github.com/spg/deis@v1.7.3/builder/rootfs/bin/entry (about) 1 #!/bin/bash 2 set -eo pipefail 3 4 if [[ -f /etc/environment_proxy ]]; then 5 source /etc/environment_proxy 6 fi 7 8 # START jpetazzo/dind wrapper 9 10 # First, make sure that cgroups are mounted correctly. 11 CGROUP=/sys/fs/cgroup 12 13 [ -d $CGROUP ] || 14 mkdir $CGROUP 15 16 mountpoint -q $CGROUP || 17 mount -n -t tmpfs -o uid=0,gid=0,mode=0755 cgroup $CGROUP || { 18 echo "Could not make a tmpfs mount. Did you use -privileged?" 19 exit 1 20 } 21 22 if [ -d /sys/kernel/security ] && ! mountpoint -q /sys/kernel/security 23 then 24 mount -t securityfs none /sys/kernel/security || { 25 echo "Could not mount /sys/kernel/security." 26 echo "AppArmor detection and -privileged mode might break." 27 } 28 fi 29 30 # Mount the cgroup hierarchies exactly as they are in the parent system. 31 for SUBSYS in $(cut -d: -f2 /proc/1/cgroup) 32 do 33 [ -d $CGROUP/$SUBSYS ] || mkdir $CGROUP/$SUBSYS 34 mountpoint -q $CGROUP/$SUBSYS || 35 mount -n -t cgroup -o $SUBSYS cgroup $CGROUP/$SUBSYS 36 37 # The two following sections address a bug which manifests itself 38 # by a cryptic "lxc-start: no ns_cgroup option specified" when 39 # trying to start containers withina container. 40 # The bug seems to appear when the cgroup hierarchies are not 41 # mounted on the exact same directories in the host, and in the 42 # container. 43 44 # Named, control-less cgroups are mounted with "-o name=foo" 45 # (and appear as such under /proc/<pid>/cgroup) but are usually 46 # mounted on a directory named "foo" (without the "name=" prefix). 47 # Systemd and OpenRC (and possibly others) both create such a 48 # cgroup. To avoid the aforementioned bug, we symlink "foo" to 49 # "name=foo". This shouldn't have any adverse effect. 50 echo $SUBSYS | grep -q ^name= && { 51 NAME=$(echo $SUBSYS | sed s/^name=//) 52 ln -s $SUBSYS $CGROUP/$NAME 53 } 54 55 # Likewise, on at least one system, it has been reported that 56 # systemd would mount the CPU and CPU accounting controllers 57 # (respectively "cpu" and "cpuacct") with "-o cpuacct,cpu" 58 # but on a directory called "cpu,cpuacct" (note the inversion 59 # in the order of the groups). This tries to work around it. 60 [ $SUBSYS = cpuacct,cpu ] && ln -s $SUBSYS $CGROUP/cpu,cpuacct 61 done 62 63 # Note: as I write those lines, the LXC userland tools cannot setup 64 # a "sub-container" properly if the "devices" cgroup is not in its 65 # own hierarchy. Let's detect this and issue a warning. 66 grep -q :devices: /proc/1/cgroup || 67 echo "WARNING: the 'devices' cgroup should be in its own hierarchy." 68 grep -qw devices /proc/1/cgroup || 69 echo "WARNING: it looks like the 'devices' cgroup is not mounted." 70 71 # Now, close extraneous file descriptors. 72 pushd /proc/self/fd >/dev/null 73 for FD in * 74 do 75 case "$FD" in 76 # Keep stdin/stdout/stderr 77 [012]) 78 ;; 79 # Nuke everything else 80 *) 81 eval exec "$FD>&-" 82 ;; 83 esac 84 done 85 popd >/dev/null 86 87 # END jpetazzo/dind wrapper 88 89 exec $@