lib/promscrape: initial implementation for gce_sd_configs aga Prometheus-compatible service discovery for Google Compute Engine

README.md

@@ -260,6 +260,7 @@ Currently the following [scrape_config](https://prometheus.io/docs/prometheus/la
 * [static_config](https://prometheus.io/docs/prometheus/latest/configuration/configuration/#static_config)
 * [file_sd_config](https://prometheus.io/docs/prometheus/latest/configuration/configuration/#file_sd_config)
 * [kubernetes_sd_config](https://prometheus.io/docs/prometheus/latest/configuration/configuration/#kubernetes_sd_config)
+* [gce_sd_config](https://prometheus.io/docs/prometheus/latest/configuration/configuration/#gce_sd_config)
 
 In the future other `*_sd_config` types will be supported.
 

app/vmagent/README.md

@@ -133,11 +133,12 @@ The following scrape types in [scrape_config](https://prometheus.io/docs/prometh
   See [these docs](https://prometheus.io/docs/prometheus/latest/configuration/configuration/#file_sd_config) for details.
 * `kubernetes_sd_configs` - for scraping targets in Kubernetes (k8s).
   See [kubernetes_sd_config](https://prometheus.io/docs/prometheus/latest/configuration/configuration/#kubernetes_sd_config) for details.
+* `gce_sd_configs` - for scraping targets in Google Compute Engine (GCE).
+  See [gce_sd_config](https://prometheus.io/docs/prometheus/latest/configuration/configuration/#gce_sd_config) for details.
 
 The following service discovery mechanisms will be added to `vmagent` soon:
 
 * [ec2_sd_config](https://prometheus.io/docs/prometheus/latest/configuration/configuration/#ec2_sd_config)
-* [gce_sd_config](https://prometheus.io/docs/prometheus/latest/configuration/configuration/#gce_sd_config)
 * [consul_sd_config](https://prometheus.io/docs/prometheus/latest/configuration/configuration/#consul_sd_config)
 * [dns_sd_config](https://prometheus.io/docs/prometheus/latest/configuration/configuration/#dns_sd_config)
 

docs/Single-server-VictoriaMetrics.md

@@ -260,6 +260,7 @@ Currently the following [scrape_config](https://prometheus.io/docs/prometheus/la
 * [static_config](https://prometheus.io/docs/prometheus/latest/configuration/configuration/#static_config)
 * [file_sd_config](https://prometheus.io/docs/prometheus/latest/configuration/configuration/#file_sd_config)
 * [kubernetes_sd_config](https://prometheus.io/docs/prometheus/latest/configuration/configuration/#kubernetes_sd_config)
+* [gce_sd_config](https://prometheus.io/docs/prometheus/latest/configuration/configuration/#gce_sd_config)
 
 In the future other `*_sd_config` types will be supported.
 

docs/vmagent.md

@@ -133,11 +133,12 @@ The following scrape types in [scrape_config](https://prometheus.io/docs/prometh
   See [these docs](https://prometheus.io/docs/prometheus/latest/configuration/configuration/#file_sd_config) for details.
 * `kubernetes_sd_configs` - for scraping targets in Kubernetes (k8s).
   See [kubernetes_sd_config](https://prometheus.io/docs/prometheus/latest/configuration/configuration/#kubernetes_sd_config) for details.
+* `gce_sd_configs` - for scraping targets in Google Compute Engine (GCE).
+  See [gce_sd_config](https://prometheus.io/docs/prometheus/latest/configuration/configuration/#gce_sd_config) for details.
 
 The following service discovery mechanisms will be added to `vmagent` soon:
 
 * [ec2_sd_config](https://prometheus.io/docs/prometheus/latest/configuration/configuration/#ec2_sd_config)
-* [gce_sd_config](https://prometheus.io/docs/prometheus/latest/configuration/configuration/#gce_sd_config)
 * [consul_sd_config](https://prometheus.io/docs/prometheus/latest/configuration/configuration/#consul_sd_config)
 * [dns_sd_config](https://prometheus.io/docs/prometheus/latest/configuration/configuration/#dns_sd_config)
 

go.mod

@@ -17,6 +17,7 @@ require (
 	github.com/valyala/histogram v1.0.1
 	github.com/valyala/quicktemplate v1.4.1
 	golang.org/x/net v0.0.0-20200421231249-e086a090c8fd // indirect
+	golang.org/x/oauth2 v0.0.0-20200107190931-bf48bf16ab8d
 	golang.org/x/sys v0.0.0-20200420163511-1957bb5e6d1f
 	golang.org/x/tools v0.0.0-20200423205358-59e73619c742 // indirect
 	google.golang.org/api v0.22.0

lib/promscrape/config.go

@@ -14,6 +14,7 @@ import (
 	"github.com/VictoriaMetrics/VictoriaMetrics/lib/promauth"
 	"github.com/VictoriaMetrics/VictoriaMetrics/lib/prompbmarshal"
 	"github.com/VictoriaMetrics/VictoriaMetrics/lib/promrelabel"
+	"github.com/VictoriaMetrics/VictoriaMetrics/lib/promscrape/discovery/gce"
 	"github.com/VictoriaMetrics/VictoriaMetrics/lib/promscrape/discovery/kubernetes"
 	"gopkg.in/yaml.v2"
 )
@@ -60,6 +61,7 @@ type ScrapeConfig struct {
 	StaticConfigs        []StaticConfig              `yaml:"static_configs"`
 	FileSDConfigs        []FileSDConfig              `yaml:"file_sd_configs"`
 	KubernetesSDConfigs  []kubernetes.SDConfig       `yaml:"kubernetes_sd_configs"`
+	GCESDConfigs         []gce.SDConfig              `yaml:"gce_sd_configs"`
 	RelabelConfigs       []promrelabel.RelabelConfig `yaml:"relabel_configs"`
 	MetricRelabelConfigs []promrelabel.RelabelConfig `yaml:"metric_relabel_configs"`
 	SampleLimit          int                         `yaml:"sample_limit"`
@@ -147,6 +149,14 @@ func (cfg *Config) kubernetesSDConfigsCount() int {
 	return n
 }
 
