Merge pull request #12 from martin-helmich/bugfix/fix-label-mixup

Provide stable sorting for label keys+values

config/structs.go

@@ -1,5 +1,9 @@
 package config
 
+import (
+	"sort"
+)
+
 // StartupFlags is a struct containing options that can be passed via the
 // command line
 type StartupFlags struct {
@@ -44,22 +48,26 @@ type NamespaceConfig struct {
 	SourceFiles []string          `hcl:"source_files"`
 	Format      string            `hcl:"format"`
 	Labels      map[string]string `hcl:"labels"`
+
+	OrderedLabelNames  []string
+	OrderedLabelValues []string
 }
 
-// LabelNames exports the names of all known additional labels
-func (c *NamespaceConfig) LabelNames() []string {
+// OrderLabels builds two lists of label keys and values, ordered by label name
+func (c *NamespaceConfig) OrderLabels() {
 	keys := make([]string, 0, len(c.Labels))
+	values := make([]string, len(c.Labels))
+
 	for k := range c.Labels {
 		keys = append(keys, k)
 	}
-	return keys
-}
 
-// LabelValues exports the values of all known additional labels
-func (c *NamespaceConfig) LabelValues() []string {
-	values := make([]string, 0, len(c.Labels))
-	for k := range c.Labels {
-		values = append(values, c.Labels[k])
+	sort.Strings(keys)
+
+	for i, k := range keys {
+		values[i] = c.Labels[k]
 	}
-	return values
+
+	c.OrderedLabelNames = keys
+	c.OrderedLabelValues = values
 }

features/custom_labels.feature

@@ -7,3 +7,16 @@ Feature: Config file allows custom labels
       172.17.0.1 - - [23/Jun/2016:16:04:20 +0000] "GET / HTTP/1.1" 200 612 "-" "curl/7.29.0" "-"
       """
     Then the exporter should report value 1 for metric nginx_http_response_count_total{foo="bar",method="GET",status="200"}
+
+  Scenario: Labels are added correctly for multiple namespaces
+    Given a running exporter listening with configuration file "test-configuration-labels-multi.hcl"
+    When the following HTTP request is logged to "access.log"
+      """
+      172.17.0.1 - - [23/Jun/2016:16:04:20 +0000] "GET / HTTP/1.1" 200 612 "-" "curl/7.29.0" "-"
+      """
+    And the following HTTP request is logged to "access-two.log"
+      """
+      172.17.0.1 - - [23/Jun/2016:16:04:20 +0000] "POST / HTTP/1.1" 500 612 "-" "curl/7.29.0" "-"
+      """
+    Then the exporter should report value 1 for metric testone_http_response_count_total{method="GET",status="200",test1="1-1",test2="1-2"}
+    And the exporter should report value 1 for metric testtwo_http_response_count_total{method="POST",status="500",test1="2-1",test2="2-2"}

features/steps/steps.py

@@ -58,8 +58,13 @@ def step_impl(context, filename):
 
 @then(u'the exporter should report value {val} for metric {metric}')
 def step_impl(context, val, metric):
-    response = requests.get('http://localhost:4040/metrics')
-    text = response.text
+    while True:
+        try:
+            response = requests.get('http://localhost:4040/metrics')
+            text = response.text
+            break
+        except request.ConnectionError:
+            continue
 
     lines = [l.strip("\n") for l in text.split("\n")]
     if not "%s %s" % (metric, val) in lines:

features/test-configuration-labels-multi.hcl

@@ -0,0 +1,49 @@
+port = 4040
+
+namespace "testone" {
+  source_files = [".behave-sandbox/access.log"]
+  format = "$remote_addr - $remote_user [$time_local] \"$request\" $status $body_bytes_sent \"$http_referer\" \"$http_user_agent\" \"$http_x_forwarded_for\""
+  labels {
+    test1 = "1-1"
+    test2 = "1-2"
+  }
+}
+
+namespace "testtwo" {
+  source_files = [".behave-sandbox/access-two.log"]
+  format = "$remote_addr - $remote_user [$time_local] \"$request\" $status $body_bytes_sent \"$http_referer\" \"$http_user_agent\" \"$http_x_forwarded_for\""
+  labels {
+    test1 = "2-1"
+    test2 = "2-2"
+  }
+}
+
+
+namespace "testthree" {
+  source_files = [".behave-sandbox/access-three.log"]
+  format = "$remote_addr - $remote_user [$time_local] \"$request\" $status $body_bytes_sent \"$http_referer\" \"$http_user_agent\" \"$http_x_forwarded_for\""
+  labels {
+    test1 = "3-1"
+    test2 = "3-2"
+  }
+}
+
+
+namespace "testfour" {
+  source_files = [".behave-sandbox/access-four.log"]
+  format = "$remote_addr - $remote_user [$time_local] \"$request\" $status $body_bytes_sent \"$http_referer\" \"$http_user_agent\" \"$http_x_forwarded_for\""
+  labels {
+    test1 = "4-1"
+    test2 = "4-2"
+  }
+}
+
+
+namespace "testfive" {
+  source_files = [".behave-sandbox/access-five.log"]
+  format = "$remote_addr - $remote_user [$time_local] \"$request\" $status $body_bytes_sent \"$http_referer\" \"$http_user_agent\" \"$http_x_forwarded_for\""
+  labels {
+    test1 = "5-1"
+    test2 = "5-2"
+  }
+}

main.go

@@ -43,8 +43,10 @@ type Metrics struct {
 
 // Init initializes a metrics struct
 func (m *Metrics) Init(cfg *config.NamespaceConfig) {
+	cfg.OrderLabels()
+
 	labels := []string{"method", "status"}
-	labels = append(labels, cfg.LabelNames()...)
+	labels = append(labels, cfg.OrderedLabelNames...)
 
 	m.countTotal = prometheus.NewCounterVec(prometheus.CounterOpts{
 		Namespace: cfg.Name,
@@ -145,8 +147,8 @@ func main() {
 					panic(err)
 				}
 
-				go func() {
-					staticLabelValues := nsCfg.LabelValues()
+				go func(nsCfg config.NamespaceConfig) {
+					staticLabelValues := nsCfg.OrderedLabelValues
 					labelValues := make([]string, len(staticLabelValues)+2)
 
 					for i := range staticLabelValues {
@@ -186,7 +188,7 @@ func main() {
 							metrics.responseSeconds.WithLabelValues(labelValues...).Observe(responseTime)
 						}
 					}
-				}()
+				}(nsCfg)
 			}
 		}(ns)
 	}