def shell_cmd(command_string,
quiet=None,
print_output=None,
show_err=1,
test_mode=0,
time_out=None,
max_attempts=1,
retry_sleep_time=5,
allowed_shell_rcs=[0],
ignore_err=None,
return_stderr=0,
fork=0):
r"""
Run the given command string in a shell and return a tuple consisting of
the shell return code and the output.
Description of argument(s):
command_string The command string to be run in a shell
(e.g. "ls /tmp").
quiet If set to 0, this function will print
"Issuing: <cmd string>" to stdout. When
the quiet argument is set to None, this
function will assign a default value by
searching upward in the stack for the
quiet variable value. If no such value is
found, quiet is set to 0.
print_output If this is set, this function will print
the stdout/stderr generated by the shell
command to stdout.
show_err If show_err is set, this function will
print a standardized error report if the
shell command fails (i.e. if the shell
command returns a shell_rc that is not in
allowed_shell_rcs). Note: Error text is
only printed if ALL attempts to run the
command_string fail. In other words, if
the command execution is ultimately
successful, initial failures are hidden.
test_mode If test_mode is set, this function will
not actually run the command. If
print_output is also set, this function
will print "(test_mode) Issuing: <cmd
string>" to stdout. A caller should call
shell_cmd directly if they wish to have
the command string run unconditionally.
They should call the t_shell_cmd wrapper
(defined below) if they wish to run the
command string only if the prevailing
test_mode variable is set to 0.
time_out A time-out value expressed in seconds. If
the command string has not finished
executing within <time_out> seconds, it
will be halted and counted as an error.
max_attempts The max number of attempts that should be
made to run the command string.
retry_sleep_time The number of seconds to sleep between
attempts.
allowed_shell_rcs A list of integers indicating which
shell_rc values are not to be considered
errors.
ignore_err Ignore error means that a failure
encountered by running the command string
will not be raised as a python exception.
When the ignore_err argument is set to
None, this function will assign a default
value by searching upward in the stack for
the ignore_err variable value. If no such
value is found, ignore_err is set to 1.
return_stderr If return_stderr is set, this function
will process the stdout and stderr streams
from the shell command separately. In
such a case, the tuple returned by this
function will consist of three values
rather than just two: rc, stdout, stderr.
fork Run the command string asynchronously
(i.e. don't wait for status of the child
process and don't try to get
stdout/stderr).
"""
# Assign default values to some of the arguments to this function.
quiet = int(gm.dft(quiet, gp.get_stack_var('quiet', 0)))
print_output = int(gm.dft(print_output, not quiet))
show_err = int(show_err)
global_ignore_err = gp.get_var_value(ignore_err, 1)
stack_ignore_err = gp.get_stack_var('ignore_err', global_ignore_err)
ignore_err = int(gm.dft(ignore_err, gm.dft(stack_ignore_err, 1)))
err_msg = gv.valid_value(command_string)
if err_msg != "":
raise ValueError(err_msg)
if not quiet:
gp.print_issuing(command_string, test_mode)
if test_mode:
if return_stderr:
return 0, "", ""
else:
return 0, ""
# Convert each list entry to a signed value.
allowed_shell_rcs = fa.source_to_object(allowed_shell_rcs)
allowed_shell_rcs = [gm.to_signed(x) for x in allowed_shell_rcs]
if return_stderr:
stderr = subprocess.PIPE
else:
stderr = subprocess.STDOUT
shell_rc = 0
out_buf = ""
err_buf = ""
