image: implement idempotent upload of os images

internal/osimage/nop/nop.go

@@ -0,0 +1,31 @@
+/*
+Copyright (c) Edgeless Systems GmbH
+
+SPDX-License-Identifier: AGPL-3.0-only
+*/
+
+// package nop implements a no-op for CSPs that don't require custom image upload functionality.
+package nop
+
+import (
+	"context"
+
+	"github.com/edgelesssys/constellation/v2/internal/logger"
+	"github.com/edgelesssys/constellation/v2/internal/osimage"
+)
+
+// Uploader is a no-op uploader.
+type Uploader struct {
+	log *logger.Logger
+}
+
+// New creates a new Uploader.
+func New(log *logger.Logger) *Uploader {
+	return &Uploader{log: log}
+}
+
+// Upload pretends to upload images to a csp.
+func (u *Uploader) Upload(_ context.Context, req *osimage.UploadRequest) (map[string]string, error) {
+	u.log.Debugf("Skipping image upload of %s since this CSP does not require images to be uploaded in advance.", req.Version.ShortPath())
+	return nil, nil
+}