freeipa/ipaserver/advise/base.py
Jan Cholasta 7a482b7c72 logging: do not log into the root logger
Deprecate `ipa_log_manager.root_logger` and replace all calls to it with
module-level logger calls.

Reviewed-By: Martin Basti <mbasti@redhat.com>
2017-07-14 15:55:59 +02:00

521 lines
16 KiB
Python

# Authors: Tomas Babej <tbabej@redhat.com>
#
# Copyright (C) 2013 Red Hat
# see file 'COPYING' for use and warranty information
#
# This program is free software; you can redistribute it and/or modify
# it under the terms of the GNU General Public License as published by
# the Free Software Foundation, either version 3 of the License, or
# (at your option) any later version.
#
# This program is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
# GNU General Public License for more details.
#
# You should have received a copy of the GNU General Public License
# along with this program. If not, see <http://www.gnu.org/licenses/>.
#
from __future__ import print_function
from contextlib import contextmanager
import logging
import os
from textwrap import wrap
from ipalib import api
from ipalib.plugable import Plugin, API
from ipalib.errors import ValidationError
from ipaplatform.paths import paths
from ipapython import admintool
from ipapython.ipa_log_manager import Filter
"""
To add configuration instructions for a new use case, define a new class that
inherits from Advice class.
You should create a plugin file for it in ipaserver/advise/plugins folder.
The class can run any arbitrary code or IPA command via api.Command['command']()
calls. It needs to override get_info() method, which returns the formatted
advice string.
Important! Do not forget to register the class to the API.
>>> @register()
>>> class sample_advice(Advice):
>>> description = 'Instructions for machine with SSSD 1.0 setup.'
Description provided shows itself as a header and in the list of all advices
currently available via ipa-advise.
Optionally, you can require root privileges for your plugin:
>>> require_root = True
The following method should be implemented in your plugin:
>>> def get_info():
>>> self.log.debug('Entering execute() method')
>>> self.log.comment('Providing useful advice just for you')
>>> self.log.command('yum update sssd -y')
As you can see, Advice's log has 3 different levels. Debug lines are printed
out with '# DEBUG:' prefix if --verbose had been used. Comment lines utilize
'# ' prefix and command lines are printed raw.
Please note that comments are automatically wrapped after 70 characters.
Use wrapped=False option to force the unwrapped line in the comment.
>>> self.log.comment("This line should not be wrapped", wrapped=False)
As a result, you can redirect the advice's output directly to a script file.
# ipa-advise sample-advice > script.sh
# ./script.sh
"""
DEFAULT_INDENTATION_INCREMENT = 2
class _IndentationTracker(object):
"""
A simple wrapper that tracks the indentation level of the generated bash
commands
"""
def __init__(self, spaces_per_indent=0):
if spaces_per_indent <= 0:
raise ValueError(
"Indentation increments cannot be zero or negative")
self.spaces_per_indent = spaces_per_indent
self._indentation_stack = []
self._total_indentation_level = 0
@property
def indentation_string(self):
"""
return a string containing number of spaces corresponding to
indentation level
"""
return " " * self._total_indentation_level
def indent(self):
"""
track a single indentation of the generated code
"""
self._indentation_stack.append(self.spaces_per_indent)
self._recompute_indentation_level()
def _recompute_indentation_level(self):
"""
Track total indentation level of the generated code
"""
self._total_indentation_level = sum(self._indentation_stack)
def dedent(self):
"""
track a single dedentation of the generated code
dedents that would result in zero or negative indentation level will be
ignored
"""
try:
self._indentation_stack.pop()
except IndexError:
# can not dedent any further
pass
self._recompute_indentation_level()
class CompoundStatement(object):
"""
Wrapper around indented blocks of Bash statements.
