--- title: "discovery.kubernetes | Grafana Agent documentation" description: "Learn about discovery.kubernetes" --- # discovery.kubernetes `discovery.kubernetes` allows you to find scrape targets from Kubernetes resources. It watches cluster state, and ensures targets are continually synced with what is currently running in your cluster. If you supply no connection information, this component defaults to an in-cluster configuration. A kubeconfig file or manual connection settings can be used to override the defaults. ## Usage Alloy ![Copy code to clipboard](/media/images/icons/icon-copy-small-2.svg) Copy ```alloy discovery.kubernetes "LABEL" { role = DISCOVERY_ROLE } ``` ## Arguments The following arguments are supported: Expand table | Name | Type | Description | Default | Required | |--------------------------|---------------------|--------------------------------------------------------------------------------------------------|---------|----------| | `api_server` | `string` | URL of Kubernetes API server. | | no | | `role` | `string` | Type of Kubernetes resource to query. | | yes | | `kubeconfig_file` | `string` | Path of kubeconfig file to use for connecting to Kubernetes. | | 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. The `role` argument is required to specify what type of targets to discover. `role` must be one of `node`, `pod`, `service`, `endpoints`, `endpointslice`, or `ingress`. ### node role The `node` role discovers one target per cluster node with the address defaulting to the HTTP port of the Kubelet daemon. The target address defaults to the first existing address of the Kubernetes node object in the address type order of `NodeInternalIP`, `NodeExternalIP`, `NodeLegacyHostIP`, and `NodeHostName`. The following labels are included for discovered nodes: - `__meta_kubernetes_node_name`: The name of the node object. - `__meta_kubernetes_node_provider_id`: The cloud provider’s name for the node object. - `__meta_kubernetes_node_label_`: Each label from the node object. - `__meta_kubernetes_node_labelpresent_`: Set to `true` for each label from the node object. - `__meta_kubernetes_node_annotation_`: Each annotation from the node object. - `__meta_kubernetes_node_annotationpresent_`: Set to `true` for each annotation from the node object. - `__meta_kubernetes_node_address_`: The first address for each node address type, if it exists. In addition, the `instance` label for the node will be set to the node name as retrieved from the API server. ### service role The `service` role discovers a target for each service port for each service. This is generally useful for externally monitoring a service. The address will be set to the Kubernetes DNS name of the service and respective service port. The following labels are included for discovered services: - `__meta_kubernetes_namespace`: The namespace of the service object. - `__meta_kubernetes_service_annotation_`: Each annotation from the service object. - `__meta_kubernetes_service_annotationpresent_`: `true` for each annotation of the service object. - `__meta_kubernetes_service_cluster_ip`: The cluster IP address of the service. This does not apply to services of type `ExternalName`. - `__meta_kubernetes_service_external_name`: The DNS name of the service. This only applies to services of type `ExternalName`. - `__meta_kubernetes_service_label_`: Each label from the service object. - `__meta_kubernetes_service_labelpresent_`: `true` for each label of the service object. - `__meta_kubernetes_service_name`: The name of the service object. - `__meta_kubernetes_service_port_name`: Name of the service port for the target. - `__meta_kubernetes_service_port_number`: Number of the service port for the target. - `__meta_kubernetes_service_port_protocol`: Protocol of the service port for the target. - `__meta_kubernetes_service_type`: The type of the service. ### pod role The `pod` role discovers all pods and exposes their containers as targets. For each declared port of a container, a single target is generated. If a container has no specified ports, a port-free target per container is created. These targets must have a port manually injected using a [`discovery.relabel` component](../discovery.relabel/) before metrics can be collected from them. The following labels are included for discovered pods: - `__meta_kubernetes_namespace`: The namespace of the pod object. - `__meta_kubernetes_pod_name`: The name of the pod object. - `__meta_kubernetes_pod_ip`: The pod IP of the pod object. - `__meta_kubernetes_pod_label_`: Each label from the pod object. - `__meta_kubernetes_pod_labelpresent_`: `true` for each label from the pod object. - `__meta_kubernetes_pod_annotation_`: Each annotation from the pod object. - `__meta_kubernetes_pod_annotationpresent_`: `true` for each annotation from the pod object. - `__meta_kubernetes_pod_container_init`: `true` if the container is an `InitContainer`. - `__meta_kubernetes_pod_container_name`: Name of the container the target address points to. - `__meta_kubernetes_pod_container_id`: ID of the container the target address points to. The ID is in the form `://`. - `__meta_kubernetes_pod_container_image`: The image the container is using. - `__meta_kubernetes_pod_container_port_name`: Name of the container port. - `__meta_kubernetes_pod_container_port_number`: