lib/promscrape/discovery/ec2: expose __meta_ec2_region label in the same way as Prometheus 2.39 does

See https://github.com/prometheus/prometheus/pull/11326

docs/CHANGELOG.md

@@ -43,6 +43,7 @@ See [these docs](https://docs.victoriametrics.com/Cluster-VictoriaMetrics.html#m
 * FEATURE: [MetricsQL](https://docs.victoriametrics.com/MetricsQL.html): add [sort_by_label_numeric](https://docs.victoriametrics.com/MetricsQL.html#sort_by_label_numeric) and [sort_by_label_numeric_desc](https://docs.victoriametrics.com/MetricsQL.html#sort_by_label_numeric_desc) functions for [numeric sort](https://www.gnu.org/software/coreutils/manual/html_node/Version-sort-is-not-the-same-as-numeric-sort.html) of input time series by the specified labels. See [this feature request](https://github.com/VictoriaMetrics/VictoriaMetrics/issues/2938).
 * FEATURE: [vmbackup](https://docs.victoriametrics.com/vmbackup.html) and [vmrestore](https://docs.victoriametrics.com/vmrestore.html): retry GCS operations for up to 3 minutes on temporary failures. See [this issue](https://github.com/VictoriaMetrics/VictoriaMetrics/issues/3147).
 * FEATURE: [vmgateway](https://docs.victoriametrics.com/vmgateway.html): add ability to extract JWT authorization token from non-standard HTTP header by passing it via `-auth.httpHeader` command-line flag. See [this feature request](https://github.com/VictoriaMetrics/VictoriaMetrics/issues/3054).
+* FEATURE: [vmagent](https://docs.victoriametrics.com/vmagent.html): expose `__meta_ec2_region` label for [ec2_sd_config](https://docs.victoriametrics.com/sd_configs.html#ec2_sd_configs) in the same way as [Prometheus 2.39 does](https://github.com/prometheus/prometheus/pull/11326).
 
 * BUGFIX: [vmagent](https://docs.victoriametrics.com/vmagent.html): properly encode query params for aws signed requests, use `%20` instead of `+` as api requires. See [this issue](https://github.com/VictoriaMetrics/VictoriaMetrics/issues/3171).
 * BUGFIX: [vmagent](https://docs.victoriametrics.com/vmagent.html): properly parse relabel config when regex ending with escaped `$`. See [this issue](https://github.com/VictoriaMetrics/VictoriaMetrics/issues/3131).

docs/sd_configs.md

@@ -473,6 +473,7 @@ The following meta labels are available on discovered targets during [relabeling
 * `__meta_ec2_private_ip`: the private IP address of the instance, if present
 * `__meta_ec2_public_dns_name`: the public DNS name of the instance, if available
 * `__meta_ec2_public_ip`: the public IP address of the instance, if available
+* `__meta_ec2_region`: EC2 region for the discovered instance
 * `__meta_ec2_subnet_id`: comma separated list of subnets IDs in which the instance is running, if available
 * `__meta_ec2_tag_<tagkey>`: each tag value of the instance
 * `__meta_ec2_vpc_id`: the ID of the VPC in which the instance is running, if available

lib/awsapi/config.go

@@ -53,11 +53,9 @@ func NewConfig(ec2Endpoint, stsEndpoint, region, roleARN, accessKey, secretKey,
 		defaultAccessKey: os.Getenv("AWS_ACCESS_KEY_ID"),
 		defaultSecretKey: os.Getenv("AWS_SECRET_ACCESS_KEY"),
 	}
-	cfg.service = service
 	if cfg.service == "" {
 		cfg.service = "aps"
 	}
-	cfg.region = region
 	if cfg.region == "" {
 		r, err := getDefaultRegion(cfg.client)
 		if err != nil {
@@ -75,8 +73,6 @@ func NewConfig(ec2Endpoint, stsEndpoint, region, roleARN, accessKey, secretKey,
 		return nil, fmt.Errorf("roleARN is missing for AWS_WEB_IDENTITY_TOKEN_FILE=%q; set it via env var AWS_ROLE_ARN", cfg.webTokenPath)
 	}
 	// explicitly set credentials has priority over env variables
-	cfg.defaultAccessKey = os.Getenv("AWS_ACCESS_KEY_ID")
-	cfg.defaultSecretKey = os.Getenv("AWS_SECRET_ACCESS_KEY")
 	if len(accessKey) > 0 {
 		cfg.defaultAccessKey = accessKey
 	}
@@ -90,6 +86,11 @@ func NewConfig(ec2Endpoint, stsEndpoint, region, roleARN, accessKey, secretKey,
 	return cfg, nil
 }
 
