--- name: implementing-secrets-management-with-vault description: 'This skill covers deploying HashiCorp Vault for centralized secrets management across cloud environments, including dynamic secret generation for databases and cloud providers, transit encryption, PKI certificate management, and Kubernetes integration. It addresses eliminating hardcoded credentials from application code and CI/CD pipelines by implementing short-lived, automatically rotated secrets. ' domain: cybersecurity subdomain: cloud-security tags: - hashicorp-vault - secrets-management - dynamic-secrets - credential-rotation - zero-trust version: 1.0.0 author: mahipal license: Apache-2.0 nist_csf: - PR.IR-01 - ID.AM-08 - GV.SC-06 - DE.CM-01 --- # Implementing Secrets Management with Vault ## When to Use - When applications store database passwords, API keys, or certificates in environment variables or config files - When migrating from static long-lived credentials to dynamic short-lived secrets - When Kubernetes workloads need secure access to database credentials or cloud provider APIs - When compliance requirements mandate centralized credential management with audit logging - When CI/CD pipelines contain hardcoded secrets that represent supply chain risk **Do not use** for AWS-only environments where AWS Secrets Manager suffices without multi-cloud requirements, for application-level encryption logic (though Vault Transit can help), or for identity federation (see managing-cloud-identity-with-okta). ## Prerequisites - HashiCorp Vault server deployed in HA mode (Consul or Raft storage backend) - TLS certificates for Vault listener endpoints - Vault Enterprise license for namespaces, Sentinel policies, and replication (optional) - Kubernetes cluster with Vault Agent Injector or CSI provider for workload integration ## Workflow ### Step 1: Deploy Vault in High Availability Mode Deploy Vault using Integrated Storage (Raft) for HA without external dependencies. Configure TLS, audit logging, and auto-unseal using a cloud KMS. ```hcl # vault-config.hcl storage "raft" { path = "/opt/vault/data" node_id = "vault-node-1" retry_join { leader_api_addr = "https://vault-node-2.internal:8200" } retry_join { leader_api_addr = "https://vault-node-3.internal:8200" } } listener "tcp" { address = "0.0.0.0:8200" tls_cert_file = "/opt/vault/tls/vault.crt" tls_key_file = "/opt/vault/tls/vault.key" } seal "awskms" { region = "us-east-1" kms_key_id = "alias/vault-unseal-key" } api_addr = "https://vault-node-1.internal:8200" cluster_addr = "https://vault-node-1.internal:8201" telemetry { prometheus_retention_time = "30s" disable_hostname = true } ``` ```bash # Initialize Vault vault operator init -key-shares=5 -key-threshold=3 # Enable audit logging vault audit enable file file_path=/var/log/vault/audit.log # Enable syslog audit for SIEM integration vault audit enable syslog tag="vault" facility="AUTH" ``` ### Step 2: Configure Authentication Methods Enable authentication backends for human operators, applications, and CI/CD pipelines. Use AppRole for machine authentication and OIDC for human access. ```bash # Enable OIDC auth for human users via Okta vault auth enable oidc vault write auth/oidc/config \ oidc_discovery_url="https://company.okta.com/oauth2/default" \ oidc_client_id="vault-client-id" \ oidc_client_secret="vault-client-secret" \ default_role="default" # Enable AppRole for application authentication vault auth enable approle vault write auth/approle/role/web-app \ secret_id_ttl=10m \ token_num_uses=10 \ token_ttl=20m \ token_max_ttl=30m \ secret_id_num_uses=1 \ token_policies="web-app-policy" # Enable Kubernetes auth for pod-based access vault auth enable kubernetes vault write auth/kubernetes/config \ kubernetes_host="https://kubernetes.default.svc:443" \ token_reviewer_jwt=@/var/run/secrets/kubernetes.io/serviceaccount/token \ kubernetes_ca_cert=@/var/run/secrets/kubernetes.io/serviceaccount/ca.crt ``` ### Step 3: Enable Dynamic Secret Engines Configure