[backend/configuration] Allow connecting to redis unix sockets, document connecting to postgres unix sockets (ISH-76)

Iceshrimp.Backend/Core/Configuration/Config.cs

@@ -33,7 +33,7 @@ public sealed class Config {
 
 		public int     ListenPort     { get; init; } = 3000;
 		public string  ListenHost     { get; init; } = "localhost";
-		public string? ListenSocket   { get; init; } = null;
+		public string? ListenSocket   { get; init; }
 		public string  WebDomain      { get; init; } = null!;
 		public string  AccountDomain  { get; init; } = null!;
 		public int     CharacterLimit { get; init; } = 8192;
@@ -59,6 +59,7 @@ public sealed class Config {
 	public sealed class RedisSection {
 		public string  Host     { get; init; } = "localhost";
 		public int     Port     { get; init; } = 6379;
+		public string? UnixDomainSocket   { get; init; }
 		public string? Prefix   { get; init; }
 		public string? Username { get; init; }
 		public string? Password { get; init; }

Iceshrimp.Backend/Core/Extensions/ServiceExtensions.cs

@@ -1,3 +1,4 @@
+using System.Net.Sockets;
 using System.Threading.RateLimiting;
 using Iceshrimp.Backend.Controllers.Mastodon.Renderers;
 using Iceshrimp.Backend.Controllers.Schemas;
@@ -97,15 +98,19 @@ public static class ServiceExtensions {
 		if (redis == null || instance == null)
 			throw new Exception("Failed to initialize redis: Failed to load configuration");
 		
+
 		var redisOptions = new ConfigurationOptions {
 			User            = redis.Username,
 			Password        = redis.Password,
 			DefaultDatabase = redis.Database,
-			EndPoints = new EndPointCollection {
-				{ redis.Host, redis.Port }
-			}
+			EndPoints = new EndPointCollection()
 		};
 
+		if (redis.UnixDomainSocket != null)
+			redisOptions.EndPoints.Add(new UnixDomainSocketEndPoint(redis.UnixDomainSocket));
+		else
+			redisOptions.EndPoints.Add(redis.Host, redis.Port);
+
 		services.AddSingleton<IConnectionMultiplexer>(_ => ConnectionMultiplexer.Connect(redisOptions));
 
 		services.AddStackExchangeRedisCache(options => {

Iceshrimp.Backend/configuration.ini

@@ -39,6 +39,7 @@ ExposeFederationList = Registered
 ExposeBlockReasons = Registered
 
 [Database]
+;; Hostname, IP address or path to unix socket directory (specifying port is required even for unix sockets)
 Host = localhost
 Port = 5432
 Database = iceshrimp
@@ -53,6 +54,9 @@ Port = 6379
 ;;Password =
 ;;Database = 0
 
+;; If you prefer connecting to your redis instance via a unix socket, uncomment the line below & specify the socket path
+;;UnixDomainSocket =
+
 [Storage]
 ;; Where to store media attachments
 ;; Options: [Local, ObjectStorage]