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Better capability/namespace management

Docker-DCO-1.1-Signed-off-by: Guillaume J. Charmes <guillaume.charmes@docker.com> (github: creack)
This commit is contained in:
Guillaume J. Charmes 2014-02-24 21:52:29 -08:00
parent a64ebabdfa
commit 91bf120c51
No known key found for this signature in database
GPG key ID: B33E4642CB6E3FF3
5 changed files with 140 additions and 107 deletions

View file

@ -48,28 +48,29 @@ func createContainer(c *execdriver.Command) *libcontainer.Container {
func getDefaultTemplate() *libcontainer.Container {
return &libcontainer.Container{
Capabilities: libcontainer.Capabilities{
libcontainer.CAP_SETPCAP,
libcontainer.CAP_SYS_MODULE,
libcontainer.CAP_SYS_RAWIO,
libcontainer.CAP_SYS_PACCT,
libcontainer.CAP_SYS_ADMIN,
libcontainer.CAP_SYS_NICE,
libcontainer.CAP_SYS_RESOURCE,
libcontainer.CAP_SYS_TIME,
libcontainer.CAP_SYS_TTY_CONFIG,
libcontainer.CAP_MKNOD,
libcontainer.CAP_AUDIT_WRITE,
libcontainer.CAP_AUDIT_CONTROL,
libcontainer.CAP_MAC_ADMIN,
libcontainer.CAP_MAC_OVERRIDE,
libcontainer.CAP_NET_ADMIN,
libcontainer.GetCapability("SETPCAP"),
libcontainer.GetCapability("SYS_MODULE"),
libcontainer.GetCapability("SYS_RAWIO"),
libcontainer.GetCapability("SYS_PACCT"),
libcontainer.GetCapability("SYS_ADMIN"),
libcontainer.GetCapability("SYS_NICE"),
libcontainer.GetCapability("SYS_RESOURCE"),
libcontainer.GetCapability("SYS_TIME"),
libcontainer.GetCapability("SYS_TTY_CONFIG"),
libcontainer.GetCapability("MKNOD"),
libcontainer.GetCapability("AUDIT_WRITE"),
libcontainer.GetCapability("AUDIT_CONTROL"),
libcontainer.GetCapability("MAC_OVERRIDE"),
libcontainer.GetCapability("MAC_ADMIN"),
libcontainer.GetCapability("NET_ADMIN"),
},
Namespaces: libcontainer.Namespaces{
libcontainer.CLONE_NEWIPC,
libcontainer.CLONE_NEWNET,
libcontainer.CLONE_NEWNS,
libcontainer.CLONE_NEWPID,
libcontainer.CLONE_NEWUTS,
libcontainer.GetNamespace("NEWNS"),
libcontainer.GetNamespace("NEWUTS"),
libcontainer.GetNamespace("NEWIPC"),
libcontainer.GetNamespace("NEWUSER"),
libcontainer.GetNamespace("NEWPID"),
libcontainer.GetNamespace("NEWNET"),
},
Cgroups: &cgroups.Cgroup{
Parent: "docker",

View file

@ -6,24 +6,6 @@ import (
"os"
)
var capMap = map[libcontainer.Capability]capability.Cap{
libcontainer.CAP_SETPCAP: capability.CAP_SETPCAP,
libcontainer.CAP_SYS_MODULE: capability.CAP_SYS_MODULE,
libcontainer.CAP_SYS_RAWIO: capability.CAP_SYS_RAWIO,
libcontainer.CAP_SYS_PACCT: capability.CAP_SYS_PACCT,
libcontainer.CAP_SYS_ADMIN: capability.CAP_SYS_ADMIN,
libcontainer.CAP_SYS_NICE: capability.CAP_SYS_NICE,
libcontainer.CAP_SYS_RESOURCE: capability.CAP_SYS_RESOURCE,
libcontainer.CAP_SYS_TIME: capability.CAP_SYS_TIME,
libcontainer.CAP_SYS_TTY_CONFIG: capability.CAP_SYS_TTY_CONFIG,
libcontainer.CAP_MKNOD: capability.CAP_MKNOD,
libcontainer.CAP_AUDIT_WRITE: capability.CAP_AUDIT_WRITE,
libcontainer.CAP_AUDIT_CONTROL: capability.CAP_AUDIT_CONTROL,
libcontainer.CAP_MAC_OVERRIDE: capability.CAP_MAC_OVERRIDE,
libcontainer.CAP_MAC_ADMIN: capability.CAP_MAC_ADMIN,
libcontainer.CAP_NET_ADMIN: capability.CAP_NET_ADMIN,
}
// DropCapabilities drops capabilities for the current process based
// on the container's configuration.
func DropCapabilities(container *libcontainer.Container) error {
@ -45,7 +27,7 @@ func DropCapabilities(container *libcontainer.Container) error {
func getCapabilities(container *libcontainer.Container) []capability.Cap {
drop := []capability.Cap{}
for _, c := range container.Capabilities {
drop = append(drop, capMap[c])
drop = append(drop, c.Value)
}
return drop
}