database secret engines to generate short-lived credentials on demand. Each credential set has a TTL and is automatically revoked when it expires. ```bash # Enable database secrets engine for PostgreSQL vault secrets enable database vault write database/config/production-db \ plugin_name=postgresql-database-plugin \ allowed_roles="readonly,readwrite" \ connection_url="postgresql://{{username}}:{{password}}@db.internal:5432/production?sslmode=require" \ username="vault_admin" \ password="initial-password" # Rotate the root credentials so Vault manages them exclusively vault write -force database/rotate-root/production-db # Create a readonly role with 1-hour TTL vault write database/roles/readonly \ db_name=production-db \ creation_statements="CREATE ROLE \"{{name}}\" WITH LOGIN PASSWORD '{{password}}' VALID UNTIL '{{expiration}}'; GRANT SELECT ON ALL TABLES IN SCHEMA public TO \"{{name}}\";" \ revocation_statements="REVOKE ALL ON ALL TABLES IN SCHEMA public FROM \"{{name}}\"; DROP ROLE IF EXISTS \"{{name}}\";" \ default_ttl="1h" \ max_ttl="24h" # Enable AWS secrets engine for dynamic IAM credentials vault secrets enable aws vault write aws/config/root \ access_key=AKIAEXAMPLE \ secret_key=secretkey \ region=us-east-1 vault write aws/roles/deploy-role \ credential_type=iam_user \ policy_document=@deploy-policy.json \ default_sts_ttl=3600 ``` ### Step 4: Integrate with Kubernetes Workloads Use the Vault Agent Injector or CSI Provider to deliver secrets to pods without application code changes. Secrets are rendered as files in a shared volume. ```yaml # Kubernetes deployment with Vault Agent Injector annotations apiVersion: apps/v1 kind: Deployment metadata: name: web-app spec: template: metadata: annotations: vault.hashicorp.com/agent-inject: "true" vault.hashicorp.com/role: "web-app" vault.hashicorp.com/agent-inject-secret-db-creds: "database/creds/readonly" vault.hashicorp.com/agent-inject-template-db-creds: | {{- with secret "database/creds/readonly" -}} export DB_USERNAME="{{ .Data.username }}" export DB_PASSWORD="{{ .Data.password }}" {{- end }} spec: serviceAccountName: web-app containers: - name: web-app image: company/web-app:v2.1 command: ["/bin/sh", "-c", "source /vault/secrets/db-creds && ./start.sh"] ``` ### Step 5: Implement Transit Encryption and PKI Use the Transit secrets engine for application-level encryption without managing keys in application code. Deploy the PKI engine for automatic TLS certificate management. ```bash # Enable Transit engine for encryption as a service vault secrets enable transit vault write -f transit/keys/payment-data type=aes256-gcm96 # Encrypt sensitive data vault write transit/encrypt/payment-data \ plaintext=$(echo "card-number-4111-1111-1111-1111" | base64) # Enable PKI for internal certificate management vault secrets enable pki vault secrets tune -max-lease-ttl=87600h pki # Generate root CA vault write pki/root/generate/internal \ common_name="Internal Root CA" \ ttl=87600h # Configure intermediate CA for issuing certificates vault secrets enable -path=pki_int pki vault write pki_int/intermediate/generate/internal \ common_name="Internal Intermediate CA" \ ttl=43800h # Create a role for issuing certificates vault write pki_int/roles/internal-services \ allowed_domains="internal.company.com" \ allow_subdomains=true \ max_ttl=720h ``` ### Step 6: Establish Policies and Audit Trail Define fine-grained ACL policies following least privilege. Enable comprehensive audit logging for all secret access and administrative operations. ```hcl # web-app-policy.hcl path "database/creds/readonly" { capabilities = ["read"] } path "transit/encrypt/payment-data" { capabilities = ["update"] } path "transit/decrypt/payment-data" { capabilities = ["update"] } path "secret/data/web-app/*" { capabilities = ["read", "list"] } # Deny access to admin paths path "sys/*" { capabilities = ["deny"] } ``` ```bash # Apply the policy vault policy write web-app-policy web-app-policy.hcl # Verify audit log captures