---
title: "discovery.linode | Grafana Agent documentation"
description: "Learn about discovery.linode"
---

# discovery.linode

`discovery.linode` allows you to retrieve scrape targets from [Linode’s](https://www.linode.com/) Linode APIv4. This service discovery uses the public IPv4 address by default, but that can be changed with relabeling.

## Usage

Alloy ![Copy code to clipboard](/media/images/icons/icon-copy-small-2.svg) Copy

```alloy
discovery.linode "LABEL" {
	bearer_token = LINODE_API_TOKEN
}
```

> Note
> 
> The linode APIv4 Token must be created with the scopes: `linodes:read_only`, `ips:read_only`, and `events:read_only`.

## Arguments

The following arguments are supported:

Expand table

| Name                     | Type                | Description                                                                                      | Default | Required |
|--------------------------|---------------------|--------------------------------------------------------------------------------------------------|---------|----------|
| `refresh_interval`       | `duration`          | The time to wait between polling update requests.                                                | `"60s"` | no       |
| `port`                   | `int`               | Port that metrics are scraped from.                                                              | `80`    | no       |
| `tag_separator`          | `string`            | The string by which Linode Instance tags are joined into the tag label.                          | `,`     | no       |
| `bearer_token_file`      | `string`            | File containing a bearer token to authenticate with.                                             |         | no       |
| `bearer_token`           | `secret`            | Bearer token to authenticate with.                                                               |         | no       |
| `enable_http2`           | `bool`              | Whether HTTP2 is supported for requests.                                                         | `true`  | no       |
| `follow_redirects`       | `bool`              | Whether redirects returned by the server should be followed.                                     | `true`  | no       |
| `proxy_url`              | `string`            | HTTP proxy to send requests through.                                                             |         | no       |
| `no_proxy`               | `string`            | Comma-separated list of IP addresses, CIDR notations, and domain names to exclude from proxying. |         | no       |
| `proxy_from_environment` | `bool`              | Use the proxy URL indicated by environment variables.                                            | `false` | no       |
| `proxy_connect_header`   | `map(list(secret))` | Specifies headers to send to proxies during CONNECT requests.                                    |         | no       |

At most, one of the following can be provided:

- [`bearer_token` argument](#arguments).
- [`bearer_token_file` argument](#arguments).
- [`basic_auth` block](#basic_auth-block).
- [`authorization` block](#authorization-block).
- [`oauth2` block](#oauth2-block).

`no_proxy` can contain IPs, CIDR notations, and domain names. IP and domain names can contain port numbers. `proxy_url` must be configured if `no_proxy` is configured.

`proxy_from_environment` uses the environment variables HTTP\_PROXY, HTTPS\_PROXY and NO\_PROXY (or the lowercase versions thereof). Requests use the proxy from the environment variable matching their scheme, unless excluded by NO\_PROXY. `proxy_url` and `no_proxy` must not be configured if `proxy_from_environment` is configured.

`proxy_connect_header` should only be configured if `proxy_url` or `proxy_from_environment` are configured.

## Blocks

The following blocks are supported inside the definition of `discovery.linode`:

Expand table

| Hierarchy               | Block                                 | Description                                               | Required |
|-------------------------|---------------------------------------|-----------------------------------------------------------|----------|
| basic\_auth             | [basic\_auth](#basic_auth-block)      | Configure basic\_auth for authenticating to the endpoint. | no       |
| authorization           | [authorization](#authorization-block) | Configure generic authorization to the endpoint.          | no       |
| oauth2                  | [oauth2](#oauth2-block)               | Configure OAuth2 for authenticating to the endpoint.      | no       |
| oauth2 > tls\_config | [tls\_config](#tls_config-block)      | Configure TLS settings for connecting to the endpoint.    | no       |
| tls\_config             | [tls\_config](#tls_config-block)      | Configure TLS settings for connecting to the endpoint.    | no       |

The `>` symbol indicates deeper levels of nesting. For example, `oauth2 > tls_config` refers to a `tls_config` block defined inside an `oauth2` block.

