feat: add prometheus plugin scaffold

2026-01-22 22:05:03 -05:00
commit 01878de01e
13 changed files with 456 additions and 0 deletions
@@ -0,0 +1,49 @@
+package com.prometheus.spigot.http;
+
+import com.prometheus.spigot.metrics.MetricsRegistry;
+import com.sun.net.httpserver.Headers;
+import com.sun.net.httpserver.HttpExchange;
+import com.sun.net.httpserver.HttpHandler;
+import java.io.IOException;
+import java.nio.charset.StandardCharsets;
+
+public final class MetricsHttpHandler implements HttpHandler {
+    private static final String CONTENT_TYPE = "text/plain; version=0.0.4";
+    private static final String AUTH_HEADER = "Authorization";
+    private static final String BEARER_PREFIX = "Bearer ";
+
+    private final MetricsRegistry registry;
+    private final String bearerToken;
+
+    public MetricsHttpHandler(MetricsRegistry registry, String bearerToken) {
+        this.registry = registry;
+        this.bearerToken = bearerToken;
+    }
+
+    @Override
+    public void handle(HttpExchange exchange) throws IOException {
+        if (!isAuthorized(exchange.getRequestHeaders())) {
+            byte[] response = "Unauthorized\n".getBytes(StandardCharsets.UTF_8);
+            exchange.sendResponseHeaders(401, response.length);
+            exchange.getResponseBody().write(response);
+            exchange.close();
+            return;
+        }
+
+        String body = registry.render();
+        byte[] response = body.getBytes(StandardCharsets.UTF_8);
+        exchange.getResponseHeaders().set("Content-Type", CONTENT_TYPE);
+        exchange.sendResponseHeaders(200, response.length);
+        exchange.getResponseBody().write(response);
+        exchange.close();
+    }
+
+    private boolean isAuthorized(Headers headers) {
+        String authHeader = headers.getFirst(AUTH_HEADER);
+        if (authHeader == null || !authHeader.startsWith(BEARER_PREFIX)) {
+            return false;
+        }
+        String token = authHeader.substring(BEARER_PREFIX.length());
+        return token.equals(bearerToken);
+    }
+}