Update libcontainer to 53eca435e63db58b06cf796d3a9

Signed-off-by: Michael Crosby <[email protected]>

project/vendor.sh

@@ -66,7 +66,7 @@ if [ "$1" = '--go' ]; then
 	mv tmp-tar src/code.google.com/p/go/src/pkg/archive/tar
 fi
 
-clone git github.com/docker/libcontainer 84c1636580a356db88b079d118b94abe6a1a0acd
+clone git github.com/docker/libcontainer 53eca435e63db58b06cf796d3a9326db5fd42253
 # see src/github.com/docker/libcontainer/update-vendor.sh which is the "source of truth" for libcontainer deps (just like this file)
 rm -rf src/github.com/docker/libcontainer/vendor
 eval "$(grep '^clone ' src/github.com/docker/libcontainer/update-vendor.sh | grep -v 'github.com/codegangsta/cli')"

vendor/src/github.com/docker/libcontainer/SPEC.md

@@ -0,0 +1,321 @@
+## Container Specification - v1
+
+This is the standard configuration for version 1 containers.  It includes
+namespaces, standard filesystem setup, a default Linux capability set, and
+information about resource reservations.  It also has information about any 
+populated environment settings for the processes running inside a container.
+
+Along with the configuration of how a container is created the standard also
+discusses actions that can be performed on a container to manage and inspect
+information about the processes running inside.
+
+The v1 profile is meant to be able to accommodate the majority of applications
+with a strong security configuration.
+
+### System Requirements and Compatibility
+
+Minimum requirements:
+* Kernel version - 3.8 recommended 2.6.2x minimum(with backported patches) 
+* Mounted cgroups with each subsystem in its own hierarchy
+
+
+### Namespaces
+
+|     Flag      | Enabled | 
+| ------------  | ------- |
+| CLONE_NEWPID  |    1    |
+| CLONE_NEWUTS  |    1    |
+| CLONE_NEWIPC  |    1    |
+| CLONE_NEWNET  |    1    |
+| CLONE_NEWNS   |    1    |
+| CLONE_NEWUSER |    0    |
+
+In v1 the user namespace is not enabled by default for support of older kernels
+where the user namespace feature is not fully implemented.  Namespaces are 
+created for the container via the `clone` syscall.  
+
+
+### Filesystem
+
+A root filesystem must be provided to a container for execution.  The container
+will use this root filesystem (rootfs) to jail and spawn processes inside where
+the binaries and system libraries are local to that directory.  Any binaries
+to be executed must be contained within this rootfs.
+
+Mounts that happen inside the container are automatically cleaned up when the
+container exits as the mount namespace is destroyed and the kernel will 
+unmount all the mounts that were setup within that namespace.
+
+For a container to execute properly there are certain filesystems that 
+are required to be mounted within the rootfs that the runtime will setup.
+
+|     Path    |  Type  |                  Flags                 |                 Data                    |
+| ----------- | ------ | -------------------------------------- | --------------------------------------- |
+| /proc       | proc   | MS_NOEXEC,MS_NOSUID,MS_NODEV           |                                         |
+| /dev        | tmpfs  | MS_NOEXEC,MS_STRICTATIME               | mode=755                                |
+| /dev/shm    | shm    | MS_NOEXEC,MS_NOSUID,MS_NODEV           | mode=1777,size=65536k                   |
+| /dev/mqueue | mqueue | MS_NOEXEC,MS_NOSUID,MS_NODEV           |                                         |
+| /dev/pts    | devpts | MS_NOEXEC,MS_NOSUID                    | newinstance,ptmxmode=0666,mode=620,gid5 |
+| /sys        | sysfs  | MS_NOEXEC,MS_NOSUID,MS_NODEV,MS_RDONLY |                                         |
+
+
+After a container's filesystems are mounted within the newly created 
+mount namespace `/dev` will need to be populated with a set of device nodes.
+It is expected that a rootfs does not need to have any device nodes specified
+for `/dev` witin the rootfs as the container will setup the correct devices
+that are required for executing a container's process.
+
+|      Path    | Mode |   Access   |
+| ------------ | ---- | ---------- |
+| /dev/null    | 0666 |  rwm       |
+| /dev/zero    | 0666 |  rwm       |
+| /dev/full    | 0666 |  rwm       |
+| /dev/tty     | 0666 |  rwm       |
+| /dev/random  | 0666 |  rwm       |
+| /dev/urandom | 0666 |  rwm       |
+| /dev/fuse    | 0666 |  rwm       |
+
+
+**ptmx**
+`/dev/ptmx` will need to be a symlink to the host's `/dev/ptmx` within
+the container.  
+
