Merge pull request #60 from infosiftr/always-head-again

Revert "Revert "Attempt to speed up deploy""

Author: tianon

registry/push.go

@@ -14,7 +14,7 @@ import (
 )
 
 var (
-	// if a manifest or blob is more than this many bytes, we'll do a pre-flight HEAD request to verify whether we need to even bother pushing it before we do so (65535 is the theoretical maximum size of a single TCP packet, although MTU means it's usually closer to 1448 bytes, but this seemed like a sane place to draw a line to where a second request that might fail is worth our time)
+	// if a blob is more than this many bytes, we'll do a pre-flight HEAD request to verify whether we need to even bother pushing it before we do so (65535 is the theoretical maximum size of a single TCP packet, although MTU means it's usually closer to 1448 bytes, but this seemed like a sane place to draw a line to where a second request that might fail is worth our time)
 	BlobSizeWorthHEAD = int64(65535)
 )
 
@@ -43,25 +43,23 @@ func EnsureManifest(ctx context.Context, ref Reference, manifest json.RawMessage
 		return desc, fmt.Errorf("%s: failed getting client: %w", ref, err)
 	}
 
-	if desc.Size > BlobSizeWorthHEAD {
-		// try HEAD request before pushing
-		// if it matches, then we can assume child objects exist as well
-		headRef := ref
-		if headRef.Tag != "" {
-			// if this function is called with *both* tag *and* digest, the code below works correctly and pushes by tag and then validates by digest, but this lookup specifically will prefer the digest instead and skip when it shouldn't
-			headRef.Digest = ""
-		}
-		r, err := Lookup(ctx, headRef, &LookupOptions{Head: true})
-		if err != nil {
-			return desc, fmt.Errorf("%s: failed HEAD: %w", ref, err)
-		}
-		// TODO if we had some kind of progress interface, this would be a great place for some kind of debug log of head's contents
-		if r != nil {
-			head := r.Descriptor()
-			r.Close()
-			if head.Digest == desc.Digest && head.Size == desc.Size {
-				return head, nil
-			}
+	// try HEAD request before pushing
+	// if it matches, then we can assume child objects exist as well
+	headRef := ref
+	if headRef.Tag != "" {
+		// if this function is called with *both* tag *and* digest, the code below works correctly and pushes by tag and then validates by digest, but this lookup specifically will prefer the digest instead and skip when it shouldn't
+		headRef.Digest = ""
+	}
+	r, err := Lookup(ctx, headRef, &LookupOptions{Head: true})
+	if err != nil {
+		return desc, fmt.Errorf("%s: failed HEAD: %w", ref, err)
+	}
+	// TODO if we had some kind of progress interface, this would be a great place for some kind of debug log of head's contents
+	if r != nil {
+		head := r.Descriptor()
+		r.Close()
+		if head.Digest == desc.Digest && head.Size == desc.Size {
+			return head, nil
 		}
 	}