# Write all output to func_history_stdout rather than directly to stdout.
# This allows us to decide what to print after all attempts to run the
# command string have been made. func_history_stdout will contain the
# complete stdout history from the current invocation of this function.
func_history_stdout = ""
for attempt_num in range(1, max_attempts + 1):
sub_proc = subprocess.Popen(command_string,
bufsize=1,
shell=True,
executable='/bin/bash',
stdout=subprocess.PIPE,
stderr=stderr)
out_buf = ""
err_buf = ""
# Output from this loop iteration is written to func_stdout for later
# processing.
func_stdout = ""
if fork:
break
command_timed_out = False
if time_out is not None:
# Designate a SIGALRM handling function and set alarm.
signal.signal(signal.SIGALRM, shell_cmd_timed_out)
signal.alarm(time_out)
try:
if return_stderr:
for line in sub_proc.stderr:
try:
err_buf += line
except TypeError:
line = line.decode("utf-8")
err_buf += line
if not print_output:
continue
func_stdout += line
for line in sub_proc.stdout:
try:
out_buf += line
except TypeError:
line = line.decode("utf-8")
out_buf += line
if not print_output:
continue
func_stdout += line
except IOError:
command_timed_out = True
sub_proc.communicate()
shell_rc = sub_proc.returncode
# Restore the original SIGALRM handler and clear the alarm.
signal.signal(signal.SIGALRM, original_sigalrm_handler)
signal.alarm(0)
if shell_rc in allowed_shell_rcs:
break
err_msg = "The prior shell command failed.\n"
if quiet:
err_msg += gp.sprint_var(command_string)
if command_timed_out:
err_msg += gp.sprint_var(command_timed_out)
err_msg += gp.sprint_var(time_out)
err_msg += gp.sprint_varx("child_pid", sub_proc.pid)
err_msg += gp.sprint_var(attempt_num)
err_msg += gp.sprint_var(shell_rc, gp.hexa())
err_msg += gp.sprint_var(allowed_shell_rcs, gp.hexa())
if not print_output:
if return_stderr:
err_msg += "err_buf:\n" + err_buf
err_msg += "out_buf:\n" + out_buf
if show_err:
func_stdout += gp.sprint_error_report(err_msg)
func_history_stdout += func_stdout
if attempt_num < max_attempts:
func_history_stdout += gp.sprint_issuing("time.sleep(" +
str(retry_sleep_time) +
")")
time.sleep(retry_sleep_time)
if shell_rc not in allowed_shell_rcs:
func_stdout = func_history_stdout
gp.gp_print(func_stdout)
if shell_rc not in allowed_shell_rcs:
if not ignore_err:
if robot_env:
BuiltIn().fail(err_msg)
else:
raise ValueError("The prior shell command failed.\n")
if return_stderr:
return shell_rc, out_buf, err_buf
else:
return shell_rc, out_buf
def filter_struct(structure, filter_dict, regex=False, invert=False):
r"""
Filter the structure by removing any entries that do NOT contain the keys/values specified in filter_dict
and return the result.
The selection process is directed only at the first-level entries of the structure.
Example:
Given a dictionary named "properties" that has the following structure:
properties:
[/redfish/v1/Systems/system/Processors]:
[Members]:
[0]:
[@odata.id]: /redfish/v1/Systems/system/Processors/cpu0
[1]:
[@odata.id]: /redfish/v1/Systems/system/Processors/cpu1
[/redfish/v1/Systems/system/Processors/cpu0]:
[Status]:
[State]: Enabled
[Health]: OK
[/redfish/v1/Systems/system/Processors/cpu1]:
[Status]:
[State]: Enabled
[Health]: Bad
The following call:
properties = filter_struct(properties, "[('Health', 'OK')]")
Would return a new properties dictionary that looks like this:
properties:
[/redfish/v1/Systems/system/Processors/cpu0]:
[Status]:
[State]: Enabled
[Health]: OK
Note that the first item in the original properties directory had no key anywhere in the structure named
"Health". Therefore, that item failed to make the cut. The next item did have a key named "Health"
whose value was "OK" so it was included in the new structure. The third item had a key named "Health"
but its value was not "OK" so it also failed to make the cut.
