[consutil] Remove actual baud and refactor lib for future change (#1130)

* [update] removed actual baud from consutil show result table
* [refine] ensure only 1 db querying per command
* [refine] refactor code for better reusing in future
* [new] add a new return value ERR_CFG for indicating configuration issue

Signed-off-by: jika@microsoft.com

consutil/lib.py

@@ -18,6 +18,7 @@
 
 ERR_CMD = 1
 ERR_DEV = 2
+ERR_CFG = 3
 
 CONSOLE_PORT_TABLE = "CONSOLE_PORT"
 LINE_KEY = "LINE"
@@ -47,48 +48,34 @@ def run_command(cmd):
  sys.exit(ERR_CMD)
  return output
 
-# returns a sorted list of all devices
-def getAllDevices():
+# returns a list of all lines
+def getAllLines():
  config_db = ConfigDBConnector()
  config_db.connect()
 
  # Querying CONFIG_DB to get configured console ports
  keys = config_db.get_keys(CONSOLE_PORT_TABLE)
- devices = []
+ lines = []
  for k in keys:
- device = config_db.get_entry(CONSOLE_PORT_TABLE, k)
- device[LINE_KEY] = k
- devices.append(device)
+ line = config_db.get_entry(CONSOLE_PORT_TABLE, k)
+ line[LINE_KEY] = k
+ lines.append(line)
 
  # Querying device directory to get all available console ports 
  cmd = "ls " + DEVICE_PREFIX + "*"
  output = run_command(cmd)
-
  availableTtys = output.split('\n')
  availableTtys = list(filter(lambda dev: re.match(DEVICE_PREFIX + r"\d+", dev) != None, availableTtys))
  for tty in availableTtys:
  k = tty[len(DEVICE_PREFIX):]
  if k not in keys:
- device = { LINE_KEY: k }
- devices.append(device)
-
- devices.sort(key=lambda dev: int(dev[LINE_KEY]))
- return devices
-
-# exits if inputted line number does not correspond to a device
-# input: linenum
-def checkDevice(linenum):
- config_db = ConfigDBConnector()
- config_db.connect()
-
- entry = config_db.get_entry(CONSOLE_PORT_TABLE, str(linenum))
- if not entry:
- click.echo("Line number {} does not exist".format(linenum))
- sys.exit(ERR_DEV)
+ line = { LINE_KEY: k }
+ lines.append(line)
+ return lines
 
-# returns a dictionary of busy devices and their info
+# returns a dictionary of busy lines and their info
 # maps line number to (pid, process start time)
-def getBusyDevices():
+def getBusyLines():
  cmd = 'ps -eo pid,lstart,cmd | grep -E "(mini|pico)com"'
  output = run_command(cmd)
  processes = output.split('\n')
@@ -103,48 +90,33 @@ def getBusyDevices():
  regexCmd = r"\S*(?:(?:mini)|(?:pico))com .*" + DEVICE_PREFIX + r"(\d+)(?: .*)?"
  regexProcess = re.compile(r"^"+regexPid+r" "+regexDate+r" "+regexCmd+r"$")
 
- busyDevices = {}
+ busyLines = {}
  for process in processes:
  match = regexProcess.match(process)
  if match != None:
  pid = match.group(1)
  date = match.group(2)
  linenum_key = match.group(3)
- busyDevices[linenum_key] = (pid, date)
- return busyDevices
-
-# returns actual baud rate, configured baud rate,
-# and flow control settings of device corresponding to line number
-# input: linenum (str), output: (actual baud (str), configured baud (str), flow control (bool))
-def getConnectionInfo(linenum):
- config_db = ConfigDBConnector()
- config_db.connect()
- entry = config_db.get_entry(CONSOLE_PORT_TABLE, str(linenum))
+ busyLines[linenum_key] = (pid, date)
+ return busyLines
 
- conf_baud = "-" if BAUD_KEY not in entry else entry[BAUD_KEY]
- act_baud = DEFAULT_BAUD if conf_baud == "-" else conf_baud
- flow_control = False
- if FLOW_KEY in entry and entry[FLOW_KEY] == "1":
- flow_control = True
-
- return (act_baud, conf_baud, flow_control)
-
-# returns the line number corresponding to target, or exits if line number cannot be found
+# returns the target device corresponding to target, or None if line number connot be found
 # if deviceBool, interprets target as device name
 # otherwise interprets target as line number
-# input: target (str), deviceBool (bool), output: linenum (str)
-def getLineNumber(target, deviceBool):
- if not deviceBool:
- return target
-
- config_db = ConfigDBConnector()
- config_db.connect()
-
- devices = getAllDevices()
- for device in devices:
- if DEVICE_KEY in device and device[DEVICE_KEY] == target:
- return device[LINE_KEY]
-
- click.echo("Device {} does not exist".format(target))
- sys.exit(ERR_DEV)
- return ""
+# input: target (str), deviceBool (bool), output: device (dict)
+def getLine(target, deviceBool=False):
+ lines = getAllLines()
+
+ # figure out the search key
+ searchKey = LINE_KEY
+ if deviceBool:
+ searchKey = DEVICE_KEY
+
+ # identify the line number by searching configuration
+ lineNumber = None
+ for line in lines:
+ if searchKey in line and line[searchKey] == target:
+ lineNumber = line[LINE_KEY]
+ targetLine = line
+
+ return targetLine if lineNumber else None

consutil/main.py

@@ -21,66 +21,80 @@ def consutil():
 
  if os.geteuid() != 0:
  click.echo("Root privileges are required for this operation")
- sys.exit(1)
+ sys.exit(ERR_CMD)
 