+The use of a pseudo TTY is optional within a container and it should support both.
+If a pseudo is provided to the container `/dev/console` will need to be 
+setup by binding the console in `/dev/` after it has been populated and mounted
+in tmpfs.
+
+|      Source     | Destination  | UID GID | Mode | Type |
+| --------------- | ------------ | ------- | ---- | ---- |
+| *pty host path* | /dev/console | 0 0     | 0600 | bind | 
+
+
+After `/dev/null` has been setup we check for any external links between
+the container's io, STDIN, STDOUT, STDERR.  If the container's io is pointing
+to `/dev/null` outside the container we close and `dup2` the the `/dev/null` 
+that is local to the container's rootfs.
+
+
+After the container has `/proc` mounted a few standard symlinks are setup 
+within `/dev/` for the io.
+
+|    Source    | Destination |
+| ------------ | ----------- |
+| /proc/1/fd   | /dev/fd     |
+| /proc/1/fd/0 | /dev/stdin  |
+| /proc/1/fd/1 | /dev/stdout |
+| /proc/1/fd/2 | /dev/stderr |
+
+A `pivot_root` is used to change the root for the process, effectively 
+jailing the process inside the rootfs.
+
+```c
+put_old = mkdir(...);
+pivot_root(rootfs, put_old);
+chdir("/");
+unmount(put_old, MS_DETACH);
+rmdir(put_old);
+```
+
+For container's running with a rootfs inside `ramfs` a `MS_MOVE` combined
+with a `chroot` is required as `pivot_root` is not supported in `ramfs`.
+
+```c
+mount(rootfs, "/", NULL, MS_MOVE, NULL);
+chroot(".");
+chdir("/");
+```
+
+The `umask` is set back to `0022` after the filesystem setup has been completed.
+
+### Resources
+
+Cgroups are used to handle resource allocation for containers.  This includes
+system resources like cpu, memory, and device access.
+
+| Subsystem  | Enabled |
+| ---------- | ------- |
+| devices    | 1       |
+| memory     | 1       |
+| cpu        | 1       |
+| cpuacct    | 1       |
+| cpuset     | 1       |
+| blkio      | 1       |
+| perf_event | 1       |
+| freezer    | 1       |
+
+
+All cgroup subsystem are joined so that statistics can be collected from
+each of the subsystems.  Freezer does not expose any stats but is joined
+so that containers can be paused and resumed.
+
+The parent process of the container's init must place the init pid inside
+the correct cgroups before the initialization begins.  This is done so
+that no processes or threads escape the cgroups.  This sync is 
+done via a pipe ( specified in the runtime section below ) that the container's
+init process will block waiting for the parent to finish setup.
+
+### Security 
+
+The standard set of Linux capabilities that are set in a container
+provide a good default for security and flexibility for the applications.
+
+
+|     Capability       | Enabled |
+| -------------------- | ------- |
+| CAP_NET_RAW          | 1       |
+| CAP_NET_BIND_SERVICE | 1       |
+| CAP_AUDIT_WRITE      | 1       |
+| CAP_DAC_OVERRIDE     | 1       |
+| CAP_SETFCAP          | 1       |
+| CAP_SETPCAP          | 1       |
+| CAP_SETGID           | 1       |
+| CAP_SETUID           | 1       |
+| CAP_MKNOD            | 1       |
+| CAP_CHOWN            | 1       |
+| CAP_FOWNER           | 1       |
+| CAP_FSETID           | 1       |
+| CAP_KILL             | 1       |
+| CAP_SYS_CHROOT       | 1       |
+| CAP_NET_BROADCAST    | 0       |
+| CAP_SYS_MODULE       | 0       |
+| CAP_SYS_RAWIO        | 0       |
+| CAP_SYS_PACCT        | 0       |
+| CAP_SYS_ADMIN        | 0       |
+| CAP_SYS_NICE         | 0       |
+| CAP_SYS_RESOURCE     | 0       |
+| CAP_SYS_TIME         | 0       |
+| CAP_SYS_TTY_CONFIG   | 0       |
+| CAP_AUDIT_CONTROL    | 0       |
+| CAP_MAC_OVERRIDE     | 0       |
+| CAP_MAC_ADMIN        | 0       |
+| CAP_NET_ADMIN        | 0       |
+| CAP_SYSLOG           | 0       |
+| CAP_DAC_READ_SEARCH  | 0       |
+| CAP_LINUX_IMMUTABLE  | 0       |
+| CAP_IPC_LOCK         | 0       |
+| CAP_IPC_OWNER        | 0       |
+| CAP_SYS_PTRACE       | 0       |
+| CAP_SYS_BOOT         | 0       |
+| CAP_LEASE            | 0       |
+| CAP_WAKE_ALARM       | 0       |
+| CAP_BLOCK_SUSPE      | 0       |
+
+
+Additional security layers like [apparmor](https://wiki.ubuntu.com/AppArmor)
+and [selinux](http://selinuxproject.org/page/Main_Page) can be used with
+the containers.  A container should support setting an apparmor profile or 
+selinux process and mount labels if provided in the configuration.  
+
+Standard apparmor profile:
+```c
+#include <tunables/global>
+profile <profile_name> flags=(attach_disconnected,mediate_deleted) {
+  #include <abstractions/base>
