dotcloud/docker

package dockerfile // import "github.com/docker/docker/builder/dockerfile"

import (
    "bytes"
    "context"
    "os"
    "path/filepath"
    "strings"

    "github.com/containerd/containerd/platforms"
    "github.com/docker/docker/api/types/container"
    "github.com/docker/docker/api/types/mount"
    "github.com/docker/docker/errdefs"
    "github.com/docker/docker/pkg/idtools"
    "github.com/docker/docker/pkg/jsonmessage"
    "golang.org/x/sys/windows"
)

func parseChownFlag(ctx context.Context, builder *Builder, state *dispatchState, chown, ctrRootPath string, identityMapping idtools.IdentityMapping) (idtools.Identity, error) {
    if builder.options.Platform == "windows" {
        return getAccountIdentity(ctx, builder, chown, ctrRootPath, state)
    }

    return identityMapping.RootPair(), nil
}

func getAccountIdentity(ctx context.Context, builder *Builder, accountName string, ctrRootPath string, state *dispatchState) (idtools.Identity, error) {
    // If this is potentially a string SID then attempt to convert it to verify
    // this, otherwise continue looking for the account.
    if strings.HasPrefix(accountName, "S-") || strings.HasPrefix(accountName, "s-") {
        sid, err := windows.StringToSid(accountName)

        if err == nil {
            return idtools.Identity{SID: sid.String()}, nil
        }
    }

    // Attempt to obtain the SID using the name.
    sid, _, accType, err := windows.LookupSID("", accountName)

    // If this is a SID that is built-in and hence the same across all systems then use that.
    if err == nil && (accType == windows.SidTypeAlias || accType == windows.SidTypeWellKnownGroup) {
        return idtools.Identity{SID: sid.String()}, nil
    }

    // Check if the account name is one unique to containers.
    if strings.EqualFold(accountName, "ContainerAdministrator") {
        return idtools.Identity{SID: idtools.ContainerAdministratorSidString}, nil
    } else if strings.EqualFold(accountName, "ContainerUser") {
        return idtools.Identity{SID: idtools.ContainerUserSidString}, nil
    }

    // All other lookups failed, so therefore determine if the account in
    // question exists in the container and if so, obtain its SID.
    return lookupNTAccount(ctx, builder, accountName, state)
}

func lookupNTAccount(ctx context.Context, builder *Builder, accountName string, state *dispatchState) (idtools.Identity, error) {
    source, _ := filepath.Split(os.Args[0])

    target := "C:\\Docker"
    targetExecutable := target + "\\containerutility.exe"

    optionsPlatform, err := platforms.Parse(builder.options.Platform)
    if err != nil {
        return idtools.Identity{}, errdefs.InvalidParameter(err)
    }

    runConfig := copyRunConfig(state.runConfig,
        withCmdCommentString("internal run to obtain NT account information.", optionsPlatform.OS))

    runConfig.Cmd = []string{targetExecutable, "getaccountsid", accountName}

    hostConfig := &container.HostConfig{
        Mounts: []mount.Mount{
            {
                Type:     mount.TypeBind,
                Source:   source,
                Target:   target,
                ReadOnly: true,
            },
        },
    }

    container, err := builder.containerManager.Create(ctx, runConfig, hostConfig)
    if err != nil {
        return idtools.Identity{}, err
    }

    stdout := new(bytes.Buffer)
    stderr := new(bytes.Buffer)

    if err := builder.containerManager.Run(ctx, container.ID, stdout, stderr); err != nil {
        if err, ok := err.(*statusCodeError); ok {
            return idtools.Identity{}, &jsonmessage.JSONError{
                Message: stderr.String(),
                Code:    err.StatusCode(),
            }
        }
        return idtools.Identity{}, err
    }

    accountSid := stdout.String()

    return idtools.Identity{SID: accountSid}, nil
}