Micronaut is a hugely popular framework in the Java world and it continues to grow in features and adoption. Recently, version 2.0.0.M3 was released which included a number of features, but of note to readers of this blog and users of Oracle Cloud is a feature that I recently contributed which adds support for using Oracle Cloud Vaults as encrypted distributed config stores for your Micronaut applications. This means that you can safely and securely store your configuration variables in your vault and with just a bit of configuration those values are made available in your microservice or serverless application. 

Hey There! If you're new to working with secrets and vaults in the Oracle Cloud, here's a perfect guide to getting started: Protect Your Sensitive Data With Secrets In The Oracle Cloud. Don't worry, I know the author of that guide. He's pretty cool!

Dependencies

To get started with this feature, add a few dependencies to your project:

Configuration

Next, you'll need to configure your application. For distributed configurations, you'll need to create a bootstrap.yaml file in src/main/resources.

You're able to supply as many vault IDs as you'd like to your configuration. Each vault will be retrieved and all of the secrets in the vault will be set to a configuration variable in your application using the same name as the vault key. This means that if you have a secret named FOO in vault "A" then a config var will be created named FOO in your application. Keep in mind, that if you have another secret named FOO in vault "B" then the variable created from vault "A" will be overwritten. 

Here's an example configuration file:

Refer to the docs for details about each configuration property, but note that this feature supports either config file-based authentication or instance principal auth. Instance principal authentication is a really easy method to use when deploying your application to the Oracle Cloud.

Accessing Configuration Variables

You're now ready to go! You can access the config vars in a few different ways. If you create a secret with the name of SECRET_ONE in your Oracle Cloud Vault, then it will be available to use in your application like any standard configuration variable:

You can also use @PropertyName:

Another option is to inject your variables in

Vault retrieved values are always String, but you can use @ConfigurationProperties on a bean in conjunction with your application.yml file to provide properly typed configuration variables.

So if you were to create secrets in your Oracle Cloud Vault like so:

And then added the following to your application.yml file:

You could add a config bean, like so:

You could then inject and use this bean in your application with properly typed values.

Calling the /hello/secret endpoint would return:

Another option is to inject your variables into your configuration files which gives you the ability to store things like database passwords and API keys in your vault:

This feature is fully documented in the official framework docs, so give it a shot today. Remember, you can create up to 5000 secrets in a vault absolutely free in your tenancy. This kind of data security is priceless, but when it costs you nothing you literally have no excuse not to keep your passwords, credentials, and API keys completely secure.

If you'd like to see a demo application that utilizes this feature, check out this project on GitHub: recursivecodes/vault-test.

Photo by Kristina Flour on Unsplash