Refactor into a client/server model, to enable multiple clients to access the BMS data

README.md

@@ -13,4 +13,16 @@ Or, to install with influxdb and/or prometheus support:
 	poetry install -E influxdb -E prometheus
 
 To run:
+	poetry run bmspyd &
+
+Or to run via systemd, copy bmspyd.service to /etc/systemd/system, adjust WorkingDirectory to point to the installation location, and enable and start the service:
+	cp bmspy-server.service /etc/systemd/system
+	$EDITOR /etc/systemd/system/bmspy-server.service
+	systemctl daemon-reload
+	systemctl enable bmspy-server
+	systemctl start bmspy-server
+
+To run a client to get the data, choose one of the following options:
 	poetry run bmspy
+	poetry run bmspy-influxdb --url ...
+

bmspy-influxdb.service

@@ -0,0 +1,13 @@
+[Unit]
+Description=BMS tracking via InfluxDB
+Requires=bmspy-server.service
+
+[Service]
+Type=exec
+WorkingDirectory=/usr/local/bmspy
+ExecStart=poetry run bmspy-influxdb --url http://localhost/ --org 0987654321 --bucket bms --token XXXX
+RestartSec=5
+Restart=on-failure
+
+[Install]
+WantedBy=default.target

bmspy-server.service

@@ -0,0 +1,14 @@
+[Unit]
+Description=Make BMS data available for consumers
+
+[Service]
+Type=exec
+# The full path of the git repo on your system
+WorkingDirectory=/usr/local/bmspy
+ExecStart=poetry run bmspy-server
+RestartSec=5
+Restart=on-failure
+
+
+[Install]
+WantedBy=default.target

bmspy/__init__.py

@@ -0,0 +1,96 @@
+#
+# bmspy
+#
+import atexit
+import argparse
+import pprint
+import time
+
+
+def parse_args():
+    parser = argparse.ArgumentParser(
+                description='Query JBD BMS and report status',
+                add_help=True,
+    )
+    parser.add_argument('--device', '-d', dest='device', action='store',
+                default='/dev/ttyUSB0', help='USB device to read')
+    parser.add_argument('--socket', '-s', dest='socket', action='store',
+                default='/run/bmspy/bms', help='Socket to communicate with daemon')
+    parser.add_argument('--json', '-j', dest='report_json', action='store_true',
+                default=False, help='Report data as JSON')
+    parser.add_argument('--prometheus', '-p', dest='report_prometheus', action='store_true',
+                default=False, help='Daemonize and report data to Prometheus')
+    parser.add_argument('--file', '-f', dest='report_textfile', type=str, action='store',
+                default=False, help='Report data to Prometheus using textfile <file>')
+    parser.add_argument('--influxdb', '-i', dest='report_influxdb', action='store_true',
+                default=False, help='Daemonize and report data to InfluxDB using INFLUXDB_V2_URL, INFLUXDB_V2_ORG and INFLUXDB_V2_TOKEN environment variables')
+    parser.add_argument('--bucket', '-b', dest='influx_bucket', type=str, action='store',
+                default="ups", help='Set the bucket name when sending data to influxdb (defaults to "ups")')
+    parser.add_argument('--url', '-u', dest='influx_url', type=str, action='store',
+                default=False, help='Set the URL when sending data to influxdb (overrides INFLUXDB environment variables)')
+    parser.add_argument('--org', '-o', dest='influx_org', type=str, action='store',
+                default=False, help='Set the influx organization when sending data to influxdb (overrides INFLUXDB environment variables)')
+    parser.add_argument('--token', '-t', dest='influx_token', type=str, action='store',
+                default=False, help='Set the influx token when sending data to influxdb (overrides INFLUXDB environment variables)')
+    parser.add_argument('--print', dest='report_print', action='store_true',
+                default=True, help='Report data as text')
+    parser.add_argument('--verbose', '-v', action='count',
+                default=0, help='Print more verbose information (can be specified multiple times)')
+    args = parser.parse_args()
+    return args
+
+
+def main():
+    try:
+        args = parse_args()
+
+        debug=args.verbose
+
+        if args.report_influxdb:
+            num_args = 0
+            for arg in [ args.influx_url, args.influx_org, args.influx_token ]:
+                if arg is not False:
+                    num_args += 1
+            if num_args != 0 and num_args != 3:
+                raise argparse.ArgumentTypeError('Missing value for --url, --org or --token')
+
+        if args.report_prometheus:
+            from bmspy import prometheus
+            prometheus.prometheus_export(daemonize=True, debug=debug)
+
+        if args.report_influxdb:
+            from bmspy import influxdb as bms_influx
+            
+            bms_influx.influxdb_export(bucket=args.influx_bucket, \
+                            url=args.influx_url, \
+                            org=args.influx_org, \
+                            token=args.influx_token, \
+                            debug=debug, \
+                            daemonize=True)
+
+        elif args.report_textfile:
+            from bmspy import promethus
+            prometheus.prometheus_export(daemonize=False, filename=args.report_textfile, debug=debug)
+
+        else:
+            from bmspy import client
+            client.handle_registration(args.socket, 'bmspy', debug)
+            atexit.register(client.handle_registration, args.socket, 'bmspy', debug)
+
+            data = client.read_data(args.socket, 'bmspy')
+
+            if args.report_json:
+                print(json.dumps(data))
+
+            elif args.report_print:
+                pp = pprint.PrettyPrinter(indent=4)
+                pp.pprint(data)
+
+    except KeyboardInterrupt as e:
+        bms.cleanup()
+        print(e)
+
+
+
+if __name__ == '__main__':
+    main()

