roshlaunch.remoteprocess

58 """ 59 Validation routine for loading the host keys and making sure that 60 they are configured properly for the desired SSH. The behavior of 61 this routine can be modified by the ROSLAUNCH_SSH_UNKNOWN 62 environment variable, which enables the paramiko.AutoAddPolicy. 63 64 @param ssh: paramiko SSH client 65 @type ssh: L{paramiko.SSHClient} 66 @param address: SSH IP address 67 @type address: str 68 @param port: SSH port 69 @type port: int 70 @param username: optional username to include in error message if check fails 71 @type username: str 72 @param logger: (optional) logger to record tracebacks to 73 @type logger: logging.Logger 74 @return: error message if improperly configured, or None 75 @rtype: str 76 """ 77 import paramiko 78 try: 79 try: 80 if os.path.isfile('/etc/ssh/ssh_known_hosts'): #default ubuntu location 81 ssh.load_system_host_keys('/etc/ssh/ssh_known_hosts') 82 except IOError: 83 pass 84 ssh.load_system_host_keys() #default user location 85 except: 86 if logger: 87 logger.error(traceback.format_exc()) 88 # as seen in #767, base64 raises generic Error. 89 # 90 # A corrupt pycrypto build can also cause this, though 91 # the cause of the corrupt builds has been fixed. 92 return "cannot load SSH host keys -- your known_hosts file may be corrupt" 93 94 # #1849: paramiko will raise an SSHException with an 'Unknown 95 # server' message if the address is not in the known_hosts 96 # file. This causes a lot of confusion to users, so we try 97 # and diagnose this in advance and offer better guidance 98 99 # - ssh.get_host_keys() does not return the system host keys 100 hk = ssh._system_host_keys 101 override = os.environ.get('ROSLAUNCH_SSH_UNKNOWN', 0) 102 if override == '1': 103 ssh.set_missing_host_key_policy(paramiko.AutoAddPolicy()) 104 elif hk.lookup(address) is None: 105 port_str = user_str = '' 106 if port != 22: 107 port_str = "-p %s "%port 108 if username: 109 user_str = username+'@' 110 return """%s is not in your SSH known_hosts file. 111 112 Please manually: 113 ssh %s%s%s 114 115 then try roslaunching again. 116 117 If you wish to configure roslaunch to automatically recognize unknown 118 hosts, please set the environment variable ROSLAUNCH_SSH_UNKNOWN=1"""%(address, user_str, port_str, address)

122 """ 123 Process wrapper for launching and monitoring a child roslaunch process over SSH 124 """

125 - def __init__(self, run_id, name, server_uri, env, machine):

126 if machine.ros_root: 127 cmd = os.path.join(machine.ros_root, 'bin', 'roslaunch') 128 else: # assumes user has mapped onto path 129 cmd = 'roslaunch' 130 args = [cmd, '-c', name, '-u', server_uri, '--run_id', run_id] 131 super(SSHChildROSLaunchProcess, self).__init__(name, args, env) 132 self.machine = machine 133 self.ssh = self.sshin = self.sshout = self.ssherr = None 134 self.started = False 135 self.uri = None 136 # self.is_dead is a flag set by is_alive that affects whether or not we 137 # log errors during a stop(). 138 self.is_dead = False

139

140 - def _ssh_exec(self, command, env, address, port, username=None, password=None):

141 if env: 142 env_command = "env "+' '.join(["%s=%s"%(k,v) for (k, v) in env.iteritems()]) 143 command = "%s %s"%(env_command, command) 144 try: 145 # as pycrypto 2.0.1 is EOL, disable it's Python 2.6 deprecation warnings 146 import warnings 147 warnings.filterwarnings("ignore", message="the sha module is deprecated; use the hashlib module instead") 148 warnings.filterwarnings("ignore", message="the md5 module is deprecated; use hashlib instead") 149 150 import Crypto 151 except ImportError, e: 152 _logger.error("cannot use SSH: pycrypto is not installed") 153 return None, "pycrypto is not installed" 154 try: 155 import paramiko 156 except ImportError, e: 157 _logger.error("cannot use SSH: paramiko is not installed") 158 return None, "paramiko is not installed" 159 #load ssh client and connect 160 ssh = paramiko.SSHClient() 161 err_msg = ssh_check_known_hosts(ssh, address, port, username=username, logger=_logger) 162 163 if not err_msg: 164 username_str = '%s@'%username if username else '' 165 try: 166 if not password: #use SSH agent 167 ssh.connect(address, port, username, timeout=TIMEOUT_SSH_CONNECT) 168 else: #use SSH with login/pass 169 ssh.connect(address, port, username, password, timeout=TIMEOUT_SSH_CONNECT) 170 except paramiko.BadHostKeyException: 171 _logger.error(traceback.format_exc()) 172 err_msg = "Unable to verify host key for remote computer[%s:%s]"%(address, port) 173 except paramiko.AuthenticationException: 174 _logger.error(traceback.format_exc()) 175 err_msg = "Authentication to remote computer[%s%s:%s] failed.\nA common cause of this error is a missing key in your authorized_keys file."%(username_str, address, port) 176 except paramiko.SSHException, e: 177 _logger.error(traceback.format_exc()) 178 if str(e).startswith("Unknown server"): 179 pass 180 err_msg = "Unable to establish ssh connection to [%s%s:%s]: %s"%(username_str, address, port, e) 181 except socket.error, e: 182 # #1824 183 if e[0] == 111: 184 err_msg = "network connection refused by [%s:%s]"%(address, port) 185 else: 186 err_msg = "network error connecting to [%s:%s]: %s"%(address, port, str(e)) 187 if err_msg: 188 return None, err_msg 189 else: 190 sshin, sshout, ssherr = ssh.exec_command(command) 191 return (ssh, sshin, sshout, ssherr), "executed remotely"

