Merge pull request #3 from jedipunkz/feature/change-struct-name

change struct name

Dockerfile

@@ -0,0 +1,17 @@
+### Builder for Golang
+FROM golang:1.19 as go-builder
+MAINTAINER @jedipunkz
+
+WORKDIR /go/src/
+ADD . /go/src/
+
+RUN go mod download
+RUN CGO_ENABLED=0 go build -o /go/bin/esp
+
+## Deployable image
+FROM alpine:latest as esp-base
+MAINTAINER @jedipunkz
+
+COPY --from=go-builder /go/bin/esp /go/bin/esp
+
+ENTRYPOINT ["/bin/sh",  "-c" , "/go/bin/esp"]

README.md

@@ -2,7 +2,116 @@
 
 ## Description
 
-ESP Retrives ECS Container Stats from Metadata Endpoint and Plots Stats to Cloudwatch Detailed Metrics.
+ESP Retrives AWS ECS Container Stats from Metadata Endpoint and Plots Stats to Cloudwatch Detailed Metrics.
+ESP enables faster autoscaling of AWS ECS Tasks by indexing AWS Cloudwatch high-resolution Custom Metrics.
+
+## Requirement
+
+### Add cloudwatch:PutMetricData Permission to Task Role.
+
+add `cloudwatch:PutMetricData` to task role.
+
+```hcl
+  statement {
+    effect = "Allow"
+    actions = [
+      "cloudwatch:PutMetricData"
+    ]
+    resources = ["*"]
+  }
+```
+
+## Usage
+
+### Build and Push to Repository
+
+Build docker image and push to ECR repository.
+
+```shell
+docker build --platform linux/amd64 -t esp .
+docker push *******.dkr.ecr.us-east-1.amazonaws.com/esp:latest
+```
+
+### Add ESP as a sidecar container
+
+Add ESP as a ECS sidecar container in the container definition below.
+
+```json
+[
+  {
+    "name": "web",
+    ...<snip>...
+  {
+    "name": "esp",
+    "image": "********.dkr.ecr.us-east-1.amazonaws.com/esp:latest",
+    "essential": true,
+    "environment": [
+      {
+        "name": "CONTAINER_NAME",
+        "value": "web"
+      },
+      {
+        "name": "REGION",
+        "value": "us-east-1"
+      },
+      {
+        "name": "NAMESPACE",
+        "value": "FOO"
+      }
+    ], 
+    "dependsOn": [
+      {
+        "containerName": "web",
+        "condition": "START"
+      }
+    ]
+  }
+]
+```
+
+| Environment Name | Description |
+|---|---|
+| CONTAINER_NAME | Container name for which you want to measure impossibility |
+| REGION | AWS Region Name |
+| NAMESPACE | Namespace name for Cloudwatch high resolution custom metrics |
+
+### Set Autoscalling
+
+Configure Cloudwatch Metric Alarm for Autoscalling. Below is an example of Terraform Code.
+
+```hcl
+resource "aws_cloudwatch_metric_alarm" "foo" {
+  alarm_name          = "foo-CPU-Utilization-High-30"
+  comparison_operator = "GreaterThanOrEqualToThreshold"
+  evaluation_periods  = "1"
+  metric_name         = "CPUUtilization"
+  namespace           = "FOO"
+  period              = "60"
+  statistic           = "Average"
+  threshold           = "15"
+  dimensions = {
+    ClusterName = aws_ecs_cluster.foo.name
+    ServiceName = aws_ecs_service.foo.name
+  }
+  alarm_actions = [aws_appautoscaling_policy.scale_out.arn]
+}
+
+resource "aws_cloudwatch_metric_alarm" "foo" {
+  alarm_name          = "foo-CPU-Utilization-Low-5"
+  comparison_operator = "LessThanThreshold"
+  evaluation_periods  = "1"
+  metric_name         = "CPUUtilization"
+  namespace           = "FOO"
+  period              = "60"
+  statistic           = "Average"
+  threshold           = "5"
+  dimensions = {
+    ClusterName = aws_ecs_cluster.foo.name
+    ServiceName = aws_ecs_service.foo.name
+  }
+  alarm_actions = [aws_appautoscaling_policy.scale_in.arn]
+}
+```
 
 ## Author
 

cloudwatch/cloudwatch.go

@@ -33,7 +33,7 @@ func NewCloudwatch(params *cloudwatch.PutMetricDataInput) *Cloudwatch {
 	return &Cloudwatch{sess, svc, params}
 }
 
-func PutMetricData(value float64) error {
+func PutMetricData(value float64) (resp string, err error) {
 	namespace := os.Getenv("NAMESPACE")
 	if namespace == "" {
 		log.Printf("error retriving namespace from environment variable")
@@ -53,12 +53,12 @@ func PutMetricData(value float64) error {
 
 	client := NewCloudwatch(params)
 
-	_, err := client.svc.PutMetricData(params)
+	_, err = client.svc.PutMetricData(params)
 	if err != nil {
 		log.Println(err.Error())
-		return err
+		return "", err
 	}
 	// log.Println(resp)
 
-	return nil
+	return resp, nil
 }

ecs/ecsmetadata.go

@@ -42,7 +42,7 @@ type TaskMetadata struct {
 	} `json:"Containers"`
 }
 
-type StatsMetadata struct {
+type ContainerMetadata struct {
 	CPUStats struct {
 		CPUUsage struct {
 			TotalUsage        int   `json:"total_usage"`
@@ -123,8 +123,8 @@ func (c *Client) RetriveTaskMetadata(ctx context.Context) (TaskMetadata, error)
 	return output, err
 }
 
-func (c *Client) RetriveStatsMetadata(ctx context.Context) (map[string]StatsMetadata, error) {
-	output := make(map[string]StatsMetadata)
+func (c *Client) RetriveContainersMetadata(ctx context.Context) (map[string]ContainerMetadata, error) {
+	output := make(map[string]ContainerMetadata)
 	err := c.request(ctx, c.endpoint+"/task/stats", &output)
 	return output, err
 }

esp.go

@@ -22,20 +22,20 @@ func main() {
 		log.Printf("error retrieving task metadata: %s", err)
 	}
 
-	statsMetadata, err := client.RetriveStatsMetadata(ctx)
+	containersMetadata, err := client.RetriveContainersMetadata(ctx)
 	if err != nil {
 		log.Printf("error retrieving task stats metadata: %s", err)
 	}
 
 	containerName := os.Getenv("CONTAINER_NAME")
 	if containerName == "" {
-		log.Printf("error retrieving container name from environment variable")
+		log.Fatal("error retrieving container name from environment variable")
 	}
 
 	for {
 		for _, container := range taskMetadata.Containers {
 			if container.Name == containerName {
-				s := statsMetadata[container.DockerID]
+				s := containersMetadata[container.DockerID]
 				if &s == nil {
 					log.Printf("Could not find stats for container %s", container.DockerID)
 					continue
@@ -45,7 +45,11 @@ func main() {
 					(float64(s.CPUStats.SystemCPUUsage) - float64(s.PreCPUStats.SystemCPUUsage)) *
 					float64(s.CPUStats.OnlineCPUs) * 100
 
-				cloudwatch.PutMetricData(cpuUsage)
+				_, err = cloudwatch.PutMetricData(cpuUsage)
+				if err != nil {
+					log.Printf("Error putting metric data: %s", err)
+				}
+
 				log.Printf("Container Name: %s, CPU Usage: %f", container.Name, cpuUsage)
 			}
 		}