Multiple prometheus services support

* Prometheus export test
* Version bump to 1.5

Makefile

@@ -1,4 +1,4 @@
-VERSION=1.4
+VERSION=1.5
 
 
 .PHONY: all

README.md

@@ -137,6 +137,8 @@ Let's check this:
 
 If you set port to *-* lobby daemon omits port entirely from the output.
 
+There can be multiple `host` labels but only one `port` label and all prometheus labels (last line) will be common for all hosts labels. If port is omitted then default 9100 is used or port can also be part of the host label.
+
 When you open URL http://localhost:1313/v1/prometheus/nodeexporter it returns this:
 
 ```json

daemon/prometheus.go

@@ -34,10 +34,10 @@ func preparePrometheusOutput(name string, discoveries []server.Discovery) Promet
 
 	for _, discovery := range discoveries {
 		port := strconv.Itoa(int(config.NodeExporterPort))
-		host := discovery.Hostname
+		hosts := []string{}
 		var add bool // add to the prometheus output when there is at least one prometheus related label
 
-		labels := map[string]string{}
+		labels := map[string]string{} // These are prometheus labels, not Lobby's labels
 
 		for _, label := range discovery.FindLabelsByPrefix("prometheus:" + name + ":") {
 			trimmed := strings.TrimPrefix(label.String(), "prometheus:"+name+":")
@@ -46,7 +46,7 @@ func preparePrometheusOutput(name string, discoveries []server.Discovery) Promet
 				if parts[0] == "port" {
 					port = parts[1]
 				} else if parts[0] == "host" {
-					host = parts[1]
+					hosts = append(hosts, parts[1])
 				} else {
 					labels[parts[0]] = parts[1]
 				}
@@ -65,20 +65,23 @@ func preparePrometheusOutput(name string, discoveries []server.Discovery) Promet
 		}
 
 		if add {
-			// Omit port part if "-" is set
+			targets := []string{}
+			for _, host := range hosts {
+				// Omit port part if "-" is set or port is part of the host
 				target := host + ":" + port
-			if port == "-" {
+				if strings.Contains(host, ":") || port == "-" {
 					target = host
 				}
+				targets = append(targets, target)
 
+			}
 			service := PrometheusService{
-				Targets: []string{target},
+				Targets: targets,
 				Labels:  labels,
 			}
 
 			services = append(services, service)
 		}
-
 	}
 
 	return services

daemon/prometheus_test.go

@@ -0,0 +1,47 @@
+package main
+
+import (
+	"testing"
+
+	"github.com/by-cx/lobby/server"
+	"github.com/stretchr/testify/assert"
+)
+
+func TestPreparePrometheusOutput(t *testing.T) {
+	discoveries := []server.Discovery{
+		{
+			Hostname: "test.server",
+			Labels: server.Labels{
+				// test1
+				"prometheus:test1:label1:l1",
+				"prometheus:test1:host:srv1:1234",
+				"prometheus:test1:host:srv1:1235",
+				"prometheus:test1:host:srv1",
+				"prometheus:test1:label2:l2",
+				// test2
+				"prometheus:test2:host:srv2",
+				"prometheus:test2:host:srv2:1235",
+				"prometheus:test2:host:srv2:1236",
+				"prometheus:test2:host:srv2:1237",
+				"prometheus:test2:label1:l3",
+			},
+		},
+	}
+	services := preparePrometheusOutput("test1", discoveries)
+	assert.Equal(t, 1, len(services))
+	assert.Equal(t, 3, len(services[0].Targets))
+	assert.Contains(t, services[0].Targets, "srv1:9100")
+	assert.Contains(t, services[0].Targets, "srv1:1234")
+	assert.Contains(t, services[0].Targets, "srv1:1235")
+	assert.Contains(t, services[0].Labels["label1"], "l1")
+	assert.Contains(t, services[0].Labels["label2"], "l2")
+
+	services = preparePrometheusOutput("test2", discoveries)
+	assert.Equal(t, 1, len(services))
+	assert.Equal(t, 4, len(services[0].Targets))
+	assert.Contains(t, services[0].Targets, "srv2:9100")
+	assert.Contains(t, services[0].Targets, "srv2:1235")
+	assert.Contains(t, services[0].Targets, "srv2:1236")
+	assert.Contains(t, services[0].Targets, "srv2:1237")
+	assert.Contains(t, services[0].Labels["label1"], "l3")
+}