Add initial HTTP API endpoints

README.md

@@ -171,3 +171,62 @@ Usage of mobius-hotline-server:
 
 To run as a systemd service, refer to this sample unit file: [mobius-hotline-server.service](https://github.com/jhalter/mobius/blob/master/cmd/mobius-hotline-server/mobius-hotline-server.service)
 
+## (Optional) HTTP API
+
+The Mobius server includes an optional HTTP API to perform out-of-band administrative functions.
+
+To enable it, include the `--api-port` flag with a string defining the IP and port to listen on in the form of `<ip>:<port>`.
+
+Example: `--api-port=127.0.0.1:5503`
+
+⚠️ The API has no authentication, so binding it to localhost is a good idea!
+
+#### GET /api/v1/stats
+
+The stats endpoint returns server runtime statistics and counters.
+
+```
+❯ curl -s localhost:5603/api/v1/stats  | jq .
+{
+  "ConnectionCounter": 0,
+  "ConnectionPeak": 0,
+  "CurrentlyConnected": 0,
+  "DownloadCounter": 0,
+  "DownloadsInProgress": 0,
+  "Since": "2024-07-18T15:36:42.426156-07:00",
+  "UploadCounter": 0,
+  "UploadsInProgress": 0,
+  "WaitingDownloads": 0
+}
+```
+
+#### GET /api/v1/reload
+
+The reload endpoint reloads the following configuration files from disk:
+
+* Agreement.txt
+* News.txt
+* Users/*.yaml
+* ThreadedNews.yaml
+* banner.jpg
+
+Example:
+
+```
+❯ curl -s localhost:5603/api/v1/reload | jq .
+{
+  "msg": "config reloaded"
+}
+```
+
+#### POST /api/v1/shutdown
+
+The shutdown endpoint accepts a shutdown message from POST payload, sends it to to all connected Hotline clients, then gracefully shuts down the server.
+
+Example:
+
+```
+❯ curl -d 'Server rebooting' localhost:5603/api/v1/shutdown
+
+{ "msg": "server shutting down" }
+```

cmd/mobius-hotline-server/main.go

@@ -3,7 +3,6 @@ package main
 import (
 	"context"
 	"embed"
-	"encoding/json"
 	"flag"
 	"fmt"
 	"github.com/jhalter/mobius/hotline"
@@ -12,7 +11,6 @@ import (
 	"io"
 	"log"
 	"log/slog"
-	"net/http"
 	"os"
 	"os/signal"
 	"path"
@@ -44,7 +42,7 @@ func main() {
 
 	netInterface := flag.String("interface", "", "IP addr of interface to listen on.  Defaults to all interfaces.")
 	basePort := flag.Int("bind", 5500, "Base Hotline server port.  File transfer port is base port + 1.")
-	statsPort := flag.String("stats-port", "", "Enable stats HTTP endpoint on address and port")
+	apiAddr := flag.String("api-addr", "", "Enable HTTP API endpoint on address and port")
 	configDir := flag.String("config", configSearchPaths(), "Path to config root")
 	printVersion := flag.Bool("version", false, "Print version and exit")
 	logLevel := flag.String("log-level", "info", "Log level")
@@ -161,26 +159,9 @@ func main() {
 		}
 	}
 
-	reloadHandler := func(reloadFunc func()) func(w http.ResponseWriter, _ *http.Request) {
-		return func(w http.ResponseWriter, _ *http.Request) {
-			reloadFunc()
-
-			_, _ = io.WriteString(w, `{ "msg": "config reloaded" }`)
-		}
-	}
-
-	sh := APIHandler{hlServer: srv}
-	if *statsPort != "" {
-		http.HandleFunc("/", sh.RenderStats)
-		http.HandleFunc("/api/v1/stats", sh.RenderStats)
-		http.HandleFunc("/api/v1/reload", reloadHandler(reloadFunc))
-
-		go func(srv *hotline.Server) {
-			err = http.ListenAndServe(":"+*statsPort, nil)
-			if err != nil {
-				log.Fatal(err)
-			}
-		}(srv)
+	if *apiAddr != "" {
+		sh := mobius.NewAPIServer(srv, reloadFunc, slogger)
+		go sh.Serve(*apiAddr)
 	}
 
 	go func() {
@@ -214,19 +195,6 @@ func main() {
 	log.Fatal(srv.ListenAndServe(ctx))
 }
 