bmspy/client.py

@@ -0,0 +1,98 @@
+#
+# Library with socket client for use by consumers
+#
+import atexit, os, sys
+import pickle, struct
+import socket
+
+
+is_registered = False
+def handle_registration(socket_path, client_name, debug=0):
+    global is_registered
+    data = dict()
+
+    if is_registered:
+        message = {'command': 'DEREGISTER', 'client': client_name}
+    else:
+        # fork server if it's not already running
+        message = {'command': 'REGISTER', 'client': client_name}
+
+    try:
+        data = socket_comms(socket_path, message, debug)
+        if data['status'] == 'REGISTERED':
+            is_registered = True
+        elif data['status'] == 'DEREGISTERED':
+            is_registered = False
+        else:
+            raise OSError("{} registration: invalid response: {}".format(client_name, data))
+
+    except Exception as e:
+        if is_registered:
+            print("{}: failed to register with daemon: {}".format(client_name, e))
+        else:
+            print("{}: failed to deregister with daemon: {}".format(client_name, e))
+
+    return data
+
+
+def socket_comms(socket_path, request_data, debug=0):
+    response_data = dict()
+    
+    # Create a UDS socket
+    sock = socket.socket(socket.AF_UNIX, socket.SOCK_STREAM)
+
+    # Connect the socket to the port where the server is listening
+    if debug > 2:
+        print('socket client: connecting to {}'.format(socket_path))
+    try:
+        sock.connect(socket_path)
+    except socket.error as msg:
+        if msg.errno == 2:
+            print("Failed to connect to bmspy daemon")
+        else:
+            print("socket client: {}".format(msg))
+
+    # Send request
+    if debug > 2:
+        print('socket client: sending {!r}'.format(request_data))
+    request = pickle.dumps(request_data)
+    # add length to the start of the pickled bytes, so we know how much to read on the other end
+    length = struct.pack('!I', len(request))
+    if debug > 3:
+        print("socket client: outgoing request length: {}, encoded as {}".format(len(request), length))
+    request = length + request
+    if debug > 4:
+        print("socket client: outgoing request: {}".format(request))
+    sock.sendall(request)
+  
+    # get length of expected pickled bytes
+    response = sock.recv(struct.calcsize('!I'))
+    length = struct.unpack('!I', response)[0]
+    if debug > 4:
+        print("socket client: incoming length: {}, encoded as {}".format(length, response))
+    # read length bytes
+    response = sock.recv(length)
+    if debug > 3:
+        print("socket client: incoming response: {}".format(response))
+    response_data = pickle.loads(response)
+    if debug > 2:
+        print('socket client: received {!r}'.format(response_data))
+
+    sock.close()
+
+    return response_data
+
+
+def read_data(socket_path, client_name, debug=0):
+    data = dict()
+
+    data = socket_comms(socket_path, {'command': 'GET', 'client': client_name}, debug)
+
+    if data is None:
+        raise
+
+    return data
+
+
+if __name__ == '__main__':
+    sys.exit(0)

