Add the first beginnings of Prometheus metrics.

[nageru] / httpd.cpp

diff --git a/httpd.cpp b/httpd.cpp
index 858d9522c9354f1ea275cd0e859e5fef60d30636..4d5966b18e6ee0bdc9ed21f66ca98129690fbf48 100644 (file)
--- a/httpd.cpp
+++ b/httpd.cpp
@@ -13,6 +13,7 @@
 
 #include "defs.h"
 #include "metacube2.h"
+#include "metrics.h"
 
 struct MHD_Connection;
 struct MHD_Response;
@@ -85,14 +86,23 @@ int HTTPD::answer_to_connection(MHD_Connection *connection,
        }
        *con_cls = stream;
 
-       // Does not strictly have to be equal to MUX_BUFFER_SIZE.
-       MHD_Response *response = MHD_create_response_from_callback(
-               (size_t)-1, MUX_BUFFER_SIZE, &HTTPD::Stream::reader_callback_thunk, stream, &HTTPD::free_stream);
+       MHD_Response *response;
 
-       // TODO: Content-type?
-       if (framing == HTTPD::Stream::FRAMING_METACUBE) {
-               MHD_add_response_header(response, "Content-encoding", "metacube");
+       if (strcmp(url, "/metrics") == 0) {
+               string contents = global_metrics.serialize();
+               response = MHD_create_response_from_buffer(
+                       contents.size(), &contents[0], MHD_RESPMEM_MUST_COPY);
+               MHD_add_response_header(response, "Content-type", "text/plain");
+       } else {
+               // Does not strictly have to be equal to MUX_BUFFER_SIZE.
+               response = MHD_create_response_from_callback(
+                       (size_t)-1, MUX_BUFFER_SIZE, &HTTPD::Stream::reader_callback_thunk, stream, &HTTPD::free_stream);
+               // TODO: Content-type?
+               if (framing == HTTPD::Stream::FRAMING_METACUBE) {
+                       MHD_add_response_header(response, "Content-encoding", "metacube");
+               }
        }
+
        int ret = MHD_queue_response(connection, MHD_HTTP_OK, response);
        MHD_destroy_response(response);  // Only decreases the refcount; actual free is after the request is done.