Add: Unix Sockets

Author: AWildLeon

docs/configuration.md

@@ -276,20 +276,30 @@ server:
 When set to `true`, Glance will use the `X-Forwarded-For` header to determine the original IP address of the request, so make sure that your reverse proxy is correctly configured to send that header.
 
 ## Server
-Server configuration is done through a top level `server` property. Example:
+Server configuration is done through a top level `server` property. You can configure the server to listen on either TCP or Unix socket.
 
+TCP example:
 ```yaml
 server:
+  host: localhost
   port: 8080
   assets-path: /home/user/glance-assets
 ```
 
+Unix socket example:
+```yaml
+server:
+  socket-path: /tmp/glance.sock
+  assets-path: /home/user/glance-assets
+```
+
 ### Properties
 
 | Name | Type | Required | Default |
 | ---- | ---- | -------- | ------- |
 | host | string | no |  |
 | port | number | no | 8080 |
+| socket-path | string | no |  |
 | proxied | boolean | no | false |
 | base-url | string | no | |
 | assets-path | string | no |  |
@@ -300,6 +310,17 @@ The address which the server will listen on. Setting it to `localhost` means tha
 #### `port`
 A number between 1 and 65,535, so long as that port isn't already used by anything else.
 
+#### `socket-path`
+Path to a Unix socket file to listen on instead of TCP host:port. When specified, the server will listen on a Unix socket rather than a TCP port. Cannot be used together with `host`. The socket file will be created if it doesn't exist, and any existing file at the path will be removed before creating the socket.
+
+Example:
+```yaml
+server:
+  socket-path: /tmp/glance.sock
+```
+
+This is useful for running behind reverse proxies that support Unix sockets, or in containerized environments where you want to share the socket via a volume mount.
+
 #### `proxied`
 Set to `true` if you're using a reverse proxy in front of Glance. This will make Glance use the `X-Forwarded-*` headers to determine the original request details.
 

internal/glance/config.go

@@ -31,6 +31,7 @@ type config struct {
 	Server struct {
 		Host       string `yaml:"host"`
 		Port       uint16 `yaml:"port"`
+		SocketPath string `yaml:"socket-path"`
 		Proxied    bool   `yaml:"proxied"`
 		AssetsPath string `yaml:"assets-path"`
 		BaseURL    string `yaml:"base-url"`
@@ -483,6 +484,18 @@ func isConfigStateValid(config *config) error {
 		}
 	}
 
+	// Validate server listening configuration
+	hasSocketPath := config.Server.SocketPath != ""
+	hasExplicitHostPort := config.Server.Host != ""
+	
+	if hasSocketPath && hasExplicitHostPort {
+		return fmt.Errorf("cannot specify both socket-path and host when using socket-path")
+	}
+	
+	if !hasSocketPath && !hasExplicitHostPort && config.Server.Port == 0 {
+		return fmt.Errorf("must specify either socket-path or host:port for server")
+	}
+
 	for i := range config.Pages {
 		page := &config.Pages[i]
 

internal/glance/glance.go

@@ -6,7 +6,9 @@ import (
 	"encoding/base64"
 	"fmt"
 	"log"
+	"net"
 	"net/http"
+	"os"
 	"path/filepath"
 	"slices"
 	"strconv"
@@ -489,19 +491,47 @@ func (a *application) server() (func() error, func() error) {
 	}
 
 	server := http.Server{
-		Addr:    fmt.Sprintf("%s:%d", a.Config.Server.Host, a.Config.Server.Port),
 		Handler: mux,
 	}
 
 	start := func() error {
-		log.Printf("Starting server on %s:%d (base-url: \"%s\", assets-path: \"%s\")\n",
-			a.Config.Server.Host,
-			a.Config.Server.Port,
-			a.Config.Server.BaseURL,
-			absAssetsPath,
-		)
-
-		if err := server.ListenAndServe(); err != nil && err != http.ErrServerClosed {
+		var listener net.Listener
+		var err error
+		
+		if a.Config.Server.SocketPath != "" {
+			// Unix socket mode
+			// Remove existing socket file if it exists
+			if err := os.RemoveAll(a.Config.Server.SocketPath); err != nil {
+				return fmt.Errorf("failed to remove existing socket file: %w", err)
+			}
+			
+			listener, err = net.Listen("unix", a.Config.Server.SocketPath)
+			if err != nil {
+				return fmt.Errorf("failed to listen on unix socket: %w", err)
+			}
+			
+			log.Printf("Starting server on unix socket %s (base-url: \"%s\", assets-path: \"%s\")\n",
+				a.Config.Server.SocketPath,
+				a.Config.Server.BaseURL,
+				absAssetsPath,
+			)
+		} else {
+			// TCP mode
+			addr := fmt.Sprintf("%s:%d", a.Config.Server.Host, a.Config.Server.Port)
+			listener, err = net.Listen("tcp", addr)
+			if err != nil {
+				return fmt.Errorf("failed to listen on tcp address: %w", err)
+			}
+			
+			log.Printf("Starting server on %s:%d (base-url: \"%s\", assets-path: \"%s\")\n",
+				a.Config.Server.Host,
+				a.Config.Server.Port,
+				a.Config.Server.BaseURL,
+				absAssetsPath,
+			)
+		}
+
+		if err := server.Serve(listener); err != nil && err != http.ErrServerClosed {
 			return err
 		}