Python MCP Server Template

# Google Cloud Authentication with Client Libraries ## Overview This document provides guidance on how to authenticate to Google Cloud APIs using client libraries in Python. Client libraries simplify the process of accessing Google Cloud APIs and managing authentication. ## Application Default Credentials (ADC) ### What is ADC? Application Default Credentials (ADC) is a mechanism that provides credentials to your application. It allows the client libraries to automatically find and use the credentials you have set up for your environment. ### Setting Up ADC 1. **Local Development Environment**: - Use your user credentials or service account impersonation via the `gcloud` CLI. - Example command to authenticate: ```bash gcloud auth application-default login ``` 2. **Production Environment**: - Attach a service account to your application (e.g., for Compute Engine, Cloud Run, or Kubernetes). ### How ADC Works - When you create a client using a client library, it automatically checks for ADC and uses the credentials to authenticate to the APIs. - Your application does not need to explicitly manage tokens; the authentication libraries handle this automatically. ### Example: Creating a Client Below is an example of creating a client for the Cloud Storage service: ```python from google.cloud import storage # Create a client client = storage.Client() # Use the client buckets = list(client.list_buckets()) print(buckets) ``` ## Using API Keys - API keys can be used with client libraries for APIs that accept them. - Ensure API keys are kept secure during storage and transmission to avoid unauthorized access. - Example of using an API key with the Cloud Natural Language API: ```python from google.cloud import language_v1 client = language_v1.LanguageServiceClient() # Set the API key client.api_key = 'YOUR_API_KEY' ``` ## Security Requirements for External Credential Configurations - Validate any credential configurations provided by external sources before using them. - For service account keys, ensure the `type` field is `service_account`. - For other credential types, validate fields like `credential_source.url` and `credential_source.executable.command` to ensure they conform to expected values. ## Best Practices - Use ADC wherever possible for seamless and secure authentication. - Avoid exposing API keys publicly. - Regularly rotate credentials and follow Google Cloud's [best practices for managing API keys](https://cloud.google.com/docs/authentication/api-keys). ## Additional Resources - [Application Default Credentials](https://cloud.google.com/docs/authentication/production) - [API Keys Best Practices](https://cloud.google.com/docs/authentication/api-keys) - [Authentication Methods Overview](https://cloud.google.com/docs/authentication)