Securing Container Registry With Harbor

Securing Container Registry with Harbor

Overview

Harbor is an open-source container registry that provides security features including vulnerability scanning (integrated Trivy), image signing (Notary/Cosign), RBAC, content trust policies, replication, and audit logging. Securing Harbor involves configuring these features to enforce image provenance, prevent vulnerable image deployment, and maintain registry access control.

When to Use

Trigger phrases:

• "securing container registry with harbor"

• "Harbor is an open-source container registry that provides security features incl"

• When deploying or configuring securing container registry with harbor capabilities in your environment

• When establishing security controls aligned to compliance requirements

• When building or improving security architecture for this domain

• When conducting security assessments that require this implementation

Prerequisites

• Harbor 2.10+ installed (Helm or Docker Compose)
• TLS certificates for HTTPS
• Trivy scanner integration
• OIDC/LDAP for authentication
• Kubernetes cluster (for deployment target)

Workflow

1. Scope the task — define objectives, boundaries, and success criteria
2. Gather information — collect all necessary data and context before proceeding
3. Execute the core workflow — follow the domain-specific steps methodically
4. Validate results — verify outputs against expected outcomes or baselines
5. Document findings — record results, anomalies, and recommendations

Step 1: Install Harbor with Security Configuration

# harbor-values.yaml for Helm deployment
expose:
  type: ingress
  tls:
    enabled: true
    certSource: secret
    secret:
      secretName: harbor-tls
      notarySecretName: harbor-tls
  ingress:
    hosts:
      core: harbor.example.com
      notary: notary.example.com

externalURL: https://harbor.example.com

persistence:
  enabled: true
  resourcePolicy: "keep"

harborAdminPassword: "<strong-password>"

trivy:
  enabled: true
  gitHubToken: "<github-token>"
  severity: "CRITICAL,HIGH,MEDIUM"
  autoScan: true

notary:
  enabled: true

core:
  secretKey: "<32-char-secret>"

database:
  type: external
  external:
    host: postgres.example.com
    port: "5432"
    username: harbor
    password: "<db-password>"
    sslmode: require

helm repo add harbor https://helm.getharbor.io
helm install harbor harbor/harbor -f harbor-values.yaml -n harbor --create-namespace

Step 2: Configure Vulnerability Scanning Policies

# Enable auto-scan on push (via Harbor API)
curl -k -X PUT "https://harbor.example.com/api/v2.0/projects/myproject" \
  -H "Authorization: Basic $(echo -n admin:Harbor12345 | base64)" \
  -H "Content-Type: application/json" \
  -d '{
    "metadata": {
      "auto_scan": "true",
      "severity": "critical",
      "prevent_vul": "true",
      "reuse_sys_cve_allowlist": "true"
    }
  }'

Step 3: Configure Content Trust

# Enable content trust at project level
curl -k -X PUT "https://harbor.example.com/api/v2.0/projects/myproject" \
  -H "Authorization: Basic $(echo -n admin:Harbor12345 | base64)" \
  -H "Content-Type: application/json" \
  -d '{
    "metadata": {
      "enable_content_trust": "true",
      "enable_content_trust_cosign": "true"
    }
  }'

# Sign image with Cosign
cosign sign --key cosign.key harbor.example.com/myproject/myapp:v1.0.0

# Verify signature
cosign verify --key cosign.pub harbor.example.com/myproject/myapp:v1.0.0

Step 4: Configure RBAC and Project Isolation

# Create project with private visibility
curl -k -X POST "https://harbor.example.com/api/v2.0/projects" \
  -H "Authorization: Basic $(echo -n admin:Harbor12345 | base64)" \
  -H "Content-Type: application/json" \
  -d '{
    "project_name": "production",
    "metadata": {
      "public": "false",
      "auto_scan": "true",
      "prevent_vul": "true",
      "severity": "high"
    }
  }'

