# Terraform Datadog App Dashboard Module

## Overview

This Terraform module creates a comprehensive Kubernetes/Docker application monitoring dashboard in Datadog with CPU and memory utilization metrics, health monitoring, and synthetic API testing.

## Features

- **Kubernetes Resource Monitoring**: Visualizes pod and node resource utilization
- **CPU & Memory Tracking**: Top 10 containers by CPU and memory usage
- **Health Monitoring**: Pod health metric alerts
- **Synthetic Testing**: HTTP API endpoint monitoring
- **Read-Only Dashboard**: Prevents accidental modifications in the UI

## Resources Created

- `datadog_dashboard`: Application monitoring dashboard with multiple widgets
- `datadog_monitor`: Kubernetes Pod Health metric alert
- `datadog_synthetics_test`: API HTTP health check

## Dashboard Widgets

1. **Kubernetes Pods Hostmap**: CPU utilization by Docker image
2. **CPU Utilization Timeseries**: Top 10 containers ranked by CPU usage
3. **Kubernetes Nodes Hostmap**: CPU utilization by host
4. **Memory Utilization Timeseries**: Top 10 containers ranked by memory usage
5. **Alert Graph**: Visualization from the pod health monitor

## Requirements

| Name | Version |
|------|---------|
| terraform | >= 0.12 |
| datadog | >= 3.2.0 |

## Usage

```hcl
module "app_dashboard" {
  source = "./terraform-datadog-app-dashboard"

  app_namespace = "production"
  cfa_name      = "my-cfa"
  app_name      = "my-application"
  team_name     = "platform-team"
  image_name    = "my-app"
  region        = "eu-west-1"
  stage         = "prd"
  url           = "https://api.example.com/health"
}
```

## Inputs

| Name | Description | Type | Required |
|------|-------------|------|----------|
| `app_namespace` | Namespace that the application runs in | `string` | yes |
| `cfa_name` | Name of the CFA | `string` | yes |
| `app_name` | Name of the application | `string` | yes |
| `team_name` | Name of the responsible team | `string` | yes |
| `image_name` | Name of the Docker Image | `string` | yes |
| `region` | AWS region where resources are located | `string` | yes |
| `stage` | Stage to monitor (dev, tst, stg, prd) | `string` | yes |
| `url` | URL for Datadog Synthetics to monitor | `string` | yes |

## Outputs

Currently, this module does not export any outputs.

## Monitor Configuration

### Pod Health Monitor

- **Query**: `avg(last_5m):sum:docker.containers.running{image_name:{image_name}} by {docker_image}.rollup(avg, 60) <= 1`
- **Type**: Metric alert
- **Thresholds**:
  - OK: 3 containers
  - Warning: 2 containers
  - Critical: 1 container
- **No Data**: Alert after 10 minutes

### Synthetic API Test

- **Type**: HTTP API test
- **Method**: GET
- **Interval**: Every 15 minutes (900 seconds)
- **Assertion**: HTTP status code is 200
- **Locations**: AWS EU and US regions

## Tagging Strategy

All resources are tagged with:
- `cfa:{cfa_name}`
- `team:{team_name}`
- `app:{app_name}`
- `env:{stage}`
- `type:kubernetes` or `type:synthetics`

## Notes

- The dashboard is set to read-only mode to prevent accidental modifications
- Metrics are filtered by the `image_name` variable
- Synthetic tests run from multiple AWS regions for geographic coverage
- Pod health monitor uses a 1-minute rollup average

## License

Internal use only - Sanoma/WeBuildYourCloud

## Authors

Created and maintained by the Platform Engineering team.