Implement getting psu related sensors in sonic_platform directly from BMC

dockers/docker-platform-monitor/Dockerfile.j2

@@ -38,8 +38,8 @@ RUN apt-get update &&   \
 RUN pip3 install grpcio==1.39.0 \
         grpcio-tools==1.39.0
 
-# Barefoot platform vendors' sonic_platform packages import the Python 'thrift' library
-RUN pip3 install thrift==0.13.0
+# Barefoot platform vendors' sonic_platform packages import these Python libraries
+RUN pip3 install thrift==0.13.0 netifaces
 
 {% if docker_platform_monitor_debs.strip() -%}
 # Copy locally-built Debian package dependencies

platform/barefoot/sonic-platform-modules-bfn-montara/sonic_platform/bfn_extensions/psu_sensors.py

@@ -0,0 +1,127 @@
+from netifaces import ifaddresses, AF_INET6
+from subprocess import Popen, PIPE, DEVNULL
+import json
+import os
+
+class Metric(object):
+
+    def __init__(self, sensor_id, sensor_key, value, label):
+        self._value = self.parse_value(value)
+        self._sensor_id = sensor_id
+        self._sensor_key = sensor_key
+        self._label = label
+
+    @classmethod
+    def parse_value(cls, value):
+        parse = getattr(cls, "parse")
+        return parse(value)
+
+    # For debug purposes
+    def __repr__(self):
+        return "%s, %s: %s %s [%s]" % (
+            self._sensor_id,
+            self._sensor_key,
+            self._value,
+            getattr(self, "unit", "?"),
+            self._label)
+
+class Temperature(Metric):
+    parse = float
+    unit = "°C"
+
+class FanRpm(Metric):
+    parse = float
+    unit = "RPM"
+
+class FanFault(Metric):
+    parse = float
+
+class Voltage(Metric):
+    parse = float
+    unit = "V"
+
+class Power(Metric):
+    parse = float
+    unit = "W"
+
+class Current(Metric):
+    parse = float
+    unit = "A"
+
+def get_metric_value(metrics, name):
+    label, sensor_id, sensor_key = name.split("_")
+    for metric in metrics:
+        if metric._label == label and metric._sensor_id == sensor_id and metric._sensor_key == sensor_key:
+            return metric._value
+    return None
+
+def get_link_local_interface():
+    cdc_ether_path = "/sys/bus/usb/drivers/cdc_ether"
+    for ether in os.listdir(cdc_ether_path):
+        concrete_ether = os.path.join(cdc_ether_path, ether)
+        if os.path.isdir(concrete_ether):
+            concrete_ether_net = os.path.join(concrete_ether, 'net')
+            if os.path.exists(concrete_ether_net):
+                return os.listdir(concrete_ether_net)[0]
+
+def get_link_local_address(link_local_interface):
+    for addr in ifaddresses(link_local_interface)[AF_INET6]:
+        address = addr['addr'].split('%')[0]
+        # according to rfc4291 this ipv6 address is used for link local connection
+        if address.startswith('fe80:'):
+            # first address is taken for BMC and second for this host
+            return address[:-1] + '1'
+    return None
+
+def get_psu_metrics():
+    link_local_interface = get_link_local_interface()
+    link_local_address = get_link_local_address(link_local_interface)
+
+    http_address = "http://[%s%%%s]:8080" % (link_local_address, link_local_interface)
+    args = "/api/sys/bmc/sensors/%20-A%20-u%20"
+    cmd = "curl " + http_address + args
+    output = Popen(cmd.split(), stdout=PIPE, stderr=DEVNULL).stdout.read()
+    output = json.loads(output.decode())["Information"]["Description"][0].strip()
+    sections = output.split("\n\n")
+
+    metrics = []
+    # iterating through drivers and their sensors
+    for section in sections:
+        fields = section.split("\n")
+
+        label = None
+        # iterating through sensors and their inputs
+        for field in fields[1:]: # skipping driver name
+            # parsing input sensor
+            if field.startswith("  "):
+                field = field.replace("  ", "")
+                # split sensor into name and value
+                field_key, field_value = field.split(": ")
+                if "_" in field_key:
+                    sensor_id, sensor_key = field_key.split("_", 1)
+                    if sensor_key == "input":
+                        if sensor_id.startswith("temp"):
+                            metrics.append(
+                                Temperature(sensor_id, sensor_key, field_value, label=label))
+                        elif sensor_id.startswith("in"):
+                            metrics.append(
+                                Voltage(sensor_id, sensor_key, field_value, label=label))
+                        elif sensor_id.startswith("power"):
+                            metrics.append(
+                                Power(sensor_id, sensor_key, field_value, label=label))
+                        elif sensor_id.startswith("curr"):
+                            metrics.append(
+                                Current(sensor_id, sensor_key, field_value, label=label))
+                        elif sensor_id.startswith("fan"):
+                            metrics.append(
+                                FanRpm(sensor_id, sensor_key, field_value, label=label))
+                    elif sensor_key == "fault":
+                        if sensor_id.startswith("fan"):
+                            metrics.append(
+                                FanFault(sensor_id, sensor_key, field_value, label=label))
+            elif field.startswith("ERROR"):
+                syslog.syslog(syslog.LOG_INFO, field)
+            else:
+                label = field[:-1]  # strip off trailing ":" character
+
+    return metrics