+func (cfg *Config) gceSDConfigsCount() int {
+	n := 0
+	for i := range cfg.ScrapeConfigs {
+		n += len(cfg.ScrapeConfigs[i].GCESDConfigs)
+	}
+	return n
+}
+
 func (cfg *Config) fileSDConfigsCount() int {
 	n := 0
 	for i := range cfg.ScrapeConfigs {
@@ -168,6 +178,19 @@ func (cfg *Config) getKubernetesSDScrapeWork() []ScrapeWork {
 	return dst
 }
 
+// getGCESDScrapeWork returns `gce_sd_configs` ScrapeWork from cfg.
+func (cfg *Config) getGCESDScrapeWork() []ScrapeWork {
+	var dst []ScrapeWork
+	for i := range cfg.ScrapeConfigs {
+		sc := &cfg.ScrapeConfigs[i]
+		for j := range sc.GCESDConfigs {
+			sdc := &sc.GCESDConfigs[j]
+			dst = appendGCEScrapeWork(dst, sdc, sc.swc)
+		}
+	}
+	return dst
+}
+
 // getFileSDScrapeWork returns `file_sd_configs` ScrapeWork from cfg.
 func (cfg *Config) getFileSDScrapeWork(prev []ScrapeWork) []ScrapeWork {
 	// Create a map for the previous scrape work.
@@ -297,13 +320,25 @@ func appendKubernetesScrapeWork(dst []ScrapeWork, sdc *kubernetes.SDConfig, base
 		logger.Errorf("error when discovering kubernetes nodes for `job_name` %q: %s; skipping it", swc.jobName, err)
 		return dst
 	}
+	return appendScrapeWorkForTargetLabels(dst, swc, targetLabels, "kubernetes_sd_config")
+}
+
+func appendGCEScrapeWork(dst []ScrapeWork, sdc *gce.SDConfig, swc *scrapeWorkConfig) []ScrapeWork {
+	targetLabels, err := gce.GetLabels(sdc)
+	if err != nil {
+		logger.Errorf("error when discovering gce nodes for `job_name` %q: %s; skippint it", swc.jobName, err)
+		return dst
+	}
+	return appendScrapeWorkForTargetLabels(dst, swc, targetLabels, "gce_sd_config")
+}
+
+func appendScrapeWorkForTargetLabels(dst []ScrapeWork, swc *scrapeWorkConfig, targetLabels []map[string]string, sectionName string) []ScrapeWork {
 	for _, metaLabels := range targetLabels {
 		target := metaLabels["__address__"]
 		var err error
 		dst, err = appendScrapeWork(dst, swc, target, nil, metaLabels)
 		if err != nil {
-			logger.Errorf("error when parsing `kubernetes_sd_config` target %q with role %q for `job_name` %q: %s; skipping it",
+			logger.Errorf("error when parsing `%s` target %q for `job_name` %q: %s; skipping it", sectionName, target, swc.jobName, err)
-				target, sdc.Role, swc.jobName, err)
 			continue
 		}
 	}

lib/promscrape/discovery/gce/api.go

@@ -0,0 +1,97 @@
+package gce
+
+import (
+	"context"
+	"fmt"
+	"net/http"
+	"net/url"
+	"sync"
+	"time"
+
+	"golang.org/x/oauth2/google"
+)
+
+type apiConfig struct {
+	client       *http.Client
+	apiURL       string
+	project      string
+	tagSeparator string
+	port         int
+}
+
+func getAPIConfig(sdc *SDConfig) (*apiConfig, error) {
+	apiConfigMapLock.Lock()
+	defer apiConfigMapLock.Unlock()
+
+	if !hasAPIConfigMapCleaner {
+		hasAPIConfigMapCleaner = true
+		go apiConfigMapCleaner()
+	}
+
+	e := apiConfigMap[sdc]
+	if e != nil {
+		e.lastAccessTime = time.Now()
+		return e.cfg, nil
+	}
+	cfg, err := newAPIConfig(sdc)
+	if err != nil {
+		return nil, err
+	}
+	apiConfigMap[sdc] = &apiConfigMapEntry{
+		cfg:            cfg,
+		lastAccessTime: time.Now(),
+	}
+	return cfg, nil
+}
+
+func apiConfigMapCleaner() {
+	tc := time.NewTicker(15 * time.Minute)
+	for currentTime := range tc.C {
+		apiConfigMapLock.Lock()
+		for k, e := range apiConfigMap {
+			if currentTime.Sub(e.lastAccessTime) > 10*time.Minute {
+				delete(apiConfigMap, k)
+			}
+		}
+		apiConfigMapLock.Unlock()
+	}
+}
+
+type apiConfigMapEntry struct {
+	cfg            *apiConfig
+	lastAccessTime time.Time
+}
+
+var (
+	apiConfigMap           = make(map[*SDConfig]*apiConfigMapEntry)
+	apiConfigMapLock       sync.Mutex
+	hasAPIConfigMapCleaner bool
+)
+
+func newAPIConfig(sdc *SDConfig) (*apiConfig, error) {
+	ctx := context.Background()
+	client, err := google.DefaultClient(ctx, "https://www.googleapis.com/auth/compute.readonly")
+	if err != nil {
+		return nil, fmt.Errorf("cannot create oauth2 client for gce: %s", err)
+	}
+	// See https://cloud.google.com/compute/docs/reference/rest/v1/instances/list
+	apiURL := fmt.Sprintf("https://compute.googleapis.com/compute/v1/projects/%s/zones/%s/instances", sdc.Project, sdc.Zone)
+	if len(sdc.Filter) > 0 {
+		apiURL += fmt.Sprintf("?filter=%s", url.QueryEscape(sdc.Filter))
+	}
+	tagSeparator := ","
+	if sdc.TagSeparator != nil {
+		tagSeparator = *sdc.TagSeparator
+	}
+	port := 80
+	if sdc.Port != nil {
+		port = *sdc.Port
+	}
+	return &apiConfig{
+		client:       client,
+		apiURL:       apiURL,
+		project:      sdc.Project,
+		tagSeparator: tagSeparator,
+		port:         port,
+	}, nil
+}

