Commit 47988778 authored by Iustin Pop's avatar Iustin Pop
Browse files

Improve the cli.AskUser() function

This patch improves the AskUser function by allowing it to:
 - choose from multiple choices (instead of only y/n)
 - give help to the user
 - preserve line breaks and whitespace formatting in the message

With this patch, an instance removal looks like this:
root@xen-test1-4:~# gnt-instance remove tsetest1
This will remove the volumes of the instance tsetest1 (including
mirrors), thus removing all the data of the instance. Continue?
y/[n]/?: ?
 y - Perform the operation
 n - Do not perform the operation

This will remove the volumes of the instance tsetest1 (including
mirrors), thus removing all the data of the instance. Continue?
y/[n]/?: y

The patch also removed the _ask_user member of the opts argument, since
external code was using it (and thus it makes no sense for it to be a
private member); now gnt-* scripts are using the AskUser function
directly.

Reviewed-by: ultrotter
parent bdd55f71
......@@ -37,7 +37,7 @@ from optparse import (OptionParser, make_option, TitledHelpFormatter,
Option, OptionValueError, SUPPRESS_HELP)
__all__ = ["DEBUG_OPT", "NOHDR_OPT", "SEP_OPT", "GenericMain", "SubmitOpCode",
"cli_option", "GenerateTable",
"cli_option", "GenerateTable", "AskUser",
"ARGS_NONE", "ARGS_FIXED", "ARGS_ATLEAST", "ARGS_ANY", "ARGS_ONE",
"USEUNITS_OPT", "FIELDS_OPT", "FORCE_OPT"]
......@@ -170,27 +170,59 @@ def _ParseArgs(argv, commands):
return func, options, args
def _AskUser(text):
"""Ask the user a yes/no question.
def AskUser(text, choices=None):
"""Ask the user a question.
Args:
questionstring - the question to ask.
text - the question to ask.
Returns:
True or False depending on answer (No for False is default).
choices - list with elements tuples (input_char, return_value,
description); if not given, it will default to: [('y', True,
'Perform the operation'), ('n', False, 'Do no do the operation')];
note that the '?' char is reserved for help
Returns: one of the return values from the choices list; if input is
not possible (i.e. not running with a tty, we return the last entry
from the list
"""
if choices is None:
choices = [('y', True, 'Perform the operation'),
('n', False, 'Do not perform the operation')]
if not choices or not isinstance(choices, list):
raise errors.ProgrammerError("Invalid choiches argument to AskUser")
for entry in choices:
if not isinstance(entry, tuple) or len(entry) < 3 or entry[0] == '?':
raise errors.ProgrammerError("Invalid choiches element to AskUser")
answer = choices[-1][1]
new_text = []
for line in text.splitlines():
new_text.append(textwrap.fill(line, 70, replace_whitespace=False))
text = "\n".join(new_text)
try:
f = file("/dev/tty", "r+")
except IOError:
return False
answer = False
return answer
try:
f.write(textwrap.fill(text))
f.write('\n')
f.write("y/[n]: ")
line = f.readline(16).strip().lower()
answer = line in ('y', 'yes')
chars = [entry[0] for entry in choices]
chars[-1] = "[%s]" % chars[-1]
chars.append('?')
maps = dict([(entry[0], entry[1]) for entry in choices])
while True:
f.write(text)
f.write('\n')
f.write("/".join(chars))
f.write(": ")
line = f.readline(2).strip().lower()
if line in maps:
answer = maps[line]
break
elif line == '?':
for entry in choices:
f.write(" %s - %s\n" % (entry[0], entry[2]))
f.write("\n")
continue
finally:
f.close()
return answer
......@@ -231,8 +263,6 @@ def GenericMain(commands):
if func is None: # parse error
return 1
options._ask_user = _AskUser
logger.SetupLogging(debug=options.debug, program=binary)
try:
......
......@@ -78,7 +78,7 @@ def RenameCluster(opts, args):
" over the network to the cluster name, the operation is very"
" dangerous as the IP address will be removed from the node"
" and the change may not go through. Continue?") % name
if not opts._ask_user(usertext):
if not AskUser(usertext):
return 1
op = opcodes.OpRenameCluster(name=name)
......
......@@ -207,7 +207,7 @@ def ReinstallInstance(opts, args):
if not opts.force:
usertext = ("This will reinstall the instance %s and remove "
"all data. Continue?") % instance_name
if not opts._ask_user(usertext):
if not AskUser(usertext):
return 1
op = opcodes.OpReinstallInstance(instance_name=instance_name,
......@@ -232,7 +232,7 @@ def RemoveInstance(opts, args):
usertext = ("This will remove the volumes of the instance %s"
" (including mirrors), thus removing all the data"
" of the instance. Continue?") % instance_name
if not opts._ask_user(usertext):
if not AskUser(usertext):
return 1
op = opcodes.OpRemoveInstance(instance_name=instance_name)
......@@ -394,7 +394,7 @@ def FailoverInstance(opts, args):
usertext = ("Failover will happen to image %s."
" This requires a shutdown of the instance. Continue?" %
(instance_name,))
if not opts._ask_user(usertext):
if not AskUser(usertext):
return 1
op = opcodes.OpFailoverInstance(instance_name=instance_name,
......
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