runc/spec_linux.go

350 lines
10 KiB
Go

// +build linux
package main
import (
"encoding/json"
"fmt"
"os"
"path/filepath"
"strings"
"syscall"
"github.com/opencontainers/runc/libcontainer/cgroups"
"github.com/opencontainers/runc/libcontainer/configs"
"github.com/opencontainers/runc/libcontainer/devices"
)
type UserMapping struct {
From int `json:"from"`
To int `json:"to"`
Count int `json:"count"`
}
type Rlimit struct {
Type int `json:"type"`
Hard uint64 `json:"hard"`
Soft uint64 `json:"soft"`
}
type HugepageLimit struct {
Pagesize string `json:"pageSize"`
Limit int `json:"limit"`
}
type IfPrioMap struct {
Interface string `json:"interface"`
Priority int64 `json:"priority"`
}
type Resources struct {
// Memory reservation or soft_limit (in bytes)
MemoryReservation int64 `json:"memoryReservation"`
// Total memory usage (memory + swap); set `-1' to disable swap
MemorySwap int64 `json:"memorySwap"`
// Kernel memory limit (in bytes)
KernelMemory int64 `json:"kernelMemory"`
// CPU shares (relative weight vs. other containers)
CpuShares int64 `json:"cpuShares"`
// CPU hardcap limit (in usecs). Allowed cpu time in a given period.
CpuQuota int64 `json:"cpuQuota"`
// CPU period to be used for hardcapping (in usecs). 0 to use system default.
CpuPeriod int64 `json:"cpuPeriod"`
// How many time CPU will use in realtime scheduling (in usecs).
CpuRtRuntime int64 `json:"cpuQuota"`
// CPU period to be used for realtime scheduling (in usecs).
CpuRtPeriod int64 `json:"cpuPeriod"`
// CPU to use
CpusetCpus string `json:"cpusetCpus"`
// MEM to use
CpusetMems string `json:"cpusetMems"`
// IO read rate limit per cgroup per device, bytes per second.
BlkioThrottleReadBpsDevice string `json:"blkioThrottleReadBpsDevice"`
// IO write rate limit per cgroup per divice, bytes per second.
BlkioThrottleWriteBpsDevice string `json:"blkioThrottleWriteBpsDevice"`
// IO read rate limit per cgroup per device, IO per second.
BlkioThrottleReadIOpsDevice string `json:"blkioThrottleReadIopsDevice"`
// IO write rate limit per cgroup per device, IO per second.
BlkioThrottleWriteIOpsDevice string `json:"blkioThrottleWriteIopsDevice"`
// Specifies per cgroup weight, range is from 10 to 1000.
BlkioWeight int64 `json:"blkioWeight"`
// Weight per cgroup per device, can override BlkioWeight.
BlkioWeightDevice string `json:"blkioWeightDevice"`
// Hugetlb limit (in bytes)
HugetlbLimit []*HugepageLimit `json:"hugetlbLimit"`
// Whether to disable OOM Killer
DisableOOMKiller bool `json:"disableOOMKiller"`
// Set priority of network traffic for container
NetPrioIfpriomap []*IfPrioMap `json:"netPrioIfpriomap"`
// Set class identifier for container's network packets
NetClsClassid string `json:"netClsClassid"`
}
type LinuxSpec struct {
PortableSpec
UserMapping map[string]UserMapping `json:"userMapping"`
Rlimits []Rlimit `json:"rlimits"`
SystemProperties map[string]string `json:"systemProperties"`
Resources *Resources `json:"resources"`
}
var namespaceMapping = map[string]configs.NamespaceType{
"process": configs.NEWPID,
"network": configs.NEWNET,
"mount": configs.NEWNS,
"user": configs.NEWUSER,
"ipc": configs.NEWIPC,
"uts": configs.NEWUTS,
}
// loadSpec loads the specification from the provided path.
