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Michael Walshbd1bb602017-06-30 17:01:25 -05001#!/usr/bin/env python
2
3r"""
4This module provides many valuable ssh functions such as sprint_connection,
5execute_ssh_command, etc.
6"""
7
8import sys
9import re
Michael Walsh2575cd62017-11-01 17:03:45 -050010import socket
Michael Walshbd1bb602017-06-30 17:01:25 -050011import paramiko
George Keishing20a34c02018-09-24 11:26:04 -050012try:
13 import exceptions
14except ImportError:
15 import builtins as exception
Michael Walshbd1bb602017-06-30 17:01:25 -050016
17import gen_print as gp
Michael Walsha48eb1a2018-08-07 14:48:13 -050018import func_timer as ft
19func_timer = ft.func_timer_class()
Michael Walshbd1bb602017-06-30 17:01:25 -050020
21from robot.libraries.BuiltIn import BuiltIn
22from SSHLibrary import SSHLibrary
23sshlib = SSHLibrary()
24
25
Michael Walshbd1bb602017-06-30 17:01:25 -050026def sprint_connection(connection,
27 indent=0):
Michael Walshbd1bb602017-06-30 17:01:25 -050028 r"""
29 sprint data from the connection object to a string and return it.
30
31 connection A connection object which is created by
32 the SSHlibrary open_connection() function.
33 indent The number of characters to indent the
34 output.
35 """
36
37 buffer = gp.sindent("", indent)
38 buffer += "connection:\n"
39 indent += 2
40 buffer += gp.sprint_varx("index", connection.index, 0, indent)
41 buffer += gp.sprint_varx("host", connection.host, 0, indent)
42 buffer += gp.sprint_varx("alias", connection.alias, 0, indent)
43 buffer += gp.sprint_varx("port", connection.port, 0, indent)
44 buffer += gp.sprint_varx("timeout", connection.timeout, 0, indent)
45 buffer += gp.sprint_varx("newline", connection.newline, 0, indent)
46 buffer += gp.sprint_varx("prompt", connection.prompt, 0, indent)
47 buffer += gp.sprint_varx("term_type", connection.term_type, 0, indent)
48 buffer += gp.sprint_varx("width", connection.width, 0, indent)
49 buffer += gp.sprint_varx("height", connection.height, 0, indent)
50 buffer += gp.sprint_varx("path_separator", connection.path_separator, 0,
51 indent)
52 buffer += gp.sprint_varx("encoding", connection.encoding, 0, indent)
53
54 return buffer
55
Michael Walshbd1bb602017-06-30 17:01:25 -050056
Michael Walshbd1bb602017-06-30 17:01:25 -050057def sprint_connections(connections=None,
58 indent=0):
Michael Walshbd1bb602017-06-30 17:01:25 -050059 r"""
60 sprint data from the connections list to a string and return it.
61
62 connections A list of connection objects which are
63 created by the SSHlibrary open_connection
64 function. If this value is null, this
65 function will populate with a call to the
66 SSHlibrary get_connections() function.
67 indent The number of characters to indent the
68 output.
69 """
70
71 if connections is None:
72 connections = sshlib.get_connections()
73
74 buffer = ""
75 for connection in connections:
76 buffer += sprint_connection(connection, indent)
77
78 return buffer
79
Michael Walshbd1bb602017-06-30 17:01:25 -050080
Michael Walshbd1bb602017-06-30 17:01:25 -050081def find_connection(open_connection_args={}):
Michael Walshbd1bb602017-06-30 17:01:25 -050082 r"""
83 Find connection that matches the given connection arguments and return
84 connection object. Return False if no matching connection is found.
85
86 Description of argument(s):
87 open_connection_args A dictionary of arg names and values which
88 are legal to pass to the SSHLibrary
89 open_connection function as parms/args.
90 For a match to occur, the value for each
91 item in open_connection_args must match
92 the corresponding value in the connection
93 being examined.
94 """
95
96 global sshlib
97
98 for connection in sshlib.get_connections():
99 # Create connection_dict from connection object.
