Public bug reported: I'm doing a bunch of testing with dozens to hundreds of Docker containers. In the process, I gather the pid, hostname, etc. for each docker instance as I spawn it so I can control what is going on in those containers.
Every so often (that is every few thousand containers), I get one which the State.Pid is "0" - and remains zero. It seems to happen more often when I spawn a lot of them (like 200) as fast as I can. Here's the command I use to get the pid: docker.io 'inspect' '--format' '{{.State.Pid}}' docker-instance-name This almost always works, but occasionally it doesn't -- and returns a line containing only "0". I retry every second for 100 seconds just in case it's a transient error. It's not. Since it takes a long time to spawn 200 containers and even longer to shut them down (like 5 seconds each), this *really* puts a kink in my testing. Here's the output from my code when it encounters this condition: .State.Pid is currently zero for instance DockerSystem.13183-00107/897886a7ad01 [0] The string in [] at the end of the line is the contents of what I read from the docker.io inspect command listed above. So, it's not an empty string being treated as or converted to a zero. It's a "0" string. The code I'm using to manage these docker instances is here: http://hg .linux-ha.org/assimilation/file/tip/cma/systemtests/docker.py $ docker.io --version Docker version 0.9.1, build 3600720 I'm running Ubuntu 14.04. Hopefully all this stuff (and a lot more) showed up in the data gathered by the ubuntu-bug command. ProblemType: Bug DistroRelease: Ubuntu 14.04 Package: docker.io 0.9.1~dfsg1-2 ProcVersionSignature: Ubuntu 3.13.0-32.57-generic 3.13.11.4 Uname: Linux 3.13.0-32-generic x86_64 ApportVersion: 2.14.1-0ubuntu2 Architecture: amd64 Date: Wed Aug 27 22:57:50 2014 InstallationDate: Installed on 2014-04-03 (146 days ago) InstallationMedia: Ubuntu-Server 14.04 LTS "Trusty Tahr" - Beta amd64 (20140326) ProcEnviron: TERM=xterm PATH=(custom, no user) XDG_RUNTIME_DIR=<set> LANG=en_US.UTF-8 SHELL=/bin/bash SourcePackage: docker.io UpgradeStatus: No upgrade log present (probably fresh install) mtime.conffile..etc.init.docker.io.conf: 2014-06-26T14:53:37.308799 ** Affects: docker.io (Ubuntu) Importance: Undecided Status: New ** Tags: amd64 apport-bug trusty -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/1362423 Title: docker.io inspect shows docker pid as 0 To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/docker.io/+bug/1362423/+subscriptions -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs