Add scrapping ECS_CONTAINER_METADATA_URI_V4 for ECS (#453)

* Add metadata point v4 and delete run in aws

* Add log and delete flag

* Add some interface and add final endpoint v4

* Fix some typo and add interface

* Fix typo

* Delete apply interface

* Delete interface and debug

* Delete Ecs Util instance variable

* Add back ecsUtilInstance

* Add type assertion

* Delete type assertion

* Add type assertion again

* Delete type assertion

* Fix typo and nitpick

* Add back mode EC2

* Add runinAws

* Add type assertion

* Add type assertion

* delete type interface

* Add log for validating

* change to parse ecs region

* Build back image

* Revert back to original

* Add back strings

* Add parseClusterName

* Parse the cluster

* Delete parse cluster

* Delete go proxy

* Fix testing

cmd/config-downloader/downloader.go

@@ -166,7 +166,7 @@ func main() {
 		outputDir,
 		func(path string, info os.FileInfo, err error) error {
 			if err != nil {
-				fmt.Printf("Cannot access %v: %v", path, err)
+				fmt.Printf("Cannot access %v: %v \n", path, err)
 				return err
 			}
 			if info.IsDir() {

plugins/processors/ecsdecorator/ecsinfo.go

@@ -104,6 +104,7 @@ func (e *ecsInfo) getMemReserved() int64 {
 func newECSInfo(hostIP string) (e *ecsInfo) {
 	e = &ecsInfo{hostIP: hostIP, refreshInterval: 1 * time.Minute, shutdownC: make(chan bool), httpClient: httpclient.New()}
 	containerInstance := e.getContainerInstanceInfo()
+	//Sample Cluster Name: https://docs.aws.amazon.com/AmazonECS/latest/developerguide/ecs-agent-introspection.html
 	e.clusterName = containerInstance.Cluster
 	e.containerInstanceId = e.getContainerInstanceIdFromArn(containerInstance.ContainerInstanceArn)
 	e.cgroup = newCGroupScannerForContainer()

translator/cmdutil/translatorutil.go

@@ -139,7 +139,7 @@ func GenerateMergedJsonConfigMap(ctx *context.Context) (map[string]interface{},
 		ctx.InputJsonDirPath(),
 		func(path string, info os.FileInfo, err error) error {
 			if err != nil {
-				fmt.Printf("Cannot access %v: %v", path, err)
+				fmt.Printf("Cannot access %v: %v \n", path, err)
 				return err
 			}
 			if info.Mode()&os.ModeSymlink != 0 {

translator/translate/logs/metrics_collected/prometheus/ruleLogGroupName.go

@@ -30,7 +30,7 @@ func (d *LogGroupName) ApplyRule(input interface{}) (string, interface{}) {
 
 	if context.CurrentContext().RunInContainer() {
 		if ecsutil.GetECSUtilSingleton().IsECS() {
-			clusterName := util.GetECSClusterNameFromEnv()
+			clusterName := ecsutil.GetECSUtilSingleton().Cluster
 			if clusterName != "" {
 				lgName = fmt.Sprintf(ECSLogGroupNameFormat, clusterName)
 			}

translator/translate/logs/util/get_ecs_cluster_name.go

@@ -4,8 +4,6 @@
 package util
 
 import (
-	"strings"
-
 	"github.com/aws/amazon-cloudwatch-agent/translator/util/ecsutil"
 )
 
@@ -17,19 +15,7 @@ func GetECSClusterName(sectionKey string, input map[string]interface{}) string {
 	}
 
 	if clusterName == "" {
-		clusterName = GetECSClusterNameFromEnv()
-	}
-	return clusterName
-}
-
-func GetECSClusterNameFromEnv() string {
-	var clusterName string
-	if ecsutil.GetECSUtilSingleton().IsECS() {
 		clusterName = ecsutil.GetECSUtilSingleton().Cluster
-		res := strings.Split(clusterName, "/")
-		if len(res) > 0 {
-			clusterName = res[len(res)-1]
-		}
 	}
 	return clusterName
-}
+}

translator/util/ecsutil/ecsutil.go

@@ -17,6 +17,7 @@ import (
 const (
 	v2MetadataEndpoint    = "http://169.254.170.2/v2/metadata"
 	v3MetadataEndpointEnv = "ECS_CONTAINER_METADATA_URI"
+	v4MetadataEndpointEnv = "ECS_CONTAINER_METADATA_URI_V4"
 )
 
 type ecsMetadataResponse struct {
@@ -32,6 +33,7 @@ type ecsUtil struct {
 }
 
 var ecsUtilInstance *ecsUtil
+
 var ecsUtilOnce sync.Once
 
 func GetECSUtilSingleton() *ecsUtil {
@@ -48,13 +50,14 @@ func initECSUtilSingleton() (newInstance *ecsUtil) {
 	}
 	log.Println("I! attempt to access ECS task metadata to determine whether I'm running in ECS.")
 	ecsMetadataResponse, err := newInstance.getECSMetadata()
+
 	if err != nil {
 		log.Printf("I! access ECS task metadata fail with response %v, assuming I'm not running in ECS.\n", err)
 		return
 	}
 
 	newInstance.parseRegion(ecsMetadataResponse)
-	newInstance.Cluster = ecsMetadataResponse.Cluster
+	newInstance.parseClusterName(ecsMetadataResponse)
 	newInstance.TaskARN = ecsMetadataResponse.TaskARN
 	return
 
