1# Copyright 2014 The Chromium OS Authors. All rights reserved. 2# Use of this source code is governed by a BSD-style license that can be 3# found in the LICENSE file. 4 5"""This module provides utility functions to help managing servers in server 6database (defined in global config section AUTOTEST_SERVER_DB). 7 8""" 9 10import socket 11import subprocess 12import sys 13 14import common 15 16import django.core.exceptions 17from autotest_lib.client.common_lib import base_utils as utils 18from autotest_lib.client.common_lib.global_config import global_config 19from autotest_lib.frontend.server import models as server_models 20from autotest_lib.site_utils.lib import infra 21 22 23class ServerActionError(Exception): 24 """Exception raised when action on server failed. 25 """ 26 27 28def use_server_db(): 29 """Check if use_server_db is enabled in configuration. 30 31 @return: True if use_server_db is set to True in global config. 32 """ 33 return global_config.get_config_value( 34 'SERVER', 'use_server_db', default=False, type=bool) 35 36 37def warn_missing_role(role, exclude_server): 38 """Post a warning if Autotest instance has no other primary server with 39 given role. 40 41 @param role: Name of the role. 42 @param exclude_server: Server to be excluded from search for role. 43 """ 44 servers = server_models.Server.objects.filter( 45 roles__role=role, 46 status=server_models.Server.STATUS.PRIMARY).exclude( 47 hostname=exclude_server.hostname) 48 if not servers: 49 message = ('WARNING! There will be no server with role %s after it\'s ' 50 'removed from server %s. Autotest will not function ' 51 'normally without any server in role %s.' % 52 (role, exclude_server.hostname, role)) 53 print >> sys.stderr, message 54 55 56def get_servers(hostname=None, role=None, status=None): 57 """Find servers with given role and status. 58 59 @param hostname: hostname of the server. 60 @param role: Role of server, default to None. 61 @param status: Status of server, default to None. 62 63 @return: A list of server objects with given role and status. 64 """ 65 filters = {} 66 if hostname: 67 filters['hostname'] = hostname 68 if role: 69 filters['roles__role'] = role 70 if status: 71 filters['status'] = status 72 return list(server_models.Server.objects.filter(**filters)) 73 74 75def get_server_details(servers, table=False, summary=False): 76 """Get a string of given servers' details. 77 78 The method can return a string of server information in 3 different formats: 79 A detail view: 80 Hostname : server2 81 Status : primary 82 Roles : drone 83 Attributes : {'max_processes':300} 84 Date Created : 2014-11-25 12:00:00 85 Date Modified: None 86 Note : Drone in lab1 87 A table view: 88 Hostname | Status | Roles | Date Created | Date Modified | Note 89 server1 | backup | scheduler | 2014-11-25 23:45:19 | | 90 server2 | primary | drone | 2014-11-25 12:00:00 | | Drone 91 A summary view: 92 scheduler : server1(backup), server3(primary), 93 host_scheduler : 94 drone : server2(primary), 95 devserver : 96 database : 97 suite_scheduler: 98 crash_server : 99 No Role : 100 101 The method returns detail view of each server and a summary view by default. 102 If `table` is set to True, only table view will be returned. 103 If `summary` is set to True, only summary view will be returned. 104 105 @param servers: A list of servers to get details. 106 @param table: True to return a table view instead of a detail view, 107 default is set to False. 108 @param summary: True to only show the summary of roles and status of 109 given servers. 110 111 @return: A string of the information of given servers. 112 """ 113 # Format string to display a table view. 114 # Hostname, Status, Roles, Date Created, Date Modified, Note 115 TABLEVIEW_FORMAT = ('%(hostname)-30s | %(status)-7s | %(roles)-20s | ' 116 '%(date_created)-19s | %(date_modified)-19s | %(note)s') 117 118 result = '' 119 if not table and not summary: 120 for server in servers: 121 result += '\n' + str(server) 122 elif table: 123 result += (TABLEVIEW_FORMAT % 124 {'hostname':'Hostname', 'status':'Status', 125 'roles':'Roles', 'date_created':'Date Created', 126 'date_modified':'Date Modified', 'note':'Note'}) 127 for server in servers: 128 roles = ','.join(server.get_role_names()) 129 result += '\n' + (TABLEVIEW_FORMAT % 130 {'hostname':server.hostname, 131 'status': server.status or '', 132 'roles': roles, 133 'date_created': server.date_created, 134 'date_modified': server.date_modified or '', 135 'note': server.note or ''}) 136 elif summary: 137 result += 'Roles and status of servers:\n\n' 138 for role, _ in server_models.ServerRole.ROLE.choices(): 139 servers_of_role = [s for s in servers if role in 140 [r.role for r in s.roles.all()]] 141 result += '%-15s: ' % role 142 for server in servers_of_role: 143 result += '%s(%s), ' % (server.hostname, server.status) 144 result += '\n' 145 servers_without_role = [s.hostname for s in servers 146 if not s.roles.all()] 147 result += '%-15s: %s' % ('No Role', ', '.join(servers_without_role)) 148 149 return result 150 151 152def check_server(hostname, role): 153 """Confirm server with given hostname is ready to be primary of given role. 154 155 If the server is a backup and failed to be verified for the role, remove 156 the role from its roles list. If it has no other role, set its status to 157 repair_required. 