---
title: "loki.source.kubernetes | Grafana Alloy documentation"
description: "Learn about loki.source.kubernetes"
---

# `loki.source.kubernetes`

`loki.source.kubernetes` tails logs from Kubernetes containers using the Kubernetes API.

> Note
> 
> This component collects logs from Kubernetes Pods. You can’t use this component to collect logs from Kubernetes Nodes.

This component has the following benefits over `loki.source.file`:

- It works without a privileged container.
- It works without a root user.
- It works without needing access to the filesystem of the Kubernetes node.
- It doesn’t require a DaemonSet to collect logs, so one Alloy could collect logs for the whole cluster.

> Note
> 
> Because `loki.source.kubernetes` uses the Kubernetes API to tail logs, it uses more network traffic and CPU consumption of Kubelets than `loki.source.file`.

You can specify multiple `loki.source.kubernetes` components by giving them different labels.

## Usage

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

```alloy
loki.source.kubernetes "<LABEL>" {
  targets    = <TARGET_LIST>
  forward_to = <RECEIVER_LIST>
}
```

## Arguments

The component starts a new reader for each of the given `targets` and fans out log entries to the list of receivers passed in `forward_to`.

You can use the following arguments with `loki.source.kubernetes`:

Expand table

| Name         | Type                 | Description                               | Default | Required |
|--------------|----------------------|-------------------------------------------|---------|----------|
| `forward_to` | `list(LogsReceiver)` | List of receivers to send log entries to. |         | yes      |
| `targets`    | `list(map(string))`  | List of targets to tail logs from.        |         | yes      |

Each target in `targets` must have the following labels:

- `__meta_kubernetes_namespace` or `__pod_namespace__` to specify the namespace of the Pod to tail.
- `__meta_kubernetes_pod_container_name` or `__pod_container_name__` to specify the container within the Pod to tail.
- `__meta_kubernetes_pod_name` or `__pod_name__` to specify the name of the Pod to tail.
- `__meta_kubernetes_pod_uid` or `__pod_uid__` to specify the UID of the Pod to tail.

By default, all of these labels are present when the output `discovery.kubernetes` is used.

A log tailer is started for each unique target in `targets`. Log tailers reconnect with exponential backoff to Kubernetes if the log stream returns before the container has permanently terminated.

## Blocks

You can use the following blocks with `loki.source.kubernetes`:

No valid configuration blocks found.

### `client`

The `client` block configures the Kubernetes client used to tail logs from containers. If the `client` block isn’t provided, the default in-cluster configuration with the service account of the running Alloy Pod is used.

The following arguments are supported:

Expand table

| Name                     | Type                | Description                                                                                      | Default | Required |
|--------------------------|---------------------|--------------------------------------------------------------------------------------------------|---------|----------|
| `api_server`             | `string`            | URL of the Kubernetes API server.                                                                |         | 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       |
| `http_headers`           | `map(list(secret))` | Custom HTTP headers to be sent along with each request. The map key is the header name.          |         | no       |
| `kubeconfig_file`        | `string`            | Path of the `kubeconfig` file to use for connecting to Kubernetes.                               |         | no       |
| `no_proxy`               | `string`            | Comma-separated list of IP addresses, CIDR notations, and domain names to exclude from proxying. |         | no       |
| `proxy_connect_header`   | `map(list(secret))` | Specifies headers to send to proxies during CONNECT requests.                                    |         | no       |
| `proxy_from_environment` | `bool`              | Use the proxy URL indicated by environment variables.                                            | `false` | no       |
| `proxy_url`              | `string`            | HTTP proxy to send requests through.                                                             |         | no       |

At most, one of the following can be provided:

- \[`authorization`]\[authorization] block
- \[`basic_auth`]\[basic\_auth] block
- \[`bearer_token_file`]\[client] argument
- \[`bearer_token`]\[client] argument
- \[`oauth2`]\[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.

### `authorization`

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.

> Warning
> 
> Using `credentials_file` causes the file to be read on every outgoing request. Use the `local.file` component with the `credentials` attribute instead to avoid unnecessary reads.

### `basic_auth`

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.

> Warning
> 
> Using `password_file` causes the file to be read on every outgoing request. Use the `local.file` component with the `password` attribute instead to avoid unnecessary reads.

### `oauth2`

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       |
| `no_proxy`               | `string`            | Comma-separated list of IP addresses, CIDR notations, and domain names to exclude from proxying. |         | no       |
| `proxy_connect_header`   | `map(list(secret))` | Specifies headers to send to proxies during CONNECT requests.                                    |         | no       |
| `proxy_from_environment` | `bool`              | Use the proxy URL indicated by environment variables.                                            | `false` | no       |
| `proxy_url`              | `string`            | HTTP proxy to send requests through.                                                             |         | 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.

> Warning
> 
> Using `client_secret_file` causes the file to be read on every outgoing request. Use the `local.file` component with the `client_secret` attribute instead to avoid unnecessary reads.

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`

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` isn’t 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)

### `clustering`

Expand table

| Name      | Type   | Description                                         | Default | Required |
|-----------|--------|-----------------------------------------------------|---------|----------|
| `enabled` | `bool` | Distribute log collection with other cluster nodes. |         | yes      |

When Alloy is [using clustering](../../../../get-started/clustering/), and `enabled` is set to true, then this `loki.source.kubernetes` component instance opts-in to participating in the cluster to distribute the load of log collection between all cluster nodes.

If Alloy is *not* running in clustered mode, then the block is a no-op and `loki.source.kubernetes` collects logs from every target it receives in its arguments.

Clustering looks only at the following labels for determining the shard key:

- `__meta_kubernetes_namespace`
- `__meta_kubernetes_pod_container_name`
- `__meta_kubernetes_pod_name`
- `__meta_kubernetes_pod_uid`
- `__pod_container_name__`
- `__pod_name__`
- `__pod_namespace__`
- `__pod_uid__`
- `container`
- `job`
- `namespace`
- `pod`

## Exported fields

`loki.source.kubernetes` doesn’t export any fields.

## Component health

`loki.source.kubernetes` is only reported as unhealthy if given an invalid configuration.

## Debug information

`loki.source.kubernetes` exposes some target-level debug information per target:

- The labels associated with the target.
- The full set of labels which were found during service discovery.
- The most recent time a log line was read and forwarded to the next components in the pipeline.
- The most recent error from tailing, if any.

## Debug metrics

`loki.source.kubernetes` doesn’t expose any component-specific debug metrics.

## Example

This example collects logs from all Kubernetes Pods and forwards them to a `loki.write` component so they’re written to Loki.

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

```alloy
discovery.kubernetes "pods" {
  role = "pod"
}

loki.source.kubernetes "pods" {
  targets    = discovery.kubernetes.pods.targets
  forward_to = [loki.write.local.receiver]
}

loki.write "local" {
  endpoint {
    url = sys.env("<LOKI_URL>")
  }
}
```

## Compatible components

`loki.source.kubernetes` can accept arguments from the following components:

- Components that export [Targets](../../../compatibility/#targets-exporters)
- Components that export [Loki `LogsReceiver`](../../../compatibility/#loki-logsreceiver-exporters)

> 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.