From edba6ff5b851b3fee3d45a51a43b0d96a353383e Mon Sep 17 00:00:00 2001
From: Xu Dongyan <dongyanxu@189.cn>
Date: Tue, 15 Aug 2023 23:49:36 +0800
Subject: [PATCH] merge const labels of all probers

---
 conf/conf.go             |  4 +++-
 conf/constlables.go      | 37 +++++++++++++++++++++++++++++++++++++
 conf/constlables_test.go | 35 +++++++++++++++++++++++++++++++++++
 probe/base/base.go       |  8 ++++++++
 probe/probe.go           |  3 +++
 5 files changed, 86 insertions(+), 1 deletion(-)
 create mode 100644 conf/constlables.go
 create mode 100644 conf/constlables_test.go

diff --git a/conf/conf.go b/conf/conf.go
index 6d810d4f..ce9d57b8 100644
--- a/conf/conf.go
+++ b/conf/conf.go
@@ -436,7 +436,9 @@ func isProbe(t reflect.Type) bool {
 // AllProbers return all probers
 func (conf *Conf) AllProbers() []probe.Prober {
 	log.Debugf("--------- Process the probers settings ---------")
-	return allProbersHelper(*conf)
+	all := allProbersHelper(*conf)
+	MergeConstLabels(all)
+	return all
 }
 
 func allProbersHelper(i interface{}) []probe.Prober {
diff --git a/conf/constlables.go b/conf/constlables.go
new file mode 100644
index 00000000..3365d97f
--- /dev/null
+++ b/conf/constlables.go
@@ -0,0 +1,37 @@
+package conf
+
+import (
+	"github.com/megaease/easeprobe/metric"
+	"github.com/megaease/easeprobe/probe"
+)
+
+var constLabels = make(map[string]bool)
+
+// MergeConstLabels merge const labels from all probers.
+// Prometheus requires all metric  of the same name have the same set of labels in a collector
+func MergeConstLabels(ps []probe.Prober) {
+	for _, p := range ps {
+		for _, k := range p.Label() {
+			constLabels[k.Name] = true
+		}
+	}
+
+	for _, p := range ps {
+		buildConstLabels(p)
+	}
+}
+func buildConstLabels(p probe.Prober) {
+	ls := p.Label()
+LA:
+	for k, _ := range constLabels {
+		for _, l := range ls {
+			if k == l.Name {
+				continue LA
+			}
+		}
+
+		ls = append(ls, metric.Label{Name: k, Value: ""})
+	}
+
+	p.SetLabel(ls)
+}
diff --git a/conf/constlables_test.go b/conf/constlables_test.go
new file mode 100644
index 00000000..e517ca61
--- /dev/null
+++ b/conf/constlables_test.go
@@ -0,0 +1,35 @@
+package conf
+
+import (
+	"github.com/megaease/easeprobe/metric"
+	"github.com/megaease/easeprobe/probe"
+	"github.com/megaease/easeprobe/probe/base"
+	"github.com/megaease/easeprobe/probe/http"
+	"github.com/megaease/easeprobe/probe/tcp"
+	"github.com/stretchr/testify/assert"
+	"testing"
+)
+
+func TestMergeConstLabels(t *testing.T) {
+
+	ps := []probe.Prober{
+		&http.HTTP{
+			DefaultProbe: base.DefaultProbe{
+				Labels: []metric.Label{{"service", "service_a"}},
+			},
+		},
+		&tcp.TCP{
+			DefaultProbe: base.DefaultProbe{
+				Labels: []metric.Label{{"host", "host_b"}},
+			},
+		},
+	}
+
+	MergeConstLabels(ps)
+
+	assert.Equal(t, "service_a", ps[0].Label()[0].Value)
+	assert.Equal(t, "host_b", ps[0].Label()[1].Value)
+
+	assert.Equal(t, "host_a", ps[1].Label()[0].Value)
+	assert.Equal(t, "service_b", ps[1].Label()[1].Value)
+}
diff --git a/probe/base/base.go b/probe/base/base.go
index 307df8a3..1a14ad1a 100644
--- a/probe/base/base.go
+++ b/probe/base/base.go
@@ -60,6 +60,14 @@ type DefaultProbe struct {
 	metrics                              *metrics      `yaml:"-" json:"-"`
 }
 
+func (d *DefaultProbe) Label() []metric.Label {
+	return d.Labels
+}
+
+func (d *DefaultProbe) SetLabel(allLabels []metric.Label) {
+	d.Labels = allLabels
+}
+
 // Kind return the probe kind
 func (d *DefaultProbe) Kind() string {
 	return d.ProbeKind
diff --git a/probe/probe.go b/probe/probe.go
index 5db1f4c8..86344ffb 100644
--- a/probe/probe.go
+++ b/probe/probe.go
@@ -22,10 +22,13 @@ import (
 	"time"
 
 	"github.com/megaease/easeprobe/global"
+	"github.com/megaease/easeprobe/metric"
 )
 
 // Prober Interface
 type Prober interface {
+	Label() []metric.Label
+	SetLabel([]metric.Label)
 	Kind() string
 	Name() string
 	Channels() []string