docker / docker-credential-helpers

Credential Management

Docker Credential Helpers provide a mechanism for storing and retrieving Docker registry credentials securely. This is crucial for automating builds and deployments, especially when working with private registries.

Key Concepts

  • Credential Helper: A program that handles the storage, retrieval, and management of Docker credentials.
  • Credential Store: The location where credentials are stored, which can be a file, keychain, or other secure storage mechanism.
  • Credential Provider: A component that retrieves credentials from the credential store and provides them to Docker.

Credential Management Options

1. Environment Variables

Motivation: This approach is suitable for development environments or when you need to quickly test credentials.

Pros:

  • Simple and easy to set up.

Cons:

  • Insecure as credentials are exposed in plain text.
  • Not recommended for production environments.

Example:

export DOCKER_USERNAME=your_username
          export DOCKER_PASSWORD=your_password

Source: https://docs.docker.com/engine/reference/commandline/login/#environment-variables

2. Docker Config File

Motivation: This is the default method for storing credentials in Docker. It provides a dedicated file for storing credentials, making it more secure than environment variables.

Pros:

  • Secure as the config file is typically stored in a hidden directory.
  • Offers a more structured approach to credential management.

Cons:

  • Credentials are stored in plain text within the config file.
  • Sharing this file with others can expose credentials.

Example:

# ~/.docker/config.json
          {
            "auths": {
              "https://index.docker.io/v1/": {
                "auth": "your_username:your_password",
                "email": "[email protected]"
              }
            }
          }

Source: https://docs.docker.com/engine/reference/commandline/login/#docker-config-file

3. Credential Helpers

Motivation: This is the recommended method for storing and managing Docker credentials securely. It offers a wide range of features and integrations.

Pros:

  • Secure storage and retrieval of credentials.
  • Integrated with Docker and other tools.
  • Provides access to various credential stores.
  • Supports authentication protocols like OAuth2.

Cons:

  • May require additional setup and configuration.

Example:

# Configure Docker to use the 'docker-credential-helpers' helper
          docker login --username=your_username --password=your_password 
          # Use the helper to manage credentials
          docker credential store

Source: https://github.com/docker/docker-credential-helpers

4. Alternative Credential Stores

Motivation: While credential helpers provide a flexible solution, you might need to integrate with specific credential stores or systems.

Pros:

  • Integration with existing enterprise security solutions.
  • Increased control and visibility over credential management.

Cons:

  • Requires specific configurations and setup.

Example:

  • Hashicorp Vault: Securely store and manage secrets using Vault.
  • Key Management Systems (KMS): Integrate with KMS like AWS KMS or Google Cloud KMS to encrypt and manage credentials.

Source: https://www.hashicorp.com/products/vault, https://aws.amazon.com/kms/, https://cloud.google.com/kms