Source Code for Module Ganga.Lib.MonitoringServices.Dashboard.CommonUtil

 1  """Common utilities. 
 2   
 3  N.B. This code is under development and should not generally be used or relied upon. 
 4   
 5  """ 
 6   
 7  #----- utility methods ----- 
 8   
 9 -def env(key): 
10      """Return the environment variable value corresponding to key. 
11       
12      If the variable is undefined or empty then None is returned. 
13      """ 
14      import os 
15      return strip_to_none(os.environ.get(key)) 
16       
17  # utility method copied from Ganga.Utility.util 
18 -def hostname(): 
19      """ Try to get the hostname in the most possible reliable way as described in the Python LibRef.""" 
20      import socket 
21      try: 
22          return socket.gethostbyaddr(socket.gethostname())[0] 
23      # [bugfix #20333]:  
24      # while working offline and with an improper /etc/hosts configuration        
25      # the localhost cannot be resolved  
26      except: 
27          return 'localhost' 
28   
29 -def stdout(command): 
30      """Execute the command in a subprocess and return stdout. 
31       
32      If the exit code is non-zero then None is returned. 
33      """ 
34      import popen2 
35      p = popen2.Popen3(command) 
36      rc = p.wait() 
37      if rc == 0: 
38          return p.fromchild.read() 
39      else: 
40          return None 
41   
42 -def strip_to_none(value): 
43      """Returns the stripped string representation of value, or None if this is 
44      None or an empty string.""" 
45      if value is None: 
46          return None 
47      text = str(value).strip() 
48      if len(text) == 0: 
49          return None 
50      return text 
51   
52 -def utcnow(): 
53      """Return a UTC datetime with no timezone specified.""" 
54      import datetime 
55      return datetime.datetime.utcnow() 
56