---
layout: docs
page_title: Plugin runtime settings
description: >-
   Learn about the available runtime settings for external plugins mounted in
   Vault.
---


# Plugin runtime settings

## Plugin environment variables

An advantage for external plugins over builtin plugins is they can specify
additional environment variables because they are run in their own process.

-> Vault 1.16.0 changed the precedence given to plugin-specific environment
variables so they take priority over Vault's environment. See full details in
the [upgrade notes](/vault/docs/upgrading/upgrade-to-1.16.x).

Use the `-env` flag once per environment variable that a plugin should be
started with:

```shell-session
$ vault plugin register -sha256=<SHA256 Hex value of the plugin binary> \
    -env REGION=eu \
    -env TOKEN_FILE=/var/run/token \
    secret \                  # type
    passthrough-plugin

Success! Registered plugin: passthrough-plugin
```

### Plugin-specific HTTP proxy settings

Many tools and libraries automatically consume `HTTP_PROXY`, `HTTPS_PROXY`, and
`NO_PROXY` environment variables to configure HTTP proxy settings, including the
Go standard library's default HTTP client. You can use these environment
variables to configure different network proxies for different plugins:

-> You must be using an external plugin to take advantage of custom environment
variables. If you are using a builtin plugin, you can still download and register
an external version of it in order to use this workflow. Check the
[HashiCorp releases page](https://releases.hashicorp.com/) for the latest
prebuilt plugin binaries.

#### Community plugins

```shell-session
$ vault plugin register -sha256=<SHA256 Hex value of the plugin binary> \
    -env HTTP_PROXY=eu.example.com \
    auth \
    jwt-eu

Success! Registered plugin: jwt-eu

$ vault plugin register -sha256=<SHA256 Hex value of the plugin binary> \
    -env HTTP_PROXY=us.example.com \
    auth \
    jwt-us

Success! Registered plugin: jwt-us
```

#### Enterprise plugins
```shell-session
$ vault plugin register -version=<version of the plugin> \
    -env HTTP_PROXY=example.com \
    secret \
    vault-plugin-secrets-keymgmt

Success! Registered plugin: vault-plugin-secrets-keymgmt
```

You can then enable each plugin on its own path, and configure clients that
should be associated with one or the other appropriately:

```shell-session
$ vault auth enable jwt-eu
Success! Enabled the jwt-eu auth method at: auth/jwt-eu/

$ vault auth enable jwt-us
Success! Enabled the jwt-us auth method at: auth/jwt-us/

$ vault secrets enable vault-plugin-secrets-keymgmt
Success! Enabled the vault-plugin-secrets-keymgmt secrets engine at: vault-plugin-secrets-keymgmt/
```

## Troubleshooting

### Unrecognized remote plugin message

If the following error is encountered when enabling a plugin secret engine or
auth method:

<CodeBlockConfig hideClipboard>

```sh
Unrecognized remote plugin message:

This usually means that the plugin is either invalid or simply
needs to be recompiled to support the latest protocol.
```

</CodeBlockConfig>

Verify whether the Vault process has `mlock` enabled, and if so, run the
following command against the plugin binary:

```shell-session
$ sudo setcap cap_ipc_lock=+ep <plugin-binary>
```
