package daemon
import (
"fmt"
"io/ioutil"
"path/filepath"
"runtime"
"strings"
containertypes "github.com/docker/docker/api/types/container"
"github.com/docker/docker/container"
"github.com/docker/docker/layer"
"github.com/docker/docker/oci"
"github.com/docker/docker/pkg/sysinfo"
"github.com/docker/docker/pkg/system"
"github.com/opencontainers/runtime-spec/specs-go"
"golang.org/x/sys/windows"
"golang.org/x/sys/windows/registry"
)
const (
credentialSpecRegistryLocation = `SOFTWARE\Microsoft\Windows NT\CurrentVersion\Virtualization\Containers\CredentialSpecs`
credentialSpecFileLocation = "CredentialSpecs"
)
func (daemon *Daemon) createSpec(c *container.Container) (*specs.Spec, error) {
img, err := daemon.GetImage(string(c.ImageID))
if err != nil {
return nil, err
}
s := oci.DefaultOSSpec(img.OS)
linkedEnv, err := daemon.setupLinkedContainers(c)
if err != nil {
return nil, err
}
// Note, unlike Unix, we do NOT call into SetupWorkingDirectory as
// this is done in VMCompute. Further, we couldn't do it for Hyper-V
// containers anyway.
// In base spec
s.Hostname = c.FullHostname()
if err := daemon.setupSecretDir(c); err != nil {
return nil, err
}
if err := daemon.setupConfigDir(c); err != nil {
return nil, err
}
// In s.Mounts
mounts, err := daemon.setupMounts(c)
if err != nil {
return nil, err
}
var isHyperV bool
if c.HostConfig.Isolation.IsDefault() {
// Container using default isolation, so take the default from the daemon configuration
isHyperV = daemon.defaultIsolation.IsHyperV()
} else {
// Container may be requesting an explicit isolation mode.
isHyperV = c.HostConfig.Isolation.IsHyperV()
}
if isHyperV {
s.Windows.HyperV = &specs.WindowsHyperV{}
}
// If the container has not been started, and has configs or secrets
// secrets, create symlinks to each config and secret. If it has been
// started before, the symlinks should have already been created. Also, it
// is important to not mount a Hyper-V container that has been started
// before, to protect the host from the container; for example, from
// malicious mutation of NTFS data structures.
if !c.HasBeenStartedBefore && (len(c.SecretReferences) > 0 || len(c.ConfigReferences) > 0) {
// The container file system is mounted before this function is called,
// except for Hyper-V containers, so mount it here in that case.
if isHyperV {
if err := daemon.Mount(c); err != nil {
return nil, err
}
defer daemon.Unmount(c)
}
if err := c.CreateSecretSymlinks(); err != nil {
return nil, err
}
if err := c.CreateConfigSymlinks(); err != nil {
return nil, err
}
}
secretMounts, err := c.SecretMounts()
if err != nil {
return nil, err
}
if secretMounts != nil {
mounts = append(mounts, secretMounts...)
}
configMounts, err := c.ConfigMounts()
if err != nil {
return nil, err
}
if configMounts != nil {
mounts = append(mounts, configMounts...)
}
for _, mount := range mounts {
m := specs.Mount{
Source: mount.Source,
Destination: mount.Destination,
}
if !mount.Writable {
m.Options = append(m.Options, "ro")
}
if img.OS != runtime.GOOS {
m.Type = "bind"
m.Options = append(m.Options, "rbind")
m.Options = append(m.Options, fmt.Sprintf("uvmpath=/tmp/gcs/%s/binds", c.ID))
}
s.Mounts = append(s.Mounts, m)
}
// In s.Process
s.Process.Args = append([]string{c.Path}, c.Args...)
if !c.Config.ArgsEscaped && img.OS == "windows" {
s.Process.Args = escapeArgs(s.Process.Args)
}
s.Process.Cwd = c.Config.WorkingDir
s.Process.Env = c.CreateDaemonEnvironment(c.Config.Tty, linkedEnv)
if c.Config.Tty {
s.Process.Terminal = c.Config.Tty
s.Process.ConsoleSize = &specs.Box{
Height: c.HostConfig.ConsoleSize[0],
Width: c.HostConfig.ConsoleSize[1],
}
}
s.Process.User.Username = c.Config.User
// Get the layer path for each layer.
max := len(img.RootFS.DiffIDs)
for i := 1; i <= max; i++ {
img.RootFS.DiffIDs = img.RootFS.DiffIDs[:i]
if !system.IsOSSupported(img.OperatingSystem()) {
return nil, fmt.Errorf("cannot get layerpath for ImageID %s: %s ", img.RootFS.ChainID(), system.ErrNotSupportedOperatingSystem)
}
layerPath, err := layer.GetLayerPath(daemon.layerStores[img.OperatingSystem()], img.RootFS.ChainID())
if err != nil {
return nil, fmt.Errorf("failed to get layer path from graphdriver %s for ImageID %s - %s", daemon.layerStores[img.OperatingSystem()], img.RootFS.ChainID(), err)
}
// Reverse order, expecting parent most first
s.Windows.LayerFolders = append([]string{layerPath}, s.Windows.LayerFolders...)
