github.com/openfaas/faas

This package provides the foundational types and interfaces for OpenFaaS function development in Go. Day-to-day usage involves importing gateway client types, function handler interfaces, and basic auth structs. The API surface is straightforward but sparse - you get what you need to interact with OpenFaaS, but not much handholding.

The biggest challenge is the lack of comprehensive documentation within the package itself. You'll find yourself referencing the broader OpenFaaS docs and examples frequently. Error handling is basic; the package doesn't provide rich error types or helpers, so you're wrapping and contextualizing errors yourself. Type definitions are clear but minimal - IDE autocompletion works, but you won't get much insight into expected values or patterns without external documentation.

Migration between versions can be tricky since this is effectively the core monorepo's module. The versioning strategy (snapshot-based rather than semantic) means you need to track OpenFaaS platform releases carefully. For teams already invested in OpenFaaS infrastructure, it's serviceable. For newcomers, expect a steeper learning curve than modern Go SDK standards.

This package is the core OpenFaaS gateway and types repository, not really intended as a standalone library for typical Go projects. When building custom integrations or extensions for OpenFaaS, you'll interact with its type definitions and HTTP handlers. The API contracts are reasonably stable, but documentation assumes familiarity with the OpenFaaS ecosystem.

From a security perspective, there are concerns. Authentication relies heavily on basic auth or external proxy configuration, which puts the burden on operators to secure properly. The gateway handles secrets via environment variables, which is standard but requires careful audit trail management. Input validation exists but isn't always comprehensive - I've had to add additional validation layers when exposing custom endpoints. TLS configuration is externalized, which is flexible but means secure-by-default isn't guaranteed out of the box.

Error handling often exposes internal details in HTTP responses, requiring middleware to sanitize before production use. The codebase moves quickly with frequent commits, which is great for features but challenging for security auditing. CVE response has been reasonable when issues arise, but the fast release cycle means you need active monitoring.

Working with the OpenFaaS core package means dealing with a serverless framework that prioritizes simplicity but requires careful security hardening. The authentication model relies on basic auth by default, which necessitates immediate TLS configuration in production. The gateway exposes function invocation endpoints, and you'll need to implement your own authorization logic for granular access control beyond the built-in basic auth.

Input validation is largely delegated to individual functions, which follows the framework's philosophy but means security is inconsistent across deployments. Error handling can leak function implementation details through stack traces if not configured properly. The framework doesn't enforce secure-by-default for secrets management—you must explicitly configure sealed secrets or external vaults.

Dependency management is reasonably maintained with CVE responses typically addressed within a release cycle. However, the package's quasi-date-based versioning scheme (0.0.0-YYYYMMDD format) makes tracking security updates less intuitive than semantic versioning. TLS configuration between gateway and functions requires manual setup and isn't enforced by default.