94 lines
2.8 KiB
Go
94 lines
2.8 KiB
Go
package storage
|
|
|
|
import (
|
|
"fmt"
|
|
"net/http"
|
|
"time"
|
|
|
|
"github.com/docker/distribution/storagedriver"
|
|
)
|
|
|
|
// delegateLayerHandler provides a simple implementation of layerHandler that
|
|
// simply issues HTTP Temporary Redirects to the URL provided by the
|
|
// storagedriver for a given Layer.
|
|
type delegateLayerHandler struct {
|
|
storageDriver storagedriver.StorageDriver
|
|
pathMapper *pathMapper
|
|
duration time.Duration
|
|
}
|
|
|
|
var _ LayerHandler = &delegateLayerHandler{}
|
|
|
|
func newDelegateLayerHandler(storageDriver storagedriver.StorageDriver, options map[string]interface{}) (LayerHandler, error) {
|
|
duration := 20 * time.Minute
|
|
d, ok := options["duration"]
|
|
if ok {
|
|
switch d := d.(type) {
|
|
case time.Duration:
|
|
duration = d
|
|
case string:
|
|
dur, err := time.ParseDuration(d)
|
|
if err != nil {
|
|
return nil, fmt.Errorf("Invalid duration: %s", err)
|
|
}
|
|
duration = dur
|
|
}
|
|
}
|
|
|
|
return &delegateLayerHandler{storageDriver: storageDriver, pathMapper: defaultPathMapper, duration: duration}, nil
|
|
}
|
|
|
|
// Resolve returns an http.Handler which can serve the contents of the given
|
|
// Layer, or an error if not supported by the storagedriver.
|
|
func (lh *delegateLayerHandler) Resolve(layer Layer) (http.Handler, error) {
|
|
// TODO(bbland): This is just a sanity check to ensure that the
|
|
// storagedriver supports url generation. It would be nice if we didn't have
|
|
// to do this twice for non-GET requests.
|
|
layerURL, err := lh.urlFor(layer, map[string]interface{}{"method": "GET"})
|
|
if err != nil {
|
|
return nil, err
|
|
}
|
|
|
|
return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
|
|
if r.Method != "GET" {
|
|
layerURL, err = lh.urlFor(layer, map[string]interface{}{"method": r.Method})
|
|
if err != nil {
|
|
http.Error(w, err.Error(), http.StatusInternalServerError)
|
|
return
|
|
}
|
|
}
|
|
|
|
http.Redirect(w, r, layerURL, http.StatusTemporaryRedirect)
|
|
}), nil
|
|
}
|
|
|
|
// urlFor returns a download URL for the given layer, or the empty string if
|
|
// unsupported.
|
|
func (lh *delegateLayerHandler) urlFor(layer Layer, options map[string]interface{}) (string, error) {
|
|
// Crack open the layer to get at the layerStore
|
|
layerRd, ok := layer.(*layerReader)
|
|
if !ok {
|
|
// TODO(stevvooe): We probably want to find a better way to get at the
|
|
// underlying filesystem path for a given layer. Perhaps, the layer
|
|
// handler should have its own layer store but right now, it is not
|
|
// request scoped.
|
|
return "", fmt.Errorf("unsupported layer type: cannot resolve blob path: %v", layer)
|
|
}
|
|
|
|
if options == nil {
|
|
options = make(map[string]interface{})
|
|
}
|
|
options["expiry"] = time.Now().Add(lh.duration)
|
|
|
|
layerURL, err := lh.storageDriver.URLFor(layerRd.path, options)
|
|
if err != nil {
|
|
return "", err
|
|
}
|
|
|
|
return layerURL, nil
|
|
}
|
|
|
|
// init registers the delegate layerHandler backend.
|
|
func init() {
|
|
RegisterLayerHandler("delegate", LayerHandlerInitFunc(newDelegateLayerHandler))
|
|
}
|