Number of the container port. - `__meta_kubernetes_pod_container_port_protocol`: Protocol of the container port. - `__meta_kubernetes_pod_ready`: Set to `true` or `false` for the pod’s ready state. - `__meta_kubernetes_pod_phase`: Set to `Pending`, `Running`, `Succeeded`, `Failed` or `Unknown` in the lifecycle. - `__meta_kubernetes_pod_node_name`: The name of the node the pod is scheduled onto. - `__meta_kubernetes_pod_host_ip`: The current host IP of the pod object. - `__meta_kubernetes_pod_uid`: The UID of the pod object. - `__meta_kubernetes_pod_controller_kind`: Object kind of the pod controller. - `__meta_kubernetes_pod_controller_name`: Name of the pod controller. ### endpoints role The `endpoints` role discovers targets from listed endpoints of a service. For each endpoint address one target is discovered per port. If the endpoint is backed by a pod, all container ports of a pod are discovered as targets even if they are not bound to an endpoint port. The following labels are included for discovered endpoints: - `__meta_kubernetes_namespace:` The namespace of the endpoints object. - `__meta_kubernetes_endpoints_name:` The names of the endpoints object. - `__meta_kubernetes_endpoints_label_`: Each label from the endpoints object. - `__meta_kubernetes_endpoints_labelpresent_`: `true` for each label from the endpoints object. - The following labels are attached for all targets discovered directly from the endpoints list: - `__meta_kubernetes_endpoint_hostname`: Hostname of the endpoint. - `__meta_kubernetes_endpoint_node_name`: Name of the node hosting the endpoint. - `__meta_kubernetes_endpoint_ready`: Set to `true` or `false` for the endpoint’s ready state. - `__meta_kubernetes_endpoint_port_name`: Name of the endpoint port. - `__meta_kubernetes_endpoint_port_protocol`: Protocol of the endpoint port. - `__meta_kubernetes_endpoint_address_target_kind`: Kind of the endpoint address target. - `__meta_kubernetes_endpoint_address_target_name`: Name of the endpoint address target. - If the endpoints belong to a service, all labels of the `service` role discovery are attached. - For all targets backed by a pod, all labels of the `pod` role discovery are attached. ### endpointslice role The endpointslice role discovers targets from existing Kubernetes endpoint slices. For each endpoint address referenced in the `EndpointSlice` object, one target is discovered. If the endpoint is backed by a pod, all container ports of a pod are discovered as targets even if they are not bound to an endpoint port. The following labels are included for discovered endpoint slices: - `__meta_kubernetes_namespace`: The namespace of the endpoints object. - `__meta_kubernetes_endpointslice_name`: The name of endpoint slice object. - The following labels are attached for all targets discovered directly from the endpoint slice list: - `__meta_kubernetes_endpointslice_address_target_kind`: Kind of the referenced object. - `__meta_kubernetes_endpointslice_address_target_name`: Name of referenced object. - `__meta_kubernetes_endpointslice_address_type`: The IP protocol family of the address of the target. - `__meta_kubernetes_endpointslice_endpoint_conditions_ready`: Set to `true` or `false` for the referenced endpoint’s ready state. - `__meta_kubernetes_endpointslice_endpoint_topology_kubernetes_io_hostname`: Name of the node hosting the referenced endpoint. - `__meta_kubernetes_endpointslice_endpoint_topology_present_kubernetes_io_hostname`: `true` if the referenced object has a `kubernetes.io/hostname` annotation. - `__meta_kubernetes_endpointslice_port`: Port of the referenced endpoint. - `__meta_kubernetes_endpointslice_port_name`: Named port of the referenced endpoint. - `__meta_kubernetes_endpointslice_port_protocol`: Protocol of the referenced endpoint. - If the endpoints belong to a service, all labels of the `service` role discovery are attached. - For all targets backed by a pod, all labels of the `pod` role discovery are attached. ### ingress role The `ingress` role discovers a target for each path of each ingress. This is generally useful for externally monitoring an ingress. The address will be set to the host specified in the Kubernetes `Ingress`’s `spec` block. The following labels are included for discovered ingress objects: - `__meta_kubernetes_namespace`: The namespace of the ingress object. - `__meta_kubernetes_ingress_name`: The name of the ingress object. - `__meta_kubernetes_ingress_label_`: Each label from the ingress object. - `__meta_kubernetes_ingress_labelpresent_`: `true` for each label from the ingress object. - `__meta_kubernetes_ingress_annotation_`: Each annotation from the ingress object. - `__meta_kubernetes_ingress_annotationpresent_`: `true` for each annotation from the ingress object. - `__meta_kubernetes_ingress_class_name`: Class name from ingress spec, if present. - `__meta_kubernetes_ingress_scheme`: Protocol scheme of ingress, `https` if TLS config is set. Defaults to `http`. - `__meta_kubernetes_ingress_path`: Path from ingress spec. Defaults to /. ## Blocks The following blocks are supported inside the definition of `discovery.kubernetes`: Expand table | Hierarchy | Block | Description | Required | |-------------------------|--------------------------------------------|-----------------------------------------------------------|----------| | namespaces | [namespaces](#namespaces-block) | Information about which Kubernetes namespaces to search. | no | | selectors | [selectors](#selectors-block) | Information about which Kubernetes namespaces to search. | no | | attach\_metadata | [attach\_metadata](#attach_metadata-block) | Optional metadata to attach to discovered targets. | no | | 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. ### namespaces block The `namespaces` block limits the namespaces to discover resources in. If omitted, all namespaces are searched. Expand table | Name | Type | Description | Default | Required | |-----------------|----------------|---------------------------------------------------------|---------|----------| | `own_namespace` | `bool` | Include the namespace Grafana Agent Flow is running in. | | no | | `names` | `list(string)` | List of namespaces to search. | | no | ### selectors block The `selectors` block contains optional label and field selectors to limit the discovery process to a subset of resources. Expand table | Name | Type | Description | Default | Required | |---------|----------|------------------------|---------|----------| | `role` | `string` | Role of the selector. | | yes | | `label` | `string` | Label selector string. | | no | | `field` | `string` | Field selector string. | | no | See Kubernetes’ documentation for [Field selectors](https://kubernetes.io/docs/concepts/overview/working-with-objects/field-selectors/) and [Labels and selectors](https://kubernetes.io/docs/concepts/overview/working-with-objects/labels/) to learn more about the possible filters that can be used. The endpoints role supports pod, service, and endpoints selectors. The pod role supports node selectors when configured with `attach_metadata: {node: true}`. Other roles only support selectors matching the role itself (e.g. node role can only contain node selectors). > **Note**: Using multiple `discovery.kubernetes` components with different selectors may result in a bigger load against the Kubernetes API. > > Selectors are recommended for retrieving a small set of resources in a very large cluster. Smaller clusters are recommended to avoid selectors in favor of filtering with [a `discovery.relabel` component](../discovery.relabel/) instead. ### attach\_metadata block The `attach_metadata` block allows to attach node metadata to discovered targets. Valid for roles: pod, endpoints, endpointslice. Expand table | Name | Type | Description | Default | Required | |--------|--------|-----------------------|---------|----------| | `node` | `bool` | Attach node metadata. | | no | ### 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 Kubernetes API. | ## Component health `discovery.kubernetes` is reported as unhealthy when given an invalid configuration. In those cases, exported fields retain their last healthy values. ## Debug information `discovery.kubernetes` does not expose any component-specific debug information. ## Debug metrics `discovery.kubernetes` does not expose any component-specific debug metrics. ## Examples ### In-cluster discovery This example uses in-cluster authentication to discover all pods: Alloy ![Copy code to clipboard](/media/images/icons/icon-copy-small-2.svg) Copy ```alloy discovery.kubernetes "k8s_pods" { role = "pod" } prometheus.scrape "demo" { targets = discovery.kubernetes.k8s_pods.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. ### Kubeconfig authentication This example uses a kubeconfig file to authenticate to the Kubernetes API: Alloy ![Copy code to clipboard](/media/images/icons/icon-copy-small-2.svg) Copy ```alloy discovery.kubernetes "k8s_pods" { role = "pod" kubeconfig_file = "/etc/k8s/kubeconfig.yaml" } prometheus.scrape "demo" { targets = discovery.kubernetes.k8s_pods.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. ### Limit searched namespaces and filter by labels value This example limits the searched namespaces and only selects pods with a specific label value attached to them: Alloy ![Copy code to clipboard](/media/images/icons/icon-copy-small-2.svg) Copy ```alloy discovery.kubernetes "k8s_pods" { role = "pod" selectors { role = "pod" label = "app.kubernetes.io/name=prometheus-node-exporter" } namespaces { names = ["myapp"] } } prometheus.scrape "demo" { targets = discovery.kubernetes.k8s_pods.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. ### Limit to only pods on the same node This example limits the search to pods on the same node as this Grafana Agent. This configuration could be useful if you are running Grafana Agent as a DaemonSet. > Note > > This example assumes you have used Helm chart to deploy Grafana Agent Flow in Kubernetes and sets `HOSTNAME` to the Kubernetes host name. If you have a custom Kubernetes deployment, you must adapt this example to your configuration. Alloy ![Copy code to clipboard](/media/images/icons/icon-copy-small-2.svg) Copy ```alloy discovery.kubernetes "k8s_pods" { role = "pod" selectors { role = "pod" field = "spec.nodeName=" + coalesce(env("HOSTNAME"), constants.hostname) } } prometheus.scrape "demo" { targets = discovery.kubernetes.k8s_pods.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. ## Compatible components `discovery.kubernetes` 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.