+// GetRegion returns region for the given cfg.
+func (cfg *Config) GetRegion() string {
+	return cfg.region
+}
+
 // GetEC2APIResponse performs EC2 API request with ghe given action.
 //
 // filtersQueryString must contain an optional percent-encoded query string for aws filters.

lib/promscrape/discovery/ec2/instance.go

@@ -16,10 +16,11 @@ func getInstancesLabels(cfg *apiConfig) ([]map[string]string, error) {
 		return nil, err
 	}
 	azMap := getAZMap(cfg)
+	region := cfg.awsConfig.GetRegion()
 	var ms []map[string]string
 	for _, r := range rs {
 		for _, inst := range r.InstanceSet.Items {
-			ms = inst.appendTargetLabels(ms, r.OwnerID, cfg.port, azMap)
+			ms = inst.appendTargetLabels(ms, r.OwnerID, region, cfg.port, azMap)
 		}
 	}
 	return ms, nil
@@ -134,7 +135,7 @@ func parseInstancesResponse(data []byte) (*InstancesResponse, error) {
 	return &v, nil
 }
 
-func (inst *Instance) appendTargetLabels(ms []map[string]string, ownerID string, port int, azMap map[string]string) []map[string]string {
+func (inst *Instance) appendTargetLabels(ms []map[string]string, ownerID, region string, port int, azMap map[string]string) []map[string]string {
 	if len(inst.PrivateIPAddress) == 0 {
 		// Cannot scrape instance without private IP address
 		return ms
@@ -157,6 +158,7 @@ func (inst *Instance) appendTargetLabels(ms []map[string]string, ownerID string,
 		"__meta_ec2_private_ip":           inst.PrivateIPAddress,
 		"__meta_ec2_public_dns_name":      inst.PublicDNSName,
 		"__meta_ec2_public_ip":            inst.PublicIPAddress,
+		"__meta_ec2_region":               region,
 		"__meta_ec2_vpc_id":               inst.VPCID,
 	}
 	if len(inst.VPCID) > 0 {

lib/promscrape/discovery/ec2/instance_test.go

@@ -238,7 +238,7 @@ func TestParseInstancesResponse(t *testing.T) {
 	ownerID := rs.OwnerID
 	port := 423
 	inst := rs.InstanceSet.Items[0]
-	labelss := inst.appendTargetLabels(nil, ownerID, port, map[string]string{
+	labelss := inst.appendTargetLabels(nil, ownerID, "region-a", port, map[string]string{
 		"eu-west-2c": "foobar-zone",
 	})
 	var sortedLabelss [][]prompbmarshal.Label
@@ -263,6 +263,7 @@ func TestParseInstancesResponse(t *testing.T) {
 			"__meta_ec2_private_ip":           "172.31.11.152",
 			"__meta_ec2_public_dns_name":      "ec2-3-8-232-141.eu-west-2.compute.amazonaws.com",
 			"__meta_ec2_public_ip":            "3.8.232.141",
+			"__meta_ec2_region":               "region-a",
 			"__meta_ec2_subnet_id":            ",subnet-57044c3e,",
 			"__meta_ec2_tag_foo":              "bar",
 			"__meta_ec2_vpc_id":               "vpc-f1eaad99",