Consul vs Vault: What are the differences?

Consul and Vault are two popular tools developed by HashiCorp that serve different purposes in the realm of infrastructure management and security. Let's explore the key differences between the two:

1. Purpose and Functionality: Consul focuses on enabling service discovery and networking functionalities within a distributed system. It provides a robust platform for service registration, health checking, distributed key-value storage, and multi-datacenter communication. In contrast, Vault is specifically built to address the security concerns of sensitive data within an infrastructure. It offers secure secret management, encryption as a service, dynamic secrets, and access control capabilities.

2. Use Case: Consul is commonly used in scenarios where there is a need for automatic service registration and discovery, load balancing, and failure detection in a distributed environment. It is often utilized in microservices architectures or containerized applications. On the other hand, Vault is utilized to secure sensitive data and manage secrets across different applications, services, or infrastructure components. Its use cases span across secure cloud migrations, secret rotation, database credential management, and more.

3. Key Features: Consul provides features like DNS-based service discovery, advanced health checking, key-value storage, service mesh integration, and distributed configuration management. It also offers powerful networking functionalities like service segmentation and load balancing. In contrast, Vault offers features like centralized secret management, dynamic secrets, transit encryption, secure key generation and rotation, cryptographic operations, and access control policies.

4. Security Focus: While both Consul and Vault have security-related features, their main focus differs. Consul offers built-in security mechanisms such as TLS encryption, ACLs (Access Control Lists), and secure gossip protocol to ensure secure communication between nodes. However, Vault's primary focus is on securing and managing sensitive data within the infrastructure. It uses various encryption techniques, provides secure storage for secrets, and allows fine-grained access control and auditing.

5. Integration and Ecosystem: Consul integrates well with various platforms, frameworks, and cloud providers. It works seamlessly with popular container orchestration tools like Kubernetes, supports service mesh architectures like Istio, and can be easily integrated with cloud platforms like AWS, Azure, or GCP. In contrast, Vault integrates with authentication providers, databases, cloud platforms, and existing infrastructure components. It can handle dynamic secrets for databases, integrate with LDAP or OAuth, and provide encryption as a service for applications.

6. Open Source vs. Enterprise Edition: Consul is available as an open-source tool with a vibrant community, and the core functionality is free to use. However, HashiCorp also offers a commercial enterprise edition called Consul Enterprise, which provides additional features and support for large-scale deployments. On the other hand, Vault is available in both open-source and enterprise editions, with the enterprise version offering advanced features like HSM (Hardware Security Module) integration, replication, and advanced audit logs.

In summary, Consul focuses on service discovery and networking aspects, while Vault excels in secure secret management and data protection. However, both tools can be used together to enhance the overall security and reliability of an infrastructure.