bmspy/influxdb.py

@@ -0,0 +1,168 @@
+import atexit, datetime, os, sys, time
+from influxdb_client import InfluxDBClient, Point
+from influxdb_client.client.write_api import SYNCHRONOUS
+from bmspy import client
+
+DAEMON_UPDATE_PERIOD = 30
+
+''' Close remote connections '''
+def influx_shutdown(influxclient):
+    if influxclient is not None:
+        influxclient.close()
+
+def writeapi_shutdown(writeapi):
+    if writeapi is not None:
+        writeapi.close()
+
+
+def influxdb_export(bucket, url=None, org=None, token=None, socket_path=None, daemonize=True, debug=0):
+    data = dict()
+
+    if url:
+        influxclient = InfluxDBClient(url=url, token=token, org=org)
+    else:
+        influxclient = InfluxDBClient.from_env_properties()
+    atexit.register(influx_shutdown, influxclient)
+
+    if daemonize:
+        while True:
+            # collect new data, delay, and start again
+            data = client.read_data(socket_path, 'influxdb')
+            influxdb_write_snapshot(influxclient, bucket, data, debug)
+            time.sleep(DAEMON_UPDATE_PERIOD)
+    else:
+        data = client.read_data(socket_path, 'influxdb')
+        influxdb_write_snapshot(influxclient, bucket, data, debug)
+
+    influxclient.close()
+    atexit.unregister(influx_shutdown)
+
+    return
+
+def influxdb_write_snapshot(influxclient, bucket, data, debug=0):
+    writeapi = influxclient.write_api(write_options=SYNCHRONOUS)
+    atexit.register(writeapi_shutdown, writeapi)
+
+    # Populate the data structure this period
+    if debug > 1:
+        print("influxdb: creating snapshot")
+    points = influxdb_create_snapshot(data, debug)
+    if debug > 1:
+        print("influxdb: writing snapshot")
+    try:
+        writeapi.write(bucket=bucket, record=points)
+    except Exception as e:
+        print(e)
+
+    writeapi.close()
+    atexit.unregister(writeapi_shutdown)
+
+    return
+
+def influxdb_create_snapshot(data, debug=0):
+    points = []
+    now = datetime.datetime.now(datetime.timezone.utc).isoformat()
+
+    for kind, contains in data.items():
+        # discard bmspy metadata
+        if kind == 'client':
+            break
+
+        helpmsg = ''
+        if contains.get('help'):
+            helpmsg = contains.get('help')
+        units = None
+        if contains.get('units'):
+            units = contains.get('units')
+        # Simple values
+        value = None
+        if contains.get('raw_value') is not None:
+            value = contains.get('raw_value')
+            if debug > 2:
+                print("value: {} : {}".format(kind, value));
+            point = Point(kind) \
+                .tag("units", units) \
+                .tag("help", helpmsg) \
+                .field("value", value) \
+                .time(now)
+            points.append(point)
+        # Doesn't have a value, but multiple values, each with a label:
+        label = None
+        if contains.get('raw_values') is not None and isinstance(contains.get('raw_values'), dict):
+            label = contains.get('label')
+            for idx, label_value in contains.get('raw_values').items():
+                if debug > 2:
+                    print("labels: {} [{}] : {}".format(kind, idx, label_value));
+                point = Point(kind) \
+                    .tag(label, idx) \
+                    .tag("units", units) \
+                    .tag("help", helpmsg) \
+                    .field("value", label_value) \
+                    .time(now)
+                points.append(point)
+        # Information (like a manufacturing date or a serial number)
+        if contains.get('info') is not None:
+            value = contains.get('info')
+            if debug > 2:
+                print("info: {} : {}".format(kind, value));
+            point = Point(kind) \
+                .tag("units", units) \
+                .tag("help", helpmsg) \
+                .field("value", value) \
+                .time(now)
+            points.append(point)
+        else:
+            pass
+
+    return points
+
+
+def main():
+    import argparse
+ 
+    parser = argparse.ArgumentParser(
+                description='Query JBD BMS and report status',
+                add_help=True,
+    )
+    parser.add_argument('--bucket', '-b', dest='influx_bucket', type=str, action='store',
+                default="ups", help='Set the bucket name when sending data to influxdb (defaults to "ups")')
+    parser.add_argument('--url', '-u', dest='influx_url', type=str, action='store',
+                default=False, help='Set the URL when sending data to influxdb (overrides INFLUXDB environment variables)')
+    parser.add_argument('--org', '-o', dest='influx_org', type=str, action='store',
+                default=False, help='Set the influx organization when sending data to influxdb (overrides INFLUXDB environment variables)')
+    parser.add_argument('--token', '-t', dest='influx_token', type=str, action='store',
+                default=False, help='Set the influx token when sending data to influxdb (overrides INFLUXDB environment variables)')
+    parser.add_argument('--socket', '-s', dest='socket', action='store',
+                default='/run/bmspy/bms', help='Socket to communicate with daemon')
+    parser.add_argument('--verbose', '-v', action='count',
+                default=0, help='Print more verbose information (can be specified multiple times)')
+    args = parser.parse_args()
+
+    debug=args.verbose
+
+    try:
+        if not os.getenv('INFLUXDB_V2_URL') and not args.influx_url:
+            raise argparse.ArgumentTypeError('Missing value for --url')
+        if not os.getenv('INFLUXDB_V2_ORG') and not args.influx_org:
+            raise argparse.ArgumentTypeError('Missing value for --url')
+        if not os.getenv('INFLUXDB_V2_TOKEN') and not args.influx_token:
+            raise argparse.ArgumentTypeError('Missing value for --token')
+    except Exception as e:
+        print("bmspy-influxdb: {}".format(e))
+        sys.exit(1)
+
+    print("Running BMS influxdb daemon on socket {}".format(args.socket))
+
+    client.handle_registration(args.socket, 'influxdb', debug)
+    atexit.register(client.handle_registration, args.socket, 'influxdb', debug)
+
+    influxdb_export(bucket=args.influx_bucket, \
+                    url=args.influx_url, \
+                    org=args.influx_org, \
+                    token=args.influx_token, \
+		    socket_path=args.socket, \
+                    daemonize=True, \
+                    debug=debug)
+
+if __name__ == "__main__":
+    main()

bmspy/prometheus.py

@@ -0,0 +1,90 @@
+import prometheus_client
+
+def prometheus_export(daemonize=True, filename=None):
+    global debug
+    if not can_export_prometheus:
+        raise ModuleNotFoundError("Unable to export to Prometheus. Is prometheus-client installed?")
+
+    data = dict()
+    # Initialize data structure, to fill in help values
+    while bool(data) is False:
+        data = collect_data()
+        time.sleep(1)
+
+    registry = prometheus_client.CollectorRegistry(auto_describe=True)
+    # Set up the metric data structure for Prometheus
+    metric = prometheus_create_metric(registry, data)
+    # Populate the metric data structure this period
+    prometheus_populate_metric(metric, data)
+
+    if daemonize:
+        prometheus_client.start_http_server(9999, registry=registry)
+
+        while True:
+            # Delay, collect new data, and start again
+            time.sleep(DAEMON_UPDATE_PERIOD)
+            # Reset data, so it is re-populated correctly
+            data = dict()
+            while bool(data) is False:
+                data = collect_data()
+            time.sleep(1)
+            prometheus_populate_metric(metric, data)
+            prometheus_client.generate_latest(registry)
+    else:
+        if filename is None:
+            print("Invalid filename supplied");
+            return False
+        prometheus_client.write_to_textfile(filename, registry=registry)
+        return True
+
+def prometheus_create_metric(registry, data):
+    metric = dict()
+    for name, contains in data.items():
+        helpmsg = ''
+        if contains.get('help') is not None:
+            helpmsg = contains.get('help')
+            if contains.get('units'):
+                helpmsg += ' (' + contains.get('units') + ')'
+        if contains.get('value') is not None:
+            metric[name] = prometheus_client.Gauge(name, helpmsg, registry=registry)
+        # Has multiple values, each a different label
+        elif contains.get('values') is not None:
+            if contains.get('label') is None:
+                print("ERROR: no label for {0} specified".format(name))
+            label = contains.get('label')
+            metric[name] = prometheus_client.Gauge(name, helpmsg, [label], registry=registry)
+        elif contains.get('info') is not None:
+            metric[name] = prometheus_client.Info(name, helpmsg, registry=registry)
+        else:
+            pass
+    return metric
+
+def prometheus_populate_metric(metric, data):
+    for name, contains in data.items():
+        if contains.get('value') is not None:
+            value = contains.get('value')
+            metric[name].set(value)
+        # doesn't have a value, but has [1-4]:
+        if contains.get('values') is not None and isinstance(contains.get('values'), dict):
+            for idx, label_value in contains.get('values').items():
+                metric[name].labels(idx).set(label_value)
+        if contains.get('info'):
+            value = contains.get('info')
+            metric[name].info({name: value})
+        else:
+            pass
+
+
+# TODO fork bms daemon if need be?
+
+def main():
+    print("TODO. At present, run from bmspy directly.")
+
+#    influxdb_export(bucket=args.influx_bucket, \
+#                    url=args.influx_url, \
+#                    org=args.influx_org, \
+#                    token=args.influx_token, \
+#                    daemonize=True)
+
+if __name__ == "__main__":
+    main()

