add plugin hosts to seperate plugins from gloomi

This adds a plugin host that seperates plugins from the gloomi process,
allowing for plugins to be unloaded and loaded. This commit also has a
fair amount of other changes, nice to haves and bug fixes, some notable
changes are:
- Highly available reverse proxy from my Flux project
- Improved gloomi functionality

pluginHost/main.go

@@ -0,0 +1,145 @@
+package main
+
+import (
+	"fmt"
+	"io"
+	"log"
+	"net"
+	"os"
+	"os/signal"
+	"path/filepath"
+	"plugin"
+
+	"github.com/gofiber/fiber/v3"
+)
+
+var pluginPath string
+var socketPath string
+var controlPath string
+
+func init() {
+	if len(os.Args) < 3 {
+		fmt.Fprintf(os.Stderr, "Usage: pluginHost <pluginPath> <socketPath>")
+		os.Exit(1)
+	}
+
+	pluginPath = os.Args[1]
+	socketPath = os.Args[2]
+	if len(os.Args) > 3 {
+		controlPath = os.Args[3]
+	}
+}
+
+type Plugin interface {
+	Init() (*fiber.Config, error)
+	RegisterRoutes(app fiber.Router)
+	// Name() string
+}
+
+type PluginInstance struct {
+	Plugin Plugin
+	Name   string
+	Path   string
+	Router *fiber.App
+}
+
+// Init is the entry point for a container process
+func (p *PluginInstance) Run(pluginName string) {
+	log.Printf("Starting container with plugin %s", pluginName)
+	// Load and initialize the plugin here
+}
+
+func main() {
+	signalChan := make(chan os.Signal, 1)
+	signal.Notify(signalChan, os.Interrupt)
+
+	go func() {
+		<-signalChan
+		// TODO: maybe do something graceful here
+		fmt.Println("Received SIGINT, shutting down...")
+		os.Exit(0)
+	}()
+
+	var writer io.Writer
+	writer = os.Stderr
+	if controlPath != "" {
+		fmt.Printf("Waiting for control connection on %s\n", controlPath)
+
+		controlListener, err := net.Listen("unix", controlPath)
+		if err != nil {
+			log.Fatalf("Error listening on control socket: %v", err)
+		}
+		defer controlListener.Close()
+
+		conn, err := controlListener.Accept()
+		if err != nil {
+			log.Printf("Error accepting control connection: %v", err)
+			return
+		}
+		defer conn.Close()
+
+		var ok bool
+		writer, ok = conn.(io.Writer)
+		if !ok {
+			log.Printf("Control connection is not a writer")
+			return
+		}
+	}
+
+	if _, err := os.Stat(socketPath); err == nil {
+		fmt.Fprintf(writer, "Error: Socket %s already exists\n", socketPath)
+		os.Exit(1)
+	}
+
+	realPluginPath, err := filepath.Abs(pluginPath)
+	if err != nil {
+		fmt.Fprintf(writer, "Error: could not get absolute plugin path: %v\n", err)
+		os.Exit(1)
+	}
+
+	p, err := plugin.Open(realPluginPath)
+	if err != nil {
+		fmt.Fprintf(writer, "Error: could not open plugin %s: %v\n", realPluginPath, err)
+		os.Exit(1)
+	}
+
+	symbol, err := p.Lookup("Plugin")
+	if err != nil {
+		fmt.Fprintf(writer, "Error: could not find 'Plugin' symbol in %s: %v\n", realPluginPath, err)
+		os.Exit(1)
+	}
+
+	pluginLib, ok := symbol.(Plugin)
+	if !ok {
+		fmt.Fprintf(writer, "Error: symbol 'Plugin' in %s is not a Plugin interface\n", realPluginPath)
+		os.Exit(1)
+	}
+
+	pluginConfig, err := pluginLib.Init()
+	if err != nil {
+		fmt.Fprintf(writer, "Error: error initializing plugin %s: %v\n", realPluginPath, err)
+		os.Exit(1)
+	}
+
+	config := fiber.Config{}
+	if pluginConfig != nil {
+		config = *pluginConfig
+	}
+	router := fiber.New(config)
+
+	pluginLib.RegisterRoutes(router)
+
+	// listen for connections on the socket
+	listener, err := net.Listen("unix", socketPath)
+	if err != nil {
+		fmt.Fprintf(writer, "Error: error listening on socket %s: %v\n", socketPath, err)
+		os.Exit(1)
+	}
+
+	fmt.Fprintf(writer, "ready\n")
+
+	// technically this can still error
+	router.Listener(listener, fiber.ListenConfig{
+		DisableStartupMessage: true,
+	})
+}