### basic\_auth block

Expand table

| Name            | Type     | Description                              | Default | Required |
|-----------------|----------|------------------------------------------|---------|----------|
| `password_file` | `string` | File containing the basic auth password. |         | no       |
| `password`      | `secret` | Basic auth password.                     |         | no       |
| `username`      | `string` | Basic auth username.                     |         | no       |

`password` and `password_file` are mutually exclusive, and only one can be provided inside a `basic_auth` block.

### authorization block

Expand table

| Name               | Type     | Description                                | Default | Required |
|--------------------|----------|--------------------------------------------|---------|----------|
| `credentials_file` | `string` | File containing the secret value.          |         | no       |
| `credentials`      | `secret` | Secret value.                              |         | no       |
| `type`             | `string` | Authorization type, for example, “Bearer”. |         | no       |

`credential` and `credentials_file` are mutually exclusive, and only one can be provided inside an `authorization` block.

### oauth2 block

Expand table

| Name                     | Type                | Description                                                                                      | Default | Required |
|--------------------------|---------------------|--------------------------------------------------------------------------------------------------|---------|----------|
| `client_id`              | `string`            | OAuth2 client ID.                                                                                |         | no       |
| `client_secret_file`     | `string`            | File containing the OAuth2 client secret.                                                        |         | no       |
| `client_secret`          | `secret`            | OAuth2 client secret.                                                                            |         | no       |
| `endpoint_params`        | `map(string)`       | Optional parameters to append to the token URL.                                                  |         | no       |
| `proxy_url`              | `string`            | HTTP proxy to send requests through.                                                             |         | no       |
| `no_proxy`               | `string`            | Comma-separated list of IP addresses, CIDR notations, and domain names to exclude from proxying. |         | no       |
| `proxy_from_environment` | `bool`              | Use the proxy URL indicated by environment variables.                                            | `false` | no       |
| `proxy_connect_header`   | `map(list(secret))` | Specifies headers to send to proxies during CONNECT requests.                                    |         | no       |
| `scopes`                 | `list(string)`      | List of scopes to authenticate with.                                                             |         | no       |
| `token_url`              | `string`            | URL to fetch the token from.                                                                     |         | no       |

`client_secret` and `client_secret_file` are mutually exclusive, and only one can be provided inside an `oauth2` block.

The `oauth2` block may also contain a separate `tls_config` sub-block.

`no_proxy` can contain IPs, CIDR notations, and domain names. IP and domain names can contain port numbers. `proxy_url` must be configured if `no_proxy` is configured.

`proxy_from_environment` uses the environment variables HTTP\_PROXY, HTTPS\_PROXY and NO\_PROXY (or the lowercase versions thereof). Requests use the proxy from the environment variable matching their scheme, unless excluded by NO\_PROXY. `proxy_url` and `no_proxy` must not be configured if `proxy_from_environment` is configured.

`proxy_connect_header` should only be configured if `proxy_url` or `proxy_from_environment` are configured.

### tls\_config block

Expand table

| Name                   | Type     | Description                                              | Default | Required |
|------------------------|----------|----------------------------------------------------------|---------|----------|
| `ca_pem`               | `string` | CA PEM-encoded text to validate the server with.         |         | no       |
| `ca_file`              | `string` | CA certificate to validate the server with.              |         | no       |
| `cert_pem`             | `string` | Certificate PEM-encoded text for client authentication.  |         | no       |
| `cert_file`            | `string` | Certificate file for client authentication.              |         | no       |
| `insecure_skip_verify` | `bool`   | Disables validation of the server certificate.           |         | no       |
| `key_file`             | `string` | Key file for client authentication.                      |         | no       |
| `key_pem`              | `secret` | Key PEM-encoded text for client authentication.          |         | no       |
| `min_version`          | `string` | Minimum acceptable TLS version.                          |         | no       |
| `server_name`          | `string` | ServerName extension to indicate the name of the server. |         | no       |

The following pairs of arguments are mutually exclusive and can’t both be set simultaneously:

- `ca_pem` and `ca_file`
- `cert_pem` and `cert_file`
- `key_pem` and `key_file`

When configuring client authentication, both the client certificate (using `cert_pem` or `cert_file`) and the client key (using `key_pem` or `key_file`) must be provided.