platform/barefoot/sonic-platform-modules-bfn-montara/sonic_platform/psu.py

@@ -6,6 +6,8 @@
     import time
     import signal
     import syslog
+    import logging
+    import threading
 
     sys.path.append(os.path.dirname(__file__))
 
@@ -14,12 +16,18 @@
     from sonic_platform_base.psu_base import PsuBase
     from sonic_platform.thermal import psu_thermals_list_get
     from platform_utils import cancel_on_sigterm
+    from sonic_platform.bfn_extensions.psu_sensors import get_psu_metrics
+    from sonic_platform.bfn_extensions.psu_sensors import get_metric_value
 except ImportError as e:
     raise ImportError (str(e) + "- required module not found")
 
 class Psu(PsuBase):
     """Platform-specific PSU class"""
 
+    __lock = threading.Lock()
+    __sensors_info = None
+    __timestamp = 0
+
     sigterm = False
     sigterm_default_handler = None
     cls_inited = False
@@ -48,6 +56,20 @@ def signal_handler(cls, sig, frame):
         syslog.syslog(syslog.LOG_INFO, "Canceling PSU platform API calls...")
         cls.sigterm = True
 
+    @classmethod
+    def __sensors_get(cls, cached=True):
+        cls.__lock.acquire()
+        if time.time() > cls.__timestamp + 15:
+            # Update cache once per 15 seconds
+            try:
+                cls.__sensors_info = get_psu_metrics()
+                cls.__timestamp = time.time()
+            except Exception as e:
+                logging.warning("Failed to update sensors cache: " + str(e))
+        info = cls.__sensors_info
+        cls.__lock.release()
+        return info
+
     '''
     Units of returned info object values:
         vin - V
@@ -105,8 +127,7 @@ def get_voltage(self):
             A float number, the output voltage in volts,
             e.g. 12.1
         """
-        info = self.__info_get()
-        return float(info.vout) if info else 0
+        return get_metric_value(Psu.__sensors_get(), "PSU%d 12V Output Voltage_in1_input" % self.__index)
 
     def get_current(self):
         """
@@ -115,8 +136,24 @@ def get_current(self):
         Returns:
             A float number, the electric current in amperes, e.g 15.4
         """
-        info = self.__info_get()
-        return info.iout / 1000 if info else 0
+        return get_metric_value(Psu.__sensors_get(), "PSU%d 12V Output Current_curr2_input" % self.__index)
+
+    def get_input_voltage(self):
+        """
+        Retrieves current PSU voltage input
+        Returns:
+            A float number, the input voltage in volts,
+            e.g. 220
+        """
+        return get_metric_value(Psu.__sensors_get(), "PSU%d Input Voltage_in0_input" % self.__index)
+
+    def get_input_current(self):
+        """
+        Retrieves the input current draw of the power supply
+        Returns:
+            A float number, the electric current in amperes, e.g 0.8
+        """
+        return get_metric_value(Psu.__sensors_get(), "PSU%d Input Current_curr1_input" % self.__index)
 
     def get_power(self):
         """