}
m, err := c.RWLayer.Metadata()
if err != nil {
return nil, fmt.Errorf("failed to get layer metadata - %s", err)
}
s.Windows.LayerFolders = append(s.Windows.LayerFolders, m["dir"])
dnsSearch := daemon.getDNSSearchSettings(c)
// Get endpoints for the libnetwork allocated networks to the container
var epList []string
AllowUnqualifiedDNSQuery := false
gwHNSID := ""
if c.NetworkSettings != nil {
for n := range c.NetworkSettings.Networks {
sn, err := daemon.FindNetwork(n)
if err != nil {
continue
}
ep, err := c.GetEndpointInNetwork(sn)
if err != nil {
continue
}
data, err := ep.DriverInfo()
if err != nil {
continue
}
if data["GW_INFO"] != nil {
gwInfo := data["GW_INFO"].(map[string]interface{})
if gwInfo["hnsid"] != nil {
gwHNSID = gwInfo["hnsid"].(string)
}
}
if data["hnsid"] != nil {
epList = append(epList, data["hnsid"].(string))
}
if data["AllowUnqualifiedDNSQuery"] != nil {
AllowUnqualifiedDNSQuery = true
}
}
}
var networkSharedContainerID string
if c.HostConfig.NetworkMode.IsContainer() {
networkSharedContainerID = c.NetworkSharedContainerID
for _, ep := range c.SharedEndpointList {
epList = append(epList, ep)
}
}
if gwHNSID != "" {
epList = append(epList, gwHNSID)
}
s.Windows.Network = &specs.WindowsNetwork{
AllowUnqualifiedDNSQuery: AllowUnqualifiedDNSQuery,
DNSSearchList: dnsSearch,
EndpointList: epList,
NetworkSharedContainerName: networkSharedContainerID,
}
switch img.OS {
case "windows":
if err := daemon.createSpecWindowsFields(c, &s, isHyperV); err != nil {
return nil, err
}
case "linux":
if !system.LCOWSupported() {
return nil, fmt.Errorf("Linux containers on Windows are not supported")
}
daemon.createSpecLinuxFields(c, &s)
default:
return nil, fmt.Errorf("Unsupported platform %q", img.OS)
}
return (*specs.Spec)(&s), nil
}
// Sets the Windows-specific fields of the OCI spec
func (daemon *Daemon) createSpecWindowsFields(c *container.Container, s *specs.Spec, isHyperV bool) error {
if len(s.Process.Cwd) == 0 {
// We default to C:\ to workaround the oddity of the case that the
// default directory for cmd running as LocalSystem (or
// ContainerAdministrator) is c:\windows\system32. Hence docker run
// <image> cmd will by default end in c:\windows\system32, rather
// than 'root' (/) on Linux. The oddity is that if you have a dockerfile
// which has no WORKDIR and has a COPY file ., . will be interpreted
// as c:\. Hence, setting it to default of c:\ makes for consistency.
s.Process.Cwd = `C:\`
}
s.Root.Readonly = false // Windows does not support a read-only root filesystem
if !isHyperV {
s.Root.Path = c.BaseFS.Path() // This is not set for Hyper-V containers
if !strings.HasSuffix(s.Root.Path, `\`) {
s.Root.Path = s.Root.Path + `\` // Ensure a correctly formatted volume GUID path \\?\Volume{GUID}\
}
}
// First boot optimization
s.Windows.IgnoreFlushesDuringBoot = !c.HasBeenStartedBefore
// In s.Windows.Resources
cpuShares := uint16(c.HostConfig.CPUShares)
cpuMaximum := uint16(c.HostConfig.CPUPercent) * 100
cpuCount := uint64(c.HostConfig.CPUCount)
if c.HostConfig.NanoCPUs > 0 {
if isHyperV {
cpuCount = uint64(c.HostConfig.NanoCPUs / 1e9)
leftoverNanoCPUs := c.HostConfig.NanoCPUs % 1e9
if leftoverNanoCPUs != 0 {
cpuCount++
cpuMaximum = uint16(c.HostConfig.NanoCPUs / int64(cpuCount) / (1e9 / 10000))
if cpuMaximum < 1 {
// The requested NanoCPUs is so small that we rounded to 0, use 1 instead
cpuMaximum = 1
}
}
} else {
cpuMaximum = uint16(c.HostConfig.NanoCPUs / int64(sysinfo.NumCPU()) / (1e9 / 10000))
if cpuMaximum < 1 {
// The requested NanoCPUs is so small that we rounded to 0, use 1 instead
cpuMaximum = 1
}
}
}
memoryLimit := uint64(c.HostConfig.Memory)
s.Windows.Resources = &specs.WindowsResources{
CPU: &specs.WindowsCPUResources{
Maximum: &cpuMaximum,
Shares: &cpuShares,
Count: &cpuCount,
},
Memory: &specs.WindowsMemoryResources{
Limit: &memoryLimit,
},
Storage: &specs.WindowsStorageResources{
Bps: &c.HostConfig.IOMaximumBandwidth,
Iops: &c.HostConfig.IOMaximumIOps,
},
}
// Read and add credentials from the security options if a credential spec has been provided.