lib/promscrape/discovery/gce/gce.go

@@ -0,0 +1,31 @@
+package gce
+
+import (
+	"fmt"
+)
+
+// SDConfig represents service discovery config for gce.
+//
+// See https://prometheus.io/docs/prometheus/latest/configuration/configuration/#gce_sd_config
+type SDConfig struct {
+	Project string `yaml:"project"`
+	Zone    string `yaml:"zone"`
+	Filter  string `yaml:"filter"`
+	// RefreshInterval time.Duration `yaml:"refresh_interval"`
+	// refresh_interval is obtained from `-promscrape.gceSDCheckInterval` command-line option.
+	Port         *int    `yaml:"port"`
+	TagSeparator *string `yaml:"tag_separator"`
+}
+
+// GetLabels returns gce labels according to sdc.
+func GetLabels(sdc *SDConfig) ([]map[string]string, error) {
+	cfg, err := getAPIConfig(sdc)
+	if err != nil {
+		return nil, fmt.Errorf("cannot get API config: %s", err)
+	}
+	ms, err := getInstancesLabels(cfg)
+	if err != nil {
+		return nil, fmt.Errorf("error when fetching instances data from GCE: %s", err)
+	}
+	return ms, nil
+}

lib/promscrape/discovery/gce/instance.go

@@ -0,0 +1,170 @@
+package gce
+
+import (
+	"encoding/json"
+	"fmt"
+	"io/ioutil"
+	"net/http"
+	"net/url"
+	"strings"
+
+	"github.com/VictoriaMetrics/VictoriaMetrics/lib/promscrape/discoveryutils"
+)
+
+// getInstancesLabels returns labels for gce instances obtained from the given cfg
+func getInstancesLabels(cfg *apiConfig) ([]map[string]string, error) {
+	insts, err := getInstances(cfg)
+	if err != nil {
+		return nil, err
+	}
+	var ms []map[string]string
+	for _, inst := range insts {
+		ms = inst.appendTargetLabels(ms, cfg.project, cfg.tagSeparator, cfg.port)
+	}
+	return ms, nil
+}
+
+func getInstances(cfg *apiConfig) ([]Instance, error) {
+	var result []Instance
+	pageToken := ""
+	for {
+		insts, nextPageToken, err := getInstancesPage(cfg, pageToken)
+		if err != nil {
+			return nil, err
+		}
+		result = append(result, insts...)
+		if len(nextPageToken) == 0 {
+			return result, nil
+		}
+		pageToken = nextPageToken
+	}
+}
+
+func getInstancesPage(cfg *apiConfig, pageToken string) ([]Instance, string, error) {
+	apiURL := cfg.apiURL
+	if len(pageToken) > 0 {
+		// See https://cloud.google.com/compute/docs/reference/rest/v1/instances/list about pageToken
+		prefix := "?"
+		if strings.Contains(apiURL, "?") {
+			prefix = "&"
+		}
+		apiURL += fmt.Sprintf("%spageToken=%s", prefix, url.QueryEscape(pageToken))
+	}
+	resp, err := cfg.client.Get(apiURL)
+	if err != nil {
+		return nil, "", fmt.Errorf("cannot obtain instances data from API server: %s", err)
+	}
+	defer resp.Body.Close()
+	data, err := ioutil.ReadAll(resp.Body)
+	if err != nil {
+		return nil, "", fmt.Errorf("cannot read instances data from API server: %s", err)
+	}
+	if resp.StatusCode != http.StatusOK {
+		return nil, "", fmt.Errorf("unexpected status code when reading instances data from API server; got %d; want %d; response body: %q",
+			resp.StatusCode, http.StatusOK, data)
+	}
+	il, err := parseInstanceList(data)
+	if err != nil {
+		return nil, "", fmt.Errorf("cannot parse instances response from API server: %s", err)
+	}
+	return il.Items, il.NextPageToken, nil
+}
+
+// InstanceList is response to https://cloud.google.com/compute/docs/reference/rest/v1/instances/list
+type InstanceList struct {
+	Items         []Instance
+	NextPageToken string
+}
+
+// Instance is instance from https://cloud.google.com/compute/docs/reference/rest/v1/instances/list
+type Instance struct {
+	ID                string `json:"id"`
+	Name              string
+	Status            string
+	MachineType       string
+	Zone              string
+	NetworkInterfaces []NetworkInterface
+	Tags              TagList
+	Metadata          MetadataList
+	Labels            discoveryutils.SortedLabels
+}
+
+// NetworkInterface is network interface from https://cloud.google.com/compute/docs/reference/rest/v1/instances/list
+type NetworkInterface struct {
+	Network       string
+	Subnetwork    string
+	NetworkIP     string
+	AccessConfigs []AccessConfig
+}
+
+// AccessConfig is access config from https://cloud.google.com/compute/docs/reference/rest/v1/instances/list
+type AccessConfig struct {
+	Type  string
+	NatIP string
+}
+
+// TagList is tag list from https://cloud.google.com/compute/docs/reference/rest/v1/instances/list
+type TagList struct {
+	Items []string
+}
+
+// MetadataList is metadataList from https://cloud.google.com/compute/docs/reference/rest/v1/instances/list
+type MetadataList struct {
+	Items []MetadataEntry
+}
+
+// MetadataEntry is a single entry from metadata
+type MetadataEntry struct {
+	Key   string
+	Value string
+}
+
+// parseInstanceList parses InstanceList from data.
+func parseInstanceList(data []byte) (*InstanceList, error) {
+	var il InstanceList
+	if err := json.Unmarshal(data, &il); err != nil {
+		return nil, fmt.Errorf("cannot unmarshal InstanceList from %q: %s", data, err)
+	}
+	return &il, nil
+}
+
+func (inst *Instance) appendTargetLabels(ms []map[string]string, project, tagSeparator string, port int) []map[string]string {
+	if len(inst.NetworkInterfaces) == 0 {
+		return ms
+	}
+	iface := inst.NetworkInterfaces[0]
+	addr := discoveryutils.JoinHostPort(iface.NetworkIP, port)
+	m := map[string]string{
+		"__address__":                addr,
+		"__meta_gce_instance_id":     inst.ID,
+		"__meta_gce_instance_status": inst.Status,
+		"__meta_gce_instance_name":   inst.Name,
+		"__meta_gce_machine_type":    inst.MachineType,
+		"__meta_gce_network":         iface.Network,
+		"__meta_gce_private_ip":      iface.NetworkIP,
+		"__meta_gce_project":         project,
+		"__meta_gce_subnetwork":      iface.Subnetwork,
+		"__meta_gce_zone":            inst.Zone,
+	}
+	if len(inst.Tags.Items) > 0 {
+		// We surround the separated list with the separator as well. This way regular expressions
+		// in relabeling rules don't have to consider tag positions.
+		m["__meta_gce_tags"] = tagSeparator + strings.Join(inst.Tags.Items, tagSeparator) + tagSeparator
+	}
+	for _, item := range inst.Metadata.Items {
+		key := discoveryutils.SanitizeLabelName(item.Key)
+		m["__meta_gce_metadata_"+key] = item.Value
+	}
+	for _, label := range inst.Labels {
+		name := discoveryutils.SanitizeLabelName(label.Name)
+		m["__meta_gce_label_"+name] = label.Value
+	}
+	if len(iface.AccessConfigs) > 0 {
+		ac := iface.AccessConfigs[0]
+		if ac.Type == "ONE_TO_ONE_NAT" {
+			m["__meta_gce_public_ip"] = ac.NatIP
+		}
+	}
+	ms = append(ms, m)
+	return ms
+}

