exit-status returns non-deterministic
muzy opened this issue · comments
Hi,
I just discovered that the exit-status is not always set (in net.schmizz.sshj.connection.channel.direct) , even though the according packets are send by the ssh host. A first evaluation of this points to the StreamCopier (net.schmizz.sshj.StreamCopier) because depending on the call of the copy() function, the exit-status is available or not (see attached logfiles).
Logfile when exit-status is fetched:
DEBUG ConnectionImpl:68 - Attaching `session` channel (#3)
TRACE Encoder:100 - Encoding packet #18: 5a 00 00 00 07 73 65 73 73 69 6f 6e 00 00 00 03 00 20 00 00 00 00 80 00
DEBUG Promise:164 - Awaiting <<chan#3 / open>>
TRACE Decoder:125 - Received packet #25: 5b 00 00 00 03 00 00 00 00 00 00 00 00 00 00 80 00
TRACE TransportImpl:471 - Received packet CHANNEL_OPEN_CONFIRMATION
DEBUG SessionChannel:125 - Initialized - < session channel: id=3, recipient=0, localWin=[winSize=2097152], remoteWin=[winSize=0] >
DEBUG Promise:78 - Setting <<chan#3 / open>> to `SOME`
INFO SessionChannel:120 - Will request to exec `test -x /tmp/nmon`
DEBUG SessionChannel:374 - Sending channel request for `exec`
TRACE Encoder:100 - Encoding packet #19: 62 00 00 00 00 00 00 00 04 65 78 65 63 01 00 00 00 11 74 65 73 74 20 2d 78 20 2f 74 6d 70 2f 6e 6d 6f 6e
DEBUG Promise:164 - Awaiting <<chan#3 / chanreq for exec>>
TRACE Decoder:125 - Received packet #26: 5d 00 00 00 03 00 20 00 00
TRACE TransportImpl:471 - Received packet CHANNEL_WINDOW_ADJUST
DEBUG SessionChannel:328 - Received window adjustment for 2097152 bytes
DEBUG Window$Remote:41 - Increasing by 2097152 up to 2097152
TRACE Decoder:125 - Received packet #27: 63 00 00 00 03
TRACE TransportImpl:471 - Received packet CHANNEL_SUCCESS
DEBUG Promise:78 - Setting <<chan#3 / chanreq for exec>> to `SOME`
DEBUG SSHWrapper:241 - < session channel: id=3, recipient=0, localWin=[winSize=2097152], remoteWin=[winSize=2097152] >
TRACE Decoder:125 - Received packet #28: 60 00 00 00 03
TRACE TransportImpl:471 - Received packet CHANNEL_EOF
DEBUG SessionChannel:410 - Got EOF
DEBUG StreamCopier:139 - 0.0 KiB transferred in 0.038 seconds (0.0 KiB/s)
TRACE Decoder:125 - Received packet #29: 62 00 00 00 03 00 00 00 0b 65 78 69 74 2d 73 74 61 74 75 73 00 00 00 00 01
TRACE TransportImpl:471 - Received packet CHANNEL_REQUEST
DEBUG SessionChannel:316 - Got chan request for `exit-status`
TRACE Decoder:125 - Received packet #30: 61 00 00 00 03
TRACE TransportImpl:471 - Received packet CHANNEL_CLOSE
DEBUG SessionChannel:223 - Got close
DEBUG SessionChannel:427 - Sending EOF
TRACE Encoder:100 - Encoding packet #20: 60 00 00 00 00
DEBUG StreamCopier:139 - 0.0 KiB transferred in 0.0 seconds (NaN KiB/s)
DEBUG SessionChannel:289 - Sending close
TRACE Encoder:100 - Encoding packet #21: 61 00 00 00 00
DEBUG Promise:164 - Awaiting <<chan#3 / close>>
DEBUG ConnectionImpl:84 - Forgetting `session` channel (#3)
DEBUG Promise:78 - Setting <<chan#3 / close>> to `SOME`
Logfile when the exit-status remains "null":
DEBUG ConnectionImpl:68 - Attaching `session` channel (#4)
TRACE Encoder:100 - Encoding packet #22: 5a 00 00 00 07 73 65 73 73 69 6f 6e 00 00 00 04 00 20 00 00 00 00 80 00
DEBUG Promise:164 - Awaiting <<chan#4 / open>>
TRACE Decoder:125 - Received packet #31: 5b 00 00 00 04 00 00 00 00 00 00 00 00 00 00 80 00
TRACE TransportImpl:471 - Received packet CHANNEL_OPEN_CONFIRMATION
DEBUG SessionChannel:125 - Initialized - < session channel: id=4, recipient=0, localWin=[winSize=2097152], remoteWin=[winSize=0] >
