@backstage-community/plugin-vault-backend

A backend for Vault, this plugin adds a few routes that are used by the frontend plugin to fetch the information from Vault.

Introduction

Vault is an identity-based secrets and encryption management system. A secret is anything that you want to tightly control access to, such as API encryption keys, passwords, or certificates. Vault provides encryption services that are gated by authentication and authorization methods.

This plugins allows you to view all the available secrets at a certain location, and redirect you to the official UI so backstage can rely on LIST permissions, which is safer.

Getting started

To get started, first you need a running instance of Vault. You can follow this tutorial to install vault and start your server locally.

1. When your Vault instance is up and running, then you will need to install the plugin into your app:

     # From your Backstage root directory
     yarn --cwd packages/backend add @backstage-community/plugin-vault-backend

2. Create a file in src/plugins/vault.ts and add a reference to it in src/index.ts:

   // In packages/backend/src/plugins/vault.ts
   import { createRouter } from '@backstage-community/plugin-vault-backend';
   import { Router } from 'express';
   import { PluginEnvironment } from '../types';
   
   export default async function createPlugin(
     env: PluginEnvironment,
   ): Promise<Router> {
     return await createRouter({
       logger: env.logger,
       config: env.config,
       scheduler: env.scheduler,
     });
   }

   diff --git a/packages/backend/src/index.ts b/packages/backend/src/index.ts
   index f2b14b2..2c64f47 100644
   --- a/packages/backend/src/index.ts
   +++ b/packages/backend/src/index.ts
   @@ -22,6 +22,7 @@ import { Config } from '@backstage/config';
    import app from './plugins/app';
   +import vault from './plugins/vault';
    import scaffolder from './plugins/scaffolder';
   @@ -56,6 +57,7 @@ async function main() {
      const authEnv = useHotMemoize(module, () => createEnv('auth'));
   +  const vaultEnv = useHotMemoize(module, () => createEnv('vault'));
      const proxyEnv = useHotMemoize(module, () => createEnv('proxy'));
   @@ -63,6 +65,7 @@ async function main() {
   
      const apiRouter = Router();
      apiRouter.use('/catalog', await catalog(catalogEnv));
   +  apiRouter.use('/vault', await vault(vaultEnv));
      apiRouter.use('/scaffolder', await scaffolder(scaffolderEnv));

3. Add some extra configurations in your app-config.yaml.

   vault:
     baseUrl: http://your-internal-vault-url.svc
     publicUrl: https://your-vault-url.example.com
     auth:
       type: static
       secret: <VAULT_TOKEN>
     secretEngine: 'customSecretEngine' # Optional. By default it uses 'secrets'. Can be overwritten by the annotation of the entity
     kvVersion: <kv-version> # Optional. The K/V version that your instance is using. The available options are '1' or '2'
     schedule: # Optional. If the token renewal is enabled this schedule will be used instead of the hourly one
       frequency: { hours: 1 }
       timeout: { hours: 1 }

4. Get a VAULT_TOKEN with LIST permissions, as it's enough for the plugin. You can check this tutorial for more info.

5. If you also want to use the renew functionality, you need to attach the following block to your custom policy, so that Backstage can perform a token-renew:

     # Allow tokens to renew themselves
     path "auth/token/renew-self" {
       capabilities = ["update"]
     }

Login via Kubernetes Auth Method

Alternatively, it's also possible to make Backstage use the Kubernetes auth method to login into Vault. For that, the configuration should look like this:

vault:
  baseUrl: http://your-internal-vault-url.svc
  publicUrl: https://your-vault-url.example.com
  token:
    type: kubernetes
    role: <KUBERNETES_ROLE>
    authPath: <KUBERNETES_AUTH_PATH> # Optional. It defaults to 'kubernetes', but you could set a different authPath if needed
    serviceAccountTokenPath: <PATH_TO_JWT> # Optional. It defaults to '/var/run/secrets/kubernetes.io/serviceaccount/token'. Where the JWT token is located
  secretEngine: 'customSecretEngine' # Optional. By default it uses 'secrets'. Can be overwritten by the annotation of the entity
  kvVersion: <kv-version> # Optional. The K/V version that your instance is using. The available options are '1' or '2'

In these cases the token renewal is not needed. The backend will automatically fetch the token for each request.

New Backend System

The Vault backend plugin has support for the new backend system, here's how you can set that up:

In your packages/backend/src/index.ts make the following changes:

  import { createBackend } from '@backstage/backend-defaults';
  const backend = createBackend();
  // ... other feature additions
+ backend.add(import('@backstage-community/plugin-vault-backend');
  backend.start();

The token renewal is enabled automatically in the new backend system depending on the app-config.yaml. If the schedule is not defined there, no task will be executed. If you want to use the default renewal scheduler (which runs hourly), set schedule: true. In case you want a custom schedule just use a configuration like the one set above.

Integration with the Catalog

The plugin can be integrated into each Component in the catalog. To allow listing the available secrets a new annotation must be added to the catalog-info.yaml:

apiVersion: backstage.io/v1alpha1
kind: Component
metadata:
  # ...
  annotations:
    vault.io/secrets-path: path/to/secrets

The path is relative to your secrets engine folder. So if you want to get the secrets for backstage and you have the following directory structure:

.
├── ...
├── secrets                 # Your secret engine name (usually it is `secrets`)
│   ├── test                # Folder with test secrets
│   │   ├── backstage       # In this folder there are secrets for Backstage
│   ├── other               # Other folder with more secrets inside
│   └── folder              # And another folder
└── ...

You will set the vault.io/secret-path to test/backstage. If the folder backstage contains other sub-folders, the plugin will fetch the secrets inside them and adapt the View and Edit URLs to point to the correct place.

In case you need to support different secret engines for entities of the catalog you can provide optional annotation to the entity in catalog-info.yaml:

 apiVersion: backstage.io/v1alpha1
 kind: Component
 metadata:
   # ...
   annotations:
     vault.io/secrets-path: path/to/secrets
+    vault.io/secrets-engine: customSecretEngine # Optional. By default it uses the 'secretEngine' value from your app-config.

That will overwrite the default secret engine from the configuration.

Renew token

In a secure Vault instance, it's usual that the tokens are refreshed after some time. In order to always have a valid token to fetch the secrets, it might be necessary to execute a renew action after some time. By default this is deactivated, but it can be easily activated and configured to be executed periodically (hourly by default, but customizable by the user within the app-config.yaml file). In order to do that, modify your src/plugins/vault.ts file to look like this one:

import { VaultBuilder } from '@backstage-community/plugin-vault-backend';
import { Router } from 'express';
import { PluginEnvironment } from '../types';

export default async function createPlugin(
  env: PluginEnvironment,
): Promise<Router> {
  const builder = await VaultBuilder.createBuilder({
    logger: env.logger,
    config: env.config,
    scheduler: env.scheduler,
  }).enableTokenRenew(
    env.scheduler.createScheduledTaskRunner({
      frequency: { minutes: 10 },
      timeout: { minutes: 1 },
    }),
  );

  const { router } = builder.build();

  return router;
}

If the taskRunner is not set when calling the enableTokenRenew, the plugin will automatically check what is set in the app-config.yaml file. Refer to the new backend system setup for more information about it.

Features

• List the secrets present in a certain path
• Use different secret engines for different entities
• Open a link to view the secret
• Open a link to edit the secret
• Renew the token automatically with a defined periodicity

The secrets cannot be edited/viewed from within Backstage to make it more secure. Backstage will only have permissions to LIST data from Vault or to renew its own token if that is needed. And the user who wants to edit/view a certain secret needs the correct permissions to do so.