Add function to get all local IP addresses, will be used in cmdlib.py.

Reviewed-by: schreiberal

lib/utils.py

@@ -749,3 +749,38 @@ def ShellQuoteArgs(args):
 
   """
   return ' '.join([ShellQuote(i) for i in args])
+
+
+def _ParseIpOutput(output):
+  """Parsing code for GetLocalIPAddresses().
+
+  This function is split out, so we can unit test it.
+
+  """
+  re_ip = re.compile('^(\d+\.\d+\.\d+\.\d+)(?:/\d+)$')
+
+  ips = []
+  for line in output.splitlines(False):
+    fields = line.split()
+    if len(line) < 4:
+      continue
+    m = re_ip.match(fields[3])
+    if m:
+      ips.append(m.group(1))
+
+  return ips
+
+
+def GetLocalIPAddresses():
+  """Gets a list of all local IP addresses.
+
+  Should this break one day, a small Python module written in C could
+  use the API call getifaddrs().
+
+  """
+  result = RunCmd(["ip", "-family", "inet", "-oneline", "addr", "show"])
+  if result.failed:
+    raise errors.OpExecError("Command '%s' failed, error: %s,"
+      " output: %s" % (result.cmd, result.fail_reason, result.output))
+
+  return _ParseIpOutput(result.output)

testing/ganeti.utils_unittest.py

@@ -32,7 +32,7 @@ import ganeti
 from ganeti.utils import IsProcessAlive, Lock, Unlock, RunCmd, \
      RemoveFile, CheckDict, MatchNameComponent, FormatUnit, \
      ParseUnit, AddAuthorizedKey, RemoveAuthorizedKey, \
-     ShellQuote, ShellQuoteArgs
+     ShellQuote, ShellQuoteArgs, _ParseIpOutput
 from ganeti.errors import LockError, UnitParseError
 
 class TestIsProcessAlive(unittest.TestCase):
@@ -424,5 +424,31 @@ class TestShellQuoting(unittest.TestCase):
     self.assertEqual(ShellQuoteArgs(['a', 'b\'', 'c']), "a 'b'\\\''' c")
 
 
+class TestIpAdressList(unittest.TestCase):
+  """Test case for local IP addresses"""
+
+  def _test(self, output, required):
+    ips = _ParseIpOutput(output)
+
+    # Sort the output, so our check below works in all cases
+    ips.sort()
+    required.sort()
+
+    self.assertEqual(required, ips)
+
+  def testSingleIpAddress(self):
+    output = \
+      ("3: lo    inet 127.0.0.1/8 brd 127.255.255.255 scope host lo\n"
+       "5: eth0    inet 10.0.0.1/24 brd 172.30.15.127 scope global eth0\n")
+    self._test(output, ['127.0.0.1', '10.0.0.1'])
+
+  def testMultipleIpAddresses(self):
+    output = \
+      ("3: lo    inet 127.0.0.1/8 brd 127.255.255.255 scope host lo\n"
+       "5: eth0    inet 10.0.0.1/24 brd 172.30.15.127 scope global eth0\n"
+       "5: eth0    inet 1.2.3.4/8 brd 1.255.255.255 scope global eth0:test\n")
+    self._test(output, ['127.0.0.1', '10.0.0.1', '1.2.3.4'])
+
+
 if __name__ == '__main__':
   unittest.main()