Hi Daniel I'm commenting below.
On Sat, Aug 20, 2011 at 12:16:11AM +0200, Daniel Alder wrote: > Sorry ola > > Even if you try it without the --exec you have to add the "; read a" > like this: > > --- > ~# vzctl enter 222; read a > entered into CT 222 > ct222:~# exit > logout > exited from CT 222 > -bash: read: read error: 0: Resource temporarily unavailable > ~# > --- Yes, and that is because read a is executing in the context of outside the VE (in the host system), but for some reason the stdin has not been gotten back (probably because it was directed to the VE) but the VE command is no longer available, because it has exited. I do not know why stdin is not directed back. That can be a bug. > I agree, calling it as two separate commands (in two lines) doesn't have > this problem > > Also, same problem when using in a script (then the commands can be > separated: > --- > ~# cat test.sh > #!/bin/sh > > set -x > > vzctl enter 222 > read a > echo $? > ~# ./test.sh > + vzctl enter 222 > entered into CT 222 > ct222:/# exit > logout > exited from CT 222 > + read a > + echo 1 > 1 > ~# > --- Yes this will cause the same problem. command1 command2 is equivivalent to command1 ; command2 > according to the documentation, "vzctl enter" is the only one command > which provides a stdin which is a terminal. it does not matter if there > is a --exec or not. For me, "vzctl enter --exec" is the only one > possibility to run an interactive command in a ct. I use it for "vzctl > enter --exec exec apt-get dist-upgrade", but I also need a terminal in > the host environment because I have to ask some questions to the user. Ok. I was not aware of this. In any case, see below. It follows the documentation. I created a /root/test.sh script in the VE to proove this: root@test1:/# cat /root/test.sh #!/bin/bash echo test 1 read a echo test 2 $a read b echo test 3 $b echo done root@test1:/# exit logout exited from CT 201 quartz:/home/ola/svn/t# vzctl enter 201 --exec /root/test.sh entered into CT 201 /root/test.sh root@test1:/# /root/test.sh test 1 aaa test 2 aaa bbb test 3 bbb done > When chrooting, there is no such problem, because it doesn't modify stdin: > --- > # chroot /var/lib/vz/root/222/ ; read a > root@eomer:/# exit > exit > here i can type > # > --- Yes and this is because in a chroot you only have one host. > the answers to your question: > > 1) see above: "vzctl enter --exec exec apt-get dist-upgrade". but this > does not matter. The problem is that i also use stdin in the host system > and as long as the calling shell process is running, I cannot use stdin > anymore there You need to be aware of where you are located. If you are executing whithin the VE or outside it. They are essentially different computers. You can not have stdin in both places at the same time. If you want to control it in the way you do, you have to use languages like expect (or some perl/python variant of that). > 2) I don't get this error before. The "read a" in my examples is always > separated by a unquoted ";" which makes it running in the host system Yes. Is that a serious problem? > 3) I really think it is a serious problem and I cannot understand what > happens. I wonder that a ressource can be left open as long as a parent > process (sh) of a child process (vzctl) is running, but the child > process itself is already terminated. I start to see what you as a problem. > Another idea would be to include a 'vzctl exec' parameter which provides > a terminal-like stdin. This would provide a nicer way for scripting, but > I does not solve this problem itself. It would even have the same > problem if it uses the same code. Alternatively you can use some language like expect to control this easier. Do you want me to forward this bug upstream? // Ola > > Cheers > Daniel > > > On 19.08.2011 07:10, Ola Lundqvist wrote: >> Hi Daniel >> >> What I can reproduce is that you get a >> "Resource temporarily unavailable" message for this line >> >> quartz:/home/ola/svn/t# vzctl enter 201 --exec exit ; read a >> entered into CT 201 >> exit >> root@test1:/# exit >> logout >> exited from CT 201 >> bash: read: read error: 0: Resource temporarily unavailable >> >> But not when you do it without --exec. >> >> quartz:/home/ola/svn/t# vzctl enter 201 >> entered into CT 201 >> root@test1:/# exit >> logout >> exited from CT 201 >> quartz:/home/ola/svn/t# read a >> ^C >> No problem this time. >> >> And not with: >> quartz:/home/ola/svn/t# vzctl enter 201 >> entered into CT 201 >> root@test1:/# read a >> ^C >> root@test1:/# exit >> logout >> exited from CT 201 >> And no problem here. >> >> When you do a enter and --exec I do not think you actually have >> any stdin available. I may be wrong here but enter is special >> in that sense. I think the same applies when you do chroot. >> >> If you want I can forward this bug report to upstream but first >> I need to understand a bit more about your problem. Is it >> one of the following? >> >> 1) You do not have a stdin in commands that you use with --exec ? >> 2) That you get resource unavailable also after you have exited >> from the CT? >> 3) Something else? >> >> Best regards, >> >> // Ola >> >> >> On Wed, Aug 17, 2011 at 12:40:31AM +0200, Daniel Alder wrote: >>> Package: vzctl >>> Architecture: i386 >>> Version: 3.0.24-12 >>> >>> Try the following command lines in bash: >>> >>> ---- >>> $ set -x >>> $ vzctl enter 222 --exec exit ; read a >>> + vzctl enter 222 --exec exit >>> entered into CT 222 >>> exit >>> root@durin:/# exit >>> logout >>> exited from CT 222 >>> + read a >>> -bash: read: read error: 0: Resource temporarily unavailable >>> $ >>> $ read a >>> + read a >>> here i can type >>> $ >>> ---- >>> >>> The command which follows after the vzctl call does not work if it uses >>> stdin. A command like apt-get will even switch to non-interactive mode. >>> >>> The strange thing is, that the next command typed at the command line >>> works without problems. >>> >>> When using the same commands in a script file, stdin is blocked until >>> the end of script execution, which makes it impossible for me to do some >>> batch jobs. >>> >>> >>> "vzctl enter 222 --exec exit" was only an example. you can also try >>> "vzctl enter 222" and type exit manually >>> >>> >>> When using the above commands using dash 'read' outputs the following >>> message: "turning off NDELAY mode" >>> >>> >>> >> > > -- --- Inguza Technology AB --- MSc in Information Technology ---- / [email protected] Annebergsslingan 37 \ | [email protected] 654 65 KARLSTAD | | http://inguza.com/ Mobile: +46 (0)70-332 1551 | \ gpg/f.p.: 7090 A92B 18FE 7994 0C36 4FE4 18A1 B1CF 0FE5 3DD9 / --------------------------------------------------------------- -- To UNSUBSCRIBE, email to [email protected] with a subject of "unsubscribe". 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