Override `begin_statement` and `end_statement` methods to issue
opening/closing commands using the passed in _AdviceOutput instance
"""
def __init__(self, advice_output):
self.advice_output = advice_output
def __enter__(self):
self.begin_statement()
self.advice_output.indent()
def begin_statement(self):
pass
def __exit__(self, exc_type, exc_value, traceback):
self.advice_output.dedent()
self.end_statement()
def end_statement(self):
pass
class IfBranch(CompoundStatement):
"""
Base wrapper around `if` branch. The closing statement is empty so it
leaves trailing block that can be closed off or continued by else branches
"""
def __init__(self, advice_output, conditional):
super(IfBranch, self).__init__(advice_output)
self.conditional = conditional
def begin_statement(self):
self.advice_output.command('if {}'.format(self.conditional))
self.advice_output.command('then')
class ElseIfBranch(CompoundStatement):
"""
Wrapper for `else if <CONDITIONAL>`
"""
def __init__(self, advice_output, alternative_conditional):
super(ElseIfBranch, self).__init__(advice_output)
self.alternative_conditional = alternative_conditional
def begin_statement(self):
command = 'else if {}'.format(self.alternative_conditional)
self.advice_output.command(command)
class ElseBranch(CompoundStatement):
"""
Wrapper for final `else` block
"""
def begin_statement(self):
self.advice_output.command('else')
def end_statement(self):
self.advice_output.command('fi')
class UnbranchedIfStatement(IfBranch):
"""
Plain `if` without branches
"""
def end_statement(self):
self.advice_output.command('fi')
class ForLoop(CompoundStatement):
"""
Wrapper around the for loop
"""
def __init__(self, advice_output, loop_variable, iterable):
super(ForLoop, self).__init__(advice_output)
self.loop_variable = loop_variable
self.iterable = iterable
def begin_statement(self):
self.advice_output.command(
'for {} in {}'.format(self.loop_variable, self.iterable))
self.advice_output.command('do')
def end_statement(self):
self.advice_output.command('done')
class _AdviceOutput(object):
def __init__(self):
self.content = []
self.prefix = '# '
self.options = None
self._indentation_tracker = _IndentationTracker(
spaces_per_indent=DEFAULT_INDENTATION_INCREMENT)
def indent(self):
"""
Indent the statements by one level
"""
self._indentation_tracker.indent()
def dedent(self):
"""
Dedent the statements by one level
"""
self._indentation_tracker.dedent()
@contextmanager
def indented_block(self):
self.indent()
try:
yield
finally:
self.dedent()
def comment(self, line, wrapped=True):
if wrapped:
self.append_wrapped_and_indented_comment(line)
else:
self.append_comment(line)
def append_wrapped_and_indented_comment(self, line, character_limit=70):
"""
append wrapped and indented comment to the output
"""
for wrapped_indented_line in wrap(
self.indent_statement(line), character_limit):
self.append_comment(wrapped_indented_line)
def append_comment(self, line):
self.append_statement(self.prefix + line)
def append_statement(self, statement):
"""
Append a line to the generated content indenting it by tracked number
of spaces
"""
self.content.append(self.indent_statement(statement))
def indent_statement(self, statement):
return '{indent}{statement}'.format(
indent=self._indentation_tracker.indentation_string,
statement=statement)
def debug(self, line):
if self.options.verbose:
self.comment('DEBUG: ' + line)
def command(self, line):
self.append_statement(line)
def echo_error(self, error_message):
self.command(self._format_error(error_message))
def _format_error(self, error_message):
return 'echo "{}" >&2'.format(error_message)
def exit_on_failed_command(self, command_to_run,
error_message_lines):
self.command(command_to_run)
self.exit_on_predicate(
'[ "$?" -ne "0" ]',
error_message_lines)
def exit_on_nonroot_euid(self):
self.exit_on_predicate(
'[ "$(id -u)" -ne "0" ]',
["This script has to be run as root user"]
)
def exit_on_predicate(self, predicate, error_message_lines):
with self.unbranched_if(predicate):
for error_message_line in error_message_lines:
self.command(self._format_error(error_message_line))
self.command('exit 1')
@contextmanager
def unbranched_if(self, predicate):
with self._compound_statement(UnbranchedIfStatement, predicate):
yield
@contextmanager
def _compound_statement(self, statement_cls, *args):
with statement_cls(self, *args):
yield
def commands_on_predicate(self, predicate, commands_to_run_when_true,
commands_to_run_when_false=None):
if commands_to_run_when_false is not None:
if_statement = self.if_branch
else:
if_statement = self.unbranched_if
with if_statement(predicate):
for command_to_run_when_true in commands_to_run_when_true:
self.command(
command_to_run_when_true)
if commands_to_run_when_false is not None:
with self.else_branch():
for command_to_run_when_false in commands_to_run_when_false:
self.command(command_to_run_when_false)
@contextmanager
def if_branch(self, predicate):
with self._compound_statement(IfBranch, predicate):
yield
@contextmanager
def else_branch(self):
with self._compound_statement(ElseBranch):
yield
@contextmanager
def else_if_branch(self, predicate):
with self._compound_statement(ElseIfBranch, predicate):
yield
@contextmanager
def for_loop(self, loop_variable, iterable):
with self._compound_statement(ForLoop, loop_variable, iterable):
yield
class Advice(Plugin):
"""
Base class for advices, plugins for ipa-advise.