100 connection_dict = dict((key, str(value)) for key, value in
101 connection._config.iteritems())
102 if dict(connection_dict, **open_connection_args) == connection_dict:
103 return connection
104
105 return False
106
Michael Walshbd1bb602017-06-30 17:01:25 -0500107
Michael Walshbd1bb602017-06-30 17:01:25 -0500108def login_ssh(login_args={},
109 max_login_attempts=5):
Michael Walshbd1bb602017-06-30 17:01:25 -0500110 r"""
111 Login on the latest open SSH connection. Retry on failure up to
112 max_login_attempts.
113
114 The caller is responsible for making sure there is an open SSH connection.
115
116 Description of argument(s):
117 login_args A dictionary containing the key/value
118 pairs which are acceptable to the
119 SSHLibrary login function as parms/args.
120 At a minimum, this should contain a
121 'username' and a 'password' entry.
122 max_login_attempts The max number of times to try logging in
123 (in the event of login failures).
124 """
125
Michael Walsha03a3312017-12-01 16:47:44 -0600126 gp.lprint_executing()
127
Michael Walshbd1bb602017-06-30 17:01:25 -0500128 global sshlib
129
130 # Get connection data for debug output.
131 connection = sshlib.get_connection()
Michael Walsha03a3312017-12-01 16:47:44 -0600132 gp.lprintn(sprint_connection(connection))
Michael Walshbd1bb602017-06-30 17:01:25 -0500133 for login_attempt_num in range(1, max_login_attempts + 1):
Michael Walsha03a3312017-12-01 16:47:44 -0600134 gp.lprint_timen("Logging in to " + connection.host + ".")
135 gp.lprint_var(login_attempt_num)
Michael Walshbd1bb602017-06-30 17:01:25 -0500136 try:
137 out_buf = sshlib.login(**login_args)
138 except Exception as login_exception:
139 # Login will sometimes fail if the connection is new.
140 except_type, except_value, except_traceback = sys.exc_info()
Michael Walsha03a3312017-12-01 16:47:44 -0600141 gp.lprint_var(except_type)
142 gp.lprint_varx("except_value", str(except_value))
Michael Walshbd1bb602017-06-30 17:01:25 -0500143 if except_type is paramiko.ssh_exception.SSHException and\
144 re.match(r"No existing session", str(except_value)):
145 continue
146 else:
147 # We don't tolerate any other error so break from loop and
148 # re-raise exception.
149 break
150 # If we get to this point, the login has worked and we can return.
Michael Walsha03a3312017-12-01 16:47:44 -0600151 gp.lpvar(out_buf)
Michael Walshbd1bb602017-06-30 17:01:25 -0500152 return
153
154 # If we get to this point, the login has failed on all attempts so the
155 # exception will be raised again.
156 raise(login_exception)
157
Michael Walshbd1bb602017-06-30 17:01:25 -0500158
Michael Walshbd1bb602017-06-30 17:01:25 -0500159def execute_ssh_command(cmd_buf,
160 open_connection_args={},
161 login_args={},
162 print_out=0,
163 print_err=0,
164 ignore_err=1,
165 fork=0,
166 quiet=None,
Michael Walsha48eb1a2018-08-07 14:48:13 -0500167 test_mode=None,
168 time_out=None):
Michael Walshbd1bb602017-06-30 17:01:25 -0500169 r"""
170 Run the given command in an SSH session and return the stdout, stderr and
171 the return code.
172
173 If there is no open SSH connection, this function will connect and login.
174 Likewise, if the caller has not yet logged in to the connection, this
175 function will do the login.
176
Michael Walsh8243ac92018-05-02 13:47:07 -0500177 NOTE: There is special handling when open_connection_args['alias'] equals
178 "device_connection".
179 - A write, rather than an execute_command, is done.
180 - Only stdout is returned (no stderr or rc).
181 - print_err, ignore_err and fork are not supported.
182
Michael Walshbd1bb602017-06-30 17:01:25 -0500183 Description of arguments:
184 cmd_buf The command string to be run in an SSH
185 session.
186 open_connection_args A dictionary of arg names and values which
187 are legal to pass to the SSHLibrary
188 open_connection function as parms/args.
189 At a minimum, this should contain a 'host'
190 entry.
191 login_args A dictionary containing the key/value
192 pairs which are acceptable to the
193 SSHLibrary login function as parms/args.
194 At a minimum, this should contain a
195 'username' and a 'password' entry.
