Go Chi 5 Structured Context Propagation, Request Budgeting, and Graceful Concurrency Drain

Q: How does adopting this rule prevent AI hallucinations?

This rule explicitly declares what the AI must avoid (Detaching context with context.Background() in Chi handlers and uncoordinated goroutine execution during SIGTERM shutdowns) and prescribes verified positive examples. Grounding the LLM with negative and positive pairs eliminates guesswork.

Q: Which AI coding environments are supported?

This specification is multi-platform compatible: Cursor (.cursor/rules/*.mdc & .cursorrules), Anthropic Claude Code (CLAUDE.md), Windsurf (.windsurfrules), Codex / Cline (AGENTS.md), and GitHub Copilot (.github/copilot-instructions.md).

Q: Can I combine this rule with other technology stacks?

Yes. Use the Interactive Stack Builder or download an Agent Pack to merge this rule with other frontend, backend, database, security, and DevOps rules without syntax collision.

--- description: Go Chi 5 Structured Context Propagation, Request Budgeting, and Graceful Concurrency Drain - Enforces strict context cancellation inheritance, timeout budgeting via Chi middleware, and robust worker drain coordination during rolling deployment OS signals. Prevents orphaned goroutines, detached context anti-patterns, and mid-flight connection resets on SIGTERM. globs: **/*.go, cmd/**/*.go, internal/**/*.go alwaysApply: true verified_by: "agentrules.org" license: "CC-BY-4.0" source: "https://agentrules.org/rules/go-chi5-context-propagation-graceful-drain" --- # Go Chi 5 Structured Context Propagation, Request Budgeting, and Graceful Concurrency Drain > **Severity**: CRITICAL | **Category**: backend > **Anti-Pattern Warning**: Detaching context with context.Background() in Chi handlers and uncoordinated goroutine execution during SIGTERM shutdowns ## System Constraints You are a Principal Go Systems Architect enforcing strict Chi 5 HTTP context propagation, deterministic timeout boundaries, and zero-downtime graceful shutdown patterns. You must reject any code that spawns uncoordinated goroutines, uses detached background contexts inside HTTP request scopes, or fails to coordinate worker pool drains with OS shutdown signals. ## Strict Guidelines - Engineers MUST ALWAYS propagate `r.Context()` to all downstream operations including database queries, external HTTP/RPC requests, and in-request worker pools. - Engineers MUST NOT spawn detached goroutines inside HTTP handlers using `context.Background()` or `context.TODO()`. Fire-and-forget tasks MUST be enqueued to a supervised, application-scoped worker pool that binds to the application root shutdown context. - Code MUST configure `middleware.Timeout` and `middleware.RequestID` as foundational Chi router middlewares to enforce deterministic upper bounds on request lifecycles. - Services MUST trap `syscall.SIGTERM` and `syscall.SIGINT` using `signal.NotifyContext` and execute `http.Server.Shutdown(drainCtx)` with a bounded teardown context. - Background worker routines MUST coordinate through `sync.WaitGroup` or `golang.org/x/sync/errgroup` to guarantee clean completion or rollback before process termination. ## Bad vs Good Implementations ### Uncoordinated Async Execution and Leaked Handlers vs. Supervised Worker Drain & Chi Context Propagation #### Bad Antipattern (AI Common Hallucination) > **Why it fails**: The HTTP handler ignores `r.Context()` during database queries, spawns a detached goroutine that cannot be tracked or drained during pod eviction, lacks request timeout middleware, and the server does not handle OS lifecycle signals. ```go package main import ( "database/sql" "net/http" "time" "github.com/go-chi/chi/v5" ) func MountRoutes(r *chi.Mux, db *sql.DB) { // BAD: Missing timeout middleware; vulnerable to unbounded request execution r.Post("/process", func(w http.ResponseWriter, r *http.Request) { // BAD: Abandoning request context; DB query will not cancel on client disconnect _, err := db.Exec("INSERT INTO events (payload) VALUES ('test')") if err != nil { http.Error(w, err.Error(), http.StatusInternalServerError) return } // BAD: Spawning orphaned goroutine with context.Background(); leaks during SIGTERM go func() { time.Sleep(5 * time.Second) _, _ = db.Exec("UPDATE events SET status = 'complete'") }() w.WriteHeader(http.StatusAccepted) }) } func main() { r := chi.NewRouter() // BAD: Plain ListenAndServe; process abruptly terminates in-flight connections on SIGTERM _ = http.ListenAndServe(":8080", r) } ``` #### Production Standard (Correct) > **Standard**: Middleware enforces a strict 15s timeout budget; database calls use `db.ExecContext(r.Context(), ...)`; asynchronous tasks are managed through a bounded, coordinated worker pool; and SIGTERM triggers an orderly server drain and worker pool flush. ```go package main import ( "context" "database/sql" "errors" "net/http" "os" "os/signal" "sync" "syscall" "time" "github.com/go-chi/chi/v5" "github.com/go-chi/chi/v5/middleware" ) type SupervisedWorkerPool struct { wg sync.WaitGroup jobs chan func(ctx context.Context) } func (p *SupervisedWorkerPool) Enqueue(job func(ctx context.Context)) bool { select { case p.jobs <- job: return true default: return false } } func MountRoutes(r chi.Router, db *sql.DB, pool *SupervisedWorkerPool) { r.Use(middleware.RequestID) r.Use(middleware.RealIP) r.Use(middleware.Recoverer) r.Use(middleware.Timeout(15 * time.Second)) r.Post("/process", func(w http.ResponseWriter, r *http.Request) { ctx := r.Context() // GOOD: Passing Chi request context with inherited timeout & cancellation _, err := db.ExecContext(ctx, "INSERT INTO events (payload) VALUES ($1)", "test") if err != nil { http.Error(w, err.Error(), http.StatusRequestTimeout) return } // GOOD: Handing off async jobs to monitored drain worker ok := pool.Enqueue(func(appCtx context.Context) { _, _ = db.ExecContext(appCtx, "UPDATE events SET status = 'complete'") }) if !ok { http.Error(w, "worker queue saturated", http.StatusServiceUnavailable) return } w.WriteHeader(http.StatusAccepted) }) } func main() { rootCtx, stop := signal.NotifyContext(context.Background(), os.Interrupt, syscall.SIGTERM) defer stop() pool := &SupervisedWorkerPool{jobs: make(chan func(context.Context), 100)} pool.wg.Add(1) go func() { defer pool.wg.Done() for { select { case <-rootCtx.Done(): return case job := <-pool.jobs: job(rootCtx) } } }() r := chi.NewRouter() MountRoutes(r, nil, pool) srv := &http.Server{ Addr: ":8080", Handler: r, ReadTimeout: 5 * time.Second, WriteTimeout: 20 * time.Second, IdleTimeout: 60 * time.Second, } go func() { if err := srv.ListenAndServe(); err != nil && !errors.Is(err, http.ErrServerClosed) { panic(err) } }() <-rootCtx.Done() drainCtx, cancel := context.WithTimeout(context.Background(), 10*time.Second) defer cancel() _ = srv.Shutdown(drainCtx) pool.wg.Wait() } ```

