distribution: update warning for deprecated image formats

- Use the same warning for both "v1 in manifest-index" and bare "v1" images.
- Update URL to use a "/go/" redirect, which allows the docs team to more
  easily redirect the URL to relevant docs (if things move).

Signed-off-by: Sebastiaan van Stijn <github@gone.nl>

distribution/pull_v2.go

@@ -439,7 +439,7 @@ func (p *puller) pullTag(ctx context.Context, ref reference.Named, platform *oci
 		// give registries time to upgrade to schema2 and only warn if we know a registry has been upgraded long time ago
 		// TODO: condition to be removed
 		if reference.Domain(ref) == "docker.io" {
-			msg := fmt.Sprintf("Image %s uses outdated schema1 manifest format. Please upgrade to a schema2 image for better future compatibility. More information at https://docs.docker.com/registry/spec/deprecated-schema-v1/", ref)
+			msg := fmt.Sprintf("[DEPRECATION NOTICE] Docker Image Format v1, and Docker Image manifest version 2, schema 1 support will be removed in an upcoming release. Suggest the author of %s to upgrade the image to the OCI Format, or Docker Image manifest v2, schema 2. More information at https://docs.docker.com/go/deprecated-image-specs/", ref)
 			log.G(ctx).Warn(msg)
 			progress.Message(p.config.ProgressOutput, "", msg)
 		}
@@ -871,7 +871,7 @@ func (p *puller) pullManifestList(ctx context.Context, ref reference.Named, mfst
 
 		switch v := manifest.(type) {
 		case *schema1.SignedManifest:
-			msg := fmt.Sprintf("[DEPRECATION NOTICE] v2 schema1 manifests in manifest lists are not supported and will break in a future release. Suggest author of %s to upgrade to v2 schema2. More information at https://docs.docker.com/registry/spec/deprecated-schema-v1/", ref)
+			msg := fmt.Sprintf("[DEPRECATION NOTICE] Docker Image Format v1, and Docker Image manifest version 2, schema 1 support will be removed in an upcoming release. Suggest the author of %s to upgrade the image to the OCI Format, or Docker Image manifest v2, schema 2. More information at https://docs.docker.com/go/deprecated-image-specs/", ref)
 			log.G(ctx).Warn(msg)
 			progress.Message(p.config.ProgressOutput, "", msg)