DEBUG Promise:78 - Setting <<chan#4 / open>> to `SOME`
INFO SessionChannel:120 - Will request to exec `test -x /tmp/nmon`
DEBUG SessionChannel:374 - Sending channel request for `exec`
TRACE Encoder:100 - Encoding packet #23: 62 00 00 00 00 00 00 00 04 65 78 65 63 01 00 00 00 11 74 65 73 74 20 2d 78 20 2f 74 6d 70 2f 6e 6d 6f 6e
DEBUG Promise:164 - Awaiting <<chan#4 / chanreq for exec>>
TRACE Decoder:125 - Received packet #32: 5d 00 00 00 04 00 20 00 00
TRACE TransportImpl:471 - Received packet CHANNEL_WINDOW_ADJUST
DEBUG SessionChannel:328 - Received window adjustment for 2097152 bytes
DEBUG Window$Remote:41 - Increasing by 2097152 up to 2097152
TRACE Decoder:125 - Received packet #33: 63 00 00 00 04
TRACE TransportImpl:471 - Received packet CHANNEL_SUCCESS
DEBUG Promise:78 - Setting <<chan#4 / chanreq for exec>> to `SOME`
DEBUG SSHWrapper:241 - < session channel: id=4, recipient=0, localWin=[winSize=2097152], remoteWin=[winSize=2097152] >
TRACE Decoder:125 - Received packet #34: 60 00 00 00 04
TRACE TransportImpl:471 - Received packet CHANNEL_EOF
DEBUG SessionChannel:410 - Got EOF
DEBUG StreamCopier:139 - 0.0 KiB transferred in 0.039 seconds (0.0 KiB/s)
DEBUG StreamCopier:139 - 0.0 KiB transferred in 0.0 seconds (NaN KiB/s)
TRACE Decoder:125 - Received packet #35: 62 00 00 00 04 00 00 00 0b 65 78 69 74 2d 73 74 61 74 75 73 00 00 00 00 01
TRACE TransportImpl:471 - Received packet CHANNEL_REQUEST
DEBUG SessionChannel:316 - Got chan request for `exit-status`
TRACE Decoder:125 - Received packet #36: 61 00 00 00 04
TRACE TransportImpl:471 - Received packet CHANNEL_CLOSE
DEBUG SessionChannel:223 - Got close
DEBUG SessionChannel:427 - Sending EOF
TRACE Encoder:100 - Encoding packet #24: 60 00 00 00 00
DEBUG SessionChannel:289 - Sending close
TRACE Encoder:100 - Encoding packet #25: 61 00 00 00 00
DEBUG Promise:164 - Awaiting <<chan#4 / close>>
DEBUG ConnectionImpl:84 - Forgetting `session` channel (#4)
DEBUG Promise:78 - Setting <<chan#4 / close>> to `SOME`
Even though the SSH related RFC (http://www.ietf.org/rfc/rfc4254.txt) only recommends to return the exit-status, an accurate exit-status would be great instead of an null value (when the host has send the packet).
seems like a visibility issue - sounds like some of SessionChannel's fields (exitStatus, exitSignal, wasCoreDumped, exitErrMsg, canDoFlowControl) need to be volatile.
The issue still persist and is not fixed using the latest snapshot version.
ok, reopening
Hello
have same problem
Methods return null in debuger see thats value is not null
Session.Command cmd = null;
Session session = ssh.startSession();
cmd = session.exec(shellCommand);
System.out.println("status = " + cmd.getExitStatus());
System.out.println("cmd.getExitSignal() = " + cmd.getExitSignal());
System.out.println("cmd = " + cmd);
LOGGER.debug("{}@{}:# {}", _login, _host, shellCommand);
return cmd.getInputStream();
If execute cmd.close(); method work.
Before getExitStatus (as i think) you must flush resources of command.
Session.Command cmd = null;
Session session = ssh.startSession();
cmd = session.exec(shellCommand);
cmd.close();
if (cmd.getExitStatus() != 0) {
throw new ExecutionException("Shell command " +
"'"+shellCommand+"' on host = "+_host+" exit w
.getExitStatus());
}
LOGGER.debug("{}@{}:# {}", _login, _host, shellCommand);stdout
exception.ExecutionException: Shell command 'asdasd' on host = hadoop08 exit with status 127