fix file_sd never stop update 'custom_sd.json' file in adapter.go (#4567)

Signed-off-by: wangyaqiang1 <wangyaqiang1@jd.com>

documentation/examples/custom-sd/adapter/adapter.go

@@ -25,6 +25,7 @@ import (
 
 	"github.com/go-kit/kit/log"
 	"github.com/go-kit/kit/log/level"
+	"github.com/prometheus/common/model"
 	"github.com/prometheus/prometheus/discovery"
 	"github.com/prometheus/prometheus/discovery/targetgroup"
 )
@@ -34,6 +35,15 @@ type customSD struct {
 	Labels  map[string]string `json:"labels"`
 }
 
+func fingerprint(group *targetgroup.Group) model.Fingerprint {
+	groupFingerprint := model.LabelSet{}.Fingerprint()
+	for _, targets := range group.Targets {
+		groupFingerprint ^= targets.Fingerprint()
+	}
+	groupFingerprint ^= group.Labels.Fingerprint()
+	return groupFingerprint
+}
+
 // Adapter runs an unknown service discovery implementation and converts its target groups
 // to JSON and writes to a file for file_sd.
 type Adapter struct {
@@ -57,13 +67,7 @@ func mapToArray(m map[string]*customSD) []customSD {
 func generateTargetGroups(allTargetGroups map[string][]*targetgroup.Group) map[string]*customSD {
 	groups := make(map[string]*customSD)
 	for k, sdTargetGroups := range allTargetGroups {
-		for i, group := range sdTargetGroups {
+		for _, group := range sdTargetGroups {
-
-			// There is no target, so no need to keep it.
-			if len(group.Targets) <= 0 {
-				continue
-			}
-
 			newTargets := make([]string, 0)
 			newLabels := make(map[string]string)
 
@@ -76,12 +80,16 @@ func generateTargetGroups(allTargetGroups map[string][]*targetgroup.Group) map[s
 			for name, value := range group.Labels {
 				newLabels[string(name)] = string(value)
 			}
-			// Make a unique key, including the current index, in case the sd_type (map key) and group.Source is not unique.
+
-			key := fmt.Sprintf("%s:%s:%d", k, group.Source, i)
+			sdGroup := customSD{
-			groups[key] = &customSD{
+
 				Targets: newTargets,
 				Labels:  newLabels,
 			}
+			// Make a unique key, including group's fingerprint, in case the sd_type (map key) and group.Source is not unique.
+			groupFingerprint := fingerprint(group)
+			key := fmt.Sprintf("%s:%s:%s", k, group.Source, groupFingerprint.String())
+			groups[key] = &sdGroup
 		}
 	}
 

documentation/examples/custom-sd/adapter/adapter_test.go

@@ -41,7 +41,16 @@ func TestGenerateTargetGroups(t *testing.T) {
 					},
 				},
 			},
-			expectedCustomSD: map[string]*customSD{},
+			expectedCustomSD: map[string]*customSD{
+				"customSD:Consul:0000000000000000": {
+					Targets: []string{},
+					Labels:  map[string]string{},
+				},
+				"customSD:Kubernetes:0000000000000000": {
+					Targets: []string{},
+					Labels:  map[string]string{},
+				},
+			},
 		},
 		{
 			title: "targetGroup filled",
@@ -78,7 +87,7 @@ func TestGenerateTargetGroups(t *testing.T) {
 				},
 			},
 			expectedCustomSD: map[string]*customSD{
-				"customSD:Azure:0": {
+				"customSD:Azure:282a007a18fadbbb": {
 					Targets: []string{
 						"host1",
 						"host2",
@@ -87,7 +96,7 @@ func TestGenerateTargetGroups(t *testing.T) {
 						"__meta_test_label": "label_test_1",
 					},
 				},
-				"customSD:Openshift:1": {
+				"customSD:Openshift:281c007a18ea2ad0": {
 					Targets: []string{
 						"host3",
 						"host4",
@@ -125,7 +134,7 @@ func TestGenerateTargetGroups(t *testing.T) {
 				},
 			},
 			expectedCustomSD: map[string]*customSD{
-				"customSD:GCE:0": {
+				"customSD:GCE:282a007a18fadbbb": {
 					Targets: []string{
 						"host1",
 						"host2",
@@ -134,6 +143,12 @@ func TestGenerateTargetGroups(t *testing.T) {
 						"__meta_test_label": "label_test_1",
 					},
 				},
+				"customSD:Kubernetes:282e007a18fad483": {
+					Targets: []string{},
+					Labels: map[string]string{
+						"__meta_test_label": "label_test_2",
+					},
+				},
 			},
 		},
 	}