lib/promscrape/discovery/gce/instance_test.go

@@ -0,0 +1,179 @@
+package gce
+
+import (
+	"reflect"
+	"testing"
+
+	"github.com/VictoriaMetrics/VictoriaMetrics/lib/prompbmarshal"
+	"github.com/VictoriaMetrics/VictoriaMetrics/lib/promscrape/discoveryutils"
+)
+
+func TestParseInstanceListFailure(t *testing.T) {
+	f := func(s string) {
+		t.Helper()
+		il, err := parseInstanceList([]byte(s))
+		if err == nil {
+			t.Fatalf("expecting non-nil error")
+		}
+		if il != nil {
+			t.Fatalf("unexpected non-nil InstanceList: %v", il)
+		}
+	}
+	f(``)
+	f(`[1,23]`)
+	f(`{"items":[{"metadata":1}]}`)
+}
+
+func TestParseInstanceListSuccess(t *testing.T) {
+	data := `
+{
+  "id": "projects/victoriametrics-test/zones/us-east1-b/instances",
+  "items": [
+    {
+      "id": "7897352091592122",
+      "creationTimestamp": "2020-02-16T07:10:14.357-08:00",
+      "name": "play-1m-1-vmagent",
+      "tags": {
+        "items": [
+          "play",
+          "play-1m-1",
+          "vmagent"
+        ],
+        "fingerprint": "O44NvJ36CCo="
+      },
+      "machineType": "https://www.googleapis.com/compute/v1/projects/victoriametrics-test/zones/us-east1-b/machineTypes/f1-micro",
+      "status": "RUNNING",
+      "zone": "https://www.googleapis.com/compute/v1/projects/victoriametrics-test/zones/us-east1-b",
+      "networkInterfaces": [
+        {
+          "network": "https://www.googleapis.com/compute/v1/projects/victoriametrics-test/global/networks/default",
+          "subnetwork": "https://www.googleapis.com/compute/v1/projects/victoriametrics-test/regions/us-east1/subnetworks/play-1m-1-snw",
+          "networkIP": "10.11.2.7",
+          "name": "nic0",
+          "fingerprint": "O4eNOfaplJ4=",
+          "kind": "compute#networkInterface"
+        }
+      ],
+      "disks": [
+        {
+          "type": "PERSISTENT",
+          "mode": "READ_WRITE",
+          "source": "https://www.googleapis.com/compute/v1/projects/victoriametrics-test/zones/us-east1-b/disks/play-1m-1-vmagent",
+          "deviceName": "boot",
+          "index": 0,
+          "boot": true,
+          "autoDelete": true,
+          "licenses": [
+            "https://www.googleapis.com/compute/v1/projects/cos-cloud-shielded/global/licenses/shielded-cos",
+            "https://www.googleapis.com/compute/v1/projects/cos-cloud/global/licenses/cos",
+            "https://www.googleapis.com/compute/v1/projects/cos-cloud/global/licenses/cos-pcid"
+          ],
+          "interface": "SCSI",
+          "guestOsFeatures": [
+            {
+              "type": "VIRTIO_SCSI_MULTIQUEUE"
+            },
+            {
+              "type": "UEFI_COMPATIBLE"
+            }
+          ],
+          "diskSizeGb": "10",
+          "kind": "compute#attachedDisk"
+        }
+      ],
+      "metadata": {
+        "fingerprint": "BAFZwTyaAxQ=",
+        "items": [
+          {
+            "key": "gce-container-declaration",
+            "value": "foobar"
+	  }
+        ],
+        "kind": "compute#metadata"
+      },
+      "serviceAccounts": [
+        {
+          "email": "12-compute@developer.gserviceaccount.com",
+          "scopes": [
+            "https://www.googleapis.com/auth/devstorage.read_write",
+            "https://www.googleapis.com/auth/logging.write",
+            "https://www.googleapis.com/auth/monitoring.write",
+            "https://www.googleapis.com/auth/servicecontrol",
+            "https://www.googleapis.com/auth/service.management.readonly"
+          ]
+        }
+      ],
+      "selfLink": "https://www.googleapis.com/compute/v1/projects/victoriametrics-test/zones/us-east1-b/instances/play-1m-1-vmagent",
+      "scheduling": {
+        "onHostMaintenance": "MIGRATE",
+        "automaticRestart": true,
+        "preemptible": false
+      },
+      "cpuPlatform": "Intel Haswell",
+      "labels": {
+        "goog-dm": "play-deployment",
+        "cluster_num": "1",
+        "cluster_retention": "1m",
+        "env": "play",
+        "type": "vmagent"
+      },
+      "labelFingerprint": "-CXeRXMQiVc=",
+      "startRestricted": false,
+      "deletionProtection": false,
+      "shieldedInstanceConfig": {
+        "enableSecureBoot": false,
