docker/pkg/archive/wrap.go

60 строки
1.4 KiB
Go

package archive
import (
"archive/tar"
"bytes"
"io/ioutil"
)
// Generate generates a new archive from the content provided
// as input.
//
// `files` is a sequence of path/content pairs. A new file is
// added to the archive for each pair.
// If the last pair is incomplete, the file is created with an
// empty content. For example:
//
// Generate("foo.txt", "hello world", "emptyfile")
//
// The above call will return an archive with 2 files:
// * ./foo.txt with content "hello world"
// * ./empty with empty content
//
// FIXME: stream content instead of buffering
// FIXME: specify permissions and other archive metadata
func Generate(input ...string) (Archive, error) {
files := parseStringPairs(input...)
buf := new(bytes.Buffer)
tw := tar.NewWriter(buf)
for _, file := range files {
name, content := file[0], file[1]
hdr := &tar.Header{
Name: name,
Size: int64(len(content)),
}
if err := tw.WriteHeader(hdr); err != nil {
return nil, err
}
if _, err := tw.Write([]byte(content)); err != nil {
return nil, err
}
}
if err := tw.Close(); err != nil {
return nil, err
}
return ioutil.NopCloser(buf), nil
}
func parseStringPairs(input ...string) (output [][2]string) {
output = make([][2]string, 0, len(input)/2+1)
for i := 0; i < len(input); i += 2 {
var pair [2]string
pair[0] = input[i]
if i+1 < len(input) {
pair[1] = input[i+1]
}
output = append(output, pair)
}
return
}