Production Secrets

The docker/docker-credential-helpers project manages secrets in production by leveraging a combination of secure storage mechanisms and integration with system-level credential stores. This documentation outlines the steps involved in storing and managing secrets and provides relevant code examples.

Key Mechanisms for Secret Management

1. Use of Credential Helpers: The project includes several credential helpers that interface with different systems such as Gnome Keyring, OSX Keychain, and Windows Credential Store. These helpers securely store the credentials without exposing them.

2. Secure Compilation and Linking: The build process incorporates various packages and dependencies relevant to secure credential handling, ensuring that the final binaries can handle secrets securely.

Step-by-Step Guide to Managing Secrets

1. Building Credential Helpers

The build process is crucial for ensuring that the secret management helpers are compiled correctly. The Dockerfile contains multiple stages, where different credential helpers are constructed based on the target platform.

For instance, the section for building the pass credential helper looks like this:

FROM base AS build-linux
ARG PACKAGE
RUN --mount=type=bind,target=. \
    --mount=type=cache,target=/root/.cache \
    --mount=type=cache,target=/go/pkg/mod \
    --mount=type=bind,source=/tmp/.version,target=/tmp/.version,from=version \
    --mount=type=bind,source=/tmp/.revision,target=/tmp/.revision,from=version <<EOT
  set -ex
  xx-go --wrap
  make build-pass build-secretservice PACKAGE=$PACKAGE VERSION=$(cat /tmp/.version) REVISION=$(cat /tmp/.revision) DESTDIR=/out
  xx-verify /out/docker-credential-pass
  xx-verify /out/docker-credential-secretservice
EOT

This code snippet demonstrates how to build the pass credential helper. It ensures that the helper is properly linked against the necessary libraries for secure credential management.

2. Integration with System Credential Stores

The integration with system-level credential stores allows for a seamless way of retrieving and storing secrets. For example, the Makefile defines functions tailored to build the specific credential helpers, such as:

osxkeychain:
    @echo "Building OSX Keychain Helper"
    $(MAKE) build-osxkeychain

pass:
    @echo "Building pass Helper"
    $(MAKE) build-pass

These helper functions are a crucial part of the production secret management system, as they define how to build and deploy the helpers that interface with specific credential stores.

3. Test and Security Validation

The testing stage ensures that the built credential helpers function as expected and adhere to security requirements. Test stages in the Dockerfile include the installation of various tools and libraries necessary for validating credential management functionality:

FROM test AS final-test
RUN apt-get install -y dbus-x11 gnome-keyring gpg-agent gpgconf libsecret-1-dev pass
RUN --mount=type=bind,target=. \
    --mount=type=cache,target=/root/.cache \
    --mount=type=cache,target=/go/pkg/mod <<EOT
  set -e
  # Configure GPG and test the credential helper
  ...
EOT

This section would contain commands to set up the test environment and validate that the credential storage works as intended.

4. Versioning and Release Management

Versioning is essential for tracking changes in the credential helpers. The Dockerfile handles versioning with this snippet to capture the current version and revision:

FROM version AS build-linux
RUN --mount=target=. \
    echo -n "$(./hack/git-meta version)" | tee /tmp/.version ; echo -n "$(./hack/git-meta revision)" | tee /tmp/.revision

By leveraging Git metadata, the build process automatically incorporates versioning information into the binaries, aligning with best practices in production systems.

Conclusion

The management of secrets in the docker/docker-credential-helpers project involves compiling secure credential helpers, integrating with system credential stores, rigorous testing, and effective version management. These practices form a comprehensive approach to handling sensitive information in production environments, providing developers with the necessary tools to build secure applications.

Source: Dockerfile, Makefile