sync with prometheus_httpd and use pre18 compat branch

Author: deadtrickster

Diff for: Makefile

@@ -1,9 +1,9 @@
 PROJECT = prometheus_rabbitmq_exporter
 PROJECT_DESCRIPTION = Prometheus.io exporter as a RabbitMQ Managment Plugin plugin
 
-DEPS = rabbitmq_management prometheus prometheus_process_collector prometheus_httpd accept
-dep_prometheus = git https://github.com/deadtrickster/prometheus.erl
-dep_prometheus_process_collector = git https://github.com/deadtrickster/prometheus_process_collector
+DEPS = rabbitmq_management prometheus prometheus_httpd accept #prometheus_process_collector
+dep_prometheus = git https://github.com/deadtrickster/prometheus.erl 3.x-pre18
+#dep_prometheus_process_collector = git https://github.com/deadtrickster/prometheus_process_collector
 dep_prometheus_httpd = git https://github.com/deadtrickster/prometheus-httpd
 dep_accept = git https://github.com/deadtrickster/accept
 

Diff for: src/prometheus_rabbitmq_exporter.erl

@@ -9,7 +9,7 @@ dispatcher() ->
   Path = prometheus_rabbitmq_exporter_config:path(),
   Registry = default,
 
-  prometheus_http:setup(),
+  prometheus_http_impl:setup(),
 
   [{Path, prometheus_rabbitmq_exporter_handler, {Registry}}].
 web_ui()     -> [].

Diff for: src/prometheus_rabbitmq_exporter_handler.erl

@@ -1,5 +1,7 @@
 -module(prometheus_rabbitmq_exporter_handler).
 
+-include_lib("prometheus_httpd/include/prometheus_http.hrl").
+
 -export([init/3,
          handle/2,
          terminate/3]).
@@ -16,10 +18,10 @@ handle(Req, {Registry}) ->
               end,
 
   %% TODO: check method, response only to GET
-  {Code, RespHeaders0, Body} = prometheus_http:reply(#{path => URI,
-                                                       headers => GetHeader,
-                                                       registry => Registry,
-                                                       standalone => false}),
+  {Code, RespHeaders0, Body} = prometheus_http_impl:reply(#request{path = URI,
+                                                              headers = GetHeader,
+                                                              registry = Registry,
+                                                              standalone = false}),
 
   ContentLength = integer_to_list(iolist_size(Body)),
   RespHeaders = lists:map(fun to_cowboy_headers/1,