Differential D1401 Diff 3574 roles/devserver/userland-software/files/shell.py

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roles/devserver/userland-software/files/shell.py

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				#!/usr/bin/env python3

				# -------------------------------------------------------------
				# Operations utilities
				# - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
				# Project: Nasqueron
				# Author: Sébastien Santoro aka Dereckson
				# Created: 2018-03-08
				# License: BSD-2-Clause
				# Source file: roles/devserver/userland-software/files/shell.sh
				# -------------------------------------------------------------
				#
				# <auto-generated>
				# This file is managed by our rOPS SaltStack repository.
				#
				# Changes to this file may cause incorrect behavior
				# and will be lost if the state is redeployed.
				# </auto-generated>

				from collections import deque

				import os
				import re
				import subprocess
				import sys
				import yaml


				# -------------------------------------------------------------
				# Configuration file locator
				# - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -


				def get_candidates_configuration_directories():
				candidates = []

				if 'HOME' in os.environ:
				candidates.append(os.environ['HOME'])

				candidates.append('/usr/local/etc')
				candidates.append('/etc')

				return candidates


				def get_candidates_configuration_files():
				return [directory + "/.shell.yml" for directory
				in get_candidates_configuration_directories()]


				def find_configuration_file():
				for candidate in get_candidates_configuration_files():
				if os.path.isfile(candidate):
				return candidate


				# -------------------------------------------------------------
				# Configuration file parser
				# - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -


				def parse_configuration_file(filename):
				configuration_file = open(filename, 'r')
				configuration = yaml.load(configuration_file)
				configuration_file.close()

				return configuration


				# -------------------------------------------------------------
				# Server connection
				# - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -


				class ServerConnection:
				"""Represents a server connection with a command to run."""

				config = {}
				args = []

				def __init__(self, config, args):
				self.config = config
				self.args = deque(args)

				def clear_args(self):
				self.args = deque([])

				def pop_all_args(self):
				to_return = list(self.args)
				self.clear_args()
				return to_return

				def get_default_command(self):
				return ["ssh"]

				def get_alias(self, alias_name):
				return self.get_config_section('aliases', alias_name)

				def get_handler(self, hander_name):
				return self.get_config_section('handlers', hander_name)

				def get_config_section(self, section, key):
				if section in self.config:
				if key in self.config[section]:
				return self.config[section][key]

				def parse_alias(self, alias):
				if 'args' in alias:
				self.args.extendleft(alias['args'])

				if 'handler' in alias:
				handler = self.config['handlers'][alias['handler']]
				return self.parse_handler(handler)

				if 'command' in alias:
				return self.parse_command(alias['command'])

				raise ValueError("Unable to parse alias")

				def parse_handler(self, handler):
				command = self.get_default_command()

				if 'interactive' in handler and handler['interactive']:
				command.append("-t")

				command.append(handler['server'])
				command.extend(self.parse_command(handler['command']))
				command.extend(self.args)

				return command

				def parse_variable_fragment(self, variable):
				# {{%s-\|bash}} means %s-, with bash as default value if we don't
				# have any more argument to substitute
				matches = re.search('(.)\\|(.)', variable)
				if matches:
				if not self.args:
				return [matches.group(2)]

				cleaned_fragment = matches.group(1)
				return self.parse_variable_fragment(cleaned_fragment)

				# Substitute with one argument
				if variable == '%s':
				return [self.args.popleft()]

				# Substitute with all arguments
				if variable == '%s-':
				return self.pop_all_args()

				raise ValueError("Can't parse " + variable)

				def parse_fragment(self, fragment):
				# If the fragment is {{something}}, this is a variable to substitute.
				matches = re.search('{{(.*)}}', fragment)
				if matches:
				return self.parse_variable_fragment(matches.group(1))

				return [fragment]

				def parse_command(self, command):
				parsed_command = []

				fragments = [self.parse_fragment(fragment) for fragment in command]
				for fragment in fragments:
				parsed_command.extend(fragment)

				return parsed_command

				def parse_connection(self):
				if not self.args:
				raise ValueError("Expected arguments missing")

				target = self.args.popleft()

				# Is it an alias?
				alias = self.get_alias(target)
				if alias is not None:
				return self.parse_alias(alias)

				# Is it an handler?
				handler = self.get_handler(target)
				if handler is not None:
				return self.parse_handler(handler)

				raise ValueError(target + ": No such target")

				# -------------------------------------------------------------
				# Runner code
				# - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -


				def get_program_name():
				return os.path.basename(sys.argv[0])


				def is_debug_mode_enabled():
				return 'DEBUG' in os.environ


				def print_error(err):
				print("{}: {}".format(get_program_name(), err), file=sys.stderr)


				def get_configuration():
				configuration_file = find_configuration_file()

				if configuration_file is None:
				print_error("No shell configuration file found")
				exit(2)

				return parse_configuration_file(configuration_file)


				def usage():
				print("usage: shell target [subtarget] [command ...]", file=sys.stderr)


				def main():
				if len(sys.argv) < 2:
				usage()
				exit(1)

				config = get_configuration()
				connection = ServerConnection(config, sys.argv[1:])
				try:
				subprocess_args = connection.parse_connection()
				except ValueError as e:
				print_error(e)
				exit(4)

				if is_debug_mode_enabled():
				print(subprocess_args, file=sys.stderr)

				subprocess.run(subprocess_args)


				if __name__ == '__main__':
				main()