1 files changed, 34 insertions, 0 deletions
diff --git a/tools/nixery/server/storage/storage.go b/tools/nixery/server/storage/storage.go
new file mode 100644
index 000000000000..15b8355e6ef5
--- /dev/null
+++ b/tools/nixery/server/storage/storage.go
@@ -0,0 +1,34 @@
+// Package storage implements an interface that can be implemented by
+// storage backends, such as Google Cloud Storage or the local
+// filesystem.
+package storage
+
+import (
+	"io"
+	"net/http"
+)
+
+type Backend interface {
+	// Name returns the name of the storage backend, for use in
+	// log messages and such.
+	Name() string
+
+	// Persist provides a user-supplied function with a writer
+	// that stores data in the storage backend.
+	//
+	// It needs to return the SHA256 hash of the data written as
+	// well as the total number of bytes, as those are required
+	// for the image manifest.
+	Persist(string, func(io.Writer) (string, int64, error)) (string, int64, error)
+
+	// Fetch retrieves data from the storage backend.
+	Fetch(path string) (io.ReadCloser, error)
+
+	// Move renames a path inside the storage backend. This is
+	// used for staging uploads while calculating their hashes.
+	Move(old, new string) error
+
+	// Serve provides a handler function to serve HTTP requests
+	// for layers in the storage backend.
+	ServeLayer(digest string, w http.ResponseWriter) error
+}