@@ -65,26 +68,29 @@ func (e *ecsUtil) IsECS() bool {
 }
 
 func (e *ecsUtil) getECSMetadata() (em *ecsMetadataResponse, err error) {
-	// choose available endpoint
-	if v3MetadataEndpoint, ok := os.LookupEnv(v3MetadataEndpointEnv); !ok {
-		em, err = e.getMetadataResponse(v2MetadataEndpoint)
-	} else {
+	// Based on endpoint to get ECS metadata, for more information on the respond, https://docs.aws.amazon.com/AmazonECS/latest/developerguide/task-metadata-endpoint.html
+	if v4MetadataEndpoint, ok := os.LookupEnv(v4MetadataEndpointEnv); ok {
+		em, err = e.getMetadataResponse(v4MetadataEndpoint + "/task")
+	} else if v3MetadataEndpoint, ok := os.LookupEnv(v3MetadataEndpointEnv); ok {
 		em, err = e.getMetadataResponse(v3MetadataEndpoint + "/task")
+	} else {
+		em, err = e.getMetadataResponse(v2MetadataEndpoint)
 	}
 	return
 }
 
 func (e *ecsUtil) getMetadataResponse(endpoint string) (em *ecsMetadataResponse, err error) {
 	em = &ecsMetadataResponse{}
 	resp, err := e.httpClient.Request(endpoint)
+
 	if err != nil {
 		return
 	}
 
 	err = json.Unmarshal(resp, em)
 	if err != nil {
-		log.Printf("E! unable to parse resp from ecsmetadata endpoint, error: %v", err)
-		log.Printf("D! resp content is %s", string(resp))
+		log.Printf("E! Unable to parse response from ecsmetadata endpoint, error: %v", err)
+		log.Printf("D! Content is %s", string(resp))
 	}
 	return
 }
@@ -97,7 +103,18 @@ func (e *ecsUtil) parseRegion(em *ecsMetadataResponse) {
 	splitedContent := strings.Split(em.TaskARN, ":")
 	// When splitting the ARN with ":", the 4th segment is the region
 	if len(splitedContent) < 4 {
-		log.Printf("E! invalid ecs task arn: %s", em.TaskARN)
+		log.Printf("E! Invalid ecs task arn: %s", em.TaskARN)
 	}
 	e.Region = splitedContent[3]
 }
+
+// There is only one format for ClusterArn (https://docs.aws.amazon.com/AmazonECS/latest/APIReference/API_Cluster.html)
+// arn:aws:ecs:region:aws_account_id:cluster/cluster-name
+func (e *ecsUtil) parseClusterName(em *ecsMetadataResponse) {
+	splitedContent := strings.Split(em.Cluster, "/")
+	// When splitting the ClusterName with /, the last is always the cluster name
+	if len(splitedContent) == 0 {
+		log.Printf("E! Invalid cluster arn: %s", em.Cluster)
+	}
+	e.Cluster = splitedContent[len(splitedContent)-1]
+}

translator/util/sdkutil.go

@@ -15,7 +15,6 @@ import (
 	"github.com/aws/amazon-cloudwatch-agent/translator/config"
 	"github.com/aws/amazon-cloudwatch-agent/translator/util/ec2util"
 	"github.com/aws/amazon-cloudwatch-agent/translator/util/ecsutil"
-
 	"github.com/aws/aws-sdk-go/aws/session"
 )
 
@@ -36,7 +35,7 @@ func DetectAgentMode(configuredMode string) string {
 		fmt.Println("I! Detected from ENV instance is EC2")
 		return config.ModeEC2
 	}
-
+	
 	if defaultEC2Region() != "" {
 		fmt.Println("I! Detected the instance is EC2")
 		return config.ModeEC2
@@ -93,15 +92,16 @@ func detectRegion(mode string, credsConfig map[string]string) (region string) {
 
 	// For ec2, fallback to metadata when no region info found in credential profile.
 	if region == "" && mode == config.ModeEC2 {
+		fmt.Println("I! Trying to detect region from ec2")
 		region = defaultEC2Region()
 	}
 
 	// try to get region from ecs metadata
 	if region == "" && mode == config.ModeEC2 {
-		fmt.Println("I! detect region from ecs")
+		fmt.Println("I! Trying to detect region from ecs")
 		region = defaultECSRegion()
 	}
-
+	
 	return
 }