When `min_version` is not provided, the minimum acceptable TLS version is inherited from Go’s default minimum version, TLS 1.2. If `min_version` is provided, it must be set to one of the following strings:

- `"TLS10"` (TLS 1.0)
- `"TLS11"` (TLS 1.1)
- `"TLS12"` (TLS 1.2)
- `"TLS13"` (TLS 1.3)

## Exported fields

The following fields are exported and can be referenced by other components:

Expand table

| Name      | Type                | Description                                        |
|-----------|---------------------|----------------------------------------------------|
| `targets` | `list(map(string))` | The set of targets discovered from the Linode API. |

The following meta labels are available on targets and can be used by the discovery.relabel component:

- `__meta_linode_instance_id`: the id of the Linode instance
- `__meta_linode_instance_label`: the label of the Linode instance
- `__meta_linode_image`: the slug of the Linode instance’s image
- `__meta_linode_private_ipv4`: the private IPv4 of the Linode instance
- `__meta_linode_public_ipv4`: the public IPv4 of the Linode instance
- `__meta_linode_public_ipv6`: the public IPv6 of the Linode instance
- `__meta_linode_region`: the region of the Linode instance
- `__meta_linode_type`: the type of the Linode instance
- `__meta_linode_status`: the status of the Linode instance
- `__meta_linode_tags`: a list of tags of the Linode instance joined by the tag separator
- `__meta_linode_group`: the display group a Linode instance is a member of
- `__meta_linode_hypervisor`: the virtualization software powering the Linode instance
- `__meta_linode_backups`: the backup service status of the Linode instance
- `__meta_linode_specs_disk_bytes`: the amount of storage space the Linode instance has access to
- `__meta_linode_specs_memory_bytes`: the amount of RAM the Linode instance has access to
- `__meta_linode_specs_vcpus`: the number of VCPUS this Linode has access to
- `__meta_linode_specs_transfer_bytes`: the amount of network transfer the Linode instance is allotted each month
- `__meta_linode_extra_ips`: a list of all extra IPv4 addresses assigned to the Linode instance joined by the tag separator

## Component health

`discovery.linode` is only reported as unhealthy when given an invalid configuration. In those cases, exported fields retain their last healthy values.

## Debug information

`discovery.linode` does not expose any component-specific debug information.

## Debug metrics

`discovery.linode` does not expose any component-specific debug metrics.

## Example

Alloy ![Copy code to clipboard](/media/images/icons/icon-copy-small-2.svg) Copy

```alloy
discovery.linode "example" {
    bearer_token = env("LINODE_TOKEN")
    port = 8876
}
prometheus.scrape "demo" {
	targets    = discovery.linode.example.targets
	forward_to = [prometheus.remote_write.demo.receiver]
}
prometheus.remote_write "demo" {
	endpoint {
		url = PROMETHEUS_REMOTE_WRITE_URL
		basic_auth {
			username = USERNAME
			password = PASSWORD
		}
	}
}
```

Replace the following:

- `PROMETHEUS_REMOTE_WRITE_URL`: The URL of the Prometheus remote\_write-compatible server to send metrics to.
- `USERNAME`: The username to use for authentication to the remote\_write API.
- `PASSWORD`: The password to use for authentication to the remote\_write API.

### Using private IP address:

![Copy code to clipboard](/media/images/icons/icon-copy-small-2.svg) Copy

```none
discovery.linode "example" {
    bearer_token = env("LINODE_TOKEN")
    port = 8876
}
discovery.relabel "private_ips" {
	targets = discovery.linode.example.targets
	rule {
    	source_labels = ["__meta_linode_private_ipv4"]
    	replacement     = "[$1]:8876"
    	target_label  = "__address__"
  	}
}
prometheus.scrape "demo" {
	targets    = discovery.relabel.private_ips.targets
	forward_to = [prometheus.remote_write.demo.receiver]
}
prometheus.remote_write "demo" {
	endpoint {
		url = PROMETHEUS_REMOTE_WRITE_URL
		basic_auth {
			username = USERNAME
			password = PASSWORD
		}
	}
}
```

## Compatible components

`discovery.linode` has exports that can be consumed by the following components:

- Components that consume [Targets](../../compatibility/#targets-consumers)

> Note
> 
> Connecting some components may not be sensible or components may require further configuration to make the connection work correctly. Refer to the linked documentation for more details.