golang-context

You propagate context.Context by passing it explicitly as the first parameter through HTTP handlers, services, and repository layers, using WithTimeout or WithCancel to ensure operations respect cancellation and deadlines across service boundaries.

The best way to use context with database queries is to consistently call the context-aware variants QueryContext, ExecContext, and QueryRowContext rather than their non-context counterparts, ensuring queries are cancellable and respect request timeouts.

Storing context in a Go struct causes problems because it decouples the context's lifecycle from the request scope, leading to missed cancellations, leaked deadlines, and unpredictable behavior when the struct outlives the originating request.

You should not use context values for business parameters. Context values should be reserved for request-scoped metadata like trace IDs, avoiding abuse that obscures function signatures and makes dependencies difficult to trace and test.

Use WithCancel when you need to manually trigger cancellation based on client disconnects or interrupts, and use WithDeadline or WithTimeout when operations must automatically cancel after a specific time or duration has elapsed.

To ensure downstream HTTP calls respect cancellation, create an outbound request with http.NewRequestWithContext, then execute it using the Do method so the call terminates immediately when the parent context is cancelled or times out.