bmspy/server.py

@@ -3,38 +3,16 @@
 # Communicate with a JBD/SZLLT BMS and return basic information
 # in order to shutdown equipment when voltage levels drop or remaining
 # capacity gets low
-# TODO: scripts to shutdown NAS when voltage goes below 13.xV or
-#       percent_capacity goes below 25%
 #
-import argparse
-import atexit
+import os, sys, stat, time
 import json
+import atexit, signal
+import serial, serial.rs485
+import pickle, struct
 import pprint
-import serial
-import serial.rs485
-import signal
-import sys
-import time
-try:
-    import prometheus_client
-    can_export_prometheus = True
-except:
-    can_export_prometheus = False
-try:
-    from influxdb_client import InfluxDBClient, Point
-    from influxdb_client.client.write_api import SYNCHRONOUS
-    import datetime
-    can_export_influxdb = True
-    influxclient = None
-    writeapi = None
-except:
-    can_export_influxdb = False
-    influxclient = None
 
-DAEMON_UPDATE_PERIOD = 30
-SERIALPORT = "/dev/ttyUSB0"
-#SERIALPORT = "/dev/rfcomm1"
-BAUDRATE = 9600
+connected_clients = list()
+current_data = dict()
 
 # usb 1-1.4: new full-speed USB device number 4 using xhci_hcd
 # usb 1-1.4: New USB device found, idVendor=0403, idProduct=6001, bcdDevice= 6.00
@@ -51,37 +29,38 @@ BAUDRATE = 9600
 # usb 1-1.4: FTDI USB Serial Device converter now attached to ttyUSB0
 # usb 1-1.4: usbfs: interface 0 claimed by ftdi_sio while 'python3' sets config #1
 
-# TODO: ensure ttyUSB0 points to  idVendor=0403, idProduct=6001
-# with serial.tools.list_ports.ListPortInfo
-# python3 -m serial.tools.list_ports USB
-ser = serial.Serial(SERIALPORT, BAUDRATE)
-ser.parity = serial.PARITY_NONE     # set parity check: no parity
-ser.bytesize = serial.EIGHTBITS     # number of bits per bytes
-ser.stopbits = serial.STOPBITS_ONE  # number of stop bits
 
-ser.timeout = 1         # timeout block read
-ser.writeTimeout = 1    # timeout for write
+# Catch systemd signals
+def signalHandler():
+    raise SystemExit('terminating')
+
+''' Clean up socket '''
+def socket_cleanup(socket_path, debug=0):
+    os.unlink(socket_path)
 
 ''' Clean up serial port '''
-def cleanup():
-    global debug
-    global ser
+def serial_cleanup(ser, debug=0):
     if debug > 2:
-        print("Cleaning up...")
+        print("serial: cleaning up...")
     if ser.is_open:
         ser.reset_input_buffer()  # flush input buffer, discarding all its contents
         ser.reset_output_buffer() # flush output buffer, aborting current output
         ser.close()
 
-''' Close remote connections '''
-def shutdown():
-    global debug
-    global influxclient
-    if influxclient is not None:
-        if writeapi is not None:
-            writeapi.close()
-        influxclient.close()
+def initialise_serial(device, debug=0):
+    # TODO: ensure ttyUSB0 points to  idVendor=0403, idProduct=6001
+    # with serial.tools.list_ports.ListPortInfo
+    # python3 -m serial.tools.list_ports USB
+    ser = serial.Serial(device, baudrate=9600)
+    ser.parity = serial.PARITY_NONE     # set parity check: no parity
+    ser.bytesize = serial.EIGHTBITS     # number of bits per bytes
+    ser.stopbits = serial.STOPBITS_ONE  # number of stop bits
+    ser.timeout = 1         # timeout block read
+    ser.writeTimeout = 1    # timeout for write
     
+    atexit.register(serial_cleanup, ser, debug)
+
+    return ser
 
 def calculate_checksum(msg):
     checksum = ''
@@ -120,18 +99,16 @@ def bytes_to_date(high, low):
     return "{:04d}-{:02d}-{:02d}".format(year, mon, day)
 
