Merge pull request #10 from t-huebner/feature/AddVersionInfoToResult

Add version info to metrics

README.md

@@ -25,17 +25,18 @@ services:
 ```
 
 ## Exported Metrics
-| Metric | Description | Labels |
-| ------ | ------- | ------ |
-| mirth_up | Was the last Mirth CLI query successful | |
-| mirth_request_duration | Histogram for the runtime of the metric pull from Mirth | |
-| mirth_channel_status | Status of all deployed channels | channel, status |
-| mirth_messages_received_total | How many messages have been received | channel |
-| mirth_messages_filtered_total  | How many messages have been filtered | channel |
-| mirth_messages_queued | How many messages are currently queued | channel |
-| mirth_messages_sent_total  | How many messages have been sent | channel |
-| mirth_messages_errored_total  | How many messages have errored | channel |
-| mirth_undeployed_revisions  |  How many channel revisions have not been deployed | channel | 
+| Metric                        | Description                                             | Labels          |
+|-------------------------------|---------------------------------------------------------|-----------------|
+| mirth_up                      | Was the last Mirth CLI query successful                 |                 |
+| mirth_info                    | Version information                                     | version         |
+| mirth_request_duration        | Histogram for the runtime of the metric pull from Mirth |                 |
+| mirth_channel_status          | Status of all deployed channels                         | channel, status |
+| mirth_messages_received_total | How many messages have been received                    | channel         |
+| mirth_messages_filtered_total | How many messages have been filtered                    | channel         |
+| mirth_messages_queued         | How many messages are currently queued                  | channel         |
+| mirth_messages_sent_total     | How many messages have been sent                        | channel         |
+| mirth_messages_errored_total  | How many messages have errored                          | channel         |
+| mirth_undeployed_revisions    | How many channel revisions have not been deployed       | channel         | 
 
 ```
 # HELP mirth_channel_status
@@ -81,6 +82,10 @@ mirth_messages_sent_total{channel="bar"} 964
 # TYPE mirth_up gauge
 mirth_up 1
 
+# HELP mirth_info Version information about this Mirth instance.
+# TYPE mirth_info gauge
+mirth_info{version="3.8.1"} 1
+
 # HELP mirth_undeployed_revisions channel.DeployedRevisionDelta of all deployed channels
 # TYPE mirth_undeployed_revisions gauge
 mirth_undeployed_revisions{channel="foo"} 13

metrics.go

@@ -11,6 +11,7 @@ import (
 
 const namespace = "mirth"
 const channelStatusesApi = "/api/channels/statuses"
+const versionApi = "/api/server/version"
 
 var (
 	tr = &http.Transport{
@@ -72,6 +73,11 @@ var (
 		Help:    "Histogram for the runtime of the metric pull from Mirth.",
 		Buckets: prometheus.LinearBuckets(0.1, 0.1, 20),
 	})
+
+	mirthVersion = prometheus.NewDesc(
+		prometheus.BuildFQName(namespace, "", "info"),
+		"Version information about this Mirth instance.", []string{"version"}, nil,
+	)
 )
 
 func (e *Exporter) LoadChannelStatuses() (*ChannelStatusMap, error) {
@@ -109,6 +115,33 @@ func (e *Exporter) LoadChannelStatuses() (*ChannelStatusMap, error) {
 	return &channelStatusMap, nil
 }
 
+func (e *Exporter) GetMirthVersion() string {
+	timer := prometheus.NewTimer(requestDuration)
+	defer timer.ObserveDuration()
+	req, err := http.NewRequest("GET", e.mirthEndpoint+versionApi, nil)
+	const errorString = "error"
+	if err != nil {
+		return errorString
+	}
+
+	req.Header.Add("X-Requested-With", "mirth_channel_exporter")
+	// This one line implements the authentication required for the task.
+	req.SetBasicAuth(e.mirthUsername, e.mirthPassword)
+	// Make request and show output.
+	resp, err := client.Do(req)
+	if err != nil {
+		return errorString
+	}
+
+	body, err := ioutil.ReadAll(resp.Body)
+	var result string = string(body)
+	resp.Body.Close()
+	if err != nil {
+		return errorString
+	}
+	return result
+}
+
 func pickMetric(status string) *prometheus.Desc {
 	switch status {
 	case "RECEIVED":
@@ -186,4 +219,10 @@ func (e *Exporter) Collect(ch chan<- prometheus.Metric) {
 	)
 
 	e.AssembleMetrics(channelIdStatusMap, ch)
+
+	versionString := e.GetMirthVersion()
+	ch <- prometheus.MustNewConstMetric(
+		mirthVersion, prometheus.GaugeValue, 1, versionString,
+	)
+
 }