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Diffstat (limited to 'app/discover/fetchers/cli/cli_access.py')
| -rw-r--r-- | app/discover/fetchers/cli/cli_access.py | 206 |
1 files changed, 206 insertions, 0 deletions
diff --git a/app/discover/fetchers/cli/cli_access.py b/app/discover/fetchers/cli/cli_access.py new file mode 100644 index 0000000..1db84ea --- /dev/null +++ b/app/discover/fetchers/cli/cli_access.py @@ -0,0 +1,206 @@ +############################################################################### +# Copyright (c) 2017 Koren Lev (Cisco Systems), Yaron Yogev (Cisco Systems) # +# and others # +# # +# All rights reserved. This program and the accompanying materials # +# are made available under the terms of the Apache License, Version 2.0 # +# which accompanies this distribution, and is available at # +# http://www.apache.org/licenses/LICENSE-2.0 # +############################################################################### +import re +import time + +from discover.fetcher import Fetcher +from utils.binary_converter import BinaryConverter +from utils.logging.console_logger import ConsoleLogger +from utils.ssh_conn import SshConn + + +class CliAccess(BinaryConverter, Fetcher): + connections = {} + ssh_cmd = "ssh -o StrictHostKeyChecking=no " + call_count_per_con = {} + max_call_count_per_con = 100 + cache_lifetime = 60 # no. of seconds to cache results + cached_commands = {} + + def __init__(self): + super().__init__() + self.log = ConsoleLogger() + + @staticmethod + def is_gateway_host(ssh_to_host): + ssh_conn = SshConn(ssh_to_host) + return ssh_conn.is_gateway_host(ssh_to_host) + + def run_on_gateway(self, cmd, ssh_to_host="", enable_cache=True, + use_sudo=True): + self.run(cmd, ssh_to_host=ssh_to_host, enable_cache=enable_cache, + on_gateway=True, use_sudo=use_sudo) + + def run(self, cmd, ssh_to_host="", enable_cache=True, on_gateway=False, + ssh=None, use_sudo=True): + ssh_conn = ssh if ssh else SshConn(ssh_to_host) + if use_sudo and not cmd.strip().startswith("sudo "): + cmd = "sudo " + cmd + if not on_gateway and ssh_to_host \ + and not ssh_conn.is_gateway_host(ssh_to_host): + cmd = self.ssh_cmd + ssh_to_host + " " + cmd + curr_time = time.time() + cmd_path = ssh_to_host + ',' + cmd + if enable_cache and cmd_path in self.cached_commands: + # try to re-use output from last call + cached = self.cached_commands[cmd_path] + if cached["timestamp"] + self.cache_lifetime < curr_time: + # result expired + self.cached_commands.pop(cmd_path, None) + else: + # result is good to use - skip the SSH call + self.log.info('CliAccess: ****** using cached result, ' + + 'host: ' + ssh_to_host + ', cmd: %s ******', cmd) + return cached["result"] + + self.log.info('CliAccess: host: %s, cmd: %s', ssh_to_host, cmd) + ret = ssh_conn.exec(cmd) + self.cached_commands[cmd_path] = {"timestamp": curr_time, "result": ret} + return ret + + def run_fetch_lines(self, cmd, ssh_to_host="", enable_cache=True): + out = self.run(cmd, ssh_to_host, enable_cache) + if not out: + return [] + # first try to split lines by whitespace + ret = out.splitlines() + # if split by whitespace did not work, try splitting by "\\n" + if len(ret) == 1: + ret = [l for l in out.split("\\n") if l != ""] + return ret + + # parse command output columns separated by whitespace + # since headers can contain whitespace themselves, + # it is the caller's responsibility to provide the headers + def parse_cmd_result_with_whitespace(self, lines, headers, remove_first): + if remove_first: + # remove headers line + del lines[:1] + results = [self.parse_line_with_ws(line, headers) + for line in lines] + return results + + # parse command output with "|" column separators and "-" row separators + def parse_cmd_result_with_separators(self, lines): + headers = self.parse_headers_line_with_separators(lines[1]) + # remove line with headers and formatting lines above it and below it + del lines[:3] + # remove formatting line in the end + lines.pop() + results = [self.parse_content_line_with_separators(line, headers) + for line in lines] + return results + + # parse a line with columns separated by whitespace + def parse_line_with_ws(self, line, headers): + s = line if isinstance(line, str) else self.binary2str(line) + parts = [word.strip() for word in s.split() if word.strip()] + ret = {} + for i, p in enumerate(parts): + header = headers[i] + ret[header] = p + return ret + + # parse a line with "|" column separators + def parse_line_with_separators(self, line): + s = self.binary2str(line) + parts = [word.strip() for word in s.split("|") if word.strip()] + # remove the ID field + del parts[:1] + return parts + + def parse_headers_line_with_separators(self, line): + return self.parse_line_with_separators(line) + + def parse_content_line_with_separators(self, line, headers): + content_parts = self.parse_line_with_separators(line) + content = {} + for i in range(0, len(content_parts)): + content[headers[i]] = content_parts[i] + return content + + def merge_ws_spillover_lines(self, lines): + # with WS-separated output, extra output sometimes spills to next line + # detect that and add to the end of the previous line for our procesing + pending_line = None + fixed_lines = [] + # remove headers line + for l in lines: + if l[0] == '\t': + # this is a spill-over line + if pending_line: + # add this line to the end of the previous line + pending_line = pending_line.strip() + "," + l.strip() + else: + # add the previous pending line to the fixed lines list + if pending_line: + fixed_lines.append(pending_line) + # make current line the pending line + pending_line = l + if pending_line: + fixed_lines.append(pending_line) + return fixed_lines + + """ + given output lines from CLI command like 'ip -d link show', + find lines belonging to section describing a specific interface + parameters: + - lines: list of strings, output of command + - header_regexp: regexp marking the start of the section + - end_regexp: regexp marking the end of the section + """ + def get_section_lines(self, lines, header_regexp, end_regexp): + if not lines: + return [] + header_re = re.compile(header_regexp) + start_pos = None + # find start_pos of section + line_count = len(lines) + for line_num in range(0, line_count-1): + matches = header_re.match(lines[line_num]) + if matches: + start_pos = line_num + break + if not start_pos: + return [] + # find end of section + end_pos = line_count + end_re = re.compile(end_regexp) + for line_num in range(start_pos+1, end_pos-1): + matches = end_re.match(lines[line_num]) + if matches: + end_pos = line_num + break + return lines[start_pos:end_pos] + + def get_object_data(self, o, lines, regexps): + """ + find object data in output lines from CLI command + parameters: + - o: object (dict), to which we'll add attributes with the data found + - lines: list of strings + - regexps: dict, keys are attribute names, values are regexp to match + for finding the value of the attribute + """ + for line in lines: + self.find_matching_regexps(o, line, regexps) + for regexp_tuple in regexps: + name = regexp_tuple['name'] + if 'name' not in o and 'default' in regexp_tuple: + o[name] = regexp_tuple['default'] + + def find_matching_regexps(self, o, line, regexps): + for regexp_tuple in regexps: + name = regexp_tuple['name'] + regex = regexp_tuple['re'] + regex = re.compile(regex) + matches = regex.search(line) + if matches: + o[name] = matches.group(1) |