add prometheus exporter template

data/templates/Makefile.am

@@ -3,7 +3,8 @@ templatesdir = $(pkgdatadir)
 TEMPLATES = \
 	debug.html \
 	default.html \
-	stats.html
+	stats.html \
+	prometheus.html
 
 templates_DATA = \
 	$(TEMPLATES)

data/templates/prometheus.html

@@ -0,0 +1,15 @@
+# HELP opens Number of open connections.
+# TYPE opens Gauge
+opens {opens}
+# HELP reqs Number of requests.
+# TYPE reqs Counter
+reqs {reqs}
+# HELP badconns Number of bad connections.
+# TYPE badconns Counter
+badconns {badconns}
+# HELP deniedconns Number of denied connections.
+# TYPE deniedconns Counter
+deniedconns {deniedconns}
+# HELP refusedconns Number of refused connections due to high load.
+# TYPE refusedconns Counter
+refusedconns {refusedconns}