192

193 - def start(self):

194 """ 195 Start the remote process. This will create an SSH connection 196 to the remote host. 197 """ 198 self.started = False #won't set to True until we are finished 199 self.ssh = self.sshin = self.sshout = self.ssherr = None 200 try: 201 self.lock.acquire() 202 name = self.name 203 m = self.machine 204 if m.user is not None: 205 printlog("remote[%s]: creating ssh connection to %s:%s, user[%s]"%(name, m.address, m.ssh_port, m.user)) 206 else: 207 printlog("remote[%s]: creating ssh connection to %s:%s"%(name, m.address, m.ssh_port)) 208 _logger.info("remote[%s]: invoking with ssh exec args [%s], env: %s"%(name, ' '.join(self.args), self.env)) 209 sshvals, msg = self._ssh_exec(' '.join(self.args), self.env, m.address, m.ssh_port, m.user, m.password) 210 if sshvals is None: 211 printerrlog("remote[%s]: failed to launch on %s:\n\n%s\n\n"%(name, m.name, msg)) 212 return False 213 self.ssh, self.sshin, self.sshout, self.ssherr = sshvals 214 printlog("remote[%s]: ssh connection created"%name) 215 self.started = True 216 return True 217 finally: 218 self.lock.release()

219

220 - def getapi(self):

221 """ 222 @return: ServerProxy to remote client XMLRPC server 223 @rtype: L{ServerProxy} 224 """ 225 if self.uri: 226 return xmlrpclib.ServerProxy(self.uri) 227 else: 228 return None

229

230 - def is_alive(self):

231 """ 232 @return: True if the process is alive. is_alive needs to be 233 called periodically as it drains the SSH buffer 234 @rtype: bool 235 """ 236 if self.started and not self.ssh: 237 return False 238 elif not self.started: 239 return True #not started is equivalent to alive in our logic 240 s = self.ssherr 241 s.channel.settimeout(0) 242 try: 243 #drain the pipes 244 data = s.read(2048) 245 if not len(data): 246 self.is_dead = True 247 return False 248 # #2012 il8n: ssh *should* be UTF-8, but often isn't 249 # (e.g. Japan) 250 data = data.decode('utf-8') 251 printerrlog("remote[%s]: %s"%(self.name, data)) 252 except socket.timeout: 253 pass 254 except IOError: 255 return False 256 except UnicodeDecodeError: 257 # #2012: soft fail, printing is not essential. This occurs 258 # with older machines that don't send utf-8 over ssh 259 pass 260 261 s = self.sshout 262 s.channel.settimeout(0) 263 try: 264 #drain the pipes 265 #TODO: write to log file 266 data = s.read(2048) 267 if not len(data): 268 self.is_dead = True 269 return False 270 # data = data.decode('utf-8') 271 #print "DATA", data 272 except socket.timeout: 273 pass 274 except IOError: 275 return False 276 return True

277

278 - def stop(self, errors=[]):

279 """ 280 Terminate this process, including the SSH connection. 281 """ 282 try: 283 self.lock.acquire() 284 if not self.ssh: 285 return 286 287 # call the shutdown API first as closing the SSH connection 288 # won't actually kill the process unless it triggers SIGPIPE 289 try: 290 api = self.getapi() 291 if api is not None: 292 #TODO: probably need a timeout on this 293 api.shutdown() 294 except socket.error: 295 # normal if process is already dead 296 address, port = self.machine.address, self.machine.ssh_port 297 if not self.is_dead: 298 printerrlog("remote[%s]: unable to contact [%s] to shutdown remote processes!"%(self.name, address)) 299 else: 300 printlog("remote[%s]: unable to contact [%s] to shutdown cleanly. The remote roslaunch may have exited already."%(self.name, address)) 301 except: 302 # temporary: don't really want to log here as this 303 # may occur during shutdown 304 traceback.print_exc() 305 306 _logger.info("remote[%s]: closing ssh connection", self.name) 307 self.sshin.close() 308 self.sshout.close() 309 self.ssherr.close() 310 self.ssh.close() 311 312 self.sshin = None 313 self.sshout = None 314 self.ssherr = None 315 self.ssh = None 316 _logger.info("remote[%s]: ssh connection closed", self.name) 317 finally: 318 self.lock.release()

Source Code for Module roshlaunch.remoteprocess