Description of argument(s):
structure Any nested combination of lists or dictionaries. See the prolog of
get_nested() for details.
filter_dict For each key/value pair in filter_dict, each entry in structure must
contain the same key/value pair at some level. A filter_dict value of
None is treated as a special case. Taking the example shown above,
[('State', None)] would mean that the result should only contain records
that have no State key at all.
regex Indicates whether the values in the filter_dict should be interpreted as
regular expressions.
invert Invert the results. Instead of including only matching entries in the
results, include only NON-matching entries in the results.
"""
# Convert filter_dict from a string containing a python object definition to an actual python object (if
# warranted).
filter_dict = fa.source_to_object(filter_dict)
# Determine whether structure is a list or a dictionary and process accordingly. The result returned
# will be of the same type as the structure.
if type(structure) is list:
result = []
for element in structure:
if match_struct(element, filter_dict, regex) != invert:
result.append(element)
else:
try:
result = collections.OrderedDict()
except AttributeError:
result = DotDict()
for struct_key, struct_value in structure.items():
if match_struct(struct_value, filter_dict, regex) != invert:
result[struct_key] = struct_value
return result
def shell_cmd(command_string,
quiet=None,
print_output=None,
show_err=1,
test_mode=0,
time_out=None,
max_attempts=1,
retry_sleep_time=5,
valid_rcs=[0],
ignore_err=None,
return_stderr=0,
fork=0,
error_regexes=None):
r"""
Run the given command string in a shell and return a tuple consisting of the shell return code and the
output.
Description of argument(s):
command_string The command string to be run in a shell (e.g. "ls /tmp").
quiet If set to 0, this function will print "Issuing: <cmd string>" to stdout.
When the quiet argument is set to None, this function will assign a
default value by searching upward in the stack for the quiet variable
value. If no such value is found, quiet is set to 0.
print_output If this is set, this function will print the stdout/stderr generated by
the shell command to stdout.
show_err If show_err is set, this function will print a standardized error report
if the shell command fails (i.e. if the shell command returns a shell_rc
that is not in valid_rcs). Note: Error text is only printed if ALL
attempts to run the command_string fail. In other words, if the command
execution is ultimately successful, initial failures are hidden.
test_mode If test_mode is set, this function will not actually run the command. If
print_output is also set, this function will print "(test_mode) Issuing:
<cmd string>" to stdout. A caller should call shell_cmd directly if they
wish to have the command string run unconditionally. They should call
the t_shell_cmd wrapper (defined below) if they wish to run the command
string only if the prevailing test_mode variable is set to 0.
time_out A time-out value expressed in seconds. If the command string has not
finished executing within <time_out> seconds, it will be halted and
counted as an error.
max_attempts The max number of attempts that should be made to run the command string.
retry_sleep_time The number of seconds to sleep between attempts.
valid_rcs A list of integers indicating which shell_rc values are not to be
considered errors.
ignore_err Ignore error means that a failure encountered by running the command
string will not be raised as a python exception. When the ignore_err
argument is set to None, this function will assign a default value by
searching upward in the stack for the ignore_err variable value. If no
such value is found, ignore_err is set to 1.
return_stderr If return_stderr is set, this function will process the stdout and stderr
streams from the shell command separately. In such a case, the tuple
returned by this function will consist of three values rather than just
two: rc, stdout, stderr.
fork Run the command string asynchronously (i.e. don't wait for status of the
child process and don't try to get stdout/stderr) and return the Popen
object created by the subprocess.popen() function. See the kill_cmd
function for details on how to process the popen object.
error_regexes A list of regular expressions to be used to identify errors in the
command output. If there is a match for any of these regular
expressions, the command will be considered a failure and the shell_rc
will be set to -1. For example, if error_regexes = ['ERROR:'] and the
command output contains 'ERROR: Unrecognized option', it will be counted
as an error even if the command returned 0. This is useful when running
commands that do not always return non-zero on error.
