Managing Grype

---
name: managing-grype
description: |
  Use when working with Grype — anchore Grype vulnerability scanner for
  container images, filesystems, and SBOMs. Covers image scanning, SBOM-based
  vulnerability matching, severity filtering, fix tracking, and database
  management. Use when scanning container images for vulnerabilities, analyzing
  SBOM security, reviewing vulnerability findings, or managing Grype database
  updates and scan configurations.
connection_type: grype
preload: false
---

# Grype Management Skill

Manage and analyze Grype vulnerability scans for container images, filesystems, and SBOMs.

## CLI Conventions

### Authentication
No authentication required for local CLI. For private registries, use standard Docker credentials.

### CLI Tool
`grype` for local scanning with JSON output

### Core Helper Function

```bash
#!/bin/bash

grype_scan() {
    local target="$1"
    local extra_args="${2:-}"
    grype "$target" -o json $extra_args 2>/dev/null
}
```

## Output Rules
- **TOKEN EFFICIENCY**: Extract only needed fields with `jq`
- Target <=50 lines per script output
- Never dump full scan output

## Discovery Phase

```bash
#!/bin/bash
echo "=== Grype Version ==="
grype version 2>&1 | head -3

echo ""
echo "=== Database Status ==="
grype db status 2>&1

echo ""
echo "=== Supported Sources ==="
echo "Container images (Docker, OCI)"
echo "Filesystem directories"
echo "SBOM files (CycloneDX, SPDX, Syft JSON)"
echo "Archive files (tar, jar, war, zip)"
```

## Analysis Phase

### Image Vulnerability Scan

```bash
#!/bin/bash
IMAGE="${1:?Container image required (e.g., nginx:latest)}"

echo "=== Scanning: $IMAGE ==="
RESULTS=$(grype_scan "$IMAGE")

echo "$RESULTS" | jq '{
    total: (.matches | length),
    critical: ([.matches[] | select(.vulnerability.severity == "Critical")] | length),
    high: ([.matches[] | select(.vulnerability.severity == "High")] | length),
    medium: ([.matches[] | select(.vulnerability.severity == "Medium")] | length),
    low: ([.matches[] | select(.vulnerability.severity == "Low")] | length),
    fixable: ([.matches[] | select(.vulnerability.fix.state == "fixed")] | length)
}'

echo ""
echo "=== Critical/High Vulnerabilities ==="
echo "$RESULTS" | jq -r '.matches[] | select(.vulnerability.severity == "Critical" or .vulnerability.severity == "High") | "\(.vulnerability.severity)\t\(.vulnerability.id)\t\(.artifact.name[0:25])\tv\(.artifact.version)\tfix:\(.vulnerability.fix.versions[0] // "none")"' \
    | column -t | head -20
```

### Fix Prioritization

```bash
#!/bin/bash
IMAGE="${1:?Container image required}"

echo "=== Fixable Vulnerabilities ==="
grype_scan "$IMAGE" \
    | jq -r '.matches[] | select(.vulnerability.fix.state == "fixed") | "\(.vulnerability.severity)\t\(.vulnerability.id)\t\(.artifact.name[0:25])\tv\(.artifact.version) -> \(.vulnerability.fix.versions[0])"' \
    | sort | column -t | head -20

echo ""
echo "=== Unfixed Critical/High ==="
grype_scan "$IMAGE" \
    | jq -r '.matches[] | select(.vulnerability.fix.state != "fixed" and (.vulnerability.severity == "Critical" or .vulnerability.severity == "High")) | "\(.vulnerability.severity)\t\(.vulnerability.id)\t\(.artifact.name[0:25])\tv\(.artifact.version)"' \
    | column -t | head -15
```

