AWS Terraform cloudwatch - Dashboard body reading from a list - amazon-web-services

Question

I have the following body for my AWS_CloudWatch_Resource on terraform:
dashboard_body = jsonencode(
dashboard_body = jsonencode(
{
"widgets": [
{
"type": "metric",
"x": 0,
"y": 0,
"width": 9,
"height": 6,
"properties": {
"view": "bar",
"stacked": false,
"metrics": [
[ "AWS/AutoScaling", "GroupDesiredCapacity", "AutoScalingGroupName", "Momo-Test-ASG1" ],
[ ".", "GroupMaxSize", ".", "." ],
[ ".", "GroupTotalCapacity", ".", "." ],
[ ".", "GroupTotalInstances", ".", "." ],
[ ".", "GroupInServiceInstances", ".", "." ]
],
"region": "eu-central-1",
"title": "ASG1 statistics"
}
},
{
"type": "metric",
"x": 9,
"y": 0,
"width": 9,
"height": 6,
"properties": {
"view": "bar",
"stacked": false,
"metrics": [
[ "AWS/AutoScaling", "GroupDesiredCapacity", "AutoScalingGroupName", "Momo-Test-ASG2" ],
[ ".", "GroupMaxSize", ".", "." ],
[ ".", "GroupTotalCapacity", ".", "." ],
[ ".", "GroupTotalInstances", ".", "." ],
[ ".", "GroupInServiceInstances", ".", "." ]
],
"region": "eu-central-1",
"period": 300,
"title": "ASG2 statistics"
}
},
{
"type": "explorer",
"x": 0,
"y": 6,
"width": 24,
"height": 15,
"properties": {
"metrics": [
{
"metricName": "CPUUtilization",
"resourceType": "AWS::EC2::Instance",
"stat": "Average"
},
{
"metricName": "NetworkIn",
"resourceType": "AWS::EC2::Instance",
"stat": "Average"
},
{
"metricName": "DiskReadOps",
"resourceType": "AWS::EC2::Instance",
"stat": "Average"
},
{
"metricName": "DiskWriteOps",
"resourceType": "AWS::EC2::Instance",
"stat": "Average"
},
{
"metricName": "NetworkOut",
"resourceType": "AWS::EC2::Instance",
"stat": "Average"
}
],
"aggregateBy": {
"key": "*",
"func": "AVG"
},
"labels": [
{
"key": "aws:autoscaling:groupName",
"value": "Momo-Test-ASG1"
},
{
"key": "aws:autoscaling:groupName",
"value": "Momo-Test-ASG2"
}
],
"widgetOptions": {
"legend": {
"position": "bottom"
},
"view": "timeSeries",
"stacked": false,
"rowsPerPage": 40,
"widgetsPerRow": 3
},
"period": 300,
"splitBy": "",
"title": "Average ASG1 and ASG2"
}
},
{
"type": "metric",
"x": 0,
"y": 21,
"width": 6,
"height": 6,
"properties": {
"metrics": [
[ { "expression": "AVG(METRICS())", "label": "Average", "id": "e1" } ],
[ "CWAgent", "mem_used_percent", "InstanceId", "i-0f67225a5c04aebf9", "AutoScalingGroupName", "Momo-Test-ASG2", "ImageId", "ami-0502e817a62226e03", "InstanceType", "t2.micro", { "yAxis": "left", "id": "m1" } ],
[ "...", "i-00198c860886391f4", ".", "Momo-Test-ASG1", ".", ".", ".", ".", { "id": "m2" } ]
],
"view": "timeSeries",
"stacked": false,
"region": "eu-central-1",
"period": 300,
"stat": "Average",
"title": "mem_used_percent"
}
}
]
}
)
}
As you can see, I am having the same widget for my Momo-Test-ASG1 ( first Autoscaling group ) and Momo-Test-ASG2 ( second Autenter code here scaling group ).
If I would have many ASGs to test, It would be problematic to hardcode the same thing for a lot of groups.
Is there any solution to make terraform read the ASGs from a list? instead of having to reproduce the same parts?

Answer 1

HashiCorp Terraform 0.12 Preview: For and For-Each
Using for
locals {
asg_names = [
"Momo-Test-ASG1",
"Momo-Test-ASG2",
]
}
locals {
body = [for asg_name in local.asg_names :
{
type: "metric",
x: 0,
y: 0,
width: 9,
height: 6,
properties: {
view: "bar",
stacked: false,
metrics: [
[ "AWS/AutoScaling", "GroupDesiredCapacity", "AutoScalingGroupName", asg_name ],
[ ".", "GroupMaxSize", ".", "." ],
[ ".", "GroupTotalCapacity", ".", "." ],
[ ".", "GroupTotalInstances", ".", "." ],
[ ".", "GroupInServiceInstances", ".", "." ]
]
region: "eu-central-1",
title: asg_name
}
}
]
}
resource "aws_cloudwatch_dashboard" "main" {
dashboard_name = "my-dashboard"
dashboard_body = jsonencode({
widgets: concat(local.body, [{
type: "text",
x: 0,
y: 7,
width: 3,
height: 3,
properties: {
markdown: "Hello world"
}
}])
})
}