# Feature Gates

Scylla Operator lets you enable or disable features using feature gates. This document provides an overview of the available feature gates and instructions on how to use them.

## Available feature gates

The following feature gates are available in Scylla Operator:

| Feature Gate             | Default   | Since   |
|--------------------------|-----------|---------|
| AutomaticTLSCertificates | `true`    | v1.11   |
| BootstrapSynchronisation | `false`   | v1.19   |
- The “Default” indicates if the feature is enabled when you don’t set it explicitly.
- The “Since” column indicates the Scylla Operator version in which the feature gate was introduced or its default was changed.

### AutomaticTLSCertificates

`AutomaticTLSCertificates` enables mTLS client connections to ScyllaDB.
When this feature is enabled, Scylla Operator automatically generates and rotates serving and client TLS certificates.
It also configures ScyllaDB nodes to use these certificates for secure client-to-node communication.

#### NOTE
Client certificates are validated by ScyllaDB nodes (the certificate chain must be trusted), but ScyllaDB does **not** perform client identity or authorization checks based on certificate contents.

Refer to [this document](https://operator.docs.scylladb.com/v1.19/resources/scyllaclusters/clients/cql.md#remote-cqlsh) for a guide to configuring ScyllaDB clients to use TLS certificates managed by Scylla Operator.

### BootstrapSynchronisation

`BootstrapSynchronisation` automates the process of ensuring that no nodes are down when a bootstrap operation is performed.
Scylla Operator will verify the status of all nodes in the cluster before allowing a new ScyllaDB node to bootstrap.

For more information, refer to the [Synchronising bootstrap operations in ScyllaDB clusters](https://operator.docs.scylladb.com/v1.19/management/bootstrap-sync.md) document explaining the feature in detail.

## Using feature gates

Feature gates can be enabled or disabled by configuring the `--feature-gates` command-line argument of Scylla Operator.
It is a comma-separated list of key-value pairs, where the key is the feature gate name and the value is a boolean indicating whether to enable or disable the feature.
For example, to enable the `AutomaticTLSCertificates` and `BootstrapSynchronisation` feature gates, set the argument to `AutomaticTLSCertificates=true,BootstrapSynchronisation=true`.

GitOps (kubectl)

To configure feature gates with GitOps (kubectl), modify the Scylla Operator Deployment by configuring the `--feature-gates` command-line argument in the Scylla Operator container.

```yaml
apiVersion: apps/v1
kind: Deployment
metadata:
  name: scylla-operator
  namespace: scylla-operator
spec:
  template:
    spec:
      containers:
      - name: scylla-operator
        args:
        - operator
        - --feature-gates=AutomaticTLSCertificates=true,BootstrapSynchronisation=true
```

Helm

To configure feature gates with Helm, configure the `--feature-gates` command-line argument through Scylla Operator’s `values.yaml`:

```yaml
additionalArgs: 
- --feature-gates=AutomaticTLSCertificates=true,BootstrapSynchronisation=true
```