Considerations for Using HashiCorp Vault

Thuan Nguyen · December 21, 2024

DevSecOps

1. What Are Normal Secrets?

Normal secrets typically refer to sensitive data stored in:

  • Environment Variables: Set directly in application runtime environments.
  • Configuration Files: Stored in files such as .env or YAML/JSON configuration files.
  • Kubernetes Secrets: Managed by Kubernetes as base64-encoded data.
  • Code Repositories: Hardcoded into application source code (though highly discouraged).

While these approaches are simple and easy to implement, they often lack security, scalability, and management capabilities.

2. What Is Vault (by HashiCorp)?

HashiCorp Vault is a centralized secrets management tool that:

  • Securely Stores Secrets: Encrypts data at rest and in transit.
  • Dynamic Secrets: Generates secrets on demand and automatically rotates them.
  • Access Control: Implements fine-grained policies using Identity and Access Management (IAM).
  • Audit Logs: Tracks access and secret usage.
  • Encryption-as-a-Service: Provides APIs for encrypting/decrypting data without exposing keys.
  • Multi-Cloud Integration: Supports AWS, Azure, GCP, Kubernetes, and other platforms.

Vault is designed to handle secrets in dynamic and scalable environments while addressing compliance requirements.

3. Key Differences Between Vault and Normal Secrets

Feature Normal Secrets HashiCorp Vault
Security Limited encryption (e.g., base64 encoding in Kubernetes). Strong encryption (AES-256) at rest and in transit.
Access Control Basic permissions or none. Fine-grained policies (ACLs) with dynamic roles.
Dynamic Secrets Not supported. Generates short-lived secrets on demand.
Secret Rotation Manual updates required. Automated rotation based on schedules or API calls.
Audit Logging Minimal or external tools required. Built-in detailed audit logs for compliance.
Scalability Difficult to scale with distributed applications. Centralized management with HA and distributed clusters.
Secret Revocation Manual revocation (delete/restart app). Dynamic revocation for expired or compromised secrets.
Integration Limited (e.g., environment variables). API-based integration with databases, cloud providers.
Encryption Service External tools required. Built-in Encryption-as-a-Service for sensitive data.

4. Considerations When Using HashiCorp Vault

1. Complexity and Learning Curve

Vault introduces additional complexity in setup and maintenance compared to traditional secret storage. It requires:

  • Deployment of Vault servers or containers.
  • Configuration of access policies and authentication methods.
  • Handling backups and scaling clusters for high availability (HA).

Tip: Use dev mode or Docker for local development to simplify testing.

2. Infrastructure Requirements

Vault demands dedicated resources and infrastructure:

  • Storage: Persistent volumes for secret storage.
  • Networking: Secure communication via TLS.
  • Monitoring: Vault’s health status must be continuously monitored.

Tip: Use Kubernetes or Docker Compose to manage deployments easily.

3. Authentication and Authorization

Vault supports multiple authentication backends such as AppRole, LDAP, and Kubernetes, but configuring them adds overhead.

  • Developers must define roles and policies to enforce fine-grained access.
  • Tokens and dynamic secrets require careful lifecycle management.

Tip: Use pre-configured roles for different environments (dev, staging, production) to simplify access control.

4. Dynamic Secrets and Rotation

Vault enables dynamic secret generation (e.g., database credentials) and automatic rotation, reducing exposure risks. However, services relying on dynamic secrets must:

  • Be capable of reloading credentials without restarts.
  • Handle secret expiration and renewals gracefully.

Tip: Test applications thoroughly to ensure compatibility with dynamic secrets.

5. Availability and Failover

Vault must always be unsealed to function. In the event of failures, it requires manual or automated recovery mechanisms.

  • High Availability (HA) setups with Consul or Integrated Storage are recommended for production.

Tip: Use Auto-Unseal with cloud services like AWS KMS or Azure Key Vault to simplify disaster recovery.

6. Cost and Licensing

HashiCorp Vault’s Community Edition is free, but advanced features like HSM integration, performance replication, and DR replication require the Enterprise Edition.

Tip: Start with the free version for development and scale up based on usage.

5. When to Use Vault Over Normal Secrets?

Use Normal Secrets If:

  • Simplicity is the top priority.
  • No dynamic secret rotation is needed.
  • Secrets are only for development or small applications.

Use HashiCorp Vault If:

  • High Security is required (e.g., financial or healthcare systems).
  • Applications require dynamic secrets (e.g., database credentials).
  • Compliance and audit logs are mandatory.
  • Teams need scalable secrets management across multiple environments.
  • Sensitive data must be encrypted without exposing keys.

6. Conclusion

HashiCorp Vault offers enterprise-grade security, scalability, and flexibility for secrets management, making it ideal for complex and regulated environments. In contrast, normal secrets stored in files or environment variables are easier to set up but lack advanced features like dynamic secrets, automatic rotation, and audit logging.

For local development, Vault can be simplified using dev mode or Docker Compose, but production deployments require more planning for HA, security, and scaling.

Whether you choose Vault or stick with normal secrets depends on your security requirements, scalability needs, and operational complexity. Evaluate your use case carefully and start experimenting with Vault in development to unlock its full potential!

7. References