# Harbor roles: ProjectAdmin, Maintainer, Developer, Guest, LimitedGuest
# Add member with specific role
curl -k -X POST "https://harbor.example.com/api/v2.0/projects/production/members" \
  -H "Authorization: Basic $(echo -n admin:Harbor12345 | base64)" \
  -H "Content-Type: application/json" \
  -d '{
    "role_id": 3,
    "member_user": {"username": "developer1"}
  }'

Step 5: Configure Immutable Tags and Retention

# Create tag immutability rule (prevent overwriting release tags)
curl -k -X POST "https://harbor.example.com/api/v2.0/projects/production/immutabletagrules" \
  -H "Authorization: Basic $(echo -n admin:Harbor12345 | base64)" \
  -H "Content-Type: application/json" \
  -d '{
    "tag_filter": "v*",
    "scope_selectors": {
      "repository": [{"kind": "doublestar", "decoration": "repoMatches", "pattern": "**"}]
    }
  }'

# Configure retention policy (keep last 10 tags, delete untagged after 7 days)
curl -k -X POST "https://harbor.example.com/api/v2.0/retentions" \
  -H "Authorization: Basic $(echo -n admin:Harbor12345 | base64)" \
  -H "Content-Type: application/json" \
  -d '{
    "algorithm": "or",
    "rules": [
      {
        "action": "retain",
        "template": "latestPushedK",
        "params": {"latestPushedK": 10},
        "tag_selectors": [{"kind": "doublestar", "decoration": "matches", "pattern": "**"}],
        "scope_selectors": {"repository": [{"kind": "doublestar", "decoration": "repoMatches", "pattern": "**"}]}
      }
    ],
    "trigger": {"kind": "Schedule", "settings": {"cron": "0 0 * * *"}}
  }'

Step 6: OIDC Authentication Integration

# Harbor configuration for OIDC
auth_mode: oidc_auth
oidc_name: "Okta"
oidc_endpoint: "https://company.okta.com/oauth2/default"
oidc_client_id: "harbor-client-id"
oidc_client_secret: "harbor-client-secret"
oidc_groups_claim: "groups"
oidc_admin_group: "harbor-admins"
oidc_scope: "openid,profile,email,groups"
oidc_verify_cert: true
oidc_auto_onboard: true

Validation Commands

# Test vulnerability prevention (should block pull of vulnerable image)
docker pull harbor.example.com/production/vulnerable-app:latest
# Expected: Error - image blocked due to vulnerabilities

# Verify content trust enforcement
DOCKER_CONTENT_TRUST=0 docker push harbor.example.com/production/unsigned:latest
# Expected: Push rejected due to content trust policy

# Check scan results via API
curl -k "https://harbor.example.com/api/v2.0/projects/production/repositories/myapp/artifacts/v1.0.0/additions/vulnerabilities" \
  -H "Authorization: Basic $(echo -n admin:Harbor12345 | base64)"

# Audit log check
curl -k "https://harbor.example.com/api/v2.0/audit-logs?page=1&page_size=10" \
  -H "Authorization: Basic $(echo -n admin:Harbor12345 | base64)"

When NOT to Use

• You need to test security controls (use performing-* skills)
• Task is about detecting bypasses (use detecting-* skills)
• You need to analyze security events (use analyzing-* skills)
• Task is about building security tools (use building-* skills)
• You don't have admin access to the system
• Task requires compliance certification (use auditing-* skills)

Red Flags

• Performing actions without explicit written authorization from the asset owner
• Testing against production systems without a defined scope and rules of engagement
• Modifying cloud IAM policies or security groups without approval
• Exposing cloud credentials or secrets in logs or reports
• Running scans that generate excessive API calls and trigger billing alerts

Verification

• All steps executed successfully against a test environment before production use
• Output documented with screenshots or logs demonstrating expected behavior
• Cloud resource changes reverted or documented as intentional
• IAM policies reviewed for least-privilege compliance after testing
• No residual test resources left running (cost and security check)

References

• Harbor Documentation
• Harbor Security Best Practices
• Harbor GitHub Repository

Process

1. Analyze the task requirements
2. Apply domain expertise
3. Verify output quality

Anti-Rationalization Table