 # takes a serial object and a message, returns a response
-def requestMessage(reqmsg):
-    global ser
-    global debug
+def requestMessage(ser, reqmsg, debug=0):
     if debug > 2:
-        print('Starting Up Serial Monitor')
+        print('serial: starting up monitor')
     if ser.is_open:
         ser.close()
 
     try:
         ser.open()
     except Exception as e:
-        print("error open serial port: {0}".format(str(e)))
+        print("serial: error open port: {0}".format(str(e)))
         return False
 
     if ser.is_open:
@@ -142,41 +119,40 @@ def requestMessage(reqmsg):
                 ser.reset_input_buffer()  # flush input buffer, discarding all its contents
                 ser.reset_output_buffer() # flush output buffer, aborting current output
             if debug > 0:
-                print("Write data: {0}".format("".join('0x{:02x} '.format(x) for x in reqmsg)))
+                print("serial: write data: {0}".format("".join('0x{:02x} '.format(x) for x in reqmsg)))
             w = ser.write(reqmsg)
             if debug > 2:
-                print("Bytes written: {0}".format(w))
+                print("serial: bytes written: {0}".format(w))
             #time.sleep(1)
             if w != len(reqmsg):
-                print("ERROR: {0} bytes written, {1} expected.".format(w, len(reqmsg)))
+                print("serial ERROR: {0} bytes written, {1} expected.".format(w, len(reqmsg)))
                 return False
             wait_time = 0
             while ser.in_waiting == 0:
                 # Return an empty string if we end up waiting too long
                 if wait_time > 2:
-                    cleanup()
+                    serial_cleanup(ser, debug)
                     return ''
                 if debug > 2:
-                    print("Waiting for data...")
+                    print("serial: waiting for data...")
                 time.sleep(0.5)
                 wait_time += 1
             if debug > 1:
-                print("Awaiting reading: {0}".format(ser.in_waiting))
+                print("serial: waiting reading: {0}".format(ser.in_waiting))
             response = ser.read_until(b'\x77')
             # Return an empty string if the read timed out or returned nothing
             if len(response) == 0:
                 return ''
             if debug > 0:
-                print("Read data: {0}".format(response.hex()))
-            cleanup()
+                print("serial: read data: {0}".format(response.hex()))
+            serial_cleanup(ser, debug)
             return response
         except Exception as e:
-            print("error communicating...: {0}".format(str(e)))
+            print("serial: error communicating: {0}".format(str(e)))
     else:
-        print("cannot open serial port")
+        print("serial: cannot open port")
 
-def parse_03_response(response):
-    global debug
+def parse_03_response(response, debug=0):
     data = dict()
     # Response is 34 bytes:
     # 00        begin:  \xDD
@@ -189,16 +165,16 @@ def parse_03_response(response):
     # length+5  checksum
     # length+6  end      \x77
     if bytes([response[0]]) != b'\xdd':
-        print("ERROR: first byte not found: {0}".format(response[0]))
+        print("parse_03_response ERROR: first byte not found: {0}".format(response[0]))
         return False
 
     if bytes([response[2]]) == b'\x80':
-        print("ERROR: error byte returned from BMS: {0}".format(response[2]))
+        print("parse_03_response ERROR: error byte returned from BMS: {0}".format(response[2]))
         return False
 
     data_len = response[3]
     if debug > 2:
-        print("Data length (trimming 4 bytes): {0}".format(data_len))
+        print("parse_03_response: data length (trimming 4 bytes): {0}".format(data_len))
 
     # The checksum is two bytes, offset by data_len + 4
     # Five bytes at the front of data
@@ -207,11 +183,11 @@ def parse_03_response(response):
     first  = data_len + 4
     second = data_len + 5
     if second > len(response):
-        print("ERROR: primary response checksum not found")
+        print("parse_03_response ERROR: primary response checksum not found")
         return False;
     checksum = bytes([response[first], response[second]])
     if not verify_checksum(response[3:first], checksum):
-        print("ERROR: failed to validate received checksum")
+        print("parse_03_response ERROR: failed to validate received checksum")
         return False
 
     if data_len > 0:
@@ -455,7 +431,7 @@ def parse_03_response(response):
 
         return data
 
-def parse_04_response(response):
+def parse_04_response(response, debug=0):
     data = dict()
     # Response is 7 + cells * 2 bytes:
     # 00        begin:  \xDD
@@ -468,11 +444,11 @@ def parse_04_response(response):
     # length+5  checksum
     # length+6  end      \x77
     if bytes([response[0]]) != b'\xdd':
-        print("ERROR: first byte not found: {0}".format(response[0]))
+        print("parse_04_response ERROR: first byte not found: {0}".format(response[0]))
         return False
 
     if bytes([response[2]]) == b'\x80':
-        print("ERROR: error byte returned from BMS: {0}".format(response[2]))
+        print("parse_04_response ERROR: error byte returned from BMS: {0}".format(response[2]))
         return False
 
     data_len = response[3]
@@ -486,11 +462,11 @@ def parse_04_response(response):
     first  = data_len + 4
     second = data_len + 5
     if second > len(response):
-        print("ERROR: cell voltage checksum not found")
+        print("parse_04_response ERROR: cell voltage checksum not found")
         return False
     checksum = bytes([response[first], response[second]])
     if not verify_checksum(response[3:first], checksum):
-        print("ERROR: failed to validate received checksum")
+        print("parse_04_response ERROR: failed to validate received checksum")
         return False
 
     if data_len > 0:
@@ -510,8 +486,7 @@ def parse_04_response(response):
                 print(" Cell {:.0f}: {:.3f}V".format(cell+1, cellv))
     return data
 
