Files
ko-build/pkg/publish/tarball.go
T

105 lines
2.8 KiB
Go

// Copyright 2020 ko Build Authors All Rights Reserved.
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
package publish
import (
"context"
"fmt"
"log"
"strings"
"github.com/google/go-containerregistry/pkg/name"
v1 "github.com/google/go-containerregistry/pkg/v1"
"github.com/google/go-containerregistry/pkg/v1/tarball"
"github.com/google/ko/pkg/build"
)
type tar struct {
file string
base string
namer Namer
tags []string
refs map[name.Reference]v1.Image
}
// NewTarball returns a new publish.Interface that saves images to a tarball.
func NewTarball(file, base string, namer Namer, tags []string) Interface {
return &tar{
file: file,
base: base,
namer: namer,
tags: tags,
refs: make(map[name.Reference]v1.Image),
}
}
// Publish implements publish.Interface.
func (t *tar) Publish(_ context.Context, br build.Result, s string) (name.Reference, error) {
s = strings.TrimPrefix(s, build.StrictScheme)
// https://github.com/google/go-containerregistry/issues/212
s = strings.ToLower(s)
// There's no way to write an index to a tarball, so attempt to downcast it to an image.
img, ok := br.(v1.Image)
if !ok {
return nil, fmt.Errorf("failed to interpret %s result as image: %v", s, br)
}
for _, tagName := range t.tags {
tag, err := name.ParseReference(fmt.Sprintf("%s:%s", t.namer(t.base, s), tagName))
if err != nil {
return nil, err
}
t.refs[tag] = img
}
h, err := img.Digest()
if err != nil {
return nil, err
}
if len(t.tags) == 0 {
ref, err := name.ParseReference(fmt.Sprintf("%s@%s", t.namer(t.base, s), h))
if err != nil {
return nil, err
}
t.refs[ref] = img
}
ref := fmt.Sprintf("%s@%s", t.namer(t.base, s), h)
if len(t.tags) == 1 && t.tags[0] != latestTag {
// If a single tag is explicitly set (not latest), then this
// is probably a release, so include the tag in the reference.
ref = fmt.Sprintf("%s:%s@%s", t.namer(t.base, s), t.tags[0], h)
}
dig, err := name.NewDigest(ref)
if err != nil {
return nil, err
}
return &dig, nil
}
func (t *tar) Close() error {
log.Printf("Saving %v", t.file)
if err := tarball.MultiRefWriteToFile(t.file, t.refs); err != nil {
// Bad practice, but we log this here because right now we just defer the Close.
log.Printf("failed to save %q: %v", t.file, err)
return err
}
log.Printf("Saved %v", t.file)
return nil
}