awsspectre

README

AWSSpectre

AWS resource waste auditor. Finds idle, orphaned, and oversized resources costing money for nothing.

Part of the Spectre family of infrastructure cleanup tools.

What it is

AWSSpectre scans your AWS account for resources that are running but not doing useful work. It checks CloudWatch metrics, attachment status, and usage patterns to identify waste across EC2, RDS, EBS, ELB, NAT Gateways, Elastic IPs, Lambda, snapshots, and security groups. Each finding includes an estimated monthly cost so you can prioritize cleanup by dollar impact.

What it is NOT

• Not a real-time monitoring tool. AWSSpectre is a point-in-time scanner, not a daemon.
• Not a remediation tool. It reports waste and lets you decide what to do.
• Not a security scanner. It checks for idle resources, not misconfigurations or vulnerabilities.
• Not a billing replacement. Cost estimates are approximations based on embedded on-demand pricing, not your actual discounted rates.
• Not a capacity planner. It flags underutilization, not rightsizing recommendations.

Philosophy

Principiis obsta -- resist the beginnings.

Compute and storage are 50-70% of every AWS bill, and every account has waste. The longer idle resources sit, the harder they are to identify and the more they cost. AWSSpectre surfaces these conditions early -- in scheduled audits, in CI, in cost reviews -- so they can be addressed before they compound.

The tool presents evidence and lets humans decide. It does not auto-terminate instances, does not guess intent, and does not use ML where deterministic checks suffice.

Installation

# Homebrew
brew install ppiankov/tap/awsspectre

# Docker
docker pull ghcr.io/ppiankov/awsspectre:latest

# From source
git clone https://github.com/ppiankov/awsspectre.git
cd awsspectre && make build

Quick start

# Scan all enabled regions (default)
awsspectre scan

# Scan specific regions
awsspectre scan --regions us-east-1,eu-west-1

# JSON output for automation
awsspectre scan --format json --output report.json

# SARIF output for GitHub Security tab
awsspectre scan --format sarif --output results.sarif

# Use a specific AWS profile
awsspectre scan --profile production

# Generate config and IAM policy
awsspectre init

Requires valid AWS credentials (environment, profile, or IAM role).

What it audits

Resource	Finding	Signal	Severity
EC2 instances	IDLE_EC2	CPU < 5% and memory < 50% (if available) over idle window	high
EC2 instances	STOPPED_EC2	Stopped > 30 days	medium
EBS volumes	DETACHED_EBS	Detached (available state)	high
Elastic IPs	UNUSED_EIP	Not associated with running instance	medium
ALB	IDLE_ALB	Zero healthy targets or zero requests	high
NLB	IDLE_NLB	Zero healthy targets or zero active flows	high
NAT Gateways	IDLE_NAT_GATEWAY	Zero bytes processed	high
NAT Gateways	LOW_TRAFFIC_NAT_GATEWAY	Below traffic threshold (default 1 GB/month)	medium
RDS instances	IDLE_RDS	CPU < 5% or zero connections, memory < 50% (if known)	high
Snapshots	STALE_SNAPSHOT	Older than stale threshold, no AMI reference	medium
Security Groups	UNUSED_SECURITY_GROUP	No attached ENIs	low
Lambda	IDLE_LAMBDA	Zero invocations over idle window	low

Usage

awsspectre scan [flags]

Flags:

Flag	Default	Description
--regions		Comma-separated region filter
--all-regions	true	Scan all enabled regions
--idle-days	7	Lookback window for utilization metrics
--stale-days	90	Age threshold for snapshots
--min-monthly-cost	1.0	Minimum monthly cost to report ($)
--idle-cpu-threshold	5.0	CPU % below which a resource is idle
--high-memory-threshold	50.0	Memory % above which a resource is not idle
--stopped-threshold-days	30	Days stopped before flagging EC2
--nat-gw-low-traffic-gb	1.0	NAT Gateway monthly GB below which to flag as low traffic
--exclude-tags		Exclude resources by tag (Key=Value or Key, comma-separated)
--format	text	Output format: text, json, sarif, spectrehub
-o, --output	stdout	Output file path
--profile		AWS profile name
--no-progress	false	Disable progress output
--timeout	10m	Scan timeout

Other commands:

Command	Description
awsspectre init	Generate .awsspectre.yaml config and IAM policy
awsspectre version	Print version, commit, and build date

Configuration

AWSSpectre reads .awsspectre.yaml from the current directory:

regions:
  - us-east-1
  - eu-west-1
idle_days: 14
stale_days: 180
min_monthly_cost: 5.0
format: json
exclude:
  resource_ids:
    - i-0abc123def456
    - vol-0abc123def456
  tags:
    - "Environment=production"
    - "awsspectre:ignore"

Generate a sample config with awsspectre init.

