Vault Plugin: Kubernetes Auth Backend
This is a standalone backend plugin for use with Hashicorp Vault.
This plugin allows for Kubernetes Service Accounts to authenticate with Vault.
Please note: We take Vault's security and our users' trust very seriously. If you believe you have found a security issue in Vault, please responsibly disclose by contacting us at security@hashicorp.com.
Quick Links
- Vault Website: https://www.vaultproject.io
- Kubernetes Auth Docs: https://www.vaultproject.io/docs/auth/kubernetes.html
- Main Project Github: https://www.github.com/hashicorp/vault
Getting Started
This is a Vault plugin
and is meant to work with Vault. This guide assumes you have already installed Vault
and have a basic understanding of how Vault works.
Otherwise, first read this guide on how to get started with Vault.
To learn specifically about how plugins work, see documentation on Vault plugins.
Security Model
The current authentication model requires providing Vault with a Service Account token, which can be used to make authenticated calls to Kubernetes. This token should not typically be shared, but in order for Kubernetes to be treated as a trusted third party, Vault must validate something that Kubernetes has cryptographically signed and that conveys the identity of the token holder.
We expect Kubernetes to support less sensitive mechanisms in the future, and the Vault integration will be updated to use those mechanisms when available.
Usage
Please see documentation for the plugin
on the Vault website.
This plugin is currently built into Vault and by default is accessed
at auth/kubernetes
. To enable this in a running Vault server:
$ vault auth-enable kubernetes
Successfully enabled 'kubernetes' at 'kubernetes'!
To see all the supported paths, see the Kubernetes auth backend docs.
Developing
If you wish to work on this plugin, you'll first need
Go installed on your machine
(version 1.8+ is required).
For local dev first make sure Go is properly installed, including
setting up a GOPATH.
Next, clone this repository into
$GOPATH/src/github.com/hashicorp/vault-plugin-auth-kubernetes
.
You can then download any required build tools by bootstrapping your
environment:
$ make bootstrap
To compile a development version of this plugin, run make
or make dev
.
This will put the plugin binary in the bin
and $GOPATH/bin
folders. dev
mode will only generate the binary for your platform and is faster:
$ make
$ make dev
Put the plugin binary into a location of your choice. This directory
will be specified as the plugin_directory
in the Vault config used to start the server.
...
plugin_directory = "path/to/plugin/directory"
...
Start a Vault server with this config file:
$ vault server -config=path/to/config.json ...
...
Once the server is started, register the plugin in the Vault server's plugin catalog:
$ vault write sys/plugins/catalog/kubernetes \
sha_256=<expected SHA256 Hex value of the plugin binary> \
command="vault-plugin-auth-kubernetes"
...
Success! Data written to: sys/plugins/catalog/kubernetes
Note you should generate a new sha256 checksum if you have made changes
to the plugin. Example using openssl:
openssl dgst -sha256 $GOPATH/vault-plugin-auth-kubernetes
...
SHA256(.../go/bin/vault-plugin-auth-kubernetes)= 896c13c0f5305daed381952a128322e02bc28a57d0c862a78cbc2ea66e8c6fa1
Enable the auth plugin backend using the Kubernetes auth plugin:
$ vault auth-enable -plugin-name='kubernetes' plugin
...
Successfully enabled 'plugin' at 'kubernetes'!
Tests
If you are developing this plugin and want to verify it is still
functioning (and you haven't broken anything else), we recommend
running the tests.
To run the tests, invoke make test
:
$ make test
You can also specify a TESTARGS
variable to filter tests like so:
$ make test TESTARGS='--run=TestConfig'