// If the path is empty then the default path will be "container.json"
func loadSpec(path string) (*LinuxSpec, error) {
if path == "" {
path = "container.json"
}
f, err := os.Open(path)
if err != nil {
if os.IsNotExist(err) {
return nil, fmt.Errorf("JSON specification file for %s not found", path)
}
return nil, err
}
defer f.Close()
var s *LinuxSpec
if err := json.NewDecoder(f).Decode(&s); err != nil {
return nil, err
}
return s, nil
}
func createLibcontainerConfig(spec *LinuxSpec) (*configs.Config, error) {
cwd, err := os.Getwd()
if err != nil {
return nil, err
}
rootfsPath := spec.Root.Path
if !filepath.IsAbs(rootfsPath) {
rootfsPath = filepath.Join(cwd, rootfsPath)
}
config := &configs.Config{
Capabilities: spec.Capabilities,
Rootfs: rootfsPath,
Readonlyfs: spec.Root.Readonly,
Hostname: spec.Hostname,
Privatefs: true,
}
for _, ns := range spec.Namespaces {
t, exists := namespaceMapping[ns.Type]
if !exists {
return nil, fmt.Errorf("namespace %q does not exist", ns)
}
config.Namespaces.Add(t, ns.Path)
}
for _, m := range spec.Mounts {
config.Mounts = append(config.Mounts, createLibcontainerMount(cwd, m))
}
if err := createDevices(spec, config); err != nil {
return nil, err
}
if err := setupUserNamespace(spec, config); err != nil {
return nil, err
}
c, err := createCgroupConfig(spec, config.Devices)
if err != nil {
return nil, err
}
config.Cgroups = c
if config.Readonlyfs {
setReadonly(config)
config.MaskPaths = []string{
"/proc/kcore",
}
config.ReadonlyPaths = []string{
"/proc/sys", "/proc/sysrq-trigger", "/proc/irq", "/proc/bus",
}
}
return config, nil
}
func createLibcontainerMount(cwd string, m Mount) *configs.Mount {
flags, data := parseMountOptions(m.Options)
source := m.Source
if m.Type == "bind" {
if !filepath.IsAbs(source) {
source = filepath.Join(cwd, m.Source)
}
}
return &configs.Mount{
Device: m.Type,
Source: source,
Destination: m.Destination,
Data: data,
Flags: flags,
}
}
func createCgroupConfig(spec *LinuxSpec, devices []*configs.Device) (*configs.Cgroup, error) {
myCgroupPath, err := cgroups.GetThisCgroupDir("devices")
if err != nil {
return nil, err
}
c := &configs.Cgroup{
Name: getDefaultID(),
Parent: myCgroupPath,
AllowedDevices: append(devices, allowedDevices...),
CpuQuota: getCPUQuota(spec.Cpus),
Memory: spec.Memory * 1024 * 1024,
MemorySwap: -1,
MemorySwappiness: -1,
}
if r := spec.Resources; r != nil {
c.MemoryReservation = r.MemoryReservation
c.MemorySwap = r.MemorySwap
c.KernelMemory = r.KernelMemory
c.CpuShares = r.CpuShares
c.CpuQuota = r.CpuQuota
c.CpuPeriod = r.CpuPeriod
c.CpuRtRuntime = r.CpuRtRuntime
c.CpuRtPeriod = r.CpuRtPeriod
c.CpusetCpus = r.CpusetCpus
c.CpusetMems = r.CpusetMems
c.BlkioThrottleReadBpsDevice = r.BlkioThrottleReadBpsDevice
c.BlkioThrottleWriteBpsDevice = r.BlkioThrottleWriteBpsDevice
c.BlkioThrottleReadIOpsDevice = r.BlkioThrottleReadIOpsDevice
c.BlkioThrottleWriteIOpsDevice = r.BlkioThrottleWriteIOpsDevice
c.BlkioWeight = r.BlkioWeight
c.BlkioWeightDevice = r.BlkioWeightDevice
for _, l := range r.HugetlbLimit {
c.HugetlbLimit = append(c.HugetlbLimit, &configs.HugepageLimit{
Pagesize: l.Pagesize,
Limit: l.Limit,
})
}
c.OomKillDisable = r.DisableOOMKiller
for _, m := range r.NetPrioIfpriomap {
c.NetPrioIfpriomap = append(c.NetPrioIfpriomap, &configs.IfPrioMap{