158 159 @param hostname: hostname of the server. 160 @param role: Role to be checked. 161 @return: True if server can be verified for the given role, otherwise 162 return False. 163 """ 164 # TODO(dshi): Add more logic to confirm server is ready for the role. 165 # For now, the function just checks if server is ssh-able. 166 try: 167 infra.execute_command(hostname, 'true') 168 return True 169 except subprocess.CalledProcessError as e: 170 print >> sys.stderr, ('Failed to check server %s, error: %s' % 171 (hostname, e)) 172 return False 173 174 175def verify_server(exist=True): 176 """Decorator to check if server with given hostname exists in the database. 177 178 @param exist: Set to True to confirm server exists in the database, raise 179 exception if not. If it's set to False, raise exception if 180 server exists in database. Default is True. 181 182 @raise ServerActionError: If `exist` is True and server does not exist in 183 the database, or `exist` is False and server exists 184 in the database. 185 """ 186 def deco_verify(func): 187 """Wrapper for the decorator. 188 189 @param func: Function to be called. 190 """ 191 def func_verify(*args, **kwargs): 192 """Decorator to check if server exists. 193 194 If exist is set to True, raise ServerActionError is server with 195 given hostname is not found in server database. 196 If exist is set to False, raise ServerActionError is server with 197 given hostname is found in server database. 198 199 @param func: function to be called. 200 @param args: arguments for function to be called. 201 @param kwargs: keyword arguments for function to be called. 202 """ 203 hostname = kwargs['hostname'] 204 try: 205 server = server_models.Server.objects.get(hostname=hostname) 206 except django.core.exceptions.ObjectDoesNotExist: 207 server = None 208 209 if not exist and server: 210 raise ServerActionError('Server %s already exists.' % 211 hostname) 212 if exist and not server: 213 raise ServerActionError('Server %s does not exist in the ' 214 'database.' % hostname) 215 if server: 216 kwargs['server'] = server 217 return func(*args, **kwargs) 218 return func_verify 219 return deco_verify 220 221 222def get_drones(): 223 """Get a list of drones in status primary. 224 225 @return: A list of drones in status primary. 226 """ 227 servers = get_servers(role=server_models.ServerRole.ROLE.DRONE, 228 status=server_models.Server.STATUS.PRIMARY) 229 return [s.hostname for s in servers] 230 231 232def delete_attribute(server, attribute): 233 """Delete the attribute from the host. 234 235 @param server: An object of server_models.Server. 236 @param attribute: Name of an attribute of the server. 237 """ 238 attributes = server.attributes.filter(attribute=attribute) 239 if not attributes: 240 raise ServerActionError('Server %s does not have attribute %s' % 241 (server.hostname, attribute)) 242 attributes[0].delete() 243 print 'Attribute %s is deleted from server %s.' % (attribute, 244 server.hostname) 245 246 247def change_attribute(server, attribute, value): 248 """Change the value of an attribute of the server. 249 250 @param server: An object of server_models.Server. 251 @param attribute: Name of an attribute of the server. 252 @param value: Value of the attribute of the server. 253 254 @raise ServerActionError: If the attribute already exists and has the 255 given value. 256 """ 257 attributes = server_models.ServerAttribute.objects.filter( 258 server=server, attribute=attribute) 259 if attributes and attributes[0].value == value: 260 raise ServerActionError('Attribute %s for Server %s already has ' 261 'value of %s.' % 262 (attribute, server.hostname, value)) 263 if attributes: 264 old_value = attributes[0].value 265 attributes[0].value = value 266 attributes[0].save() 267 print ('Attribute `%s` of server %s is changed from %s to %s.' % 268 (attribute, server.hostname, old_value, value)) 269 else: 270 server_models.ServerAttribute.objects.create( 271 server=server, attribute=attribute, value=value) 272 print ('Attribute `%s` of server %s is set to %s.' % 273 (attribute, server.hostname, value)) 274 275 276def get_shards(): 277 """Get a list of shards in status primary. 278 279 @return: A list of shards in status primary. 280 """ 281 servers = get_servers(role=server_models.ServerRole.ROLE.SHARD, 282 status=server_models.Server.STATUS.PRIMARY) 283 return [s.hostname for s in servers] 284 285 286def confirm_server_has_role(hostname, role): 287 """Confirm a given server has the given role, and its status is primary. 288 289 @param hostname: hostname of the server. 290 @param role: Name of the role to be checked. 291 @raise ServerActionError: If localhost does not have given role or it's 292 not in primary status. 293 """ 294 if hostname.lower() in ['localhost', '127.0.0.1']: 295 hostname = socket.gethostname() 296 hostname = utils.normalize_hostname(hostname) 297 298 servers = get_servers(role=role, status=server_models.Server.STATUS.PRIMARY) 299 for server in servers: 300 if hostname == utils.normalize_hostname(server.hostname): 301 return True 302 raise ServerActionError('Server %s does not have role of %s running in ' 303 'status primary.' % (hostname, role)) 304