undermybelt 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
- 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
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)"