sync: add redis backplane for signalr

Notesnook.API/Notesnook.API.csproj

@@ -17,6 +17,7 @@
     <PackageReference Include="AspNetCore.HealthChecks.MongoDb" Version="6.0.1-rc2.2" />
     <PackageReference Include="AWSSDK.S3" Version="3.7.310.8" />
     <PackageReference Include="Microsoft.AspNetCore.SignalR.Protocols.MessagePack" Version="6.0.3" />
+    <PackageReference Include="Microsoft.AspNetCore.SignalR.StackExchangeRedis" Version="9.0.13" />
     <PackageReference Include="Microsoft.AspNetCore.Server.Kestrel.Https" Version="2.2.0" />
     <PackageReference Include="Nanoid" Version="3.1.0" />
     <PackageReference Include="OpenTelemetry.Exporter.Prometheus.AspNetCore" Version="1.9.0-alpha.2" />

Notesnook.API/Startup.cs

@@ -210,13 +210,16 @@ namespace Notesnook.API
 
             services.AddHealthChecks();
 
-            services.AddSignalR((hub) =>
+            var signalR = services.AddSignalR((hub) =>
             {
                 hub.MaximumReceiveMessageSize = 100 * 1024 * 1024;
                 hub.ClientTimeoutInterval = TimeSpan.FromMinutes(10);
                 hub.EnableDetailedErrors = true;
             }).AddMessagePackProtocol().AddJsonProtocol();
 
+            if (!string.IsNullOrEmpty(Constants.SIGNALR_REDIS_CONNECTION_STRING))
+                signalR.AddStackExchangeRedis(Constants.SIGNALR_REDIS_CONNECTION_STRING);
+
             services.AddResponseCompression(options =>
             {
                 options.EnableForHttps = true;

Streetwriters.Common/Constants.cs

@@ -79,6 +79,7 @@ namespace Streetwriters.Common
         public static string? SUBSCRIPTIONS_CERT_PATH => ReadSecret("SUBSCRIPTIONS_CERT_PATH");
         public static string? SUBSCRIPTIONS_CERT_KEY_PATH => ReadSecret("SUBSCRIPTIONS_CERT_KEY_PATH");
         public static string[] NOTESNOOK_CORS_ORIGINS => ReadSecret("NOTESNOOK_CORS")?.Split(",") ?? [];
+        public static string? SIGNALR_REDIS_CONNECTION_STRING => ReadSecret("SIGNALR_REDIS_CONNECTION_STRING");
 
         public static string? ReadSecret(string name)
         {