// Filesystem storage backend for Nixery.
package storage
import (
"fmt"
"io"
"net/http"
"os"
"path"
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(key string, f func(io.Writer) (string, int64, error)) (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()
return f(file)
}
func (b *FSBackend) Fetch(key string) (io.ReadCloser, error) {
full := path.Join(b.path, key)
return os.Open(full)
}
func (b *FSBackend) Move(old, new string) error {
return os.Rename(path.Join(b.path, old), path.Join(b.path, new))
}
func (b *FSBackend) ServeLayer(digest string, w http.ResponseWriter) error {
// http.Serve* functions attempt to be a lot more clever than
// I want, but I also would prefer to avoid implementing error
// translation myself - thus a fake request is created here.
req := http.Request{Method: "GET"}
http.ServeFile(w, &req, path.Join(b.path, "sha256:"+digest))
return nil
}