-def collect_data():
-    global debug
+def collect_data(ser, debug=0):
     # Request is 7 bytes:
     # \xDD for start
     # \xA5 for read, \x5A for write
@@ -519,30 +494,30 @@ def collect_data():
     # \x77 ends
     data = dict()
     reqmsg = bytearray([ 0xDD, 0xA5, 0x03, 0x00, 0xFF, 0xFD, 0x77 ])
-    response_03 = requestMessage(reqmsg)
+    response_03 = requestMessage(ser, reqmsg, debug)
 
     if len(response_03) == 0:
         if debug > 0:
-            print("Error retrieving BMS info. Trying again...")
+            print("collect_data: Error retrieving BMS info. Trying again...")
         return False
     response_03 = bytearray(response_03)
 
     reqmsg = bytearray([ 0xDD, 0xA5, 0x04, 0x00, 0xFF, 0xFC, 0x77 ])
-    response_04 = requestMessage(reqmsg)
+    response_04 = requestMessage(ser, reqmsg, debug)
 
     if len(response_04) == 0:
         if debug > 0:
-            print("Error retrieving BMS info. Trying again...")
+            print("collect_data: Error retrieving BMS info. Trying again...")
         return False
     response_04 = bytearray(response_04)
 
-    parsed_03 = parse_03_response(response_03)
+    parsed_03 = parse_03_response(response_03, debug)
     if parsed_03 is not False:
         data.update(parsed_03)
     else:
         return False
 
-    parsed_04 = parse_04_response(response_04)
+    parsed_04 = parse_04_response(response_04, debug)
     if parsed_04 is not False:
         data.update(parsed_04)
     else:
@@ -551,252 +526,188 @@ def collect_data():
     return data
 
 
-def prometheus_export(daemonize=True, filename=None):
-    global debug
-    if not can_export_prometheus:
-        raise ModuleNotFoundError("Unable to export to Prometheus. Is prometheus-client installed?")
+def read_request(connection, debug=0):
+    # get length of expected pickle bytes
+    request = connection.recv(struct.calcsize('!I'))
+    length = struct.unpack('!I', request)[0]
+    if debug > 4:
+        print("socket: incoming length: {}, encoded as {}".format(length, request))
 
-    data = dict()
-    # Initialize data structure, to fill in help values
-    while bool(data) is False:
-        data = collect_data()
-        time.sleep(1)
-
-    registry = prometheus_client.CollectorRegistry(auto_describe=True)
-    # Set up the metric data structure for Prometheus
-    metric = prometheus_create_metric(registry, data)
-    # Populate the metric data structure this period
-    prometheus_populate_metric(metric, data)
-
-    if daemonize:
-        prometheus_client.start_http_server(9999, registry=registry)
-
-        while True:
-            # Delay, collect new data, and start again
-            time.sleep(DAEMON_UPDATE_PERIOD)
-            # Reset data, so it is re-populated correctly
-            data = dict()
-            while bool(data) is False:
-                data = collect_data()
-            time.sleep(1)
-            prometheus_populate_metric(metric, data)
-            prometheus_client.generate_latest(registry)
-    else:
-        if filename is None:
-            print("Invalid filename supplied");
-            return False
-        prometheus_client.write_to_textfile(filename, registry=registry)
-        return True
-
-def prometheus_create_metric(registry, data):
-    metric = dict()
-    for name, contains in data.items():
-        helpmsg = ''
-        if contains.get('help') is not None:
-            helpmsg = contains.get('help')
-            if contains.get('units'):
-                helpmsg += ' (' + contains.get('units') + ')'
-        if contains.get('value') is not None:
-            metric[name] = prometheus_client.Gauge(name, helpmsg, registry=registry)
-        # Has multiple values, each a different label
-        elif contains.get('values') is not None:
-            if contains.get('label') is None:
-                print("ERROR: no label for {0} specified".format(name))
-            label = contains.get('label')
-            metric[name] = prometheus_client.Gauge(name, helpmsg, [label], registry=registry)
-        elif contains.get('info') is not None:
-            metric[name] = prometheus_client.Info(name, helpmsg, registry=registry)
-        else:
-            pass
-    return metric
-
-def prometheus_populate_metric(metric, data):
-    for name, contains in data.items():
-        if contains.get('value') is not None:
-            value = contains.get('value')
-            metric[name].set(value)
-        # doesn't have a value, but has [1-4]:
-        if contains.get('values') is not None and isinstance(contains.get('values'), dict):
-            for idx, label_value in contains.get('values').items():
-                metric[name].labels(idx).set(label_value)
-        if contains.get('info'):
-            value = contains.get('info')
-            metric[name].info({name: value})
-        else:
-            pass
-
-
-def influxdb_export(bucket, url=None, org=None, token=None, daemonize=True):
-    global debug
-    global influxclient
-
-    if not can_export_influxdb:
-        raise ModuleNotFoundError("Unable to export to InfluxDB. Is influxdb-client installed?")
-
-    data = dict()
-    # Initialize data structure, to fill in help values
-    while bool(data) is False:
-        data = collect_data()
-        time.sleep(1)
-
-    if url:
-        influxclient = InfluxDBClient(url=url, token=token, org=org)
-    else:
-        influxclient = InfluxDBClient.from_env_properties()
-    influxdb_write_snapshot(bucket, data)
-
-    if daemonize:
-        while True:
-            # Delay, collect new data, and start again
-            time.sleep(DAEMON_UPDATE_PERIOD)
-            # Reset data, so it is re-populated correctly
-            data = dict()
-            while bool(data) is False:
-                data = collect_data()
-            time.sleep(1)
-            influxdb_write_snapshot(bucket, data)
-    influxclient.close()
-    return
-
-def influxdb_write_snapshot(bucket, data):
-    global debug
-    global influxclient
-    global writeapi
-    writeapi = influxclient.write_api(write_options=SYNCHRONOUS)
-    # Populate the data structure this period
-    points = influxdb_create_snapshot(data)
-    writeapi.write(bucket=bucket, record=points)
-    writeapi.close()
-    return
-
-def influxdb_create_snapshot(data):
-    global debug
-    points = []
-    helpmsg = ''
-    units = ''
-    now = datetime.datetime.now(datetime.timezone.utc).isoformat()
-    for kind, contains in data.items():
-        helpmsg = None
-        if contains.get('help'):
-            helpmsg = contains.get('help')
-        units = None
-        if contains.get('units'):
-            units = contains.get('units')
-        # Simple values
-        value = None
-        if contains.get('raw_value') is not None:
-            value = contains.get('raw_value')
+    # read length bytes
+    request = connection.recv(length)
+    if debug > 3:
+        print("socket: incoming request: {}".format(request))
+    request_data = pickle.loads(request)
     if debug > 2:
-                print("value: {} : {}".format(kind, value));
-            point = Point(kind) \
-                .tag("units", units) \
-                .tag("help", helpmsg) \
-                .field("value", value) \
-                .time(now)
-            points.append(point)
-        # Doesn't have a value, but multiple values, each with a label:
-        label = None
-        if contains.get('raw_values') is not None and isinstance(contains.get('raw_values'), dict):
-            label = contains.get('label')
-            for idx, label_value in contains.get('raw_values').items():
-                if debug > 2:
-                    print("labels: {} [{}] : {}".format(kind, idx, label_value));
-                point = Point(kind) \
-                    .tag(label, idx) \
-                    .tag("units", units) \
-                    .tag("help", helpmsg) \
-                    .field("value", label_value) \
-                    .time(now)
-                points.append(point)
-        # Information (like a manufacturing date or a serial number)
-        if contains.get('info') is not None:
-            value = contains.get('info')
-            if debug > 2:
-                print("info: {} : {}".format(kind, value));
-            point = Point(kind) \
-                .tag("units", units) \
-                .tag("help", helpmsg) \
-                .field("value", value) \
-                .time(now)
-            points.append(point)
-        else:
-            pass
-    return points
+        print('socket: received {!r}'.format(request_data))
+
+    return request_data
 
