OpenBao is a **secret management tool** embedded into your application stack. It can handle the creation, storage, and management of secrets, ensuring they remain secure. For seamless integration across multiple Kubernetes applications, OpenBao works with the [Kubernetes External Secrets Operator](https://external-secrets.io/latest/), which converts OpenBao’s secrets into Kubernetes secrets.
- **Authentication:** Before a human or machine can gain any access, an administrator must configure OpenBao with an auth method. When a client tries to log in to OpenBao, the system checks client’s data against an internal or external (see *Validation* below) system. Once authenticated, Vault generates an **access token** for the client. This token is then used for every action performed in OpenBao.
<bstyle="color:orange">Note: the administrator can provide you with an already generated access token</b>
- **Validation:** If trusted third-party credential repositories (e.g., GitHub, LDAP, AppRole) are specified, OpenBao forwards authentication to them.
- **Authorization:** Vault applies policies based on the authentication method and rules set by the admin to the token that was generated during authentication. Policies provide a declarative way to grant or forbid access to certain **paths** and **operations** in OpenBao.
- **Access:** The client uses the token for access to secrets, keys, or encryption capabilities, as per the associated policies.
If you want to read more about authentication, visit https://openbao.org/docs/concepts/auth/
### Controlled Access
OpenBao uses policies to manage access to secrets. Policies are basically a **combination of paths and capabilities** (operations) that they allow on these path. Let’s consider this example:
This policy permits *creating*, *reading*, *listing*, and *deleting* the password at `secret/app1/`, but only allows *reading* and *listing***all** resources in `secret/app2/` and its subpaths.
[Here's a tutorial how to use it.](#controlled-access-2)
For even deeper understanding, go to https://openbao.org/docs/concepts/policies/
### Leasing and Revocation
To simplify key rolling processes, consumers using OpenBao should regularly verify their subscription status to either renew leases where permitted or request replacements for secrets that need updating.
In addition to that, a lease can be revoked manually. When this happens, it invalidates that secret immediately and prevents any further renewals. OpenBao can revoke not only single secrets, but a tree of secrets, for example all secrets read by a specific user, or all secrets of a particular type.
For example:
In the Kubernetes secrets engine, revoking a lease deletes associated Kubernetes service accounts, immeditally rendering their access keys invalid.
[Here's a tutorial how to use it.](#leasing-and-revocation-2)
### Dynamic Secrets
OpenBao generates temporary secrets for systems like Kubernetes, AWS, or SQL databases, only when needed. These secrets are revoked automatically after their Time-To-Live expires.
For example:
An application requests Kubernetes credentials from OpenBao, which generates a token with specific permissions. The token is automatically revoked after its lease ends.
[Here's a tutorial how to use it.](#dynamic-secrets-2)
### Encryption as a Service
The transit secrets engine handles cryptographic operations on data in transit without storing it. It can encrypt, decrypt, sign, verify, and generate hashes or random bytes.
For example:
Your application sends data to OpenBao for encryption before saving it to a database. OpenBao can then decrypt the data on demand, ensuring security even if the database is compromised.
[Here's a tutorial how to use it.](#encryption-as-a-service-2)
Here you can read more about the transit secrets engine https://openbao.org/docs/secrets/transit/
### Audit devices and logs
**Audit devices** are the tool for collecting detailed **logs** of all requests to OpenBao, and their responses. Because every operation with OpenBao is an API request/response, when using a single audit device, the audit log contains every interaction with the OpenBao API, including errors - except for a few paths which do not go via the audit system.
**Audit log** telemetry on the other hand provides information on the health of your configured audit devices.
[Here's a tutorial how to use it.](#audit-devices-and-logs-2)
For more information, plese read https://openbao.org/docs/audit/ and https://openbao.org/docs/internals/telemetry/metrics/audit/
### Secret Engines
One of the core concepts of OpenBao are secret engines. Think of them as a set of path-based APIs, that can be provided with some set of data, after which they take some action on that data, and they return a result.
Let’s shortly take a look at all the OpenBao’s secret engines to better understand what they are.
1. **Key-Value** secret engines – for storing key value pairs
6. **Kubernetes** secrets engine - for seamless integration with containerized applications
Here you can find out more about secret engines https://openbao.org/docs/secrets/
## How to set it up?
<bstyle="color:red; background:pink"> Note: This paragraph will be absolete in the future as the functionality will be automated.</b>
<br>
<bstyle="color: orange"> Hint: To be able to use OpenBao it has to be unsealed first. This happens automatically. While unsealing an initial token is being created. To access this token just run the ./getpassword.sh script. </b>
The External Secrets Operator needs a kubernetes secret containing the **OpenBao's initial token** (see above) to access its secrets. You can create it with:
To fetch it as a kubernetes secret you'll need to create an **external-secrets.yaml** file and apply it to the cluster with `kubectl apply -f external-secrets.yaml`
refreshInterval: "15s" #This specifies the time interval at which the ExternalSecret controller will refresh the secrets.
secretStoreRef: # This references the first file.
name: bao-backend
kind: SecretStore
target: #This specifies the target Kubernetes secret that the ExternalSecret will create.
name: postgres-secret
creationPolicy: Owner
data: # This is an array of secret key-value pairs that the ExternalSecret will retrieve from the Vault secret store and store in the Kubernetes secret.
- secretKey: POSTGRES_USER #Name of the k8 secret that is being created
remoteRef: #This is an object that contains the reference to the secret in the Vault secret store.
key: data/postgres # This specifies the path to the secret in the Vault secret store
property: POSTGRES_USER #This specifies the name of the secret property to retrieve from the Vault secret.
- secretKey: POSTGRES_PASSWORD
remoteRef:
key: data/postgres
property: POSTGRES_PASSWORD
```
After that just run `kubectl get externalsecrets -A` to check that there are no problems with synchronization. And to access the secret on your cluster run: `kubectl get secrets -n openbao`
