Merge branch 'docker-registry-manifest-v1' into 'master'

Add support for Docker Registry manifest v1

## What does this MR do?

Adds support for Manifest V1 generated by older versions of Docker (before 1.10).

## What are the relevant issue numbers?

Fixes https://gitlab.com/gitlab-org/gitlab-ce/issues/18609


See merge request !4669

3 files changed, 16 insertions, 4 deletions

diff --git a/lib/container_registry/blob.rb b/lib/container_registry/blob.rb
index 4e20dc4f875..eb5a2596177 100644
--- a/lib/container_registry/blob.rb
+++ b/lib/container_registry/blob.rb
@@ -18,7 +18,7 @@ module ContainerRegistry
     end
 
     def digest
-      config['digest']
+      config['digest'] || config['blobSum']
     end
 
     def type
diff --git a/lib/container_registry/client.rb b/lib/container_registry/client.rb
index 4d726692f45..e0b3f14d384 100644
--- a/lib/container_registry/client.rb
+++ b/lib/container_registry/client.rb
@@ -47,7 +47,9 @@ module ContainerRegistry
       conn.request :json
       conn.headers['Accept'] = MANIFEST_VERSION
 
-      conn.response :json, content_type: /\bjson$/
+      conn.response :json, content_type: 'application/vnd.docker.distribution.manifest.v1+prettyjws'
+      conn.response :json, content_type: 'application/vnd.docker.distribution.manifest.v1+json'
+      conn.response :json, content_type: 'application/vnd.docker.distribution.manifest.v2+json'
 
       if options[:user] && options[:password]
         conn.request(:basic_auth, options[:user].to_s, options[:password].to_s)
diff --git a/lib/container_registry/tag.rb b/lib/container_registry/tag.rb
index 43f8d6dc8c2..7a0929d774e 100644
--- a/lib/container_registry/tag.rb
+++ b/lib/container_registry/tag.rb
@@ -12,6 +12,14 @@ module ContainerRegistry
       manifest.present?
     end
 
+    def v1?
+      manifest && manifest['schemaVersion'] == 1
+    end
+
+    def v2?
+      manifest && manifest['schemaVersion'] == 2
+    end
+
     def manifest
       return @manifest if defined?(@manifest)
 
@@ -57,7 +65,9 @@ module ContainerRegistry
       return @layers if defined?(@layers)
       return unless manifest
 
-      @layers = manifest['layers'].map do |layer|
+      layers = manifest['layers'] || manifest['fsLayers']
+
+      @layers = layers.map do |layer|
         repository.blob(layer)
       end
     end
@@ -65,7 +75,7 @@ module ContainerRegistry
     def total_size
       return unless layers
 
-      layers.map(&:size).sum
+      layers.map(&:size).sum if v2?
     end
 
     def delete