better handling of openmetrics mtype

DNSLG/Formatter.py

@@ -415,7 +415,8 @@ class JsonFormatter(Formatter):
 
 
 from prometheus_client.core import InfoMetricFamily, GaugeMetricFamily
-from prometheus_client import CollectorRegistry, generate_latest
+from prometheus_client import CollectorRegistry
+from prometheus_client.openmetrics.exposition import generate_latest
 
 class OpenMetricsFormatter(Formatter):
     class DnsLgCollector(object):

DNSLG/__init__.py

@@ -131,7 +131,7 @@ Disallow: /
         if not format:
             mformat = req.accept.best_match(['text/html', 'application/xml',
                                             'application/json', 'text/dns',
-                                            'text/plain', 'application/openmetrics-text'])
+                                            'text/plain', 'application/openmetrics-text;version=0.0.1'])
             if mformat == "text/html":
                 format = "HTML"
             elif mformat == "application/xml":
@@ -142,7 +142,7 @@ Disallow: /
                 format = "ZONE"
             elif mformat == "text/plain":
                 format = "TEXT"
-            elif mformat == 'application/openmetrics-text':
+            elif mformat == 'application/openmetrics-text;version=0.0.1':
                 format = 'OPENMETRICS'
             if not mformat:
                 output = "No suitable output format found\n"
@@ -163,7 +163,7 @@ Disallow: /
             elif format == "XML":
                 mtype = 'application/xml'
             elif format == 'OPENMETRICS':
-                mtype = 'text/plain; charset=%s' % self.encoding
+                mtype = 'application/openmetrics-text; version=0.0.1; charset=%s' % self.encoding
             else:
                 output = "Unsupported format \"%s\"\n" % format
                 send_response(start_response, '400 Bad request', output, plaintype)