1 | # Python interface to remctl. |
---|
2 | # |
---|
3 | # This is the high-level interface that most Python programs that use remctl |
---|
4 | # should be using. It's a Python wrapper around the _remctl C module, which |
---|
5 | # exposes exactly the libremctl API. |
---|
6 | # |
---|
7 | # Original implementation by Thomas L. Kula <kula@tproa.net> |
---|
8 | # Copyright 2008 Thomas L. Kula <kula@tproa.net> |
---|
9 | # Copyright 2008 Board of Trustees, Leland Stanford Jr. University |
---|
10 | # |
---|
11 | # Permission to use, copy, modify, and distribute this software and its |
---|
12 | # documentation for any purpose and without fee is hereby granted, provided |
---|
13 | # that the above copyright notice appear in all copies and that both that |
---|
14 | # copyright notice and this permission notice appear in supporting |
---|
15 | # documentation, and that the name of Thomas L. Kula not be used in |
---|
16 | # advertising or publicity pertaining to distribution of the software without |
---|
17 | # specific, written prior permission. Thomas L. Kula makes no representations |
---|
18 | # about the suitability of this software for any purpose. It is provided "as |
---|
19 | # is" without express or implied warranty. |
---|
20 | # |
---|
21 | # THIS SOFTWARE IS PROVIDED "AS IS" AND WITHOUT ANY EXPRESS OR IMPLIED |
---|
22 | # WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED WARRANTIES OF |
---|
23 | # MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE. |
---|
24 | |
---|
25 | """Interface to remctl. |
---|
26 | |
---|
27 | This module is an interface to remctl, a client/server |
---|
28 | protocol for running single commands on a remote host |
---|
29 | using Kerberos v5 authentication. |
---|
30 | """ |
---|
31 | |
---|
32 | VERSION = '2.14' |
---|
33 | |
---|
34 | import _remctl |
---|
35 | |
---|
36 | # Exception classes. |
---|
37 | |
---|
38 | class RemctlError(Exception): |
---|
39 | """The underlying remctl library has returned an error.""" |
---|
40 | def __init__(self, value): |
---|
41 | self.value = value |
---|
42 | def __str__(self): |
---|
43 | return str(self.value) |
---|
44 | |
---|
45 | class RemctlProtocolError(RemctlError): |
---|
46 | """A remctl protocol error occurred. |
---|
47 | |
---|
48 | This exception is only used with the remctl.remctl() simple interface; |
---|
49 | for the full interface, errors are returned as a regular output token. |
---|
50 | """ |
---|
51 | pass |
---|
52 | |
---|
53 | class RemctlNotOpenedError(RemctlError): |
---|
54 | """No open connection to a server.""" |
---|
55 | pass |
---|
56 | |
---|
57 | # Simple interface. |
---|
58 | |
---|
59 | class RemctlSimpleResult: |
---|
60 | """An object holding the results from the simple interface.""" |
---|
61 | def __init__(self): |
---|
62 | self.stdout = None |
---|
63 | self.stderr = None |
---|
64 | self.status = None |
---|
65 | |
---|
66 | def remctl(host, port = None, principal = None, command = []): |
---|
67 | """Simple interface to remctl. |
---|
68 | |
---|
69 | Connect to HOST on PORT, using PRINCIPAL as the server principal for |
---|
70 | authentication, and issue COMMAND. Returns the result as a |
---|
71 | RemctlSimpleResult object, which has three attributes. stdout holds the |
---|
72 | complete standard output, stderr holds the complete standard error, and |
---|
73 | status holds the exit status. |
---|
74 | """ |
---|
75 | if port == None: |
---|
76 | port = 0 |
---|
77 | else: |
---|
78 | try: |
---|
79 | port = int(port) |
---|
80 | except ValueError: |
---|
81 | raise TypeError, 'port must be a number: ' + `port` |
---|
82 | if (port < 0) or (port > 65535): |
---|
83 | raise ValueError, 'invalid port number: ' + `port` |
---|
84 | if isinstance(command, (basestring, bool, int, float)): |
---|
85 | raise TypeError, 'command must be a sequence or iterator' |
---|
86 | |
---|
87 | # Convert the command to a list of strings. |
---|
88 | mycommand = [] |
---|
89 | for item in command: |
---|
90 | mycommand.append(str(item)) |
---|
91 | if len(mycommand) < 1: |
---|
92 | raise ValueError, 'command must not be empty' |
---|
93 | |
---|
94 | # At this point, things should be sane. Call the low-level interface. |
---|
95 | output = _remctl.remctl(host, port, principal, mycommand) |
---|
96 | if output[0] != None: |
---|
97 | raise RemctlProtocolError, output[0] |
---|
98 | result = RemctlSimpleResult() |
---|
99 | setattr(result, 'stdout', output[1]) |
---|
100 | setattr(result, 'stderr', output[2]) |
---|
101 | setattr(result, 'status', output[3]) |
---|
102 | return result |
---|
103 | |
---|
104 | # Complex interface. |
---|
105 | |
---|
106 | class Remctl: |
---|
107 | def __init__(self, host = None, port = None, principal = None): |
---|
108 | self.r = _remctl.remctl_new() |
---|
109 | self.opened = False |
---|
110 | |
---|
111 | if host != None: |
---|
112 | self.open(host, port, principal) |
---|
113 | |
---|
114 | def open(self, host, port = None, principal = None): |
---|
115 | if port == None: |
---|
116 | port = 0 |
---|
117 | else: |
---|
118 | try: |
---|
119 | port = int(port) |
---|
120 | except ValueError: |
---|
121 | raise TypeError, 'port must be a number: ' + `port` |
---|
122 | if (port < 0) or (port > 65535): |
---|
123 | raise ValueError, 'invalid port number: ' + `port` |
---|
124 | |
---|
125 | # At this point, things should be sane. Call the low-level interface. |
---|
126 | if not _remctl.remctl_open(self.r, host, port, principal): |
---|
127 | raise RemctlError, self.error() |
---|
128 | self.opened = True |
---|
129 | |
---|
130 | def command(self, comm): |
---|
131 | commlist = [] |
---|
132 | if not self.opened: |
---|
133 | raise RemctlNotOpenedError, 'no currently open connection' |
---|
134 | if isinstance(comm, (basestring, bool, int, float)): |
---|
135 | raise TypeError, 'command must be a sequence or iterator' |
---|
136 | |
---|
137 | # Convert the command to a list of strings. |
---|
138 | for item in comm: |
---|
139 | commlist.append(str(item)) |
---|
140 | if len(commlist) < 1: |
---|
141 | raise ValueError, 'command must not be empty' |
---|
142 | |
---|
143 | # At this point, things should be sane. Call the low-level interface. |
---|
144 | if not _remctl.remctl_commandv(self.r, commlist): |
---|
145 | raise RemctlError, self.error() |
---|
146 | |
---|
147 | def output(self): |
---|
148 | if not self.opened: |
---|
149 | raise RemctlNotOpenedError, 'no currently open connection' |
---|
150 | return _remctl.remctl_output(self.r) |
---|
151 | |
---|
152 | def close(self): |
---|
153 | del(self.r) |
---|
154 | self.r = None |
---|
155 | self.opened = False |
---|
156 | |
---|
157 | def error(self): |
---|
158 | if self.r == None: |
---|
159 | # We do this instead of throwing an exception so that callers |
---|
160 | # don't have to handle an exception when they are trying to find |
---|
161 | # out why an exception occured. |
---|
162 | return 'no currently open connection' |
---|
163 | return _remctl.remctl_error(self.r) |
---|