Vault installation to Red Hat OpenShift via Helm
Red Hat's OpenShift is a distribution of the Kubernetes platform that provides a number of usability and security enhancements
In this tutorial, you login to an OpenShift cluster, install Vault via the Helm chart and then configure the authentication between Vault and the cluster. Then you deploy two web applications. One that authenticates and requests secrets directly from the Vault server. The other that employs deployment annotations that enable it to remain Vault unaware.
Prerequisites
This tutorial was last tested 14 Jul 2020 on a macOS 10.15.5 using this configuration.
Verify the RedHat OpenShift Local version.
Verify the Helm version.
These are recommended software versions and the output displayed may vary depending on your environment and the software versions you use.
Retrieve the web application and additional configuration by cloning the hashicorp/learn-vault-redhat-openshift repository from GitHub.
This repository contains the supporting content for this tutorial.
Go to the
learn-vault-redhat-openshift
directory.Working directory
This tutorial assumes that the remainder of commands are executed within this directory.
Configure and start the OpenShift cluster
RedHat OpenShift Local provisions and manages the lifecycle of OpenShift clusters running on your local system.
Configure RedHat OpenShift Local.
Start the OpenShift cluster and enter the pull secret.
Image Pull Secret
This secret is generated and stored in your Red Hat account.
The cluster starts and describes how to setup the environment and login as an administrator.
Apply the
oc-env
into the current shell session.The OpenShift CLI is accessed using the command
oc
. From here, you can administrate the entire OpenShift cluster and deploy new applications. The CLI exposes the underlying Kubernetes orchestration system with the enhancements made by OpenShift.Login to the OpenShift cluster with as the user admin with the command provided by the
crc start
command. Replace the user (-u
), password (-p), and URL with the values from the
crc start` command.Example:
The output displays that you are logged in as an admin within the
default
project.
Install the Vault Helm chart
The recommended way to run Vault on OpenShift is via the Helm chart. Helm is a package manager that installs and configures all the necessary components to run Vault in several different modes. To install Vault via the Helm chart in the next step requires that you are logged in as administrator within a project.
Add the Hashicorp Helm repository.
Update all the repositories to ensure
helm
is aware of the latest versions.Install the latest version of the Vault server running in development mode configured to work with OpenShift.
Example output:
The Vault pod and Vault Agent Injector pod are deployed in the default namespace.
Display all the pods within the default namespace.
The
vault-0
pod runs a Vault server in development mode. Thevault-agent-injector
pod performs the injection based on the annotations present or patched on a deployment.Wait until the
vault-0
pod andvault-agent-injector
pod are running and ready (1/1
).
Configure Kubernetes authentication
Vault provides a Kubernetes authentication method that enables clients to authenticate with Vault within an OpenShift cluster. This authentication method configuration requires the location of the Kubernetes API, which is available in environment variables within the pod.
Start an interactive shell session on the
vault-0
pod.Your system prompt is replaced with a new prompt
/ #
. Commands issued at this prompt are executed on thevault-0
container.Enable the Kubernetes authentication method.
Configure the Kubernetes authentication method to use the location of the Kubernetes host. It will automatically use the pod's own identity to authenticate with Kubernetes when querying the token review API.
Example output:
The authentication method is now configured.
Exit the
vault-0
pod.
Deployment: Request secrets directly from Vault
Applications on pods can directly communicate with Vault to authenticate and request secrets. An application needs a:
- Service account
- Vault secret
- Vault policy to read the secret
- Kubernetes authentication role
Create the service account
Display the service account defined in
service-account-webapp.yml
.This definition of the service account creates the account with the name
webapp
.Apply the service account.
Get all the service accounts within the default namespace.
The
webapp
service account is displayed.
Create the secret
Start an interactive shell session on the
vault-0
pod.Your system prompt is replaced with a new prompt
/ #
. Commands issued at this prompt are executed on thevault-0
container.Create a secret at path
secret/webapp/config
with ausername
andpassword
.Example output:
Get the secret at path
secret/webapp/config
.The secret with the username and password is displayed.
