lib/portus: we can now remove image manifests

Signed-off-by: Miquel Sabaté <msabate@suse.com>

bin/client.rb

@@ -5,7 +5,7 @@
 #
 # These are the available commands:
 #   - catalog
-#   - delete <name> <digest>
+#   - delete <name> <digest> blobs/manifests
 #   - manifest <name>[:<tag>]
 #   - ping <hostname:port> [use_ssl]
 
@@ -23,11 +23,17 @@
   puts catalog.inspect
   puts "Size: #{catalog.size}"
 when "delete"
-  if ARGV.length == 2
-    puts "You have to specify first the name, and then the digest"
+  if ARGV.length != 4
+    puts "usage: delete <name> <digest> blobs/manifests"
     exit 1
   end
-  pp registry.client.delete(ARGV[1], ARGV[2])
+
+  if ARGV[3] != "blobs" && ARGV[3] != "manifests"
+    puts "Unknown #{ARGV[3]} object. Only available: blobs and manifests."
+    exit 1
+  end
+
+  pp registry.client.delete(ARGV[1], ARGV[2], ARGV[3])
 when "manifest"
   if ARGV.length == 1
     puts "You have to at least specify the name of the image"
@@ -39,7 +45,9 @@
   else
     name, tag = ARGV[1], "latest"
   end
+
   puts JSON.pretty_generate(registry.client.manifest(name, tag))
+  puts "Manifest digest: #{registry.client.manifest(name, tag, true)}"
 when "ping"
   # No registry was found, trying to ping another one.
   if registry.nil?

lib/portus/http_helpers.rb

@@ -32,6 +32,10 @@ def perform_request(path, method = "get", request_auth_token = true)
       uri = URI.join(@base_url, path)
       req = Net::HTTP.const_get(method.capitalize).new(uri)
 
+      # So we deal with compatibility issues in distribution 2.3 and later.
+      # See: https://github.com/docker/distribution/blob/master/docs/compatibility.md#content-addressable-storage-cas
+      req["Accept"] = "application/vnd.docker.distribution.manifest.v2+json"
+
       # This only happens if the auth token has already been set by a previous
       # call.
       req["Authorization"] = "Bearer #{@token}" if @token

lib/portus/registry_client.rb

@@ -28,13 +28,17 @@ def reachable?
       !res.nil? && res.code.to_i == 401
     end
 
-    # Retrieves the manifest for the required repository:tag. If everything goes
-    # well, it will return a parsed response from the registry, otherwise it will
-    # raise either ManifestNotFoundError or a RuntimeError.
-    def manifest(repository, tag = "latest")
-      res = perform_request("#{repository}/manifests/#{tag}")
+    # Calls the `/:repository/manifests/:tag` endpoint from the registry. With
+    # the `digest` parameter you can tell this method whether you want the full
+    # manifest for this tag, or just the digest. It defaults to false, meaning
+    # that the caller wants the full manifest. It will raise either a
+    # ManifestNotFoundError or a RuntimeError if something goes wrong.
+    def manifest(repository, tag = "latest", digest = false)
+      method = digest ? "head" : "get"
+      res = perform_request("#{repository}/manifests/#{tag}", method)
+
       if res.code.to_i == 200
-        JSON.parse(res.body)
+        digest ? res["Docker-Content-Digest"] : JSON.parse(res.body)
       elsif res.code.to_i == 404
         handle_error res, repository: repository, tag: tag
       else
@@ -61,11 +65,10 @@ def tags(repository)
       paged_response("#{repository}/tags/list", "tags")
     end
 
-    # Deletes a layer of the specified image. The layer is pointed by the digest
-    # as given by the manifest of the image itself. Returns true if the request
-    # was successful, otherwise it raises an exception.
-    def delete(name, digest)
-      res = perform_request("#{name}/blobs/#{digest}", "delete")
+    # Deletes a blob/manifest of the specified image. Returns true if the
+    # request was successful, otherwise it raises an exception.
+    def delete(name, digest, object = "blobs")
+      res = perform_request("#{name}/#{object}/#{digest}", "delete")
       if res.code.to_i == 202
         true
       elsif res.code.to_i == 404 || res.code.to_i == 405