---
layout: docs
page_title: Agent Sidecar Injector Installation
description: The Vault Agent Sidecar Injector can be installed using Vault Helm.
---

# Installing the agent injector

The [Vault Helm chart](/vault/docs/platform/k8s/helm) is the recommended way to
install and configure the Agent Injector in Kubernetes.

~> The Vault Agent Injector requires Vault 1.3.1 or greater.

To install a new instance of Vault and the Vault Agent Injector, first add the
Hashicorp helm repository and ensure you have access to the chart:

@include 'helm/repo.mdx'

Then install the chart and enable the injection feature by setting the
`injector.enabled` value to `true`:

```bash
helm install vault hashicorp/vault --set="injector.enabled=true"
```

Upgrades may be performed with `helm upgrade` on an existing install. Please
always run Helm with `--dry-run` before any install or upgrade to verify
changes.

You can see all the available values settings by running `helm inspect values hashicorp/vault` or by reading the [Vault Helm Configuration
Docs](/vault/docs/platform/k8s/helm/configuration). Commonly used values in the Helm
chart include limiting the namespaces the injector runs in, TLS options and
more.

## TLS options

Admission webhook controllers require TLS to run within Kubernetes. The Injector
defaults to supporting TLS 1.2 and above, and supports configuring the minimum
supported TLS version and list of enabled cipher suites. These can be set via
the following environment variables:

| Environment variable             | Description                                                                                                                    |
| -------------------------------- | ------------------------------------------------------------------------------------------------------------------------------ |
| `AGENT_INJECT_TLS_MIN_VERSION`   | Minimum supported version of TLS. Defaults to **tls12**. Accepted values are `tls10`, `tls11`, `tls12`, or `tls13`.            |
| `AGENT_INJECT_TLS_CIPHER_SUITES` | Comma-separated list of enabled [cipher suites][tls-suites] for TLS 1.0-1.2. (Cipher suites are not configurable for TLS 1.3.) |

~> **Warning**: TLS 1.1 and lower are generally considered insecure.

These may be set in a Helm chart deployment via the
[injector.extraEnvironmentVars](/vault/docs/platform/k8s/helm/configuration#extraenvironmentvars)
option:

```bash
helm install vault hashicorp/vault \
  --set="injector.extraEnvironmentVars.AGENT_INJECT_TLS_MIN_VERSION=tls13" \
  --set="injector.extraEnvironmentVars.AGENT_INJECT_TLS_CIPHER_SUITES=..."
```

The Vault Agent Injector also supports two TLS management options:

- Auto TLS generation (default)
- Manual TLS

### Auto TLS

By default, the Vault Agent Injector will bootstrap TLS by generating a certificate
authority and creating a certificate/key to be used by the controller. If using
Vault Helm, the chart will automatically create the necessary DNS entries for the
controller's service used to verify the certificate.

### Manual TLS

If desired, users can supply their own TLS certificates, key and certificate authority.
The following is required to configure TLS manually:

- Server certificate/key
- Base64 PEM encoded Certificate Authority bundle

For more information on configuring manual TLS, see the [Vault Helm cert values](/vault/docs/platform/k8s/helm/configuration#certs).

This option may also be used in conjunction with [cert-manager for certificate management](/vault/docs/platform/k8s/helm/examples/injector-tls-cert-manager).

## Multiple replicas and TLS

The Vault Agent Injector can be run with multiple replicas if using [Manual
TLS](#manual-tls) or [cert-manager](/vault/docs/platform/k8s/helm/examples/injector-tls-cert-manager), and as of v0.7.0 multiple replicas are also supported with
[Auto TLS](#auto-tls). The number of replicas is controlled in the Vault Helm
chart by the [injector.replicas
value](/vault/docs/platform/k8s/helm/configuration#replicas).

With Auto TLS and multiple replicas, a leader replica is determined by ownership
of a ConfigMap named `vault-k8s-leader`. Another replica can become the leader
once the current leader replica stops running, and the Kubernetes garbage
collector deletes the ConfigMap. The leader replica is in charge of generating
the CA and patching the webhook caBundle in Kubernetes, and also generating and
distributing the certificate and key to the "followers". The followers read the
certificate and key needed for the webhook service listener from a Kubernetes
Secret, which is updated by the leader when a certificate is near expiration.

With Manual TLS and multiple replicas,
[injector.leaderElector.enabled](/vault/docs/platform/k8s/helm/configuration#enabled-2)
can be set to `false` since leader determination is not necessary in this case.

## Namespace selector

By default, the Vault Agent Injector will process all namespaces in Kubernetes except
the system namespaces `kube-system` and `kube-public`. To limit what namespaces
the injector can work in a namespace selector can be defined to match labels attached
to namespaces.

For more information on configuring namespace selection, see the [Vault Helm namespaceSelector value](/vault/docs/platform/k8s/helm/configuration#namespaceselector).

[tls-suites]: https://golang.org/src/crypto/tls/cipher_suites.go