196 print_out If this is set, this function will print
197 the stdout/stderr generated by the shell
198 command.
199 print_err If show_err is set, this function will
200 print a standardized error report if the
201 shell command returns non-zero.
202 ignore_err Indicates that errors encountered on the
203 sshlib.execute_command are to be ignored.
204 fork Indicates that sshlib.start is to be used
205 rather than sshlib.execute_command.
206 quiet Indicates whether this function should run
207 the pissuing() function which prints an
208 "Issuing: <cmd string>" to stdout. This
209 defaults to the global quiet value.
210 test_mode If test_mode is set, this function will
211 not actually run the command. This
212 defaults to the global test_mode value.
Michael Walsha48eb1a2018-08-07 14:48:13 -0500213 time_out The amount of time to allow for the
214 execution of cmd_buf. A value of None
215 means that there is no limit to how long
216 the command may take.
Michael Walshbd1bb602017-06-30 17:01:25 -0500217 """
218
Michael Walsha03a3312017-12-01 16:47:44 -0600219 gp.lprint_executing()
Michael Walshbd1bb602017-06-30 17:01:25 -0500220
221 # Obtain default values.
222 quiet = int(gp.get_var_value(quiet, 0))
223 test_mode = int(gp.get_var_value(test_mode, 0))
224
225 if not quiet:
226 gp.pissuing(cmd_buf, test_mode)
Michael Walsha03a3312017-12-01 16:47:44 -0600227 gp.lpissuing(cmd_buf, test_mode)
Michael Walshbd1bb602017-06-30 17:01:25 -0500228
229 if test_mode:
230 return "", "", 0
231
232 global sshlib
233
Michael Walsh019817d2018-07-24 16:00:06 -0500234 max_exec_cmd_attempts = 2
Michael Walshbd1bb602017-06-30 17:01:25 -0500235 # Look for existing SSH connection.
236 # Prepare a search connection dictionary.
237 search_connection_args = open_connection_args.copy()
238 # Remove keys that don't work well for searches.
239 search_connection_args.pop("timeout", None)
240 connection = find_connection(search_connection_args)
241 if connection:
Michael Walsha03a3312017-12-01 16:47:44 -0600242 gp.lprint_timen("Found the following existing connection:")
243 gp.lprintn(sprint_connection(connection))
Michael Walshbd1bb602017-06-30 17:01:25 -0500244 if connection.alias == "":
245 index_or_alias = connection.index
246 else:
247 index_or_alias = connection.alias
Joy Onyerikwu004ad3c2018-06-11 16:29:56 -0500248 gp.lprint_timen("Switching to existing connection: \""
249 + str(index_or_alias) + "\".")
Michael Walshbd1bb602017-06-30 17:01:25 -0500250 sshlib.switch_connection(index_or_alias)
251 else:
Michael Walsha03a3312017-12-01 16:47:44 -0600252 gp.lprint_timen("Connecting to " + open_connection_args['host'] + ".")
Michael Walshbd1bb602017-06-30 17:01:25 -0500253 cix = sshlib.open_connection(**open_connection_args)
Michael Walsh019817d2018-07-24 16:00:06 -0500254 try:
255 login_ssh(login_args)
256 except Exception as login_exception:
257 except_type, except_value, except_traceback = sys.exc_info()
258 rc = 1
259 stderr = str(except_value)
260 stdout = ""
261 max_exec_cmd_attempts = 0
Michael Walshbd1bb602017-06-30 17:01:25 -0500262
Michael Walshbd1bb602017-06-30 17:01:25 -0500263 for exec_cmd_attempt_num in range(1, max_exec_cmd_attempts + 1):
Michael Walsha03a3312017-12-01 16:47:44 -0600264 gp.lprint_var(exec_cmd_attempt_num)
Michael Walshbd1bb602017-06-30 17:01:25 -0500265 try:
266 if fork:
267 sshlib.start_command(cmd_buf)
268 else:
Michael Walsh8243ac92018-05-02 13:47:07 -0500269 if open_connection_args['alias'] == "device_connection":
270 stdout = sshlib.write(cmd_buf)
271 stderr = ""
272 rc = 0
273 else:
274 stdout, stderr, rc = \
Michael Walsha48eb1a2018-08-07 14:48:13 -0500275 func_timer.run(sshlib.execute_command,
276 cmd_buf,
277 return_stdout=True,
278 return_stderr=True,
279 return_rc=True,
280 time_out=time_out)
Michael Walshbd1bb602017-06-30 17:01:25 -0500281 except Exception as execute_exception:
282 except_type, except_value, except_traceback = sys.exc_info()
Michael Walsha03a3312017-12-01 16:47:44 -0600283 gp.lprint_var(except_type)
284 gp.lprint_varx("except_value", str(except_value))
Michael Walsha24de032018-11-01 14:03:30 -0500285 # This may be our last time through the retry loop, so setting
286 # return variables.
