[consutil] Remove actual baud and refactor lib for future change

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()