springboot-vault-examples

The goal of this project is to explore the capabilities of Vault. To achieve this, we will develop applications that utilize Vault to store and retrieve secrets. Vault dynamically generates credentials for accessing databases and relies on Consul as the backend. The authentication method employed in Vault is AppRole.

Proof-of-Concepts & Articles

On ivangfr.github.io, I have compiled my Proof-of-Concepts (PoCs) and articles. You can easily search for the technology you are interested in by using the filter. Who knows, perhaps I have already implemented a PoC or written an article about what you are looking for.

Additional Readings

• [Medium] Using HashiCorp Vault & Spring Cloud Vault to handle Spring Boot App Key/Value Secrets
• [Medium] Using HashiCorp Vault & Spring Cloud Vault to obtain Dynamic MySQL Credentials
• [Medium] How to Rotate Expired Spring Cloud Vault Relational DB Credentials Without Restarting the App

Lease Rotation

Many people encounter issues when using Vault, particularly with rotating the lease for backend databases. When a Spring Boot application requests a lease from Vault through the Spring Cloud Vault library, the library can automatically renew the lease periodically (based on default_lease_ttl).

However, once the maximum lease expiration time (max_lease_ttl) is reached, the lease cannot be renewed, and a new lease is needed. In this case, the Spring Cloud Vault library cannot rotate the lease, which may leave the application unable to connect to the database.

To address this issue, we have developed solutions for applications using Spring Cloud Vault or Spring Vault. Please see the examples below.

Examples

Example	Diagram
spring-cloud-vault-approle-mysql (with lease rotation)
spring-cloud-vault-approle-cassandra
spring-vault-approle-mysql (with lease rotation)
spring-vault-approle-multi-datasources-mysql (with lease rotation)

Prerequisites

• Java 25 or higher.
• A containerization tool (e.g., Docker, Podman, etc.)

Initialize Environment

Open a terminal and, inside the springboot-vault-examples root folder, run the following script:

./init-environment.sh

This script will:

• start Consul, Vault, MySQL, and Cassandra Docker containers.
• unseal Vault and enable AppRole in it.
• set up Database roles and policies in Vault for the applications so that they can access their databases using dynamically generated credentials.
• set up KV Secrets in Vault for the application.

Shutdown Environment

To shut down the environment, go to a terminal and, inside the springboot-vault-examples root folder, run the script below:

./shutdown-environment.sh

Cleanup

To remove all Docker images created by this project, go to a terminal and, inside the springboot-vault-examples root folder, run the following script:

./remove-docker-images.sh all