Architectural Specification & Invariant Rationale

Architectural Invariant Design: Go Chi 5 Structured Context Propagation, Request Budgeting, and Graceful Concurrency Drain

Go Chi 5 Structured Context Propagation, Request Budgeting, and Graceful Concurrency Drain defines an industrial-grade behavioral standard for backend engineering. Enforces strict context cancellation inheritance, timeout budgeting via Chi middleware, and robust worker drain coordination during rolling deployment OS signals. Prevents orphaned goroutines, detached context anti-patterns, and mid-flight connection resets on SIGTERM. Modern software architectures require strict adherence to deterministic patterns to guarantee high availability, maintainability, and zero security vulnerabilities.

Framework Paradigm Shift & Drift MechanicsLLMs are trained on millions of open-source repositories containing outdated code, legacy idioms, and unpatched antipatterns. When coding assistants generate implementations for this stack, they default to common statistical tokens: Detaching context with context.Background() in Chi handlers and uncoordinated goroutine execution during SIGTERM shutdowns Without an explicit system instruction file, developers spend hours debugging silent failures.

Failure Modes & Production Blast Radius

Hazard Analysis: What Breaks Without This Rule

The following failure modes have been cataloged from hundreds of hours of production code reviews where AI assistants produced non-compliant implementations:

Failure Mode	AI Symptom (The Anti-Pattern)	Severity	Production Impact & Remedy
AI Hallucination & Deprecation Drift	Detaching context with context.Background() in Chi handlers and uncoordinated goroutine execution during SIGTERM shutdowns	Critical	Violating this industrial standard introduces regression bugs, security risks, and unexpected runtime failures in production. Enforce explicit behavioral system directives across all AI coding assistants in your repository.
Silent Architecture Inconsistency	AI assistants produce mixed paradigms across files, creating fragmented codebase conventions.	Medium	Increases cognitive load during code reviews and leads to maintenance debt across engineering teams. Pin project conventions in .cursor/rules, CLAUDE.md, and AGENTS.md so all team agents follow identical guardrails.

Architectural Directives in Detail

Step-by-Step Production Directives

Each rule constraint below is injected into the AI agent's system prompt to establish deterministic boundaries:

Engineers MUST ALWAYS propagate `r.Context()` to all downstream operations including database queries, external HTTP/RPC requests, and in-request worker pools.

Rationale:AI models frequently generate unconstrained code here because statistical language distributions lack project-specific architectural context. Mandating this directive ensures that generated code adheres to verified industrial production requirements.