Colon is not permitted in label names

brian-brazil · brian-brazil · commit 5e9b0b1b4ad4 · 2016-11-03T12:06:01.000Z
diff --git a/prometheus_client/core.py b/prometheus_client/core.py
@@ -24,7 +24,7 @@
 from .decorator import decorate
 
 _METRIC_NAME_RE = re.compile(r'^[a-zA-Z_:][a-zA-Z0-9_:]*$')
-_METRIC_LABEL_NAME_RE = re.compile(r'^[a-zA-Z_:][a-zA-Z0-9_:]*$')
+_METRIC_LABEL_NAME_RE = re.compile(r'^[a-zA-Z_][a-zA-Z0-9_]*$')
 _RESERVED_METRIC_LABEL_NAME_RE = re.compile(r'^__.*$')
 _INF = float("inf")
 _MINUS_INF = float("-inf")
diff --git a/tests/test_core.py b/tests/test_core.py
@@ -299,6 +299,7 @@ def test_invalid_names_raise(self):
         self.assertRaises(ValueError, Counter, '', 'help', namespace='&')
         self.assertRaises(ValueError, Counter, '', 'help', subsystem='(')
         self.assertRaises(ValueError, Counter, 'c', '', labelnames=['^'])
+        self.assertRaises(ValueError, Counter, 'c', '', labelnames=['a:b'])
         self.assertRaises(ValueError, Counter, 'c', '', labelnames=['__reserved'])
         self.assertRaises(ValueError, Summary, 'c', '', labelnames=['quantile'])
 
