PATCH 6/7] usertools/telemetry-watcher: add eth name shortcuts

[Bruce Richardson]

Since an expected main use of the script is to monitor ethdev packet
stats, provide a shortened form of parameters to make it easier to
monitor all ports on the system. Any stat starting with "eth." is taken
not as a direct command, but instead as a shortcut for getting the stats
for all ports on the system. For example: eth.ibytes shows the byte
counts for all ports.

Beyond that, provide a shortcut for ipackets and opackets as just rx and
tx respectively. Therefore, to monitor the output rate of an app, one
can use "dpdk-telemetry-watcher -dT eth.tx"

Signed-off-by: Bruce Richardson <bruce.richardson at intel.com>
---
 usertools/dpdk-telemetry-watcher.py | 49 ++++++++++++++++++++++++++++-
 1 file changed, 48 insertions(+), 1 deletion(-)

diff --git a/usertools/dpdk-telemetry-watcher.py b/usertools/dpdk-telemetry-watcher.py
index 59ec4c85b6..6beb67d29a 100755
--- a/usertools/dpdk-telemetry-watcher.py
+++ b/usertools/dpdk-telemetry-watcher.py
@@ -139,6 +139,48 @@ def print_connected_app(process):
             print(f'Connected to application: "{app_name}"')
 
 
+def expand_shortcuts(process, stat_specs):
+    """Expand special shortcuts like eth.rx and eth.tx into actual stat specifications.
+
+    Args:
+        process: The subprocess.Popen handle to the telemetry process
+        stat_specs: List of stat specifications, possibly including shortcuts
+
+    Returns:
+        List of expanded stat specifications
+    """
+    expanded = []
+    for spec in stat_specs:
+        if not spec.startswith("eth."):
+            expanded.append(spec)
+            continue
+
+        # Extract the field name after "eth."
+        field = spec[4:]  # Remove "eth." prefix
+        if not field:
+            print(f"Error: Invalid shortcut '{spec}' - missing field name", file=sys.stderr)
+            return None
+
+        # Map common shortcuts to actual field names
+        field_map = {
+            "rx": "ipackets",
+            "tx": "opackets",
+        }
+        field = field_map.get(field, field)
+
+        # Get list of ethernet devices
+        port_list = query_telemetry(process, "/ethdev/list")
+        if not isinstance(port_list, list):
+            print(f"Error: Failed to get ethernet device list", file=sys.stderr)
+            return None
+
+        # Create stat specs for each port
+        for port in port_list:
+            expanded.append(f"/ethdev/stats,{port}.{field}")
+
+    return expanded
+
+
 def validate_stats(process, stat_specs):
     """Validate stat specifications and check that fields are numeric.
 
@@ -202,8 +244,13 @@ def monitor_stats(process, args):
         process: The subprocess.Popen handle to the telemetry process
         args: Parsed command line arguments
     """
+    # Expand any shortcuts like eth-rx, eth-tx
+    expanded_stats = expand_shortcuts(process, args.stats)
+    if not expanded_stats:
+        return
+
     # Validate all stat specifications and get initial values
-    parsed_specs, prev_values = validate_stats(process, args.stats)
+    parsed_specs, prev_values = validate_stats(process, expanded_stats)
     if not parsed_specs:
         return
 
-- 
2.51.0