nghttp

A lightweight Go library providing utilities for handling HTTP responses and middleware in a consistent manner.

Installation

go get github.com/nickelghost/nghttp

Features

Middleware

Request ID (UseRequestID)

Reads a request ID from an incoming header (e.g. X-Request-ID). If not present, generates a new UUID. Stores the ID in the request context and reflects it back in the response header.

The maxIDLen parameter sets the maximum accepted byte length of an incoming request ID — values exceeding it are replaced with a fresh UUID to guard against log injection. Set it to 0 to disable the limit.

handler = nghttp.UseRequestID(handler, nghttp.DefaultRequestIDHeader, 128)

Request Logging (UseRequestLogging)

Logs each request's method, path, status code, duration, and request ID using log/slog structured logging.

handler = nghttp.UseRequestLogging(handler, nil)

CORS (UseCORS)

Adds Access-Control-Allow-Origin, Access-Control-Allow-Headers, and Access-Control-Allow-Methods headers. Automatically handles OPTIONS preflight requests.

handler = nghttp.UseCORS(
    handler,
    []string{"https://example.com"},
    []string{"Content-Type", "Authorization"},
    []string{"GET", "POST", "PUT", "DELETE"},
    false, // set to true to send Access-Control-Allow-Credentials: true
    nil,
)

Response Helpers

Respond

Encodes any value as JSON and writes it with the given status code. Automatically logs at the appropriate level (Info, Warn, or Error) based on the status code, including the request ID from context. If res is nil, a {"message": "<status text>"} body is sent instead.

nghttp.Respond(w, r, http.StatusOK, nil, myData, nil)

GetNotFoundHandler

Returns an http.HandlerFunc that responds with 404 Not Found using RespondGeneric.

mux.NotFound(nghttp.GetNotFoundHandler(nil))

Utilities

GetRequestID

Retrieves the request ID stored in a context.Context by UseRequestID.

id := nghttp.GetRequestID(r.Context())

Custom Log Arguments

Most functions accept an optional getLogArgs func(ctx context.Context) []any parameter. When provided, the returned key-value pairs are appended to every structured log entry, allowing you to inject per-request fields (e.g. authenticated user ID) from context.

getLogArgs := func(ctx context.Context) []any {
    return []any{"userID", UserIDFromContext(ctx)}
}

handler = nghttp.UseRequestLogging(handler, getLogArgs)

Requirements

• Go 1.24+