Answer HEAD requests and give 405 a plain message (closes #111)

Every route was registered for GET only, so HEAD answered 405, and on
the JSON routes that 405 said "Internal server error". chi's GetHead
now serves HEAD with the GET handler. The /api/v1 and /ip route groups
answer a path they lack with a JSON 404 "Not found", and another method
with a JSON 405 "Method not allowed" whose Allow header names GET and
HEAD. JSONValidationMiddleware gives a 4xx sent without a JSON body the
status's standard text instead of "Internal server error".

Model: opus-5-5

README.md

@@ -93,10 +93,10 @@ An AS number, prefix or mask length that does not parse answers 400, as does a
 mask length out of range for its IP version. An AS the database does not hold,
 or a prefix with no live route, answers 404. The HTML pages give these errors as
 plain text. Under `/api/v1` and `/ip/`, a path no route matches answers 404 with
-the message `Not found`, and `POST`, `PUT`, `PATCH`, `DELETE`, `OPTIONS`,
-`TRACE` or `CONNECT` answers 405 with `Method not allowed`. A 500 answer says
-only `Internal server error`, and a host name that does not resolve only
-`could not resolve host name`; the detail goes to the log.
+the message `Not found`, and a method other than `GET` and `HEAD` answers 405
+with `Method not allowed`. A 500 answer says only `Internal server error`, and a
+host name that does not resolve only `could not resolve host name`; the detail
+goes to the log.
 
 Every answer carries `Strict-Transport-Security`, `Content-Security-Policy`,
 `X-Frame-Options`, `X-Content-Type-Options`, `Referrer-Policy` and

internal/routewatch/cli.go

@@ -3,8 +3,10 @@ package routewatch
 import (
 	"context"
 	"os"
+	"os/signal"
 	"runtime"
 	"strings"
+	"syscall"
 	"time"
 
 	"git.eeqj.de/sneak/routewatch/internal/logger"
@@ -60,10 +62,10 @@ func logDebugStats(logger *logger.Logger) {
 }
 
 // CLIEntry is the main entry point for the routewatch command-line interface.
-// It initializes the application using the fx dependency injection framework
-// and starts the RouteWatch service. It blocks until fx receives SIGINT or
-// SIGTERM or RouteWatch stops on an error; fx then runs the stop hook and sets
-// the exit code.
+// It initializes the application using the fx dependency injection framework,
+// sets up signal handling for graceful shutdown, and starts the RouteWatch
+// service. This function blocks until the application receives a shutdown
+// signal or encounters a fatal error.
 func CLIEntry() {
 	app := fx.New(
 		fx.Options(getModule()...),
@@ -79,6 +81,20 @@ func CLIEntry() {
 					// Start debug stats logging
 					go logDebugStats(logger)
 
+					// Handle shutdown signals
+					sigCh := make(chan os.Signal, 1)
+					signal.Notify(sigCh, os.Interrupt, syscall.SIGTERM)
+
+					go func() {
+						<-sigCh
+						logger.Info("Received shutdown signal")
+
+						err := shutdowner.Shutdown()
+						if err != nil {
+							logger.Error("Failed to shutdown gracefully", "error", err)
+						}
+					}()
+
 					go func() {
 						err := rw.Run(ctx)
 						if err != nil {