### Multi-Image Comparison

```bash
#!/bin/bash
echo "=== Multi-Image Vulnerability Comparison ==="
for IMAGE in "$@"; do
    RESULTS=$(grype_scan "$IMAGE" 2>/dev/null)
    CRITICAL=$(echo "$RESULTS" | jq '[.matches[] | select(.vulnerability.severity == "Critical")] | length')
    HIGH=$(echo "$RESULTS" | jq '[.matches[] | select(.vulnerability.severity == "High")] | length')
    TOTAL=$(echo "$RESULTS" | jq '.matches | length')
    FIXABLE=$(echo "$RESULTS" | jq '[.matches[] | select(.vulnerability.fix.state == "fixed")] | length')
    echo "$IMAGE\ttotal:${TOTAL}\tcritical:${CRITICAL}\thigh:${HIGH}\tfixable:${FIXABLE}"
done | column -t
```

### SBOM Scanning

```bash
#!/bin/bash
SBOM_FILE="${1:?SBOM file path required}"

echo "=== SBOM Vulnerability Scan ==="
RESULTS=$(grype "sbom:${SBOM_FILE}" -o json 2>/dev/null)

echo "$RESULTS" | jq '{
    total_vulns: (.matches | length),
    by_severity: (.matches | group_by(.vulnerability.severity) | map({severity: .[0].vulnerability.severity, count: length}) | sort_by(.count) | reverse)
}'

echo ""
echo "=== Top Vulnerable Components ==="
echo "$RESULTS" | jq -r '[.matches[] | {name: .artifact.name, severity: .vulnerability.severity}] | group_by(.name) | map({name: .[0].name, count: length, worst: ([.[].severity] | if any(. == "Critical") then "Critical" elif any(. == "High") then "High" else "Medium" end)}) | sort_by(.count) | reverse | .[:10][] | "\(.count)\t\(.worst)\t\(.name)"' \
    | column -t
```

## Output Format

Present results as a structured report:
```
Managing Grype Report
═════════════════════
Resources discovered: [count]

Resource       Status    Key Metric    Issues
──────────────────────────────────────────────
[name]         [ok/warn] [value]       [findings]

Summary: [total] resources | [ok] healthy | [warn] warnings | [crit] critical
Action Items: [list of prioritized findings]
```

Target ≤50 lines of output. Use tables for multi-resource comparisons.

## Anti-Hallucination Rules

1. **NEVER assume resource names** — always discover via CLI/API in Phase 1 before referencing in Phase 2.
2. **NEVER fabricate metric names or dimensions** — verify against the service documentation or `--help` output.
3. **NEVER mix CLI commands between service versions** — confirm which version/API you are targeting.
4. **ALWAYS use the discovery → verify → analyze chain** — every resource referenced must have been discovered first.
5. **ALWAYS handle empty results gracefully** — an empty response is valid data, not an error to retry.

## Counter-Rationalizations

| Shortcut | Counter | Why |
|----------|---------|-----|
| "I'll skip discovery and check known resources" | Always run Phase 1 discovery first | Resource names change, new resources appear — assumed names cause errors |
| "The user only asked for a quick check" | Follow the full discovery → analysis flow | Quick checks miss critical issues; structured analysis catches silent failures |
| "Default configuration is probably fine" | Audit configuration explicitly | Defaults often leave logging, security, and optimization features disabled |
| "Metrics aren't needed for this" | Always check relevant metrics when available | API/CLI responses show current state; metrics reveal trends and intermittent issues |
| "I don't have access to that" | Try the command and report the actual error | Assumed permission failures prevent useful investigation; actual errors are informative |

## Common Pitfalls

- **Database freshness**: Run `grype db update` regularly -- stale DB misses recent CVEs
- **Image pull**: Grype pulls images from registry -- ensure registry credentials are configured
- **Output formats**: Use `-o json` for parsing, `-o table` for display, `-o cyclonedx` for SBOM
- **Severity filtering**: Use `--only-fixed` to show only fixable vulns, `--fail-on critical` for CI/CD
- **Distroless images**: May have limited OS-level detection -- rely on language-specific matchers
- **SBOM prefix**: Use `sbom:` prefix for SBOM file input, `dir:` for filesystem scanning