+        "enableVtpm": true,
+        "enableIntegrityMonitoring": true
+      },
+      "shieldedInstanceIntegrityPolicy": {
+        "updateAutoLearnPolicy": true
+      },
+      "fingerprint": "hd3NB2-9QIg=",
+      "kind": "compute#instance"
+    }
+  ]
+}
+`
+	il, err := parseInstanceList([]byte(data))
+	if err != nil {
+		t.Fatalf("unexpected error: %s", err)
+	}
+	if len(il.Items) != 1 {
+		t.Fatalf("unexpected length of InstanceList.Items; got %d; want %d", len(il.Items), 1)
+	}
+	inst := il.Items[0]
+
+	// Check inst.appendTargetLabels()
+	project := "proj-1"
+	tagSeparator := ","
+	port := 80
+	labelss := inst.appendTargetLabels(nil, project, tagSeparator, port)
+	var sortedLabelss [][]prompbmarshal.Label
+	for _, labels := range labelss {
+		sortedLabelss = append(sortedLabelss, discoveryutils.GetSortedLabels(labels))
+	}
+	expectedLabelss := [][]prompbmarshal.Label{
+		discoveryutils.GetSortedLabels(map[string]string{
+			"__address__":                                   "10.11.2.7:80",
+			"__meta_gce_instance_id":                        "7897352091592122",
+			"__meta_gce_instance_name":                      "play-1m-1-vmagent",
+			"__meta_gce_instance_status":                    "RUNNING",
+			"__meta_gce_label_cluster_num":                  "1",
+			"__meta_gce_label_cluster_retention":            "1m",
+			"__meta_gce_label_env":                          "play",
+			"__meta_gce_label_goog_dm":                      "play-deployment",
+			"__meta_gce_label_type":                         "vmagent",
+			"__meta_gce_machine_type":                       "https://www.googleapis.com/compute/v1/projects/victoriametrics-test/zones/us-east1-b/machineTypes/f1-micro",
+			"__meta_gce_metadata_gce_container_declaration": "foobar",
+			"__meta_gce_network":                            "https://www.googleapis.com/compute/v1/projects/victoriametrics-test/global/networks/default",
+			"__meta_gce_private_ip":                         "10.11.2.7",
+			"__meta_gce_project":                            "proj-1",
+			"__meta_gce_subnetwork":                         "https://www.googleapis.com/compute/v1/projects/victoriametrics-test/regions/us-east1/subnetworks/play-1m-1-snw",
+			"__meta_gce_tags":                               ",play,play-1m-1,vmagent,",
+			"__meta_gce_zone":                               "https://www.googleapis.com/compute/v1/projects/victoriametrics-test/zones/us-east1-b",
+		}),
+	}
+	if !reflect.DeepEqual(sortedLabelss, expectedLabelss) {
+		t.Fatalf("unexpected labels:\ngot\n%v\nwant\n%v", sortedLabelss, expectedLabelss)
+	}
+}

lib/promscrape/discovery/kubernetes/common_types.go

@@ -1,13 +1,10 @@
 package kubernetes
 
 import (
-	"encoding/json"
 	"fmt"
 	"net/url"
-	"sort"
 	"strings"
 
-	"github.com/VictoriaMetrics/VictoriaMetrics/lib/prompbmarshal"
 	"github.com/VictoriaMetrics/VictoriaMetrics/lib/promscrape/discoveryutils"
 )
 
@@ -18,8 +15,8 @@ type ObjectMeta struct {
 	Name            string
 	Namespace       string
 	UID             string
-	Labels          SortedLabels
+	Labels          discoveryutils.SortedLabels
-	Annotations     SortedLabels
+	Annotations     discoveryutils.SortedLabels
 	OwnerReferences []OwnerReference
 }
 
@@ -36,33 +33,6 @@ func (om *ObjectMeta) registerLabelsAndAnnotations(prefix string, m map[string]s
 	}
 }
 
-// SortedLabels represents sorted labels.
-type SortedLabels []prompbmarshal.Label
-
-// UnmarshalJSON unmarshals JSON from data.
-func (sls *SortedLabels) UnmarshalJSON(data []byte) error {
-	var m map[string]string
-	if err := json.Unmarshal(data, &m); err != nil {
-		return err
-	}
-	*sls = getSortedLabels(m)
-	return nil
-}
-
-func getSortedLabels(m map[string]string) SortedLabels {
-	a := make([]prompbmarshal.Label, 0, len(m))
-	for k, v := range m {
-		a = append(a, prompbmarshal.Label{
-			Name:  k,
-			Value: v,
-		})
-	}
-	sort.Slice(a, func(i, j int) bool {
-		return a[i].Name < a[j].Name
-	})
-	return a
-}
-
 // OwnerReference represents OwnerReferense from k8s API.
 //
 // See https://kubernetes.io/docs/reference/generated/kubernetes-api/v1.17/#ownerreference-v1-meta

lib/promscrape/discovery/kubernetes/endpoints_test.go

@@ -5,6 +5,7 @@ import (
 	"testing"
 
