Use a custom root endpoint if defined on GH ominiauth provider settings

lib/github/import.rb

@@ -48,9 +48,9 @@ module Github
       @project = project
       @repository = project.repository
       @repo = project.import_source
-      @options = options
       @repo_url = project.import_url
       @wiki_url = project.import_url.sub(/\.git\z/, '.wiki.git')
+      @options = options.reverse_merge(url: root_endpoint)
       @verbose = options.fetch(:verbose, false)
       @cached  = Hash.new { |hash, key| hash[key] = Hash.new }
       @errors  = []
@@ -383,5 +383,20 @@ module Github
     def error(type, url, message)
       errors << { type: type, url: Gitlab::UrlSanitizer.sanitize(url), error: message }
     end
+
+    def root_endpoint
+      @root_endpoint ||= custom_endpoint || githup_endpoint
+    end
+
+    def custom_endpoint
+      Gitlab.config.omniauth.providers
+                            .find { |provider| provider.name == 'github' }
+                            .to_h
+                            .dig('args', 'client_options', 'site')
+    end
+
+    def github_endpoint
+      OmniAuth::Strategies::GitHub.default_options[:client_options][:site]
+    end
   end
 end

lib/tasks/import.rake

@@ -7,7 +7,7 @@ class GithubImport
   end
 
   def initialize(token, gitlab_username, project_path, extras)
-    @options = { url: 'https://api.github.com', token: token, verbose: true }
+    @options = { token: token, verbose: true }
     @project_path = project_path
     @current_user = User.find_by_username(gitlab_username)
     @github_repo = extras.empty? ? nil : extras.first