Process to retrieve identity token from GCP

Author: ragalie

lib/shopify_api/auth/id_token/google_id_token.rb

@@ -0,0 +1,30 @@
+# typed: strict
+# frozen_string_literal: true
+
+module ShopifyAPI
+  module Auth
+    module IdToken
+      class GoogleIdToken
+        METADATA_IDENTITY_URL = "http://metadata/computeMetadata/v1/instance/service-accounts/default/identity"
+
+        class << self
+          extend T::Sig
+
+          sig { params(shop: String).returns(T.nilable(String)) }
+          def request(shop:)
+            response = HTTParty.get(
+              "#{METADATA_IDENTITY_URL}?audience=#{shop}&format=full",
+              headers: {
+                "Metadata-Flavor" => "Google",
+              },
+            )
+
+            return unless response.success?
+
+            response.body
+          end
+        end
+      end
+    end
+  end
+end

test/auth/id_token/google_id_token_test.rb

@@ -0,0 +1,33 @@
+# typed: true
+# frozen_string_literal: true
+
+require_relative "../../test_helper"
+
+module ShopifyAPITest
+  module Auth
+    module IdToken
+      class GoogleIdTokenTest < Test::Unit::TestCase
+        def setup
+          super
+          @sample_jwt = "eyJhbGciOiJIUzI1NiJ9.eyJhdWQiOiJ0ZXN0LXNob3AubXlzaG9waWZ5LmlvIn0.CnoHeW_Z0oMKQcBPqezcbFyWLlkioPKPz8X0wchUkeQ"
+        end
+
+        def test_successful_requests_returns_id_token
+          stub_request(:get, "http://metadata/computeMetadata/v1/instance/service-accounts/default/identity?audience=test-shop.myshopify.io&format=full")
+            .with(headers: { "Metadata-Flavor" => "Google" })
+            .to_return(body: @sample_jwt, status: 200)
+
+          assert_equal(@sample_jwt, ShopifyAPI::Auth::IdToken::GoogleIdToken.request(shop: "test-shop.myshopify.io"))
+        end
+
+        def test_unsuccessful_requests_returns_nil
+          stub_request(:get, "http://metadata/computeMetadata/v1/instance/service-accounts/default/identity?audience=test-shop.myshopify.io&format=full")
+            .with(headers: { "Metadata-Flavor" => "Google" })
+            .to_return(status: 404)
+
+          assert_nil(ShopifyAPI::Auth::IdToken::GoogleIdToken.request(shop: "test-shop.myshopify.io"))
+        end
+      end
+    end
+  end
+end