287 rc = 1
288 stderr = str(except_value)
289 stdout = ""
Michael Walshbd1bb602017-06-30 17:01:25 -0500290
291 if except_type is exceptions.AssertionError and\
292 re.match(r"Connection not open", str(except_value)):
Michael Walsh3e792622018-08-20 11:17:41 -0500293 try:
294 login_ssh(login_args)
295 # Now we must continue to next loop iteration to retry the
296 # execute_command.
297 continue
298 except Exception as login_exception:
299 except_type, except_value, except_traceback =\
300 sys.exc_info()
301 rc = 1
302 stderr = str(except_value)
303 stdout = ""
304 break
305
Joy Onyerikwu004ad3c2018-06-11 16:29:56 -0500306 if (except_type is paramiko.ssh_exception.SSHException
307 and re.match(r"SSH session not active", str(except_value))) or\
308 (except_type is socket.error
309 and re.match(r"\[Errno 104\] Connection reset by peer",
Michael Walshe2bcab82018-10-02 15:16:42 -0500310 str(except_value))) or\
311 (except_type is paramiko.ssh_exception.SSHException
312 and re.match(r"Timeout opening channel\.",
Joy Onyerikwu004ad3c2018-06-11 16:29:56 -0500313 str(except_value))):
Michael Walshbd1bb602017-06-30 17:01:25 -0500314 # Close and re-open a connection.
Michael Walsh2575cd62017-11-01 17:03:45 -0500315 # Note: close_connection() doesn't appear to get rid of the
316 # connection. It merely closes it. Since there is a concern
317 # about over-consumption of resources, we use
318 # close_all_connections() which also gets rid of all
319 # connections.
Michael Walsha03a3312017-12-01 16:47:44 -0600320 gp.lprint_timen("Closing all connections.")
Michael Walsh2575cd62017-11-01 17:03:45 -0500321 sshlib.close_all_connections()
Joy Onyerikwu004ad3c2018-06-11 16:29:56 -0500322 gp.lprint_timen("Connecting to "
323 + open_connection_args['host'] + ".")
Michael Walshbd1bb602017-06-30 17:01:25 -0500324 cix = sshlib.open_connection(**open_connection_args)
325 login_ssh(login_args)
326 continue
327
328 # We do not handle any other RuntimeErrors so we will raise the
329 # exception again.
Michael Walshe77585a2017-12-14 11:02:28 -0600330 sshlib.close_all_connections()
Michael Walshbd1bb602017-06-30 17:01:25 -0500331 raise(execute_exception)
332
333 # If we get to this point, the command was executed.
334 break
335
336 if fork:
337 return
338
339 if rc != 0 and print_err:
340 gp.print_var(rc, 1)
341 if not print_out:
342 gp.print_var(stderr)
343 gp.print_var(stdout)
344
345 if print_out:
346 gp.printn(stderr + stdout)
347
348 if not ignore_err:
Joy Onyerikwu004ad3c2018-06-11 16:29:56 -0500349 message = gp.sprint_error("The prior SSH"
350 + " command returned a non-zero return"
351 + " code:\n" + gp.sprint_var(rc, 1) + stderr
352 + "\n")
Michael Walshbd1bb602017-06-30 17:01:25 -0500353 BuiltIn().should_be_equal(rc, 0, message)
354
Michael Walsh8243ac92018-05-02 13:47:07 -0500355 if open_connection_args['alias'] == "device_connection":
356 return stdout
Michael Walshbd1bb602017-06-30 17:01:25 -0500357 return stdout, stderr, rc