 
-def parse_args():
+def send_response(connection, response_data, debug=0):
+    try:
+        client = response_data['client']
+    except:
+        client = "unknown client"
+
+    if debug > 2:
+        print('socket: sending {!r}'.format(response_data))
+    response = pickle.dumps(response_data)
+    # add length to the start of the pickled bytes, so we know how much to read on the other end
+    length = struct.pack('!I', len(response))
+    if debug > 4:
+        print('socket: sending {} data of length: {}'.format(client, length))
+    response = length + response
+    if debug > 3:
+        print("socket: outgoing response: {}".format(response))
+    return connection.sendall(response)
+
+
+def main():
+    import argparse
+    import socket, socketserver
+    import pwd, grp
+ 
+    signal.signal(signal.SIGTERM, signalHandler)
+
+    global current_data
+    timestamp = 0
+
     parser = argparse.ArgumentParser(
                 description='Query JBD BMS and report status',
                 add_help=True,
     )
-    parser.add_argument('--json', '-j', dest='report_json', action='store_true',
-                default=False, help='Report data as JSON')
-    parser.add_argument('--prometheus', '-p', dest='report_prometheus', action='store_true',
-                default=False, help='Daemonize and report data to Prometheus')
-    parser.add_argument('--file', '-f', dest='report_textfile', type=str, action='store',
-                default=False, help='Report data to Prometheus using textfile <file>')
-    parser.add_argument('--influxdb', '-i', dest='report_influxdb', action='store_true',
-                default=False, help='Daemonize and report data to InfluxDB using INFLUXDB_V2_URL, INFLUXDB_V2_ORG and INFLUXDB_V2_TOKEN environment variables')
-    parser.add_argument('--bucket', '-b', dest='influx_bucket', type=str, action='store',
-                default="ups", help='Set the bucket name when sending data to influxdb (defaults to "ups")')
-    parser.add_argument('--url', '-u', dest='influx_url', type=str, action='store',
-                default=False, help='Set the URL when sending data to influxdb (overrides INFLUXDB environment variables)')
-    parser.add_argument('--org', '-o', dest='influx_org', type=str, action='store',
-                default=False, help='Set the influx organization when sending data to influxdb (overrides INFLUXDB environment variables)')
-    parser.add_argument('--token', '-t', dest='influx_token', type=str, action='store',
-                default=False, help='Set the influx token when sending data to influxdb (overrides INFLUXDB environment variables)')
-    parser.add_argument('--print', dest='report_print', action='store_true',
-                default=True, help='Report data as text')
+    parser.add_argument('--device', '-d', dest='device', action='store',
+                default='/dev/ttyUSB0', help='USB device to read')
+    parser.add_argument('--socket', '-s', dest='socket', action='store',
+                default='/run/bmspy/bms', help='Socket to communicate with daemon')
+    parser.add_argument('--user', '-u', dest='uid_name', action='store',
+                default='nobody', help='Run daemon as user')
+    parser.add_argument('--group', '-g', dest='gid_name', action='store',
+                default='dialout', help='Run daemon as group')
     parser.add_argument('--verbose', '-v', action='count',
                 default=0, help='Print more verbose information (can be specified multiple times)')
     args = parser.parse_args()
-    return args
-
-
-def main():
-    global debug
-    try:
-        args = parse_args()
 
     debug=args.verbose
 
-        if args.report_influxdb:
-            num_args = 0
-            for arg in [ args.influx_url, args.influx_org, args.influx_token ]:
-                if arg is not False:
-                    num_args += 1
-            if num_args != 0 and num_args != 3:
-                raise argparse.ArgumentTypeError('Missing value for --url, --org or --token')
+    if debug > 0:
+        print("Running BMS query daemon on socket {}".format(args.socket))
 
