Excellent Migrations is an Elixir library that analyzes Ecto migration files to detect potentially dangerous database operations that could cause downtime or data loss. It provides a Credo check, Mix tasks, and direct API usage to identify issues such as adding columns with default values, removing columns, running raw SQL, and more. The tool allows marking operations as safe via special comments or configuration to avoid false positives. The architecture is centered around AST parsing of migration files, with separate modules for detecting dangers, parsing safety comments, and filtering results. Key components like the AST parser and comment parser are well-crafted and reusable in other contexts.
Firezone is a zero-trust network access platform providing secure remote access through VPN-like tunnels. The production system consists of a cloud-based management portal (Elixir/Phoenix), data-plane components (Rust gateways and relays), and native clients for macOS/iOS, Android, Windows, and Linux. The portal manages multi-tenant accounts, identity (OIDC, SAML, email OTP, X.509), access policies, device posture, and logs. It exposes a REST API (PortalAPI) for CRUD operations and WebSocket channels for real-time client/gateway connectivity. The Rust core (connlib) handles ICE/STUN/TURN connectivity, WireGuard tunnels, and eBPF-accelerated packet routing. PostgreSQL is used for persistence with logical replication for change data capture, Oban for background job processing, and Redis for caching/presence. External dependencies include identity providers (Entra, Okta, Google Workspace), device management systems (Intune, Defender, SentinelOne, etc.), log sinks (Splunk, Datadog, Elastic, S3), and billing (Stripe). The architecture separates the web admin interface (PortalWeb), REST API (PortalAPI), and internal ops (PortalOps) into distinct endpoints. Data-plane components (gateway, relay) communicate via WebSockets with the API to receive policy updates. Clients connect to relays using ICE/STUN/TURN. The system uses Phoenix PubSub for real-time updates and Postgres logical replication to propagate changes to connected clients and gateways. Key entry points: PortalWeb.Endpoint (admin UI), PortalAPI.Endpoint (REST/WebSocket for clients and gateways), PortalOps.Endpoint (ops dashboard). Rust binaries: firezone-gateway, firezone-relay, firezone-headless-client, firezone-gui-client. Mobile apps: Firezone iOS/macOS (Swift), Firezone Android (Kotlin).