+  network,
+  capability,
+  file,
+  umount,
+
+  mount fstype=tmpfs,
+  mount fstype=mqueue,
+  mount fstype=fuse.*,
+  mount fstype=binfmt_misc -> /proc/sys/fs/binfmt_misc/,
+  mount fstype=efivarfs -> /sys/firmware/efi/efivars/,
+  mount fstype=fusectl -> /sys/fs/fuse/connections/,
+  mount fstype=securityfs -> /sys/kernel/security/,
+  mount fstype=debugfs -> /sys/kernel/debug/,
+  mount fstype=proc -> /proc/,
+  mount fstype=sysfs -> /sys/,
+
+  deny @{PROC}/sys/fs/** wklx,
+  deny @{PROC}/sysrq-trigger rwklx,
+  deny @{PROC}/mem rwklx,
+  deny @{PROC}/kmem rwklx,
+  deny @{PROC}/sys/kernel/[^s][^h][^m]* wklx,
+  deny @{PROC}/sys/kernel/*/** wklx,
+
+  deny mount options=(ro, remount) -> /,
+  deny mount fstype=debugfs -> /var/lib/ureadahead/debugfs/,
+  deny mount fstype=devpts,
+
+  deny /sys/[^f]*/** wklx,
+  deny /sys/f[^s]*/** wklx,
+  deny /sys/fs/[^c]*/** wklx,
+  deny /sys/fs/c[^g]*/** wklx,
+  deny /sys/fs/cg[^r]*/** wklx,
+  deny /sys/firmware/efi/efivars/** rwklx,
+  deny /sys/kernel/security/** rwklx,
+}
+```
+
+*TODO: seccomp work is being done to find a good default config*
+
+### Runtime and Init Process
+
+During container creation the parent process needs to talk to the container's init 
+process and have a form of synchronization.  This is accomplished by creating
+a pipe that is passed to the container's init.  When the init process first spawns 
+it will block on its side of the pipe until the parent closes its side.  This
+allows the parent to have time to set the new process inside a cgroup hierarchy 
+and/or write any uid/gid mappings required for user namespaces.  
+The pipe is passed to the init process via FD 3.
+
+The application consuming libcontainer should be compiled statically.  libcontainer
+does not define any init process and the arguments provided are used to `exec` the
+process inside the application.  There should be no long running init within the 
+container spec.
+
+If a pseudo tty is provided to a container it will open and `dup2` the console
+as the container's STDIN, STDOUT, STDERR as well as mounting the console
+as `/dev/console`.
+
+An extra set of mounts are provided to a container and setup for use.  A container's
+rootfs can contain some non portable files inside that can cause side effects during
+execution of a process.  These files are usually created and populated with the container
+specific information via the runtime.  
+
+**Extra runtime files:**
+* /etc/hosts 
+* /etc/resolv.conf
+* /etc/hostname
+* /etc/localtime
+
+
+#### Defaults
+
+There are a few defaults that can be overridden by users, but in their omission
+these apply to processes within a container.
+
+|       Type          |             Value              |
+| ------------------- | ------------------------------ |
+| Parent Death Signal | SIGKILL                        | 
+| UID                 | 0                              |
+| GID                 | 0                              |
+| GROUPS              | 0, NULL                        |
+| CWD                 | "/"                            |
+| $HOME               | Current user's home dir or "/" |
+| Readonly rootfs     | false                          |
+| Pseudo TTY          | false                          |
+
+
+## Actions
+
+After a container is created there is a standard set of actions that can
+be done to the container.  These actions are part of the public API for 
+a container.
+
+|     Action     |                         Description                                |
+| -------------- | ------------------------------------------------------------------ |
+| Get processes  | Return all the pids for processes running inside a container       | 
+| Get Stats      | Return resource statistics for the container as a whole            |
+| Wait           | Wait waits on the container's init process ( pid 1 )               |
+| Wait Process   | Wait on any of the container's processes returning the exit status | 
+| Destroy        | Kill the container's init process and remove any filesystem state  |
+| Signal         | Send a signal to the container's init process                      |
+| Signal Process | Send a signal to any of the container's processes                  |
+| Pause          | Pause all processes inside the container                           |
+| Resume         | Resume all processes inside the container if paused                |
+| Exec           | Execute a new process inside of the container  ( requires setns )  |
+
+

