nelsnelson

2013-04-15  Daniel P. Berrange  <[email protected]> 

Track symlinks for co-mounted cgroup controllers 
If a cgroup controller is co-mounted with another, eg 

   /sys/fs/cgroup/cpu,cpuacct 

Then it is a requirement that there exist symlinks at 

   /sys/fs/cgroup/cpu 

nelsnelson

/sys/fs/cgroup$ ls -la
total 0
drwxr-xr-x. 4 root root 0 Mar 28 18:42 .
drwxr-xr-x. 7 root root 0 Mar 28 18:42 ..
-r--r--r--. 1 root root 0 Mar 28 18:42 blkio.io_merged
-r--r--r--. 1 root root 0 Mar 28 18:42 blkio.io_merged_recursive
-r--r--r--. 1 root root 0 Mar 28 18:42 blkio.io_queued
-r--r--r--. 1 root root 0 Mar 28 18:42 blkio.io_queued_recursive
-r--r--r--. 1 root root 0 Mar 28 18:42 blkio.io_service_bytes
-r--r--r--. 1 root root 0 Mar 28 18:42 blkio.io_service_bytes_recursive

nelsnelson

# lxc-create -n outer -t minimal
# lxc-start -n outer -d
# lxc-attach -n outer -- bash
bash-4.2# mkdir /var/lib/lxc
bash-4.2# lxc-create -n inner -t minimal
bash-4.2# lxc-start -n inner -d
bash-4.2# lxc-attach -n inner -- bash
bash-4.2# ls /sys/fs/cgroup
blkio  cpu  cpuacct  cpuset  devices  freezer  hugetlb	hugetlb,net_prio,perf_event,blkio,freezer,devices,memory,cpuacct,cpu,cpuset  memory  net_prio  perf_event
bash-4.2# 

nelsnelson

bash-4.2# pwd
/sys/fs/cgroup
bash-4.2# ls
blkio  cpu  cpuacct  cpuset  devices  freezer  hugetlb	hugetlb,net_prio,perf_event,blkio,freezer,devices,memory,cpuacct,cpu,cpuset  memory  net_prio  perf_event
bash-4.2# ls -la
total 0
drwxr-xr-x. 3 root root 260 Apr  9 21:13 .
drwxr-xr-x. 7 root root   0 Apr  9 21:13 ..
lrwxrwxrwx. 1 root root  75 Apr  9 21:13 blkio -> hugetlb,net_prio,perf_event,blkio,freezer,devices,memory,cpuacct,cpu,cpuset
lrwxrwxrwx. 1 root root  75 Apr  9 21:13 cpu -> hugetlb,net_prio,perf_event,blkio,freezer,devices,memory,cpuacct,cpu,cpuset

nelsnelson

#!/bin/bash

# Detect use under userns (unsupported)
for arg in "$@"; do
    [ "$arg" = "--" ] && break
    if [ "$arg" = "--mapped-uid" -o "$arg" = "--mapped-gid" ]; then
        echo "This template can't be used for unprivileged containers." 1>&2
        echo "You may want to try the \"download\" template instead." 1>&2
        exit 1
    fi

nelsnelson

#
# First attempt without apparmor
#

# lxc-create -n outer -t minimal
# ls /var/lib/lxc/outer/rootfs
bin  dev  etc  home  lib  lib64  proc  root  run  run-dhcp  sbin  sys  tmp  usr  var
# ls /var/lib/lxc/outer/rootfs/sys
# lxc-start -n outer -- bash
bash: cannot set terminal process group (-1): Inappropriate ioctl for device

nelsnelson

#! /usr/bin/env bash

exec &>/dev/null
sudo lxc-stop -n outer -t 5
sudo lxc-destroy -n outer
exec &>/dev/tty

set -x

sudo lxc-create -n outer -t minimal -l DEBUG -o /tmp/lxc.log

nelsnelson

#!/bin/bash

#
# lxc: linux Container library

# Authors:
# Daniel Lezcano <[email protected]>
# Nels Nelson <[email protected]>

# This library is free software; you can redistribute it and/or

nelsnelson

$ cat /tmp/lxc.log
     lxc-create 1392051349.564 WARN     lxc_log - lxc_log_init called with log already initialized
     lxc-create 1392051349.588 INFO     lxc_create_ui - container test created
      lxc-start 1392051366.650 INFO     lxc_start_ui - using rcfile /var/lib/lxc/test/config
      lxc-start 1392051366.650 WARN     lxc_log - lxc_log_init called with log already initialized
      lxc-start 1392051366.652 DEBUG    lxc_cgroup - cgroup_init
      lxc-start 1392051366.652 INFO     lxc_cgroup - Initialized cgroup driver cgroupfs
      lxc-start 1392051366.652 INFO     lxc_lsm - LSM security driver SELinux
      lxc-start 1392051366.653 DEBUG    lxc_start - sigchild handler set
      lxc-start 1392051366.653 DEBUG    lxc_console - no console peer

nelsnelson

#!/bin/bash

#
# lxc: linux Container library

# Authors:
# Daniel Lezcano <[email protected]>

# This library is free software; you can redistribute it and/or
# modify it under the terms of the GNU Lesser General Public