if c.HostConfig.SecurityOpt != nil {
cs := ""
for _, sOpt := range c.HostConfig.SecurityOpt {
sOpt = strings.ToLower(sOpt)
if !strings.Contains(sOpt, "=") {
return fmt.Errorf("invalid security option: no equals sign in supplied value %s", sOpt)
}
var splitsOpt []string
splitsOpt = strings.SplitN(sOpt, "=", 2)
if len(splitsOpt) != 2 {
return fmt.Errorf("invalid security option: %s", sOpt)
}
if splitsOpt[0] != "credentialspec" {
return fmt.Errorf("security option not supported: %s", splitsOpt[0])
}
var (
match bool
csValue string
err error
)
if match, csValue = getCredentialSpec("file://", splitsOpt[1]); match {
if csValue == "" {
return fmt.Errorf("no value supplied for file:// credential spec security option")
}
if cs, err = readCredentialSpecFile(c.ID, daemon.root, filepath.Clean(csValue)); err != nil {
return err
}
} else if match, csValue = getCredentialSpec("registry://", splitsOpt[1]); match {
if csValue == "" {
return fmt.Errorf("no value supplied for registry:// credential spec security option")
}
if cs, err = readCredentialSpecRegistry(c.ID, csValue); err != nil {
return err
}
} else {
return fmt.Errorf("invalid credential spec security option - value must be prefixed file:// or registry:// followed by a value")
}
}
s.Windows.CredentialSpec = cs
}
// Assume we are not starting a container for a servicing operation
s.Windows.Servicing = false
return nil
}
// Sets the Linux-specific fields of the OCI spec
// TODO: @jhowardmsft LCOW Support. We need to do a lot more pulling in what can
// be pulled in from oci_linux.go.
func (daemon *Daemon) createSpecLinuxFields(c *container.Container, s *specs.Spec) {
if len(s.Process.Cwd) == 0 {
s.Process.Cwd = `/`
}
s.Root.Path = "rootfs"
s.Root.Readonly = c.HostConfig.ReadonlyRootfs
}
func escapeArgs(args []string) []string {
escapedArgs := make([]string, len(args))
for i, a := range args {
escapedArgs[i] = windows.EscapeArg(a)
}
return escapedArgs
}
// mergeUlimits merge the Ulimits from HostConfig with daemon defaults, and update HostConfig
// It will do nothing on non-Linux platform
func (daemon *Daemon) mergeUlimits(c *containertypes.HostConfig) {
return
}
// getCredentialSpec is a helper function to get the value of a credential spec supplied
// on the CLI, stripping the prefix
func getCredentialSpec(prefix, value string) (bool, string) {
if strings.HasPrefix(value, prefix) {
return true, strings.TrimPrefix(value, prefix)
}
return false, ""
}
// readCredentialSpecRegistry is a helper function to read a credential spec from
// the registry. If not found, we return an empty string and warn in the log.
// This allows for staging on machines which do not have the necessary components.
func readCredentialSpecRegistry(id, name string) (string, error) {
var (
k registry.Key
err error
val string
)
if k, err = registry.OpenKey(registry.LOCAL_MACHINE, credentialSpecRegistryLocation, registry.QUERY_VALUE); err != nil {
return "", fmt.Errorf("failed handling spec %q for container %s - %s could not be opened", name, id, credentialSpecRegistryLocation)
}
if val, _, err = k.GetStringValue(name); err != nil {
if err == registry.ErrNotExist {
return "", fmt.Errorf("credential spec %q for container %s as it was not found", name, id)
}
return "", fmt.Errorf("error %v reading credential spec %q from registry for container %s", err, name, id)
}
return val, nil
}
// readCredentialSpecFile is a helper function to read a credential spec from
// a file. If not found, we return an empty string and warn in the log.
// This allows for staging on machines which do not have the necessary components.
func readCredentialSpecFile(id, root, location string) (string, error) {
if filepath.IsAbs(location) {
return "", fmt.Errorf("invalid credential spec - file:// path cannot be absolute")
}
base := filepath.Join(root, credentialSpecFileLocation)
full := filepath.Join(base, location)
if !strings.HasPrefix(full, base) {
return "", fmt.Errorf("invalid credential spec - file:// path must be under %s", base)
}
bcontents, err := ioutil.ReadFile(full)
if err != nil {
return "", fmt.Errorf("credential spec '%s' for container %s as the file could not be read: %q", full, id, err)
}
return string(bcontents[:]), nil
}