Interface: m.Interface,
Priority: m.Priority,
})
}
c.NetClsClassid = r.NetClsClassid
}
return c, nil
}
func createDevices(spec *LinuxSpec, config *configs.Config) error {
for _, name := range spec.Devices {
d, err := devices.DeviceFromPath(filepath.Join("/dev", name), "rwm")
if err != nil {
return err
}
config.Devices = append(config.Devices, d)
}
return nil
}
func setReadonly(config *configs.Config) {
for _, m := range config.Mounts {
if m.Device == "sysfs" {
m.Flags |= syscall.MS_RDONLY
}
}
}
func getCPUQuota(cpus float64) int64 {
return int64(cpus * cpuQuotaMultiplyer)
}
func setupUserNamespace(spec *LinuxSpec, config *configs.Config) error {
if len(spec.UserMapping) == 0 {
return nil
}
config.Namespaces.Add(configs.NEWUSER, "")
mappings := make(map[string][]configs.IDMap)
for k, v := range spec.UserMapping {
mappings[k] = append(mappings[k], configs.IDMap{
ContainerID: v.From,
HostID: v.To,
Size: v.Count,
})
}
config.UidMappings = mappings["uid"]
config.GidMappings = mappings["gid"]
rootUid, err := config.HostUID()
if err != nil {
return err
}
rootGid, err := config.HostGID()
if err != nil {
return err
}
for _, node := range config.Devices {
node.Uid = uint32(rootUid)
node.Gid = uint32(rootGid)
}
return nil
}
// parseMountOptions parses the string and returns the flags and any mount data that
// it contains.
func parseMountOptions(options string) (int, string) {
var (
flag int
data []string
)
flags := map[string]struct {
clear bool
flag int
}{
"defaults": {false, 0},
"ro": {false, syscall.MS_RDONLY},
"rw": {true, syscall.MS_RDONLY},
"suid": {true, syscall.MS_NOSUID},
"nosuid": {false, syscall.MS_NOSUID},
"dev": {true, syscall.MS_NODEV},
"nodev": {false, syscall.MS_NODEV},
"exec": {true, syscall.MS_NOEXEC},
"noexec": {false, syscall.MS_NOEXEC},
"sync": {false, syscall.MS_SYNCHRONOUS},
"async": {true, syscall.MS_SYNCHRONOUS},
"dirsync": {false, syscall.MS_DIRSYNC},
"remount": {false, syscall.MS_REMOUNT},
"mand": {false, syscall.MS_MANDLOCK},
"nomand": {true, syscall.MS_MANDLOCK},
"atime": {true, syscall.MS_NOATIME},
"noatime": {false, syscall.MS_NOATIME},
"diratime": {true, syscall.MS_NODIRATIME},
"nodiratime": {false, syscall.MS_NODIRATIME},
"bind": {false, syscall.MS_BIND},
"rbind": {false, syscall.MS_BIND | syscall.MS_REC},
"unbindable": {false, syscall.MS_UNBINDABLE},
"runbindable": {false, syscall.MS_UNBINDABLE | syscall.MS_REC},
"private": {false, syscall.MS_PRIVATE},
"rprivate": {false, syscall.MS_PRIVATE | syscall.MS_REC},
"shared": {false, syscall.MS_SHARED},
"rshared": {false, syscall.MS_SHARED | syscall.MS_REC},
"slave": {false, syscall.MS_SLAVE},
"rslave": {false, syscall.MS_SLAVE | syscall.MS_REC},
"relatime": {false, syscall.MS_RELATIME},
"norelatime": {true, syscall.MS_RELATIME},
"strictatime": {false, syscall.MS_STRICTATIME},
"nostrictatime": {true, syscall.MS_STRICTATIME},
}
for _, o := range strings.Split(options, ",") {
// If the option does not exist in the flags table or the flag
// is not supported on the platform,
// then it is a data value for a specific fs type
if f, exists := flags[o]; exists && f.flag != 0 {
if f.clear {
flag &= ^f.flag
} else {
flag |= f.flag
}
} else {
data = append(data, o)
}
}
return flag, strings.Join(data, ",")
}