vendor/src/github.com/docker/libcontainer/config.go

@@ -68,6 +68,10 @@ type Config struct {
 	// RestrictSys will remount /proc/sys, /sys, and mask over sysrq-trigger as well as /proc/irq and
 	// /proc/bus
 	RestrictSys bool `json:"restrict_sys,omitempty"`
+
+	// Rlimits specifies the resource limits, such as max open files, to set in the container
+	// If Rlimits are not set, the container will inherit rlimits from the parent process
+	Rlimits []Rlimit `json:"rlimits,omitempty"`
 }
 
 // Routes can be specified to create entries in the route table as the container is started
@@ -90,3 +94,9 @@ type Route struct {
 	// The device to set this route up for, for example: eth0
 	InterfaceName string `json:"interface_name,omitempty"`
 }
+
+type Rlimit struct {
+	Type int    `json:"type,omitempty"`
+	Hard uint64 `json:"hard,omitempty"`
+	Soft uint64 `json:"soft,omitempty"`
+}

vendor/src/github.com/docker/libcontainer/integration/exec_test.go

@@ -156,3 +156,24 @@ func TestIPCBadPath(t *testing.T) {
 		t.Fatal("container succeded with bad ipc path")
 	}
 }
+
+func TestRlimit(t *testing.T) {
+	if testing.Short() {
+		return
+	}
+
+	rootfs, err := newRootFs()
+	if err != nil {
+		t.Fatal(err)
+	}
+	defer remove(rootfs)
+
+	config := newTemplateConfig(rootfs)
+	out, _, err := runContainer(config, "", "/bin/sh", "-c", "ulimit -n")
+	if err != nil {
+		t.Fatal(err)
+	}
+	if limit := strings.TrimSpace(out.Stdout.String()); limit != "1024" {
+		t.Fatalf("expected rlimit to be 1024, got %s", limit)
+	}
+}

vendor/src/github.com/docker/libcontainer/integration/template_test.go

@@ -1,6 +1,8 @@
 package integration
 
 import (
+	"syscall"
+
 	"github.com/docker/libcontainer"
 	"github.com/docker/libcontainer/cgroups"
 	"github.com/docker/libcontainer/devices"
@@ -60,5 +62,12 @@ func newTemplateConfig(rootfs string) *libcontainer.Config {
 				Gateway: "localhost",
 			},
 		},
+		Rlimits: []libcontainer.Rlimit{
+			{
+				Type: syscall.RLIMIT_NOFILE,
+				Hard: uint64(1024),
+				Soft: uint64(1024),
+			},
+		},
 	}
 }