chore: add sample for APIKey usage (#534)

Author: viacheslav-rostovtsev

samples/Gemfile

@@ -14,6 +14,7 @@
 
 source "https://rubygems.org"
 
+gem "google-cloud-language-v1"
 gem "google-cloud-storage"
 
 group :test do

samples/acceptance/authenticate_with_api_key_test.rb

@@ -0,0 +1,32 @@
+# Copyright 2025 Google LLC
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     https://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+require_relative "../authenticate_with_api_key"
+require_relative "helper"
+require "minitest/autorun"
+
+describe "authenticate_with_api_key" do
+  let(:api_key) { ENV["GOOGLE_API_KEY"] }
+
+  it "authenticates with API key" do
+    skip "No API key available" if api_key.nil? || api_key.empty?
+
+    stdout_output = capture_io { authenticate_with_api_key api_key }
+
+    output = stdout_output[0]
+    assert_includes output, "Text: Hello, world!"
+    assert_includes output, "Sentiment:"
+    assert_includes output, "Successfully authenticated using the API key"
+  end
+end

samples/authenticate_with_api_key.rb

@@ -0,0 +1,67 @@
+# Copyright 2025 Google LLC
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+# [START apikeys_authenticate_api_key]
+require "googleauth"
+require "google/cloud/language/v1"
+
+def authenticate_with_api_key api_key_string
+  # Authenticates with an API key for Google Language service.
+  #
+  # TODO(Developer): Uncomment the following line and set the value before running this sample.
+  #
+  # api_key_string = "mykey12345"
+  #
+  # Note: You can also set the API key via environment variable:
+  #   export GOOGLE_API_KEY=your-api-key
+  # and use Google::Auth::APIKeyCredentials.from_env method to load it.
+  # Example:
+  #   credentials = Google::Auth::APIKeyCredentials.from_env
+  #   if credentials.nil?
+  #     puts "No API key found in environment"
+  #     exit
+  #   end
+
+  # Initialize API key credentials using the class factory method
+  credentials = Google::Auth::APIKeyCredentials.make_creds api_key: api_key_string
+
+  # Initialize the Language Service client with the API key credentials
+  client = Google::Cloud::Language::V1::LanguageService::Client.new do |config|
+    config.credentials = credentials
+  end
+
+  # Create a document to analyze
+  text = "Hello, world!"
+  document = {
+    content: text,
+    type: :PLAIN_TEXT
+  }
+
+  # Make a request to analyze the sentiment of the text
+  sentiment = client.analyze_sentiment(document: document).document_sentiment
+
+  puts "Text: #{text}"
+  puts "Sentiment: #{sentiment.score}, #{sentiment.magnitude}"
+  puts "Successfully authenticated using the API key"
+end
+# [END apikeys_authenticate_api_key]
+
+if $PROGRAM_NAME == __FILE__
+  api_key = ARGV[0]
+  if api_key.nil? || api_key.empty?
+    puts "Usage: ruby #{__FILE__} api-key"
+    exit
+  end
+  authenticate_with_api_key api_key
+end

spec/googleauth/external_account/aws_credentials_spec.rb

@@ -198,7 +198,7 @@ def impersonation_endpoint_success access_token
     return unless access_token and service_account_impersonation_url
     impersonation_endpoint(access_token).to_return(
       body: MultiJson.dump(google_token_impersonation_response.merge({
-        "accessToken" => access_token
+        accessToken: access_token
       }))
     )
   end