Jenkins Vault Plugin

This plugin adds a build wrapper to set environment variables from a HashiCorp Vault secret. Secrets are generally masked in the build log, so you can't accidentally print them.

Vault Authentication Backends

This plugin allows authenticating against Vault using the AppRole authentication backend. Hashicorp recommends using AppRole for Servers / automated workflows (like Jenkins) and using Tokens (default mechanism, Github Token, ...) for every developer's machine. Furthermore, this plugin allows using a Github personal access token, or a Vault Token - either configured directly in Jenkins or read from an arbitrary file on the Jenkins Machine.

How does AppRole work?

In short: you register an approle auth backend using a self-chosen name (e.g. Jenkins). This approle is identified by a role-id and secured with a secret_id. If you have both of those values you can ask Vault for a token that can be used to access vault. When registering the approle backend you can set a couple of different parameters:

How long should the secret_id live (can be indefinite)
how often can one use a token that is obtained via this backend
which IP addresses can obtain a token using role-id and secret-id?
many more

This is just a short introduction, please refer to Hashicorp itself to get detailed information.

What about other backends?

Hashicorp explicitly recommends the AppRole Backend for machine-to-machine authentication. Token based auth is mainly supported for backwards compatibility. Other backends that might make sense are the AWS EC2 backend, the Azure backend, and the Kubernetes backend. But we do not support these yet. Feel free to contribute!

Implementing additional authentication backends is actually quite easy:

Simply provide a class implementing VaultTokenCredential that contains a Descriptor extending BaseStandardCredentialsDescriptor. The Descriptor needs to be annotated with @Extension. Your credential needs to know how to authenticate with Vault and provide an authenticated Vault session. See VaultAppRoleCredential.java for an example.

Plugin Usage

Configuration

You can configure the plugin on three different levels:

Global: in your global config
Folder-Level: on the folder your job is running in
Job-Level: either on your freestyle project job or directly in the Jenkinsfile

The lower the level the higher its priority, meaning: if you configure a URL in your global settings, but override it in your particular job, this URL will be used for communicating with Vault. In your configuration (may it be global, folder or job) you see the following screen:

The credential you provide determines what authentication backend will be used. Currently, there are three different Credential Types you can use:

Vault App Role Credential

You enter your role-id and secret-id there. The description helps to find your credential later, the id is not mandatory (a UUID is generated by default), but it helps to set it if you want to use your credential inside the Jenkinsfile.

Vault GCP Credential

You enter your Vault GCP auth role name and audience. The JWT will be automatically retrieved from GCE metdata. This requires that Jenkins master is running on a GCE instance.

Vault Token Credential

Directly specify a token to be used when authenticating with vault.

Vault Token File Credential

Basically the same as the Vault Token Credential, just that the token is read from a file on your Jenkins Machine. You can use this in combination with a script that periodically refreshes your token.

Usage in FreeStyle Jobs

If you still use free style jobs (hint: you should consider migrating to Jenkinsfile), you can configure both configuration and the secrets you need on the job level.

The secrets are available as environment variables then.

Usage via Jenkinsfile

Let the code speak for itself:

node {
  // define the secrets and the env variables
  def secrets = [
      [$class: 'VaultSecret', path: 'secret/testing', secretValues: [
          [$class: 'VaultSecretValue', envVar: 'testing', vaultKey: 'value_one'],
          [$class: 'VaultSecretValue', envVar: 'testing_again', vaultKey: 'value_two']]],
      [$class: 'VaultSecret', path: 'secret/another_test', secretValues: [
          [$class: 'VaultSecretValue', envVar: 'another_test', vaultKey: 'value']]]
  ]

  // optional configuration, if you do not provide this the next higher configuration
  // (e.g. folder or global) will be used
  def configuration = [$class: 'VaultConfiguration',
                       vaultUrl: 'http://my-very-other-vault-url.com',
                       vaultCredentialId: 'my-vault-cred-id']

  // inside this block your credentials will be available as env variables
  wrap([$class: 'VaultBuildWrapper', configuration: configuration, vaultSecrets: secrets]) {
      sh 'echo $testing'
      sh 'echo $testing_again'
      sh 'echo $another_test'
  }
}

In the future we might migrate to a BuildStep instead of a BuildWrapper.

Migration Guide

Upgrade from 1.x to 2.0

The BuildWrapper did not change, so no changes to your Jenkinsfile should be necessary. However, you need to reconfigure Vault in your Jenkins instance based on the instructions above. There is no way to smoothly upgrade this, because this is a major rewrite and handling of configuration completly changed.

CHANGELOG

2018/08/22 - Feature Release - 2.2.0
- Add support for GCP authentication
2018/05/01 - Bugfix Release - 2.1.1
- MaskingConsoleLogFilter should filter out null secrets JENKINS-46792
- Avoid NPE Crash
- Switch to SimpleBuildWrapper for pipeline compatibility JENKINS-48049
- Dynamic secrets should be revoked after build wrapper completes JENKINS-46794
2017/05/22 - Feature Release - 2.1.0
- Vault Key Not Saved In Vault Error Messaging JENKINS-38647
- Add support github token auth JENKINS-38939
2017/05/19 - Bugfix Release - 2.0.1
- Build fails if plugin is enabled for a job without secrets specified JENKINS-44163
2017/04/27 - Breaking change release (AppRole auth backend, Folder ability, improved configuration, ...)
2017/04/10 - Feature Release - 1.4
- Support reading Vault Token from file on disk JENKINS-37713
- Using credentials plugin for authentication token JENKINS-38646
2017/03/03 - Feature Release - 1.3
- Vault Plugin should mask credentials in build log JENKINS-39383
2016/08/15 - Re-release due to failed maven release - 1.2
2016/08/11 - Bugfix release - 1.1
- Refactor to allow getting multiple vault keys in a single API call JENKINS-37151
2016/08/02 - Initial release - 1.0

jedidiahB/hashicorp-vault-plugin