 	"github.com/VictoriaMetrics/VictoriaMetrics/lib/prompbmarshal"
+	"github.com/VictoriaMetrics/VictoriaMetrics/lib/promscrape/discoveryutils"
 )
 
 func TestParseEndpointsListFailure(t *testing.T) {
@@ -85,10 +86,10 @@ func TestParseEndpointsListSuccess(t *testing.T) {
 	labelss := endpoint.appendTargetLabels(nil, nil, nil)
 	var sortedLabelss [][]prompbmarshal.Label
 	for _, labels := range labelss {
-		sortedLabelss = append(sortedLabelss, getSortedLabels(labels))
+		sortedLabelss = append(sortedLabelss, discoveryutils.GetSortedLabels(labels))
 	}
 	expectedLabelss := [][]prompbmarshal.Label{
-		getSortedLabels(map[string]string{
+		discoveryutils.GetSortedLabels(map[string]string{
 			"__address__": "172.17.0.2:8443",
 			"__meta_kubernetes_endpoint_address_target_kind": "Pod",
 			"__meta_kubernetes_endpoint_address_target_name": "coredns-6955765f44-lnp6t",

lib/promscrape/discovery/kubernetes/ingress_test.go

@@ -5,6 +5,7 @@ import (
 	"testing"
 
 	"github.com/VictoriaMetrics/VictoriaMetrics/lib/prompbmarshal"
+	"github.com/VictoriaMetrics/VictoriaMetrics/lib/promscrape/discoveryutils"
 )
 
 func TestParseIngressListFailure(t *testing.T) {
@@ -83,10 +84,10 @@ func TestParseIngressListSuccess(t *testing.T) {
 	labelss := ig.appendTargetLabels(nil)
 	var sortedLabelss [][]prompbmarshal.Label
 	for _, labels := range labelss {
-		sortedLabelss = append(sortedLabelss, getSortedLabels(labels))
+		sortedLabelss = append(sortedLabelss, discoveryutils.GetSortedLabels(labels))
 	}
 	expectedLabelss := [][]prompbmarshal.Label{
-		getSortedLabels(map[string]string{
+		discoveryutils.GetSortedLabels(map[string]string{
 			"__address__": "foobar",
 			"__meta_kubernetes_ingress_annotation_kubectl_kubernetes_io_last_applied_configuration":        `{"apiVersion":"networking.k8s.io/v1beta1","kind":"Ingress","metadata":{"annotations":{},"name":"test-ingress","namespace":"default"},"spec":{"backend":{"serviceName":"testsvc","servicePort":80}}}` + "\n",
 			"__meta_kubernetes_ingress_annotationpresent_kubectl_kubernetes_io_last_applied_configuration": "true",

lib/promscrape/discovery/kubernetes/kubernetes.go

@@ -6,30 +6,6 @@ import (
 	"github.com/VictoriaMetrics/VictoriaMetrics/lib/promauth"
 )
 
-// GetLabels returns labels for the given k8s role and the given cfg.
-func GetLabels(ac *promauth.Config, sdc *SDConfig) ([]map[string]string, error) {
-	cfg := &apiConfig{
-		Server:     sdc.APIServer,
-		AuthConfig: ac,
-		Namespaces: sdc.Namespaces.Names,
-		Selectors:  sdc.Selectors,
-	}
-	switch sdc.Role {
-	case "node":
-		return getNodesLabels(cfg)
-	case "service":
-		return getServicesLabels(cfg)
-	case "pod":
-		return getPodsLabels(cfg)
-	case "endpoints":
-		return getEndpointsLabels(cfg)
-	case "ingress":
-		return getIngressesLabels(cfg)
-	default:
-		return nil, fmt.Errorf("unexpected `role`: %q; must be one of `node`, `service`, `pod`, `endpoints` or `ingress`; skipping it", sdc.Role)
-	}
-}
-
 // SDConfig represents kubernetes-based service discovery config.
 //
 // See https://prometheus.io/docs/prometheus/latest/configuration/configuration/#kubernetes_sd_config
@@ -58,3 +34,27 @@ type Selector struct {
 	Label string `yaml:"label"`
 	Field string `yaml:"field"`
 }
+
+// GetLabels returns labels for the given k8s role and the given ac and sdc.
+func GetLabels(ac *promauth.Config, sdc *SDConfig) ([]map[string]string, error) {
+	cfg := &apiConfig{
+		Server:     sdc.APIServer,
+		AuthConfig: ac,
+		Namespaces: sdc.Namespaces.Names,
+		Selectors:  sdc.Selectors,
+	}
+	switch sdc.Role {
+	case "node":
+		return getNodesLabels(cfg)
+	case "service":
+		return getServicesLabels(cfg)
+	case "pod":
+		return getPodsLabels(cfg)
+	case "endpoints":
+		return getEndpointsLabels(cfg)
+	case "ingress":
+		return getIngressesLabels(cfg)
+	default:
+		return nil, fmt.Errorf("unexpected `role`: %q; must be one of `node`, `service`, `pod`, `endpoints` or `ingress`; skipping it", sdc.Role)
+	}
+}

lib/promscrape/discovery/kubernetes/node_test.go

@@ -3,6 +3,8 @@ package kubernetes
 import (
 	"reflect"
 	"testing"
+
+	"github.com/VictoriaMetrics/VictoriaMetrics/lib/promscrape/discoveryutils"
 )
 