IAM permissions

AWSSpectre requires read-only access. Run awsspectre init to generate the minimal IAM policy, or attach these permissions:

• ec2:DescribeInstances, ec2:DescribeVolumes, ec2:DescribeAddresses, ec2:DescribeSnapshots, ec2:DescribeSecurityGroups, ec2:DescribeNetworkInterfaces, ec2:DescribeNatGateways, ec2:DescribeImages, ec2:DescribeRegions
• elasticloadbalancing:DescribeLoadBalancers, elasticloadbalancing:DescribeTargetGroups, elasticloadbalancing:DescribeTargetHealth
• rds:DescribeDBInstances
• lambda:ListFunctions
• cloudwatch:GetMetricData

Output formats

Text (default): Human-readable table with severity, resource, region, waste, and message.

JSON (--format json): spectre/v1 envelope with findings and summary:

{
  "$schema": "spectre/v1",
  "tool": "awsspectre",
  "version": "0.1.0",
  "findings": [...],
  "summary": {
    "total_resources_scanned": 150,
    "total_findings": 5,
    "total_monthly_waste": 250.00
  }
}

SARIF (--format sarif): SARIF v2.1.0 for GitHub Security tab integration.

SpectreHub (--format spectrehub): spectrehub/v1 envelope for SpectreHub ingestion.

Architecture

awsspectre/
├── cmd/awsspectre/main.go         # Entry point (22 lines, LDFLAGS)
├── internal/
│   ├── commands/                  # Cobra CLI: scan, init, version
│   ├── aws/                       # AWS SDK v2 clients + 9 resource scanners
│   │   ├── types.go               # Finding, Severity, ResourceType, ScanConfig
│   │   ├── client.go              # AWS config loader, region discovery
│   │   ├── cloudwatch.go          # Batched GetMetricData (up to 500 queries/call)
│   │   ├── scanner.go             # MultiRegionScanner orchestrator
│   │   ├── ec2.go                 # EC2: idle CPU, stopped instances
│   │   ├── ebs.go                 # EBS: detached volumes
│   │   ├── eip.go                 # EIP: unassociated addresses
│   │   ├── elb.go                 # ALB/NLB: zero targets, zero requests
│   │   ├── natgw.go               # NAT Gateway: zero bytes processed
│   │   ├── rds.go                 # RDS: idle CPU, no connections
│   │   ├── snapshot.go            # Snapshots: old, no AMI reference
│   │   ├── secgroup.go            # Security groups: no attached ENIs
│   │   └── lambda.go              # Lambda: zero invocations
│   ├── pricing/                   # Embedded on-demand pricing (go:embed)
│   ├── analyzer/                  # Filter by min cost, compute summary
│   └── report/                    # Text, JSON, SARIF, SpectreHub reporters
├── Makefile
└── go.mod

Key design decisions:

• cmd/awsspectre/main.go is minimal -- a single Execute() call with LDFLAGS version injection.
• All logic lives in internal/ to prevent external import.
• Each resource type has its own scanner implementing ResourceScanner interface.
• CloudWatch uses batched GetMetricData API (up to 500 queries per call) for efficiency.
• Two-level bounded concurrency: max 4 regions, max 10 API calls per region.
• Pricing data is embedded via go:embed with curated on-demand rates, falling back to us-east-1 for unknown regions.
• Scanner errors are collected, not fatal -- one scanner failure does not abort the whole scan.

Project Status

Status: Beta · v0.1.0 · Pre-1.0

Milestone	Status
9 resource scanners (EC2, EBS, EIP, ALB, NLB, NAT GW, RDS, Lambda, snapshots, security groups)	Complete
Multi-region parallel scanning with bounded concurrency	Complete
Embedded on-demand pricing with per-finding cost estimates	Complete
4 output formats (text, JSON, SARIF, SpectreHub)	Complete
Config file + init command with IAM policy generation	Complete
CI pipeline (test/lint/build)	Complete
Homebrew + Docker distribution	Complete
Test coverage >85%	Complete
API stability guarantees	Partial
v1.0 release	Planned

Pre-1.0: CLI flags and config schemas may change between minor versions. JSON output structure (spectre/v1) is stable.

Known limitations

• Approximate pricing. Cost estimates use embedded on-demand rates, not your actual pricing (reserved instances, savings plans, spot). Treat estimates as directional, not exact.
• CloudWatch data lag. Metrics may take up to 15 minutes to appear. Very recently provisioned resources may not have enough data for idle detection.
• No cross-account support. Scans a single AWS account at a time.
• No rightsizing. Flags underutilized resources but does not recommend smaller instance types.
• Security group references. Only checks ENI attachment and in-rules cross-references. Does not trace through nested group chains.
• Snapshot AMI check. Only validates against AMIs owned by the account. Shared AMIs referencing the snapshot will not be detected.
• Single metric thresholds. CPU < 5% is a simple heuristic. Some workloads (batch, cron) may appear idle but are not.

License

MIT License -- see LICENSE.

Contributing

See CONTRIBUTING.md. Issues and pull requests welcome.

Part of the Spectre family.