-type APIHandler struct {
-	hlServer *hotline.Server
-}
-
-func (sh *APIHandler) RenderStats(w http.ResponseWriter, _ *http.Request) {
-	u, err := json.Marshal(sh.hlServer.CurrentStats())
-	if err != nil {
-		panic(err)
-	}
-
-	_, _ = io.WriteString(w, string(u))
-}
-
 func configSearchPaths() string {
 	for _, cfgPath := range mobius.ConfigSearchOrder {
 		if _, err := os.Stat(cfgPath); err == nil {

hotline/server.go

@@ -13,6 +13,7 @@ import (
 	"log"
 	"log/slog"
 	"net"
+	"os"
 	"strings"
 	"sync"
 	"time"
@@ -586,3 +587,18 @@ func (s *Server) handleFileTransfer(ctx context.Context, rwc io.ReadWriter) erro
 	}
 	return nil
 }
+
+func (s *Server) SendAll(t TranType, fields ...Field) {
+	for _, c := range s.ClientMgr.List() {
+		s.outbox <- NewTransaction(t, c.ID, fields...)
+	}
+}
+
+func (s *Server) Shutdown(msg []byte) {
+	s.Logger.Info("Shutdown signal received")
+	s.SendAll(TranDisconnectMsg, NewField(FieldData, msg))
+
+	time.Sleep(3 * time.Second)
+
+	os.Exit(0)
+}

internal/mobius/api.go

@@ -0,0 +1,96 @@
+package mobius
+
+import (
+	"bytes"
+	"encoding/json"
+	"github.com/jhalter/mobius/hotline"
+	"io"
+	"log"
+	"log/slog"
+	"net/http"
+)
+
+type logResponseWriter struct {
+	http.ResponseWriter
+	statusCode int
+	buf        bytes.Buffer
+}
+
+func NewLogResponseWriter(w http.ResponseWriter) *logResponseWriter {
+	return &logResponseWriter{w, http.StatusOK, bytes.Buffer{}}
+}
+
+func (lrw *logResponseWriter) WriteHeader(code int) {
+	lrw.statusCode = code
+	lrw.ResponseWriter.WriteHeader(code)
+}
+
+func (lrw *logResponseWriter) Write(b []byte) (int, error) {
+	lrw.buf.Write(b)
+	return lrw.ResponseWriter.Write(b)
+}
+
+type APIServer struct {
+	hlServer *hotline.Server
+	logger   *slog.Logger
+	mux      *http.ServeMux
+}
+
+func (srv *APIServer) logMiddleware(next http.Handler) http.Handler {
+	return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+		lrw := NewLogResponseWriter(w)
+		next.ServeHTTP(lrw, r)
+
+		srv.logger.Info("req", "method", r.Method, "url", r.URL.Path, "remoteAddr", r.RemoteAddr, "response_code", lrw.statusCode)
+	})
+}
+
+func NewAPIServer(hlServer *hotline.Server, reloadFunc func(), logger *slog.Logger) *APIServer {
+	srv := APIServer{
+		hlServer: hlServer,
+		logger:   logger,
+		mux:      http.NewServeMux(),
+	}
+
+	srv.mux.Handle("/api/v1/reload", srv.logMiddleware(http.HandlerFunc(srv.ReloadHandler(reloadFunc))))
+	srv.mux.Handle("/api/v1/shutdown", srv.logMiddleware(http.HandlerFunc(srv.ShutdownHandler)))
+	srv.mux.Handle("/api/v1/stats", srv.logMiddleware(http.HandlerFunc(srv.RenderStats)))
+
+	return &srv
+}
+
+func (srv *APIServer) ShutdownHandler(w http.ResponseWriter, r *http.Request) {
+	msg, err := io.ReadAll(r.Body)
+	if err != nil || len(msg) == 0 {
+		w.WriteHeader(http.StatusBadRequest)
+		return
+	}
+
+	go srv.hlServer.Shutdown(msg)
+
+	_, _ = io.WriteString(w, `{ "msg": "server shutting down" }`)
+}
+
+func (srv *APIServer) ReloadHandler(reloadFunc func()) func(w http.ResponseWriter, _ *http.Request) {
+	return func(w http.ResponseWriter, _ *http.Request) {
+		reloadFunc()
+
+		_, _ = io.WriteString(w, `{ "msg": "config reloaded" }`)
+	}
+}
+
+func (srv *APIServer) RenderStats(w http.ResponseWriter, _ *http.Request) {
+	u, err := json.Marshal(srv.hlServer.CurrentStats())
+	if err != nil {
+		panic(err)
+	}
+
+	_, _ = io.WriteString(w, string(u))
+}
+
+func (srv *APIServer) Serve(port string) {
+	err := http.ListenAndServe(port, srv.mux)
+	if err != nil {
+		log.Fatal(err)
+	}
+}