Add HTTP GET function

The function performs a HTTP GET on a URL and returns the HTTP response.

include/maxscale/utils.hh

@@ -22,12 +22,14 @@
 #include <array>
 #include <functional>
 #include <iterator>
+#include <memory>
 #include <string>
 #include <unordered_map>
 #include <vector>
 
 #include <maxscale/buffer.h>
 #include <maxscale/utils.h>
+#include <maxscale/jansson.hh>
 
 namespace maxscale
 {
@@ -645,4 +647,26 @@ uint64_t get_byteN(const uint8_t* ptr, int bytes);
  */
 uint8_t* set_byteN(uint8_t* ptr, uint64_t value, int bytes);
 
+namespace http
+{
+
+struct Result
+{
+    int code; // HTTP response code
+    std::string raw_body; // Raw response body
+    std::unique_ptr<json_t> body; // JSON form of the body if it was valid JSON
+    std::unordered_map<std::string, std::string> headers; // Headers attached to the response
+};
+
+/**
+ * Do a HTTP GET
+ *
+ * @param url     URL to use
+ *
+ * @return A Result
+ */
+Result get(const std::string& url);
+
+}
+
 }