all operations vault audit list -detailed ``` ## Key Concepts | Term | Definition | |------|------------| | Dynamic Secrets | Credentials generated on-demand with automatic expiration and revocation, eliminating long-lived static credentials | | Secret Engine | Vault component that stores, generates, or encrypts data; includes KV, database, AWS, PKI, and Transit engines | | Auto-Unseal | Cloud KMS-based mechanism that automatically unseals Vault nodes on restart without manual key entry | | AppRole | Machine-oriented authentication method using Role ID and Secret ID for application and CI/CD pipeline access | | Transit Engine | Encryption-as-a-service engine that handles cryptographic operations without exposing encryption keys to applications | | Lease | Time-bound credential with a TTL that Vault automatically revokes on expiration unless renewed | | Namespace | Vault Enterprise feature providing tenant isolation with separate auth, secrets, and policy management | | Response Wrapping | Technique that wraps secret responses in a single-use token to prevent man-in-the-middle exposure during delivery | ## Tools & Systems - **HashiCorp Vault**: Core secrets management platform providing dynamic secrets, encryption, and identity-based access - **Vault Agent Injector**: Kubernetes mutating webhook that automatically injects Vault secrets into pod volumes via sidecar containers - **Vault CSI Provider**: Kubernetes CSI driver that mounts Vault secrets directly into pod volumes without sidecar containers - **consul-template**: Template rendering daemon that watches Vault secrets and re-renders configuration files when secrets change - **Vault Radar**: Secret scanning tool that detects hardcoded credentials in source code, CI/CD pipelines, and cloud configurations ## Common Scenarios ### Scenario: Eliminating Hardcoded Database Credentials from CI/CD Pipeline **Context**: A DevOps team stores PostgreSQL credentials in GitHub Actions secrets and Jenkins credential stores. The same credentials are shared across staging and production environments with no rotation for 18 months. **Approach**: 1. Deploy Vault with AppRole auth enabled for CI/CD systems 2. Configure the database secrets engine with separate roles for staging (readwrite, 2h TTL) and production (readonly, 1h TTL) 3. Create separate Vault policies for each pipeline stage restricting access to the appropriate database role 4. Update GitHub Actions workflows to authenticate via AppRole and request dynamic credentials at the start of each job 5. Rotate the static PostgreSQL credentials and hand root access to Vault exclusively 6. Enable audit logging to track every credential request with pipeline job metadata **Pitfalls**: Failing to rotate the original static credentials after Vault migration leaves the old credentials valid. Setting TTLs too short causes credential expiry mid-deployment for long-running jobs. ## Output Format ``` Vault Secrets Management Audit Report ======================================= Vault Cluster: vault.internal.company.com Version: 1.18.1 Enterprise HA Mode: Raft (3 nodes) Seal Type: AWS KMS Auto-Unseal Report Date: 2025-02-23 SECRET ENGINES: database/ PostgreSQL dynamic creds Leases Active: 47 aws/ Dynamic IAM credentials Leases Active: 12 transit/ Encryption as a service Keys: 8 pki/ Root CA Certs Issued: 0 pki_int/ Intermediate CA Certs Issued: 234 secret/ KV v2 static secrets Versions: 1,892 AUTH METHODS: oidc/ Okta SSO for humans Active Tokens: 23 approle/ CI/CD pipelines Active Tokens: 156 kubernetes/ Pod-based auth Active Tokens: 89 AUDIT FINDINGS: [WARN] 3 AppRole secret_id_num_uses set to 0 (unlimited) [WARN] 12 KV secrets not accessed in 90+ days (potential orphans) [PASS] All dynamic secret TTLs under 24 hours [PASS] Audit logging enabled on all nodes [PASS] Root token revoked after initial setup CREDENTIAL HYGIENE: Static Secrets (KV): 234 Dynamic Secrets Active: 59 Average Lease TTL: 2.3 hours Secrets Rotated This Month: 12,456 ```