refactor: sha256 and tag parser refactored. Digest's hash value moved to function parse_docker_uri

Author: serdarozerr

lib/cloud_controller/diego/docker/docker_uri_converter.rb

@@ -4,15 +4,12 @@ module VCAP::CloudController
   class DockerURIConverter
     def convert(docker_uri)
       raise UriUtils::InvalidDockerURI.new "Docker URI [#{docker_uri}] should not contain scheme" if docker_uri.include? '://'
+      host, path, tag_digest = UriUtils.parse_docker_uri(docker_uri)
 
-      host, path, tag = UriUtils.parse_docker_uri(docker_uri)
-
-      if !tag.nil? && tag.start_with?('@sha256:')
-        path = "#{path}@sha256"
-        tag.slice!('@sha256:')
-      end
-
-      Addressable::URI.new(scheme: 'docker', host: host, path: path, fragment: tag).to_s
+      # add tag or digest part as fragment to the uri, since ruby uri parser confuses with ':'
+      # when it presented in path. We convert user's uri to, for example;
+      # docker://docker.io/publish/ubuntu:latest -> docker://docker.io/publish/ubuntu#latest
+      Addressable::URI.new(scheme: 'docker', host: host, path: path, fragment: tag_digest).to_s
     end
   end
 end

lib/utils/uri_utils.rb

@@ -4,6 +4,10 @@ module UriUtils
   SSH_REGEX = %r{ \A (?:ssh://)? git@ .+? : .+? \.git \z }x
   GIT_REGEX = %r{ \A git:// .+? : .+? \.git \z }x
   DOCKER_INDEX_SERVER = 'docker.io'.freeze
+  DOCKER_PATH_REGEX = %r{\A[a-z0-9_\-\.\/]{2,255}\Z}
+  DOCKER_TAG_REGEX = %r{[a-zA-Z0-9_\-\.]{1,128}}
+  DOCKER_DIGEST_REGEX = %r{sha256:[a-z0-9]{64}}
+  DOCKER_TAG_DIGEST_REGEX = Regexp.new("\\A(#{DOCKER_TAG_REGEX.source} | (#{DOCKER_TAG_REGEX.source}@#{DOCKER_DIGEST_REGEX.source}) | #{DOCKER_DIGEST_REGEX.source})\\Z", Regexp::EXTENDED)
 
   class InvalidDockerURI < StandardError; end
 
@@ -62,13 +66,20 @@ def self.parse_docker_uri(docker_uri)
     end
 
     path = 'library/' + path if (official_docker_registry(name_parts[0]) || missing_registry(name_parts)) && path.exclude?('/')
+    path, tag_digest = parse_docker_tag_or_digest_from_path(path)
 
-    path, tag = parse_docker_repository_tag(path)
+    raise InvalidDockerURI.new "Invalid image name [#{path}]" unless DOCKER_PATH_REGEX =~ path
+    raise InvalidDockerURI.new "Invalid image tag [#{tag_digest}]" if tag_digest && !(DOCKER_TAG_DIGEST_REGEX =~ tag_digest)
 
-    raise InvalidDockerURI.new "Invalid image name [#{path}]" unless %r{\A[a-z0-9_\-\.\/]{2,255}\Z} =~ path
-    raise InvalidDockerURI.new "Invalid image tag [#{tag}]" if tag && !(/\A(([a-zA-Z0-9_\-\.]{1,128})|(([a-zA-Z0-9_\-\.]{0,128})(@sha256:[a-z0-9]{64})))\Z/ =~ tag)
+    # if only sha256 presented, we add hash value as fragment to the uri,
+    # since the ruby uri parser confuses because of second ':' in uri's path part.
+    if tag_digest && tag_digest.start_with?("sha256:")
+      hash_algo, hash_value = tag_digest.split(":")
+      path = path + "@sha256"
+      tag_digest = hash_value
+    end
 
-    [host, path, tag]
+    [host, path, tag_digest]
   end
 
   private_class_method def self.official_docker_registry(host)
@@ -78,13 +89,12 @@ def self.parse_docker_uri(docker_uri)
   private_class_method def self.missing_registry(name_parts)
     host = name_parts[0]
     name_parts.length == 1 ||
-    (host.exclude?('.') && host.exclude?(':') && host != 'localhost')
+      (host.exclude?('.') && host.exclude?(':') && host != 'localhost')
   end
 
-  private_class_method def self.parse_docker_repository_tag(path)
-    path, tag = path.split(/(?=@)|:/, 2)
-
-    return [path, tag] unless tag && tag.include?('/')
+  private_class_method def self.parse_docker_tag_or_digest_from_path(path)
+    path, tag_digest = path.split(/@|:/, 2)
+    return [path, tag_digest] unless tag_digest && tag_digest.include?('/')
 
     [path, 'latest']
   end

spec/unit/lib/utils/uri_utils_spec.rb

@@ -159,7 +159,7 @@
       expect(UriUtils.parse_docker_uri('publish/buildpack:tag')).to eq ['', 'publish/buildpack', 'tag']
 
       actual_result = UriUtils.parse_docker_uri('publish/buildpack@sha256:e118d023acaee5cf13471ead39f68416ad6172ff0899f3257ce1481cd2b28a6a')
-      expected_result = ['', 'publish/buildpack', '@sha256:e118d023acaee5cf13471ead39f68416ad6172ff0899f3257ce1481cd2b28a6a']
+      expected_result = ['', 'publish/buildpack@sha256', 'e118d023acaee5cf13471ead39f68416ad6172ff0899f3257ce1481cd2b28a6a']
       expect(actual_result).to eq expected_result
 
       actual_result = UriUtils.parse_docker_uri('publish/buildpack:tag@sha256:e118d023acaee5cf13471ead39f68416ad6172ff0899f3257ce1481cd2b28a6a')