 # 'show' subcommand
 @consutil.command()
 def show():
- """Show all /dev/ttyUSB lines and their info"""
- devices = getAllDevices()
- busyDevices = getBusyDevices()
+ """Show all lines and their info"""
+ lines = getAllLines()
+ busyLines = getBusyLines()
 
- header = ["Line", "Actual/Configured Baud", "PID", "Start Time", "Device"]
+ # sort lines for table rendering
+ lines.sort(key=lambda dev: int(dev[LINE_KEY]))
+
+ # set table header style
+ header = ["Line", "Baud", "PID", "Start Time", "Device"]
  body = []
- for device in devices:
- lineNum = device[LINE_KEY]
+ for line in lines:
+ # configured information
+ lineNum = line[LINE_KEY]
+ baud = '-' if BAUD_KEY not in line else line[BAUD_KEY]
+ remoteDevice = '-' if DEVICE_KEY not in line else line[DEVICE_KEY]
+
+ # runtime information
  busy = " "
  pid = ""
  date = ""
- remoteDevice = '-' if DEVICE_KEY not in device else device[DEVICE_KEY]
- if lineNum in busyDevices:
- pid, date = busyDevices[lineNum]
+ if lineNum in busyLines:
+ pid, date = busyLines[lineNum]
  busy = "*"
- actBaud, confBaud, _ = getConnectionInfo(lineNum)
- # repeated "~" will be replaced by spaces - hacky way to align the "/"s
- baud = "{}/{}{}".format(actBaud, confBaud, "~"*(15-len(confBaud)))
  body.append([busy+lineNum, baud, pid, date, remoteDevice])
-
- # replace repeated "~" with spaces - hacky way to align the "/"s
- click.echo(tabulate(body, header, stralign="right").replace('~', ' ')) 
+ click.echo(tabulate(body, header, stralign='right')) 
 
 # 'clear' subcommand
 @consutil.command()
-@click.argument('linenum')
-def clear(linenum):
+@click.argument('target')
+def clear(target):
  """Clear preexisting connection to line"""
- checkDevice(linenum)
- linenum = str(linenum)
+ targetLine = getLine(target)
+ if not targetLine:
+ click.echo("Target [{}] does not exist".format(linenum))
+ sys.exit(ERR_DEV)
+ lineNumber = targetLine[LINE_KEY]
 
- busyDevices = getBusyDevices()
- if linenum in busyDevices:
- pid, _ = busyDevices[linenum]
+ busyLines = getBusyLines()
+ if lineNumber in busyLines:
+ pid, _ = busyLines[lineNumber]
  cmd = "sudo kill -SIGTERM " + pid
  click.echo("Sending SIGTERM to process " + pid)
  run_command(cmd)
  else:
- click.echo("No process is connected to line " + linenum)
+ click.echo("No process is connected to line " + lineNumber)
 
 # 'connect' subcommand
 @consutil.command()
 @click.argument('target')
 @click.option('--devicename', '-d', is_flag=True, help="connect by name - if flag is set, interpret linenum as device name instead")
 def connect(target, devicename):
  """Connect to switch via console device - TARGET is line number or device name of switch"""
- lineNumber = getLineNumber(target, devicename)
- checkDevice(lineNumber)
- lineNumber = str(lineNumber)
+ # identify the target line
+ targetLine = getLine(target, devicename)
+ if not targetLine:
+ click.echo("Cannot connect: target [{}] does not exist".format(target))
+ sys.exit(ERR_DEV)
+ lineNumber = targetLine[LINE_KEY]
 
  # build and start picocom command
- actBaud, _, flowBool = getConnectionInfo(lineNumber)
+ if BAUD_KEY in targetLine:
+ baud = targetLine[BAUD_KEY]
+ else:
+ click.echo("Cannot connect: line [{}] has no baud rate".format(lineNumber))
+ sys.exit(ERR_CFG)
+ flowBool = True if FLOW_KEY in targetLine and targetLine[FLOW_KEY] == "1" else False
  flowCmd = "h" if flowBool else "n"
  quietCmd = "-q" if QUIET else ""
- cmd = "sudo picocom -b {} -f {} {} {}{}".format(actBaud, flowCmd, quietCmd, DEVICE_PREFIX, lineNumber)
+ cmd = "sudo picocom -b {} -f {} {} {}{}".format(baud, flowCmd, quietCmd, DEVICE_PREFIX, lineNumber)
  proc = pexpect.spawn(cmd)
  proc.send("\n")
 
@@ -106,4 +120,4 @@ def connect(target, devicename):
  click.echo("Cannot connect: unable to open picocom process")
 
 if __name__ == '__main__':
- consutil()
+ consutil()