Reintroduce old digest functionality

* This digest function executes HEAD requests instead of querying the manifest * GET requests are ratelimited in some registries
deitch · Jul 20, 2023 · ff75f52 · ff75f52
1 parent 153b31e
commit ff75f52
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diff --git a/lib/docker_registry2.rb b/lib/docker_registry2.rb
@@ -22,4 +22,8 @@ def self.tags(repository)
   def self.manifest(repository, tag)
     @reg.manifest(repository, tag)
   end
+
+  def self.manifest_digest(repository, tag)
+    @reg.manifest_digest(repository, tag)
+  end
 end
diff --git a/lib/registry/registry.rb b/lib/registry/registry.rb
@@ -126,6 +126,14 @@ def blob(repo, digest, outpath = nil)
       end
     end
 
+    def manifest_digest(image, tag)
+      tag_path = "/v2/#{repo}/manifests/#{tag}"
+      dohead(tag_path).headers[:docker_content_digest]
+    rescue DockerRegistry2::InvalidMethod
+      # Pre-2.3.0 registries didn't support manifest HEAD requests
+      doget(tag_path).headers[:docker_content_digest]
+    end
+
     def digest(image, tag, architecture = nil, os = nil, variant = nil)
       manifest = manifest(image, tag)
       parsed_manifest = JSON.parse(manifest.body)