Certification: Vault Associate (002)

Go Beyond Secrets

Joaquín Menchaca (智裕)
6 min readMay 15, 2024

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Hashicorp Vault is commonly recognized as a secrets manager, allowing for secure storage and retrieval of sensitive information. This function places it alongside similar solutions such as Keywhiz, Conjur, Doppler, Azure Key Vault, AWS Secrets Manager, and Google Cloud Secrets Manager.

However, Vault offers much more beyond the scope of securing secrets. The design patterns it utilizes are critical for developing scalable cloud-native infrastructure, regardless of whether Vault is the chosen tool. Consequently, pursuing the Hashicorp Certified Vault Associate certification is a worthwhile endeavor, providing valuable knowledge and skills for anyone building modern cloud infrastructure.

Vault Basics

Vault offers a range of secrets engines, with the most widely recognized being the key-value store called kv. To access these secrets or other Vault resources, you can utilize built-in authentication methods like UserPass and AppRole or various external authentication methods such as LDAP, Kerberos, RADIUS, and TLS. Additionally, Vault supports federated SSO with OIDC/JWT, SAML2, Okta, Github, and others.

Beyond basic secure storage and retrieval, Vault boasts advanced features. In this article, I’ll delve into two of these features before exploring how you can seamlessly integrate Vault into your local pipelines and applications:

  • Dynamic Secrets
  • Kubernetes Secrets

Dynamic Secrets

Most secrets that are commonly used are known as static secrets, which are credentials maintained over long periods, sometimes shared among developers, CI/CD pipelines, and potentially accessible by unauthorized users. The process of rotating and renewing these static secrets is often cumbersome, requiring the reconfiguration of numerous systems that utilized the key, and it might even lead to some outages. The risks associated with not regularly rotating static, especially shared secrets, include potential data breaches.

A viable alternative is the use of dynamic secrets, where passwords are generated on demand and rotated seamlessly behind the scenes without the need for any system reconfiguration. This approach enhances security by minimizing the exposure time of sensitive credentials.

Dynamic Secrets for the Cloud

So how does this work? Essentially Vault acts as an intermediary, where a client first logs into Vault to obtain the credential, such as an identity for AWS, Google Cloud, or Azure. Vault then provides the client with the necessary secret to access the specified cloud resource.

Dynamic Secrets for Databases

Vault’s capabilities extend beyond cloud environments to databases like PostgreSQL, MySQL/MariaDB, Elasticsearch, Cassandra, Redis, among others. Additional database support can be integrated through the creation of custom database plugin. This makes Vault a versatile tool for managing access across a variety of platforms.

Kubernetes Secrets

Kubernetes has emerged as a ubiquitous platform for orchestrating and scheduling container workloads. A key factor contributing to Kubernetes’ success is its built-in service discovery mechanism, enabling applications to locate their components and automatically replace failed instances through auto-healing features.

Behind the scenes, Kubernetes utilizes etcd to facilitate these functionalities. However, challenges arise when it comes to storing configurations and secrets in etcd. Despite their sensitive nature, secrets are stored with only base64 encoding, rendering them vulnerable to unauthorized access and retrieval by unknown actors.

📔 Side note: Hashicorp’s service discovery tool, Consul, faces a similar issue where secrets are stored using only base64 encoding, making them susceptible to unauthorized access just like etcd.

This makes it essential to use a solution that can encrypt secrets so that they are only accessed by the designated authorized service.

Integration with Kubernetes

There are a few methods to integrate Vault:

  1. VSO (Vault Secrets Operator): This service actively monitors and intercepts access to Kubernetes secrets, facilitating their automatic protection and secure management.
  2. Agent Injector (vault-k8s): This component deploys a sidecar alongside your applications, designed to inject secrets directly where they are needed.
  3. Vault CSI Provider (via Kubernetes Secrets Store CSI Driver): This feature employs a storage driver that can be integrated with various secret management systems, including Vault, enabling the mounting of secrets as a volume within a container.
  4. External Secrets Operator (unofficial community, not by Hashicorp): This tool automates the injection of values into Kubernetes secrets and can interface with different secret management systems, such as Vault.

Client Integrations

These are some ways to integrate with Vault for secrets management. Client support can be built into the application itself, but if this is not possible, then there are ways external scripts or services can access secrets.

The Official Hashicorp Integrations

Beyond the integration with Kubernetes orchestration platform, you can use some external tools to inject values into your application. For immutable infrastructure using containers, two common ways to inject values are through mounting a configuration file into the running container, or setting environment variables. Hashicorp has some tools to help with this integration:

  • Consul Template: a service that can fetch values from Consul, Nomad, or Vault and render them in a template. A common use case is to create configuration files dynamically.
  • envconsul: can set environment variables with the values fetched from Consul or Vault.
  • Vault Agent: can help facilitate token renewal, caching, proxying of Vault APIs, and auto-auth for legacy applications. This tool supports templating and facilitates access to Vault locally, which off loads some of the burden from the secrets infrastructure.

Community Integrations

There still may be a need to access secrets locally by a developer or a deployment system with tools like Helm, Ansible, or Terraform. Here are some methods on how this can be integrated locally.

  1. Mozilla SOPS: is a tool to encrypt secrets for local use using a variety of methods including Vault.
  2. Vals: a values loader that supports a variety of backends including Vault.

The Mozilla SOPS tool has a lot of community interests and so therefore, there are other forms of integration:

Some other integration with direct support for Hashicorp Vault:

Resources

Here are some articles that I came across when writing this article.

Articles

Code Repositories

Training

Conclusion

In conclusion, while Hashicorp Vault is renowned for its capabilities as a secrets manager, its significance extends far beyond mere secret storage and retrieval. Understanding Vault’s design patterns is pivotal for building scalable cloud-native infrastructure, making the pursuit of the Hashicorp Certified Vault Associate certification a valuable investment for modern cloud infrastructure practitioners.

Dynamic Secrets and Kubernetes Secrets are two advanced features that exemplify Vault’s versatility and power. Dynamic Secrets revolutionize the management of sensitive credentials by generating and rotating them on-demand, enhancing security and minimizing exposure risks. Meanwhile, integration with Kubernetes streamlines the management of configurations and secrets, ensuring they remain encrypted and accessible only to authorized services.

Whether through official methods like VSO and Agent Injector or community integrations like Mozilla SOPS and Helm Secrets plugin, there are numerous avenues to seamlessly integrate Vault into your systems and workflows, ensuring robust security and efficient secrets management across the board. As organizations continue to embrace cloud-native architectures, the role of tools like Vault becomes increasingly indispensable in safeguarding sensitive data and enabling seamless, secure operations.

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