"""
options = None
require_root = False
description = ''
def __init__(self, api):
super(Advice, self).__init__(api)
self.log = _AdviceOutput()
def set_options(self, options):
self.options = options
self.log.options = options
def get_info(self):
"""
This method should be overridden by child Advices.
Returns a string with instructions.
"""
raise NotImplementedError
class AdviseAPI(API):
bases = (Advice,)
@property
def packages(self):
import ipaserver.advise.plugins
return (ipaserver.advise.plugins,)
advise_api = AdviseAPI()
class IpaAdvise(admintool.AdminTool):
"""
Admin tool that given systems's configuration provides instructions how to
configure the systems for various use cases.
"""
command_name = 'ipa-advise'
usage = "%prog ADVICE"
description = "Provides configuration advice for various use cases. To "\
"see the list of possible ADVICEs, run ipa-advise without "\
"any arguments."
def __init__(self, options, args):
super(IpaAdvise, self).__init__(options, args)
@classmethod
def add_options(cls, parser):
super(IpaAdvise, cls).add_options(parser)
def validate_options(self):
super(IpaAdvise, self).validate_options(needs_root=False)
if len(self.args) > 1:
raise self.option_parser.error("You can only provide one "
"positional argument.")
def log_success(self):
pass
def print_config_list(self):
self.print_header('List of available advices')
max_keyword_len = max(
(len(advice.name) for advice in advise_api.Advice))
for advice in advise_api.Advice:
description = getattr(advice, 'description', '')
keyword = advice.name.replace('_', '-')
# Compute the number of spaces needed for the table to be aligned
offset = max_keyword_len - len(keyword)
prefix = " {key} {off}: ".format(key=keyword, off=' ' * offset)
wrapped_description = wrap(description, 80 - len(prefix))
# Print the first line with the prefix (keyword)
print(prefix + wrapped_description[0])
# Print the rest wrapped behind the colon
for line in wrapped_description[1:]:
print("{off}{line}".format(off=' ' * len(prefix), line=line))
def print_header(self, header, print_shell=False):
header_size = len(header)
prefix = ''
if print_shell:
prefix = '# '
print('#!/bin/sh')
# Do not print out empty header
if header_size > 0:
print((prefix + '-' * 70))
for line in wrap(header, 70):
print((prefix + line))
print((prefix + '-' * 70))
def print_advice(self, keyword):
advice = getattr(advise_api.Advice, keyword, None)
# Ensure that Configuration class for given --setup option value exists
if advice is None:
raise ValidationError(
name="advice",
error="No instructions are available for '{con}'. "
"See the list of available configuration "
"by invoking the ipa-advise command with no argument."
.format(con=keyword.replace('_', '-')))
# Check whether root privileges are needed
if advice.require_root and os.getegid() != 0:
raise admintool.ScriptError(
'Must be root to get advice for {adv}'
.format(adv=keyword.replace('_', '-')), 1)
# Print out nicely formatted header
self.print_header(advice.description, print_shell=True)
# Set options so that plugin can use verbose/quiet options
advice.set_options(self.options)
# Print out the actual advice
api.Backend.rpcclient.connect()
advice.get_info()
api.Backend.rpcclient.disconnect()
for line in advice.log.content:
print(line)
def run(self):
super(IpaAdvise, self).run()
api.bootstrap(in_server=False,
context='cli',
confdir=paths.ETC_IPA)
api.finalize()
advise_api.bootstrap(in_server=False,
context='cli',
confdir=paths.ETC_IPA)
advise_api.finalize()
if not self.options.verbose:
# Do not print connection information by default
logger_name = r'ipalib\.rpc'
root_logger = logging.getLogger()
root_logger.addFilter(Filter(logger_name, logging.WARNING))
# With no argument, print the list out and exit
if not self.args:
self.print_config_list()
return
else:
keyword = self.args[0].replace('-', '_')
self.print_advice(keyword)