View file

@ -14,7 +14,7 @@ import (
// ExecIn uses an existing pid and joins the pid's namespaces with the new command.
func (ns *linuxNs) ExecIn(container *libcontainer.Container, nspid int, args []string) (int, error) {
for _, ns := range container.Namespaces {
if err := system.Unshare(namespaceMap[ns]); err != nil {
if err := system.Unshare(ns.Value); err != nil {
return -1, err
}
}
@ -42,8 +42,7 @@ func (ns *linuxNs) ExecIn(container *libcontainer.Container, nspid int, args []s
// if the container has a new pid and mount namespace we need to
// remount proc and sys to pick up the changes
if container.Namespaces.Contains(libcontainer.CLONE_NEWNS) &&
container.Namespaces.Contains(libcontainer.CLONE_NEWPID) {
if container.Namespaces.Contains("CLONE_NEWNS") && container.Namespaces.Contains("CLONE_NEWPID") {
pid, err := system.Fork()
if err != nil {
return -1, err
@ -84,7 +83,7 @@ dropAndExec:
func (ns *linuxNs) getNsFds(pid int, container *libcontainer.Container) ([]uintptr, error) {
fds := make([]uintptr, len(container.Namespaces))
for i, ns := range container.Namespaces {
f, err := os.OpenFile(filepath.Join("/proc/", strconv.Itoa(pid), "ns", namespaceFileMap[ns]), os.O_RDONLY, 0)
f, err := os.OpenFile(filepath.Join("/proc/", strconv.Itoa(pid), "ns", ns.File), os.O_RDONLY, 0)
if err != nil {
return fds, err
}

View file

@ -2,35 +2,13 @@ package nsinit
import (
"github.com/dotcloud/docker/pkg/libcontainer"
"syscall"
)
var namespaceMap = map[libcontainer.Namespace]int{
libcontainer.CLONE_NEWNS: syscall.CLONE_NEWNS,
libcontainer.CLONE_NEWUTS: syscall.CLONE_NEWUTS,
libcontainer.CLONE_NEWIPC: syscall.CLONE_NEWIPC,
libcontainer.CLONE_NEWUSER: syscall.CLONE_NEWUSER,
libcontainer.CLONE_NEWPID: syscall.CLONE_NEWPID,
libcontainer.CLONE_NEWNET: syscall.CLONE_NEWNET,
}
// namespaceFileMap is used to convert the libcontainer types
// into the names of the files located in /proc/<pid>/ns/* for
// each namespace
var namespaceFileMap = map[libcontainer.Namespace]string{
libcontainer.CLONE_NEWNS: "mnt",
libcontainer.CLONE_NEWUTS: "uts",
libcontainer.CLONE_NEWIPC: "ipc",
libcontainer.CLONE_NEWUSER: "user",
libcontainer.CLONE_NEWPID: "pid",
libcontainer.CLONE_NEWNET: "net",
}
// getNamespaceFlags parses the container's Namespaces options to set the correct
// flags on clone, unshare, and setns
func GetNamespaceFlags(namespaces libcontainer.Namespaces) (flag int) {
for _, ns := range namespaces {
flag |= namespaceMap[ns]
flag |= ns.Value
}
return flag
}

