Consul vs Vault: What are the differences?

Developers describe Consul as "A tool for service discovery, monitoring and configuration". Consul is a tool for service discovery and configuration. Consul is distributed, highly available, and extremely scalable. On the other hand, Vault is detailed as "Secure, store, and tightly control access to tokens, passwords, certificates, API keys, and other secrets in modern computing". Vault is a tool for securely accessing secrets. A secret is anything that you want to tightly control access to, such as API keys, passwords, certificates, and more. Vault provides a unified interface to any secret, while providing tight access control and recording a detailed audit log.

Consul can be classified as a tool in the "Open Source Service Discovery" category, while Vault is grouped under "Secrets Management".

Some of the features offered by Consul are:

• Service Discovery - Consul makes it simple for services to register themselves and to discover other services via a DNS or HTTP interface. External services such as SaaS providers can be registered as well.
• Health Checking - Health Checking enables Consul to quickly alert operators about any issues in a cluster. The integration with service discovery prevents routing traffic to unhealthy hosts and enables service level circuit breakers.
• Key/Value Storage - A flexible key/value store enables storing dynamic configuration, feature flagging, coordination, leader election and more. The simple HTTP API makes it easy to use anywhere.

On the other hand, Vault provides the following key features:

• Secure Secret Storage: Arbitrary key/value secrets can be stored in Vault. Vault encrypts these secrets prior to writing them to persistent storage, so gaining access to the raw storage isn't enough to access your secrets. Vault can write to disk, Consul, and more.
• Dynamic Secrets: Vault can generate secrets on-demand for some systems, such as AWS or SQL databases. For example, when an application needs to access an S3 bucket, it asks Vault for credentials, and Vault will generate an AWS keypair with valid permissions on demand. After creating these dynamic secrets, Vault will also automatically revoke them after the lease is up.
• Data Encryption: Vault can encrypt and decrypt data without storing it. This allows security teams to define encryption parameters and developers to store encrypted data in a location such as SQL without having to design their own encryption methods.

"Great service discovery infrastructure" is the top reason why over 49 developers like Consul, while over 11 developers mention "Secure" as the leading cause for choosing Vault.

Consul and Vault are both open source tools. Consul with 16.4K GitHub stars and 2.85K forks on GitHub appears to be more popular than Vault with 13.2K GitHub stars and 1.98K GitHub forks.

According to the StackShare community, Consul has a broader approval, being mentioned in 134 company stacks & 55 developers stacks; compared to Vault, which is listed in 71 company stacks and 17 developer stacks.