// Copyright 2019 Google LLC
//
// 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
//
// https://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.
// Filesystem storage backend for Nixery.
package storage
import (
"context"
"fmt"
"io"
"net/http"
"os"
"path"
"github.com/pkg/xattr"
log "github.com/sirupsen/logrus"
)
type FSBackend struct {
path string
}
func NewFSBackend() (*FSBackend, error) {
p := os.Getenv("STORAGE_PATH")
if p == "" {
return nil, fmt.Errorf("STORAGE_PATH must be set for filesystem storage")
}
p = path.Clean(p)
err := os.MkdirAll(p, 0755)
if err != nil {
return nil, fmt.Errorf("failed to create storage dir: %s", err)
}
return &FSBackend{p}, nil
}
func (b *FSBackend) Name() string {
return fmt.Sprintf("Filesystem (%s)", b.path)
}
func (b *FSBackend) Persist(ctx context.Context, key, contentType string, f Persister) (string, int64, error) {
full := path.Join(b.path, key)
dir := path.Dir(full)
err := os.MkdirAll(dir, 0755)
if err != nil {
log.WithError(err).WithField("path", dir).Error("failed to create storage directory")
return "", 0, err
}
file, err := os.OpenFile(full, os.O_RDWR|os.O_CREATE|os.O_TRUNC, 0644)
if err != nil {
log.WithError(err).WithField("file", full).Error("failed to write file")
return "", 0, err
}
defer file.Close()
err = xattr.Set(full, "user.mime_type", []byte(contentType))
if err != nil {
log.WithError(err).WithField("file", full).Error("failed to store file type in xattrs")
return "", 0, err
}
return f(file)
}
func (b *FSBackend) Fetch(ctx context.Context, key string) (io.ReadCloser, error) {
full := path.Join(b.path, key)
return os.Open(full)
}
func (b *FSBackend) Move(ctx context.Context, old, new string) error {
newpath := path.Join(b.path, new)
err := os.MkdirAll(path.Dir(newpath), 0755)
if err != nil {
return err
}
return os.Rename(path.Join(b.path, old), newpath)
}
func (b *FSBackend) Serve(digest string, r *http.Request, w http.ResponseWriter) error {
p := path.Join(b.path, "layers", digest)
log.WithFields(log.Fields{
"digest": digest,
"path": p,
}).Info("serving blob from filesystem")
contentType, err := xattr.Get(p, "user.mime_type")
if err != nil {
log.WithError(err).WithField("file", p).Error("failed to read file type from xattrs")
return err
}
w.Header().Add("Content-Type", string(contentType))
http.ServeFile(w, r, p)
return nil
}
