func buildWalker(root string, aw aci.ArchiveWriter, rootfs bool) filepath.WalkFunc {
// cache of inode -> filepath, used to leverage hard links in the archive
inos := map[uint64]string{}
return func(path string, info os.FileInfo, err error) error {
if err != nil {
return err
}
relpath, err := filepath.Rel(root, path)
if err != nil {
return err
}
if rootfs {
if relpath == "." {
relpath = ""
}
relpath = "rootfs/" + relpath
}
if relpath == "." {
return nil
}
link := ""
var file *os.File
switch info.Mode() & os.ModeType {
default:
file, err = os.Open(path)
if err != nil {
return err
}
defer file.Close()
case os.ModeSymlink:
target, err := os.Readlink(path)
if err != nil {
return err
}
link = target
}
hdr, err := tar.FileInfoHeader(info, link)
if err != nil {
panic(err)
}
// Because os.FileInfo's Name method returns only the base
// name of the file it describes, it may be necessary to
// modify the Name field of the returned header to provide the
// full path name of the file.
hdr.Name = relpath
tarheader.Populate(hdr, info, inos)
// If the file is a hard link we don't need the contents
if hdr.Typeflag == tar.TypeLink {
hdr.Size = 0
file = nil
}
aw.AddFile(relpath, hdr, file)
return nil
}
}
func runBuild(args []string) (exit int) {
if len(args) != 2 {
stderr("build: Must provide directory and output file")
return 1
}
switch {
case buildFilesetName != "" && buildAppManifest == "":
case buildFilesetName == "" && buildAppManifest != "":
default:
stderr("build: must specify either --fileset-name or --app-manifest")
return 1
}
root := args[0]
tgt := args[1]
ext := filepath.Ext(tgt)
if ext != schema.ACIExtension {
stderr("build: Extension must be %s (given %s)", schema.ACIExtension, ext)
return 1
}
mode := os.O_CREATE | os.O_WRONLY
if !buildOverwrite {
mode |= os.O_EXCL
}
fh, err := os.OpenFile(tgt, mode, 0644)
if err != nil {
if os.IsExist(err) {
stderr("build: Target file exists (try --overwrite)")
} else {
stderr("build: Unable to open target %s: %v", tgt, err)
}
return 1
}
gw := gzip.NewWriter(fh)
tr := tar.NewWriter(gw)
defer func() {
tr.Close()
gw.Close()
fh.Close()
if exit != 0 && !buildOverwrite {
os.Remove(tgt)
}
}()
var aw aci.ArchiveWriter
if buildFilesetName != "" {
aw, err = aci.NewFilesetWriter(buildFilesetName, tr)
if err != nil {
stderr("build: Unable to create FilesetWriter: %v", err)
return 1
}
} else {
b, err := ioutil.ReadFile(buildAppManifest)
if err != nil {
stderr("build: Unable to read App Manifest: %v", err)
return 1
}
var am schema.AppManifest
if err := am.UnmarshalJSON(b); err != nil {
stderr("build: Unable to load App Manifest: %v", err)
return 1
}
aw = aci.NewAppWriter(am, tr)
}
err = filepath.Walk(root, buildWalker(root, aw, buildRootfs))
if err != nil {
stderr("build: Error walking rootfs: %v", err)
return 1
}
err = aw.Close()
if err != nil {
stderr("build: Unable to close Fileset image %s: %v", tgt, err)
return 1
}
return
}