-        if args.report_prometheus:
-            prometheus_export(daemonize=True)
-        if args.report_influxdb:
-            influxdb_export(bucket=args.influx_bucket, \
-                            url=args.influx_url, \
-                            org=args.influx_org, \
-                            token=args.influx_token, \
-                            daemonize=True)
-        elif args.report_textfile:
-            prometheus_export(daemonize=False, filename=args.report_textfile)
-        else:
-            data = dict()
-            while bool(data) is False:
-                data = collect_data()
+    ser = initialise_serial(args.device)
+
+    # Create any necessary directories for the socket
+    socket_dir = os.path.dirname(args.socket)
+    socket_dir_created = False
+    if not os.path.isdir(socket_dir):
+        os.makedirs(socket_dir, exist_ok=True)
+        socket_dir_created = True
+
+    starting_uid = os.getuid()
+    starting_gid = os.getgid()
+    if starting_uid == 0:
+        running_uid = pwd.getpwnam(args.uid_name)[2]
+        running_gid = grp.getgrnam(args.gid_name)[2]
+
+        # If we've created a new directory for the socket, ensure that
+        # the highest-level directory has the correct permissions
+        if socket_dir_created:
+            os.chown(socket_dir, running_uid, running_gid)
+            os.chmod(socket_dir, stat.S_IRUSR | stat.S_IWUSR | stat.S_IXUSR | stat.S_IRGRP | stat.S_IWGRP | stat.S_IXGRP | stat.S_IXGRP | stat.S_IROTH | stat.S_IXOTH)
+
+        new_umask = 0o003
+        old_umask = os.umask(new_umask)
+        if debug > 1:
+            print('socket: old umask: %s, new umask: %s' % \
+                 (oct(old_umask), oct(new_umask)))
+
+        # Try setting the new uid/gid
+        try:
+            os.setgid(running_gid)
+        except OSError as e:
+            print('could not set effective group id: {}'.format(e))
+        try:
+            os.setuid(running_uid)
+        except OSError as e:
+            print('could not set effective user id: {}'.format(e))
+
+    final_uid = os.getuid()
+    final_gid = os.getgid()
+
+    if debug > 0:
+        print('socket: running as {}:{}'.format(pwd.getpwuid(final_uid)[0], grp.getgrgid(final_gid)[0]))
+
+    # Make sure the socket does not exist
+    if os.path.exists(args.socket):
+        raise OSError("socket {} already exists; exiting...".format(args.socket))
+
+    # Create socket
+    sock = socket.socket(socket.AF_UNIX, socket.SOCK_STREAM)
+
+    # Bind the socket to the port
+    if debug > 2:
+        print('starting up on {}'.format(args.socket))
+    sock.bind(args.socket)
+    atexit.register(socket_cleanup, args.socket, debug)
+    
+    # Listen for incoming connections
+    sock.listen(1)
+
+    while True:
+        connection = None
+        client_address = None
+
+        try:
+            # Wait for a connection
+            if debug > 2:
+                print('socket: waiting for a connection')
+            connection, client_address = sock.accept()
+
+            request_data = dict()
+            request_data = read_request(connection, debug)
+            client = request_data['client'] or 'unknown'
+
+            match request_data['command']:
+                case 'REGISTER':
+                    connected_clients.append(client)
+
+                    send_response(connection, {'status': 'REGISTERED', 'client': client}, debug)
+
+                case 'DEREGISTER':
+                    try:
+                        connected_clients.remove(client)
+                    except:
+                        pass
+
+                    send_response(connection, {'status': 'DEREGISTERED', 'client': client}, debug)
+
+                case 'GET':
+                    print("reading data, current timestamp is {}, time is {}".format(timestamp, time.time()))
+                    # only get new data five seconds after the last read
+                    if timestamp <= time.time() - 5:
+                        current_data = None
+                        # Retry every second until we get a result
+                        while bool(current_data) is False:
+                            current_data = collect_data(ser, debug)
                             time.sleep(1)
+                        timestamp = time.time()
+                        current_data['client'] = client
   
-            if args.report_json:
-                print(json.dumps(data))
+                    send_response(connection, current_data, debug)
+
+                case _:
+                    print('socket: invalid request from {}'.format(request_data['client']))
+                    break
 
-            elif args.report_print:
-                pp = pprint.PrettyPrinter(indent=4)
-                pp.pprint(data)
         except KeyboardInterrupt:
-        cleanup()
+            if connection:
+                connection.close()
+            sys.exit(1)
 
+        finally:
+            # Clean up the connection
+            if connection:
+                connection.close()
 
-
-if __name__ == '__main__':
-    debug = 0
-    atexit.register(cleanup)
-    atexit.register(shutdown)
+if __name__ == "__main__":
     main()

pyproject.toml

@@ -1,6 +1,6 @@
 [tool.poetry]
 name = "bmspy"
-version = "1.0"
+version = "2.0"
 description = "bmspy is a tool to get information from a xiaoxiang-type BMS system"
 authors = ["Timothy Allen <tim@treehouse.org.za>"]
 license = "CC BY-NC-SA 4.0"
@@ -21,4 +21,8 @@ requires = ["poetry-core"]
 build-backend = "poetry.core.masonry.api"
 
 [tool.poetry.scripts]
-bmspy = "bmspy.bms:main"
+bmspy = "bmspy:main"
+bmspy-server = "bmspy.server:main"
+bmspy-influxdb = "bmspy.influxdb:main"
+bmspy-prometheus = "bmspy.prometheus:main"
+#bmspy-usbd = "bmspy.usbhid:main"