Add support for static labels in queries.yaml (#4)

* add support for static labels in queries.yaml. Fixes #3

* update README.md with the example query and short description

* small renaming fixes proposed by crevil, along with a small correction in the README

* add a description in the design section about static label values

README.md

@@ -65,7 +65,12 @@ queries:
   repo: humio
   interval: 30m
   metric_name: humio_status_sum
+  metric_labels:
+  - key: squad
+    value: nasa
 ```
+As seen in the last example query, you can also specify a set of static labels to be outputtet along with the metric.
+
 Currently the export supports the above aggregate query functions
 
 ```
@@ -111,11 +116,24 @@ The specified queries in the configuration file will be exporter with two labels
 - `repo` - the repository that the query was executed against
 - `interval` - the interval the query result represent.
 
-Here is an example.
+There is an option to add static labels as well. This can be done as follows:
+
+```
+- query: sum(status)
+  repo: humio
+  interval: 30m
+  metric_name: humio_status_sum
+  metric_labels:
+  - key: squad
+    value: nasa
+```
+
+Example.
 
 ```
 humio_total{interval="5m", repo="humio"} 3458
 humio_audit_total{interval="5m", repo="humio-audit"} 2976
+humio_status_sum{interval="30m", repo="humio", squad="nasa"} 235
 ```
 
 # Build

examples/queries.yaml

@@ -38,6 +38,9 @@ queries:
   repo: humio
   interval: 30m
   metric_name: humio_status_sum
+  metric_labels:
+  - key: squad
+    value: nasa
 
 
 

humio.go

@@ -25,7 +25,7 @@ type startQueryPayload struct {
 	IsLive      bool   `json:"isLive"`
 }
 
-func (c *client) startQueryJob(query, repo, metricName, start, end string) (queryJob, error) {
+func (c *client) startQueryJob(query, repo, metricName, start, end string, labels []MetricLabel) (queryJob, error) {
 	postData := startQueryPayload{
 		QueryString: query,
 		Start:       start,
@@ -57,6 +57,7 @@ func (c *client) startQueryJob(query, repo, metricName, start, end string) (quer
 	queryResponse.Timespan = start
 	queryResponse.Repo = repo
 	queryResponse.MetricName = metricName
+	queryResponse.MetricLabels = labels
 
 	return queryResponse, nil
 }

main.go

@@ -18,10 +18,11 @@ import (
 )
 
 type queryJob struct {
-	Id         string
-	Timespan   string
-	Repo       string
-	MetricName string
+	Id           string
+	Timespan     string
+	Repo         string
+	MetricName   string
+	MetricLabels []MetricLabel
 }
 
 type queryJobData struct {
@@ -39,13 +40,19 @@ type MetricMap struct {
 
 type YamlConfig struct {
 	Queries []struct {
-		Query      string `yaml:"query"`
-		Repo       string `yaml:"repo"`
-		Interval   string `yaml:"interval"`
-		MetricName string `yaml:"metric_name"`
+		Query        string        `yaml:"query"`
+		Repo         string        `yaml:"repo"`
+		Interval     string        `yaml:"interval"`
+		MetricName   string        `yaml:"metric_name"`
+		MetricLabels []MetricLabel `yaml:"metric_labels"`
 	} `yaml:"queries"`
 }
 
+type MetricLabel struct {
+	Key   string `yaml:"key"`
+	Value string `yaml:"value"`
+}
+
 var (
 	version            = ""
 	supportedFunctions = []string{"_count", "_min", "_max", "_avg", "_rate", "_range", "_stddev", "_sum"}
@@ -91,7 +98,7 @@ func main() {
 	}
 
 	for _, q := range yamlConfig.Queries {
-		metricMap.AddGauge(q.MetricName, q.Repo, q.Interval)
+		metricMap.AddGauge(q.MetricName, q.MetricLabels)
 	}
 
 	err = metricMap.Register()
@@ -142,7 +149,7 @@ func runAPIPolling(done chan error, url, token string, yamlConfig YamlConfig, re
 	var jobs []queryJob
 
 	for _, q := range yamlConfig.Queries {
-		job, err := client.startQueryJob(q.Query, q.Repo, q.MetricName, q.Interval, "now")
+		job, err := client.startQueryJob(q.Query, q.Repo, q.MetricName, q.Interval, "now", q.MetricLabels)
 		if err != nil {
 			done <- err
 			return
@@ -185,7 +192,7 @@ func runAPIPolling(done chan error, url, token string, yamlConfig YamlConfig, re
 			}
 
 			if poll.Done {
-				metricMap.UpdateMetricValue(job.MetricName, job.Timespan, job.Repo, floatValue)
+				metricMap.UpdateMetricValue(job.MetricName, job.Timespan, job.Repo, floatValue, job.MetricLabels)
 				if err != nil {
 					done <- err
 					return
@@ -212,17 +219,32 @@ func (m *MetricMap) Register() error {
 	return nil
 }
 
-func (m *MetricMap) UpdateMetricValue(metricName, timespan, repo string, value float64) error {
+func (m *MetricMap) UpdateMetricValue(metricName, timespan, repo string, value float64, staticLabels []MetricLabel) error {
+
+	labels := make(map[string]string)
+	labels[intervalLabel] = timespan
+	labels[repoLabel] = repo
+	for _, l := range staticLabels {
+		labels[l.Key] = l.Value
+	}
+
 	gauge := m.Gauges[metricName]
-	gauge.WithLabelValues(timespan, repo).Set(value)
+	gauge.With(labels).Set(value)
 	return nil
 }
 
-func (m *MetricMap) AddGauge(metricName, repo, interval string) error {
+func (m *MetricMap) AddGauge(metricName string, staticLabels []MetricLabel) error {
+	var labelKeys []string
+	labelKeys = append(labelKeys, intervalLabel)
+	labelKeys = append(labelKeys, repoLabel)
+	for _, l := range staticLabels {
+		labelKeys = append(labelKeys, l.Key)
+	}
+
 	m.Gauges[metricName] = prometheus.NewGaugeVec(
 		prometheus.GaugeOpts{
 			Name: metricName,
 			Help: "Gauge for humio query",
-		}, []string{intervalLabel, repoLabel})
+		}, labelKeys)
 	return nil
 }