View file

@ -1,58 +1,131 @@
package libcontainer
// These constants are defined as string types so that
// it is clear when adding the configuration in config files
// instead of using ints or other types
const (
CAP_SETPCAP Capability = "SETPCAP"
CAP_SYS_MODULE Capability = "SYS_MODULE"
CAP_SYS_RAWIO Capability = "SYS_RAWIO"
CAP_SYS_PACCT Capability = "SYS_PACCT"
CAP_SYS_ADMIN Capability = "SYS_ADMIN"
CAP_SYS_NICE Capability = "SYS_NICE"
CAP_SYS_RESOURCE Capability = "SYS_RESOURCE"
CAP_SYS_TIME Capability = "SYS_TIME"
CAP_SYS_TTY_CONFIG Capability = "SYS_TTY_CONFIG"
CAP_MKNOD Capability = "MKNOD"
CAP_AUDIT_WRITE Capability = "AUDIT_WRITE"
CAP_AUDIT_CONTROL Capability = "AUDIT_CONTROL"
CAP_MAC_OVERRIDE Capability = "MAC_OVERRIDE"
CAP_MAC_ADMIN Capability = "MAC_ADMIN"
CAP_NET_ADMIN Capability = "NET_ADMIN"
import (
"encoding/json"
"errors"
"github.com/syndtr/gocapability/capability"
"os"
"syscall"
)
CLONE_NEWNS Namespace = "NEWNS" // mount
CLONE_NEWUTS Namespace = "NEWUTS" // utsname
CLONE_NEWIPC Namespace = "NEWIPC" // ipc
CLONE_NEWUSER Namespace = "NEWUSER" // user
CLONE_NEWPID Namespace = "NEWPID" // pid
CLONE_NEWNET Namespace = "NEWNET" // network
var (
ErrUnkownNamespace error = errors.New("Unkown namespace")
)
// namespaceList is used to convert the libcontainer types
// into the names of the files located in /proc/<pid>/ns/* for
// each namespace
var (
namespaceList = Namespaces{
{Key: "NEWNS", Value: syscall.CLONE_NEWNS, File: "mnt"},
{Key: "NEWUTS", Value: syscall.CLONE_NEWUTS, File: "uts"},
{Key: "NEWIPC", Value: syscall.CLONE_NEWIPC, File: "ipc"},
{Key: "NEWUSER", Value: syscall.CLONE_NEWUSER, File: "user"},
{Key: "NEWPID", Value: syscall.CLONE_NEWPID, File: "pid"},
{Key: "NEWNET", Value: syscall.CLONE_NEWNET, File: "net"},
}
capabilityList = Capabilities{
{Key: "SETPCAP", Value: capability.CAP_SETPCAP},
{Key: "SYS_MODULE", Value: capability.CAP_SYS_MODULE},
{Key: "SYS_RAWIO", Value: capability.CAP_SYS_RAWIO},
{Key: "SYS_PACCT", Value: capability.CAP_SYS_PACCT},
{Key: "SYS_ADMIN", Value: capability.CAP_SYS_ADMIN},
{Key: "SYS_NICE", Value: capability.CAP_SYS_NICE},
{Key: "SYS_RESOURCE", Value: capability.CAP_SYS_RESOURCE},
{Key: "SYS_TIME", Value: capability.CAP_SYS_TIME},
{Key: "SYS_TTY_CONFIG", Value: capability.CAP_SYS_TTY_CONFIG},
{Key: "MKNOD", Value: capability.CAP_MKNOD},
{Key: "AUDIT_WRITE", Value: capability.CAP_AUDIT_WRITE},
{Key: "AUDIT_CONTROL", Value: capability.CAP_AUDIT_CONTROL},
{Key: "MAC_OVERRIDE", Value: capability.CAP_MAC_OVERRIDE},
{Key: "MAC_ADMIN", Value: capability.CAP_MAC_ADMIN},
{Key: "NET_ADMIN", Value: capability.CAP_NET_ADMIN},
}
)
type (
Namespace string
Namespaces []Namespace
Capability string
Capabilities []Capability
Namespace struct {
Key string
Value int
File string
}
Namespaces []*Namespace
)
func (ns *Namespace) MarshalJSON() ([]byte, error) {
return json.Marshal(ns.Key)
}
func (ns *Namespace) UnmarshalJSON(src []byte) error {
var nsName string
if err := json.Unmarshal(src, &nsName); err != nil {
return err
}
ret := GetNamespace(nsName)
if ret == nil {
return ErrUnkownNamespace
}
*ns = *ret
return nil
}
func GetNamespace(key string) *Namespace {
for _, ns := range namespaceList {
if ns.Key == key {
return ns
}
}
if os.Getenv("DEBUG") != "" {
panic("Unreachable: Namespace not found")
}
return nil
}
// Contains returns true if the specified Namespace is
// in the slice
func (n Namespaces) Contains(ns Namespace) bool {
for _, nns := range n {
if nns == ns {
return true
func (n Namespaces) Contains(ns string) bool {
return GetNamespace(ns) != nil
}
type (
Capability struct {
Key string
Value capability.Cap
}
Capabilities []*Capability
)
func (ns *Capability) MarshalJSON() ([]byte, error) {
return json.Marshal(ns.Key)
}
func (ns *Capability) UnmarshalJSON(src []byte) error {
var capName string
if err := json.Unmarshal(src, &capName); err != nil {
return err
}
ret := GetCapability(capName)
if ret == nil {
return ErrUnkownNamespace
}
*ns = *ret
return nil
}
func GetCapability(key string) *Capability {
for _, capp := range capabilityList {
if capp.Key == key {
return capp
}
}
return false
if os.Getenv("DEBUG") != "" {
panic("Unreachable: Namespace not found")
}
return nil
}
// Contains returns true if the specified Capability is
// in the slice
func (c Capabilities) Contains(capp Capability) bool {
for _, cc := range c {
if cc == capp {
return true
}
}
return false
func (c Capabilities) Contains(capp string) bool {
return GetCapability(capp) != nil
}