 func TestParseNodeListFailure(t *testing.T) {
@@ -236,7 +238,7 @@ func TestParseNodeListSuccess(t *testing.T) {
 	if meta.Name != "m01" {
 		t.Fatalf("unexpected ObjectMeta.Name; got %q; want %q", meta.Name, "m01")
 	}
-	expectedLabels := getSortedLabels(map[string]string{
+	expectedLabels := discoveryutils.GetSortedLabels(map[string]string{
 		"beta.kubernetes.io/arch":        "amd64",
 		"beta.kubernetes.io/os":          "linux",
 		"kubernetes.io/arch":             "amd64",
@@ -251,7 +253,7 @@ func TestParseNodeListSuccess(t *testing.T) {
 	if !reflect.DeepEqual(meta.Labels, expectedLabels) {
 		t.Fatalf("unexpected ObjectMeta.Labels\ngot\n%v\nwant\n%v", meta.Labels, expectedLabels)
 	}
-	expectedAnnotations := getSortedLabels(map[string]string{
+	expectedAnnotations := discoveryutils.GetSortedLabels(map[string]string{
 		"kubeadm.alpha.kubernetes.io/cri-socket":                 "/var/run/dockershim.sock",
 		"node.alpha.kubernetes.io/ttl":                           "0",
 		"volumes.kubernetes.io/controller-managed-attach-detach": "true",
@@ -275,8 +277,8 @@ func TestParseNodeListSuccess(t *testing.T) {
 	}
 
 	// Check node.appendTargetLabels()
-	labels := getSortedLabels(node.appendTargetLabels(nil)[0])
+	labels := discoveryutils.GetSortedLabels(node.appendTargetLabels(nil)[0])
-	expectedLabels = getSortedLabels(map[string]string{
+	expectedLabels = discoveryutils.GetSortedLabels(map[string]string{
 		"instance":                    "m01",
 		"__address__":                 "172.17.0.2:10250",
 		"__meta_kubernetes_node_name": "m01",

lib/promscrape/discovery/kubernetes/pod_test.go

@@ -5,6 +5,7 @@ import (
 	"testing"
 
 	"github.com/VictoriaMetrics/VictoriaMetrics/lib/prompbmarshal"
+	"github.com/VictoriaMetrics/VictoriaMetrics/lib/promscrape/discoveryutils"
 )
 
 func TestParsePodListFailure(t *testing.T) {
@@ -240,10 +241,10 @@ func TestParsePodListSuccess(t *testing.T) {
 	labelss := pod.appendTargetLabels(nil)
 	var sortedLabelss [][]prompbmarshal.Label
 	for _, labels := range labelss {
-		sortedLabelss = append(sortedLabelss, getSortedLabels(labels))
+		sortedLabelss = append(sortedLabelss, discoveryutils.GetSortedLabels(labels))
 	}
 	expectedLabels := [][]prompbmarshal.Label{
-		getSortedLabels(map[string]string{
+		discoveryutils.GetSortedLabels(map[string]string{
 			"__address__": "172.17.0.2:1234",
 
 			"__meta_kubernetes_namespace":                   "kube-system",

lib/promscrape/discovery/kubernetes/service_test.go

@@ -5,6 +5,7 @@ import (
 	"testing"
 
 	"github.com/VictoriaMetrics/VictoriaMetrics/lib/prompbmarshal"
+	"github.com/VictoriaMetrics/VictoriaMetrics/lib/promscrape/discoveryutils"
 )
 
 func TestParseServiceListFailure(t *testing.T) {
@@ -100,7 +101,7 @@ func TestParseServiceListSuccess(t *testing.T) {
 	if meta.Name != "kube-dns" {
 		t.Fatalf("unexpected ObjectMeta.Name; got %q; want %q", meta.Name, "kube-dns")
 	}
-	expectedLabels := getSortedLabels(map[string]string{
+	expectedLabels := discoveryutils.GetSortedLabels(map[string]string{
 		"k8s-app":                       "kube-dns",
 		"kubernetes.io/cluster-service": "true",
 		"kubernetes.io/name":            "KubeDNS",
@@ -108,7 +109,7 @@ func TestParseServiceListSuccess(t *testing.T) {
 	if !reflect.DeepEqual(meta.Labels, expectedLabels) {
 		t.Fatalf("unexpected ObjectMeta.Labels\ngot\n%v\nwant\n%v", meta.Labels, expectedLabels)
 	}
-	expectedAnnotations := getSortedLabels(map[string]string{
+	expectedAnnotations := discoveryutils.GetSortedLabels(map[string]string{
 		"prometheus.io/port":   "9153",
 		"prometheus.io/scrape": "true",
 	})
@@ -148,10 +149,10 @@ func TestParseServiceListSuccess(t *testing.T) {
 	labelss := service.appendTargetLabels(nil)
 	var sortedLabelss [][]prompbmarshal.Label
 	for _, labels := range labelss {
-		sortedLabelss = append(sortedLabelss, getSortedLabels(labels))
+		sortedLabelss = append(sortedLabelss, discoveryutils.GetSortedLabels(labels))
 	}
 	expectedLabelss := [][]prompbmarshal.Label{
-		getSortedLabels(map[string]string{
+		discoveryutils.GetSortedLabels(map[string]string{
 			"__address__":                             "kube-dns.kube-system.svc:53",
 			"__meta_kubernetes_namespace":             "kube-system",
 			"__meta_kubernetes_service_name":          "kube-dns",
@@ -174,7 +175,7 @@ func TestParseServiceListSuccess(t *testing.T) {
 			"__meta_kubernetes_service_annotationpresent_prometheus_io_port":   "true",
 			"__meta_kubernetes_service_annotationpresent_prometheus_io_scrape": "true",
 		}),
-		getSortedLabels(map[string]string{
+		discoveryutils.GetSortedLabels(map[string]string{
 			"__address__":                             "kube-dns.kube-system.svc:53",
 			"__meta_kubernetes_namespace":             "kube-system",
 			"__meta_kubernetes_service_name":          "kube-dns",
@@ -197,7 +198,7 @@ func TestParseServiceListSuccess(t *testing.T) {
 			"__meta_kubernetes_service_annotationpresent_prometheus_io_port":   "true",
 			"__meta_kubernetes_service_annotationpresent_prometheus_io_scrape": "true",
 		}),
-		getSortedLabels(map[string]string{
+		discoveryutils.GetSortedLabels(map[string]string{
 			"__address__":                             "kube-dns.kube-system.svc:9153",
 			"__meta_kubernetes_namespace":             "kube-system",
 			"__meta_kubernetes_service_name":          "kube-dns",

lib/promscrape/discoveryutils/utils.go

@@ -1,9 +1,13 @@
 package discoveryutils
 
 import (
+	"encoding/json"
 	"net"
 	"regexp"
+	"sort"
 	"strconv"
+
+	"github.com/VictoriaMetrics/VictoriaMetrics/lib/prompbmarshal"
 )
 
