Cloud Armor Skill

Manage and analyze Google Cloud Armor security policies using gcloud compute security-policies commands.

Discovery-First Rule

ALWAYS discover before acting. Never assume policy names, rule priorities, or backend service names.

# Discover security policies
gcloud compute security-policies list --format=json \
  | jq '[.[] | {name: .name, type: .type, adaptiveProtection: .adaptiveProtectionConfig.layer7DdosDefenseConfig.enable, ruleCount: .rules | length}]'

Parallel Execution Requirement

ALL independent operations MUST run in parallel using background jobs (&) and wait.

for policy in $(gcloud compute security-policies list --format="value(name)"); do
  {
    gcloud compute security-policies describe "$policy" --format=json
  } &
done
wait

Helper Functions

# Get policy details with rules
get_policy_details() {
  local policy="$1"
  gcloud compute security-policies describe "$policy" --format=json \
    | jq '{name: .name, type: .type, fingerprint: .fingerprint, adaptiveProtection: .adaptiveProtectionConfig, advancedOptions: .advancedOptionsConfig, rules: [.rules[] | {priority: .priority, action: .action, description: .description, preview: .preview, match: .match}]}'
}

# List rules in a policy
list_rules() {
  local policy="$1"
  gcloud compute security-policies rules list "$policy" --format=json \
    | jq '[.[] | {priority: .priority, action: .action, description: .description, preview: .preview, matchType: (if .match.expr then "CEL" elif .match.config then "IP/Range" else "default" end), rateLimit: .rateLimitOptions}]'
}

# Get backend services using a policy
get_backend_services() {
  gcloud compute backend-services list --format=json \
    | jq '[.[] | select(.securityPolicy) | {name: .name, securityPolicy: .securityPolicy | split("/") | last, protocol: .protocol}]'
}

# Get security policy logs
get_armor_logs() {
  local policy="$1" limit="${2:-50}"
  gcloud logging read "resource.type=\"http_load_balancer\" AND jsonPayload.enforcedSecurityPolicy.name=\"$policy\"" --limit="$limit" --format=json \
    | jq '[.[] | {timestamp: .timestamp, action: .jsonPayload.enforcedSecurityPolicy.outcome, rule: .jsonPayload.enforcedSecurityPolicy.priority, remoteIp: .httpRequest.remoteIp, requestUrl: .httpRequest.requestUrl}]'
}

Common Operations

1. Security Policy Overview

policies=$(gcloud compute security-policies list --format="value(name)")
for policy in $policies; do
  {
    get_policy_details "$policy"
  } &
done
wait

2. WAF Rule Analysis

# Detailed rule inspection
list_rules "$POLICY"

# Check preconfigured WAF rules (OWASP)
gcloud compute security-policies describe "$POLICY" --format=json \
  | jq '[.rules[] | select(.match.expr.expression | contains("evaluatePreconfiguredWaf")) | {priority: .priority, action: .action, wafRule: .match.expr.expression, preview: .preview}]'

# Available preconfigured rules
gcloud compute security-policies list-preconfigured-expression-sets --format=json

3. Adaptive Protection

# Check adaptive protection config
gcloud compute security-policies describe "$POLICY" --format=json \
  | jq '{adaptiveProtection: .adaptiveProtectionConfig.layer7DdosDefenseConfig, autoDeployConfig: .adaptiveProtectionConfig.autoDeployConfig}'

# Check adaptive protection events via logging
gcloud logging read "resource.type=\"http_load_balancer\" AND jsonPayload.enforcedSecurityPolicy.adaptiveProtection" --limit=20 --format=json

4. Rate Limiting Rules

# List rate limiting rules
gcloud compute security-policies describe "$POLICY" --format=json \
  | jq '[.rules[] | select(.rateLimitOptions) | {priority: .priority, action: .action, rateLimitThreshold: .rateLimitOptions.rateLimitThreshold, conformAction: .rateLimitOptions.conformAction, exceedAction: .rateLimitOptions.exceedAction, enforceOnKey: .rateLimitOptions.enforceOnKey, banDuration: .rateLimitOptions.banDurationSec}]'

5. Policy Attachment and Coverage

# Which backend services have security policies
get_backend_services

# Backend services WITHOUT security policies (unprotected)
gcloud compute backend-services list --format=json \
  | jq '[.[] | select(.securityPolicy == null) | {name: .name, protocol: .protocol, backends: [.backends[]?.group | split("/") | last]}]'

# Edge security policies
gcloud compute security-policies list --filter="type=CLOUD_ARMOR_EDGE" --format=json \
  | jq '[.[] | {name: .name, ruleCount: .rules | length}]'

Output Format

Present results as a structured report:

Gcp Cloud Armor 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

1. Preview mode: Rules in preview mode (preview: true) log matches but do not enforce. Always check preview status before assuming protection.
2. Rule priority ordering: Lower priority number = higher precedence. The default rule (priority 2147483647) is always last. Ensure custom rules have appropriate priorities.
3. CEL expression limits: Custom CEL expressions have complexity limits. Overly complex expressions cause policy update failures.
4. Rate limiting granularity: enforceOnKey determines rate limit scope (IP, header, etc.). Without it, rate limiting applies globally, not per-client.
5. Adaptive protection delay: Adaptive protection needs traffic baseline data. New policies may not generate alerts for the first 24-48 hours.