feat: implement jsz and live jetstream monitoring

src/NATS.Server/Monitoring/JszHandler.cs

@@ -0,0 +1,62 @@
+using System.Text.Json.Serialization;
+
+namespace NATS.Server.Monitoring;
+
+public sealed class JszHandler
+{
+    private readonly NatsServer _server;
+    private readonly NatsOptions _options;
+
+    public JszHandler(NatsServer server, NatsOptions options)
+    {
+        _server = server;
+        _options = options;
+    }
+
+    public JszResponse Build()
+    {
+        return new JszResponse
+        {
+            ServerId = _server.ServerId,
+            Now = DateTime.UtcNow,
+            Enabled = _server.Stats.JetStreamEnabled,
+            Memory = 0,
+            Storage = 0,
+            Streams = _server.JetStreamStreams,
+            Consumers = _server.JetStreamConsumers,
+            Config = new JetStreamConfig
+            {
+                MaxMemory = _options.JetStream?.MaxMemoryStore ?? 0,
+                MaxStorage = _options.JetStream?.MaxFileStore ?? 0,
+                StoreDir = _options.JetStream?.StoreDir ?? string.Empty,
+            },
+        };
+    }
+}
+
+public sealed class JszResponse
+{
+    [JsonPropertyName("server_id")]
+    public string ServerId { get; set; } = string.Empty;
+
+    [JsonPropertyName("now")]
+    public DateTime Now { get; set; }
+
+    [JsonPropertyName("enabled")]
+    public bool Enabled { get; set; }
+
+    [JsonPropertyName("memory")]
+    public ulong Memory { get; set; }
+
+    [JsonPropertyName("storage")]
+    public ulong Storage { get; set; }
+
+    [JsonPropertyName("streams")]
+    public int Streams { get; set; }
+
+    [JsonPropertyName("consumers")]
+    public int Consumers { get; set; }
+
+    [JsonPropertyName("config")]
+    public JetStreamConfig Config { get; set; } = new();
+}