 // SanitizeLabelName replaces anything that doesn't match
@@ -25,3 +29,31 @@ func JoinHostPort(host string, port int) string {
 	portStr := strconv.Itoa(port)
 	return net.JoinHostPort(host, portStr)
 }
+
+// SortedLabels represents sorted labels.
+type SortedLabels []prompbmarshal.Label
+
+// UnmarshalJSON unmarshals JSON from data.
+func (sls *SortedLabels) UnmarshalJSON(data []byte) error {
+	var m map[string]string
+	if err := json.Unmarshal(data, &m); err != nil {
+		return err
+	}
+	*sls = GetSortedLabels(m)
+	return nil
+}
+
+// GetSortedLabels returns SortedLabels built from m.
+func GetSortedLabels(m map[string]string) SortedLabels {
+	a := make([]prompbmarshal.Label, 0, len(m))
+	for k, v := range m {
+		a = append(a, prompbmarshal.Label{
+			Name:  k,
+			Value: v,
+		})
+	}
+	sort.Slice(a, func(i, j int) bool {
+		return a[i].Name < a[j].Name
+	})
+	return a
+}

lib/promscrape/scraper.go

@@ -18,10 +18,13 @@ var (
 	configCheckInterval = flag.Duration("promscrape.configCheckInterval", 0, "Interval for checking for changes in '-promscrape.config' file. "+
 		"By default the checking is disabled. Send SIGHUP signal in order to force config check for changes")
 	fileSDCheckInterval = flag.Duration("promscrape.fileSDCheckInterval", 30*time.Second, "Interval for checking for changes in 'file_sd_config'. "+
-		"See https://prometheus.io/docs/prometheus/latest/configuration/configuration/#file_sd_config")
+		"See https://prometheus.io/docs/prometheus/latest/configuration/configuration/#file_sd_config for details")
 	kubernetesSDCheckInterval = flag.Duration("promscrape.kubernetesSDCheckInterval", 30*time.Second, "Interval for checking for changes in Kubernetes API server. "+
 		"This works only if `kubernetes_sd_configs` is configured in '-promscrape.config' file. "+
 		"See https://prometheus.io/docs/prometheus/latest/configuration/configuration/#kubernetes_sd_config for details")
+	gceSDCheckInterval = flag.Duration("promscrape.gceSDCheckInterval", time.Minute, "Interval for checking for changes in gce. "+
+		"This works only if `gce_sd_configs` is configured in '-promscrape.config' file. "+
+		"See https://prometheus.io/docs/prometheus/latest/configuration/configuration/#gce_sd_config for details")
 	promscrapeConfigFile = flag.String("promscrape.config", "", "Optional path to Prometheus config file with 'scrape_configs' section containing targets to scrape. "+
 		"See https://prometheus.io/docs/prometheus/latest/configuration/configuration/#scrape_config for details")
 )
@@ -89,6 +92,11 @@ func runScraper(configFile string, pushData func(wr *prompbmarshal.WriteRequest)
 			defer wg.Done()
 			runKubernetesSDScrapers(cfg, pushData, stopCh)
 		}()
+		wg.Add(1)
+		go func() {
+			defer wg.Done()
+			runGCESDScrapers(cfg, pushData, stopCh)
+		}()
 
 	waitForChans:
 		select {
@@ -194,6 +202,51 @@ var (
 	kubernetesSDReloads = metrics.NewCounter(`vm_promscrape_reloads_total{type="kubernetes_sd"}`)
 )
 
+func runGCESDScrapers(cfg *Config, pushData func(wr *prompbmarshal.WriteRequest), stopCh <-chan struct{}) {
+	if cfg.gceSDConfigsCount() == 0 {
+		return
+	}
+	sws := cfg.getGCESDScrapeWork()
+	ticker := time.NewTicker(*gceSDCheckInterval)
+	defer ticker.Stop()
+	mustStop := false
+	for !mustStop {
+		localStopCh := make(chan struct{})
+		var wg sync.WaitGroup
+		wg.Add(1)
+		go func(sws []ScrapeWork) {
+			defer wg.Done()
+			logger.Infof("starting %d scrapers for `gce_sd_config` targets", len(sws))
+			gceSDTargets.Set(uint64(len(sws)))
+			runScrapeWorkers(sws, pushData, localStopCh)
+			gceSDTargets.Set(0)
+			logger.Infof("stopped all the %d scrapers for `gce_sd_config` targets", len(sws))
+		}(sws)
+	waitForChans:
+		select {
+		case <-ticker.C:
+			swsNew := cfg.getGCESDScrapeWork()
+			if equalStaticConfigForScrapeWorks(swsNew, sws) {
+				// Nothing changed, continue waiting for updated scrape work
+				goto waitForChans
+			}
+			logger.Infof("restarting scrapers for changed `gce_sd_config` targets")
+			sws = swsNew
+		case <-stopCh:
+			mustStop = true
+		}
+
+		close(localStopCh)
+		wg.Wait()
+		gceSDReloads.Inc()
+	}
+}
+
+var (
+	gceSDTargets = metrics.NewCounter(`vm_promscrape_targets{type="gce_sd"}`)
+	gceSDReloads = metrics.NewCounter(`vm_promscrape_reloads_total{type="gce_sd"}`)
+)
+
 func runFileSDScrapers(cfg *Config, pushData func(wr *prompbmarshal.WriteRequest), stopCh <-chan struct{}) {
 	if cfg.fileSDConfigsCount() == 0 {
 		return