Merge pull request #967 from fabric8io/relabelable-scheme

Make scheme relabelable via discovery

Godeps/_workspace/src/github.com/prometheus/client_golang/model/labelname.go

@@ -29,6 +29,10 @@ const (
 	// timeseries.
 	MetricNameLabel LabelName = "__name__"
 
+	// SchemeLabel is the name of the label that holds the scheme on which to
+	// scrape a target.
+	SchemeLabel LabelName = "__scheme__"
+
 	// AddressLabel is the name of the label that holds the address of
 	// a scrape target.
 	AddressLabel LabelName = "__address__"

retrieval/target.go

@@ -177,7 +177,8 @@ type Target struct {
 func NewTarget(cfg *config.ScrapeConfig, baseLabels, metaLabels clientmodel.LabelSet) *Target {
 	t := &Target{
 		url: &url.URL{
-			Host: string(baseLabels[clientmodel.AddressLabel]),
+			Scheme: string(baseLabels[clientmodel.SchemeLabel]),
+			Host:   string(baseLabels[clientmodel.AddressLabel]),
 		},
 		status:          &TargetStatus{},
 		scraperStopping: make(chan struct{}),
@@ -205,7 +206,7 @@ func (t *Target) Update(cfg *config.ScrapeConfig, baseLabels, metaLabels clientm
 	}
 	t.httpClient = httpClient
 
-	t.url.Scheme = cfg.Scheme
+	t.url.Scheme = string(baseLabels[clientmodel.SchemeLabel])
 	t.url.Path = string(baseLabels[clientmodel.MetricsPathLabel])
 	params := url.Values{}
 	for k, v := range cfg.Params {
@@ -510,6 +511,7 @@ func (t *Target) fullLabels() clientmodel.LabelSet {
 	}
 	lset[clientmodel.MetricsPathLabel] = clientmodel.LabelValue(t.url.Path)
 	lset[clientmodel.AddressLabel] = clientmodel.LabelValue(t.url.Host)
+	lset[clientmodel.SchemeLabel] = clientmodel.LabelValue(t.url.Scheme)
 	return lset
 }
 

retrieval/target_test.go

@@ -426,6 +426,7 @@ func TestURLParams(t *testing.T) {
 			},
 		},
 		clientmodel.LabelSet{
+			clientmodel.SchemeLabel:  clientmodel.LabelValue(serverURL.Scheme),
 			clientmodel.AddressLabel: clientmodel.LabelValue(serverURL.Host),
 			"__param_foo":            "bar",
 		},

retrieval/targetmanager.go

@@ -339,6 +339,7 @@ func (tm *TargetManager) targetsFromGroup(tg *config.TargetGroup, cfg *config.Sc
 		labelsets := []clientmodel.LabelSet{
 			tg.Labels,
 			{
+				clientmodel.SchemeLabel:      clientmodel.LabelValue(cfg.Scheme),
 				clientmodel.MetricsPathLabel: clientmodel.LabelValue(cfg.MetricsPath),
 				clientmodel.JobLabel:         clientmodel.LabelValue(cfg.JobName),
 			},