aws-ecs-monitor

# AWS ECS Monitor

Production health monitoring and log analysis for AWS ECS services.

## What It Does

- **Health Checks**: HTTP probes against your domain, ECS service status (desired vs running), ALB target group health, SSL certificate expiry
- **Log Analysis**: Pulls CloudWatch logs, categorizes errors (panics, fatals, OOM, timeouts, 5xx), detects container restarts, filters health check noise
- **Auto-Diagnosis**: Reads health status and automatically investigates failing services via log analysis

## Prerequisites

- `aws` CLI configured with appropriate IAM permissions:
  - `ecs:ListServices`, `ecs:DescribeServices`
  - `elasticloadbalancing:DescribeTargetGroups`, `elasticloadbalancing:DescribeTargetHealth`
  - `logs:FilterLogEvents`, `logs:DescribeLogGroups`
- `curl` for HTTP health checks
- `python3` for JSON processing and log analysis
- `openssl` for SSL certificate checks (optional)

## Configuration

All configuration is via environment variables:

| Variable | Required | Default | Description |
|---|---|---|---|
| `ECS_CLUSTER` | **Yes** | — | ECS cluster name |
| `ECS_REGION` | No | `us-east-1` | AWS region |
| `ECS_DOMAIN` | No | — | Domain for HTTP/SSL checks (skip if unset) |
| `ECS_SERVICES` | No | auto-detect | Comma-separated service names to monitor |
| `ECS_HEALTH_STATE` | No | `./data/ecs-health.json` | Path to write health state JSON |
| `ECS_HEALTH_OUTDIR` | No | `./data/` | Output directory for logs and alerts |
| `ECS_LOG_PATTERN` | No | `/ecs/{service}` | CloudWatch log group pattern (`{service}` is replaced) |
| `ECS_HTTP_ENDPOINTS` | No | — | Comma-separated `name=url` pairs for HTTP probes |

## Directories Written

- **`ECS_HEALTH_STATE`** (default: `./data/ecs-health.json`) — Health state JSON file
- **`ECS_HEALTH_OUTDIR`** (default: `./data/`) — Output directory for logs, alerts, and analysis reports

## Scripts

### `scripts/ecs-health.sh` — Health Monitor

```bash
# Full check
ECS_CLUSTER=my-cluster ECS_DOMAIN=example.com ./scr...