Add support for running a specific (non-auto) monitor in runmonitors.py

The ability to pass options to the sub-program with "--opts" is *definitely*
clunky, but I don't have the time nor motivation to do that part "right" at the
moment. Whoops.

runmonitors.py

@@ -6,16 +6,29 @@ import socket
 import subprocess
 import sys
 
+
+def run_monitor(filename, args):
+    p = subprocess.Popen([sys.executable, filename] + args, stdout=subprocess.PIPE)
+    out, err = p.communicate()
+    return [r.strip() for r in out.split('\n') if r]
+
+
 def main():
     options = optparse.OptionParser()
     options.add_option('-p', '--port', default=2003, dest='port',
                         help='Define the port where Carbon is running')
+    options.add_option('-d', '--debug', dest='debug', action='store_true',
+                        help='Switch runmonitors.py into debug mode, which prevents it from connecting to Carbon')
     options.add_option('--host', default='127.0.0.1', dest='host',
                         help='Define the host where Carbon is running')
     options.add_option('--prefix', dest='prefix',
                         help='Prefix to pass along to all monitors (to prefix the label in Graphite)')
     options.add_option('--suffix', dest='suffix',
                         help='Suffix for all monitors, useful for identifying the machine')
+    options.add_option('-f', '--file', default=None, dest='file',
+                        help='Run a specific monitor file')
+    options.add_option('--opts', dest='fopts',
+                        help='Options string to pass to the monitor being executed')
 
     opts, args = options.parse_args()
 
@@ -25,11 +38,21 @@ def main():
     if opts.suffix:
         args = args + ['-s', opts.suffix]
 
+    if opts.fopts:
+        args = args + opts.fopts.split(' ')
+
     messages = []
-    for f in glob.iglob('monitors/auto/*'):
-        p = subprocess.Popen([sys.executable, f] + args, stdout=subprocess.PIPE)
-        out, err = p.communicate()
-        messages.extend([r.strip() for r in out.split('\n') if r])
+
+    if opts.file:
+        messages.extend(run_monitor(opts.file, args))
+    else:
+        for f in glob.iglob('monitors/auto/*'):
+            messages.extend(run_monitor(f, args))
+
+    if opts.debug:
+        for m in messages:
+            print m
+        return 0
 
     packet = '\n'.join(messages) + '\n'