"""
err_msg = gv.valid_value(command_string)
if err_msg:
raise ValueError(err_msg)
# Assign default values to some of the arguments to this function.
quiet = int(gm.dft(quiet, gp.get_stack_var('quiet', 0)))
print_output = int(gm.dft(print_output, not quiet))
show_err = int(show_err)
ignore_err = int(gm.dft(ignore_err, gp.get_stack_var('ignore_err', 1)))
gp.qprint_issuing(command_string, test_mode)
if test_mode:
return (0, "", "") if return_stderr else (0, "")
# Convert a string python dictionary definition to a dictionary.
valid_rcs = fa.source_to_object(valid_rcs)
# Convert each list entry to a signed value.
valid_rcs = [gm.to_signed(x) for x in valid_rcs]
stderr = subprocess.PIPE if return_stderr else subprocess.STDOUT
# Write all output to func_out_history_buf rather than directly to stdout. This allows us to decide
# what to print after all attempts to run the command string have been made. func_out_history_buf will
# contain the complete history from the current invocation of this function.
global command_timed_out
command_timed_out = False
func_out_history_buf = ""
for attempt_num in range(1, max_attempts + 1):
sub_proc = subprocess.Popen(command_string,
preexec_fn=os.setsid,
bufsize=1,
shell=True,
universal_newlines=True,
executable='/bin/bash',
stdout=subprocess.PIPE,
stderr=stderr)
if fork:
return sub_proc
if time_out:
command_timed_out = False
# Designate a SIGALRM handling function and set alarm.
signal.signal(signal.SIGALRM, shell_cmd_timed_out)
signal.alarm(time_out)
try:
stdout_buf, stderr_buf = sub_proc.communicate()
except IOError:
command_timed_out = True
# Restore the original SIGALRM handler and clear the alarm.
signal.signal(signal.SIGALRM, original_sigalrm_handler)
signal.alarm(0)
# Output from this loop iteration is written to func_out_buf for later processing. This can include
# stdout, stderr and our own error messages.
func_out_buf = ""
if print_output:
if return_stderr:
func_out_buf += stderr_buf
func_out_buf += stdout_buf
shell_rc = sub_proc.returncode
if shell_rc in valid_rcs:
# Check output for text indicating there is an error.
if error_regexes and re.match('|'.join(error_regexes), stdout_buf):
shell_rc = -1
else:
break
err_msg = "The prior shell command failed.\n"
err_msg += gp.sprint_var(attempt_num)
err_msg += gp.sprint_vars(command_string, command_timed_out, time_out)
err_msg += gp.sprint_varx("child_pid", sub_proc.pid)
err_msg += gp.sprint_vars(shell_rc, valid_rcs, fmt=gp.hexa())
if error_regexes:
err_msg += gp.sprint_vars(error_regexes)
if not print_output:
if return_stderr:
err_msg += "stderr_buf:\n" + stderr_buf
err_msg += "stdout_buf:\n" + stdout_buf
if show_err:
func_out_buf += gp.sprint_error_report(err_msg)
if attempt_num < max_attempts:
cmd_buf = "time.sleep(" + str(retry_sleep_time) + ")"
if show_err:
func_out_buf += gp.sprint_issuing(cmd_buf)
exec(cmd_buf)
func_out_history_buf += func_out_buf
if shell_rc in valid_rcs:
gp.gp_print(func_out_buf)
else:
if show_err:
gp.gp_print(func_out_history_buf, stream='stderr')
else:
# There is no error information to show so just print output from last loop iteration.
gp.gp_print(func_out_buf)
if not ignore_err:
# If the caller has already asked to show error info, avoid repeating that in the failure message.
err_msg = "The prior shell command failed.\n" if show_err \
else err_msg
if robot_env:
BuiltIn().fail(err_msg)
else:
raise ValueError(err_msg)
return (shell_rc, stdout_buf, stderr_buf) if return_stderr \
else (shell_rc, stdout_buf)