Define the read policy
Write out the policy named
webapp
that enables theread
capability for secrets at pathsecret/data/webapp/config
.Example output:
The policy
webapp
is used in the Kubernetes authentication role definition.
Create a Kubernetes authentication role
Create a Kubernetes authentication role, named
webapp
, that connects the Kubernetes service account name andwebapp
policy.Example output:
The role connects the Kubernetes service account,
webapp
, the namespace,default
, with the Vault policy,webapp
. The tokens returned are valid for 24 hours.Exit the
vault-0
pod.
Deploy the application
Display the webapp deployment defined in
deployment-webapp.yml
.deployment-webapp.ymlThe deployment deploys a pod with a web application running under the
webapp
service account that talks directly to the Vault service created by the Vault Helm charthttp://vault:8200
.Apply the webapp deployment.
Display all the pods within the default namespace.
Wait until the
webapp
pod is running and ready (1/1
).This web application runs an HTTP service that listens on port 8080.
Perform a
curl
request athttp://localhost:8080
on thewebapp
pod.Example output:
The web application running on port 8080 in the webapp pod:
- authenticates with the Kubernetes service account token
- receives a Vault token with the read capability at the
secret/data/webapp/config
path - retrieves the secrets from
secret/data/webapp/config
path - displays the secrets as JSON
Deployment: Secrets through annotations
Applications on pods can remain Vault unaware if they provide deployment annotations that the Vault Agent Injector detects. This injector service leverages the Kubernetes mutating admission webhook to intercept pods that define specific annotations and inject a Vault Agent container to manage these secrets. An application needs a:
- service account
- Vault secret
- Vault policy to read the secret
- Kubernetes authentication role
- Deployment with Vault Agent Injector annotations
Create the service account
Display the service account defined in
service-account-issues.yml
.This definition of the service account creates the account with the name
issues
.Apply the service account.
Get all the service accounts within the default namespace.
The
issues
service account is displayed.
Create the secret
Start an interactive shell session on the
vault-0
pod.Your system prompt is replaced with a new prompt
/ #
. Commands issued at this prompt are executed on thevault-0
container.Create a secret at path
secret/issues/config
with ausername
andpassword
.Example output:
Get the secret at path
secret/issues/config
.The secret with the username and password is displayed.
Define the read policy
Write the policy named
issues
that enables theread
capability for secrets at pathsecret/data/issues/config
.Example output:
The policy
issues
is used in the Kubernetes authentication role definition.
Create a Kubernetes authentication role
Create a Kubernetes authentication role, named
issues
, that connects the Kubernetes service account name andissues
policy.Example output:
The role connects the Kubernetes service account,
issues
, the namespace,default
, with the Vault policy,issues
. The tokens returned are valid for 24 hours.Exit the
vault-0
pod.
Deploy the application
Display the issues deployment defined in
deployment-issues.yml
.deployment-issues.yamlThe Vault Agent Injector service reads the metadata annotations prefixed with
vault.hashicorp.com
.agent-image
specifies the registry for the Vault Agent Injectoragent-inject
enables the Vault Agent injector servicerole
is the Vault Kubernetes authentication roleagent-inject-secret-FILEPATH
prefixes the path of the file,issues-config.txt
written to the/vault/secrets
directory. The value is the path to the Vault secret.agent-inject-template-FILEPATH
formats the secret with a provided template.
Apply the issues deployment.
Display all the pods within the default namespace.
Wait until the
issues
pod is running and ready (2/2
).This new pod now launches two containers. The application container, named
issues
, and the Vault Agent container, namedvault-agent
.Display the logs of the
vault-agent
container in theissues
pod.Example output:
Display the secret written to the
issues
container.Example output:
The secrets are rendered in a PostgreSQL connection string is present on the container.
Next steps
You launched Vault within OpenShift with a Helm chart. Learn more about the Vault Helm chart by reading the documentation or exploring the project source code.
Then you deployed a web application that authenticated and requested a secret directly from Vault. And finally, deployed a web application that injected secrets based on deployment annotations supported by the Vault Agent Injector service. Learn more by reading the blog post announcing the Injecting Vault Secrets into Kubernetes Pods via a Sidecar, or the documentation for Vault Agent Injector service.