Documentation Grafana Agent Flow mode Reference Components reference loki.rules.kubernetes

loki.rules.kubernetes

loki.rules.kubernetes discovers PrometheusRule Kubernetes resources and loads them into a Loki instance.

• You can specify multiple loki.rules.kubernetes components by giving them different labels.
• Kubernetes label selectors can be used to limit the Namespace and PrometheusRule resources considered during reconciliation.
• Compatible with the Ruler APIs of Grafana Loki, Grafana Cloud, and Grafana Enterprise Metrics.
• Compatible with the PrometheusRule CRD from the prometheus-operator.
• This component accesses the Kubernetes REST API from within a Pod.

Usage

Alloy Copy

loki.rules.kubernetes "LABEL" {
  address = LOKI_RULER_URL
}

Arguments

loki.rules.kubernetes supports the following arguments:

At most, one of the following can be provided:

• bearer_token argument.
• bearer_token_file argument.
• basic_auth block.
• authorization block.
• oauth2 block.

If no tenant_id is provided, the component assumes that the Loki instance at address is running in single-tenant mode and no X-Scope-OrgID header is sent.

The sync_interval argument determines how often Loki’s ruler API is accessed to reload the current state. Interaction with the Kubernetes API works differently. Updates are processed as events from the Kubernetes API server according to the informer pattern.

You can use the loki_namespace_prefix argument to separate the rules managed by multiple Grafana Agent deployments across your infrastructure. You should set the prefix to a unique value for each deployment.

Blocks

The following blocks are supported inside the definition of loki.rules.kubernetes:

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

label_selector block

The label_selector block describes a Kubernetes label selector for rule or namespace discovery.

The following arguments are supported:

When the match_labels argument is empty, all resources will be matched.

match_expression block

The match_expression block describes a Kubernetes label match expression for rule or namespace discovery.

The following arguments are supported:

The operator argument should be one of the following strings:

• "in"
• "notin"
• "exists"

basic_auth block

authorization block

oauth2 block

tls_config block

Exported fields

loki.rules.kubernetes does not export any fields.

Component health

loki.rules.kubernetes is reported as unhealthy if given an invalid configuration or an error occurs during reconciliation.

Debug information

loki.rules.kubernetes exposes resource-level debug information.

The following are exposed per discovered PrometheusRule resource:

• The Kubernetes namespace.
• The resource name.
• The resource uid.
• The number of rule groups.

The following are exposed per discovered Loki rule namespace resource:

• The namespace name.
• The number of rule groups.

Only resources managed by the component are exposed - regardless of how many actually exist.

Debug metrics

Example

This example creates a loki.rules.kubernetes component that loads discovered rules to a local Loki instance under the team-a tenant. Only namespaces and rules with the agent label set to yes are included.

Alloy Copy

loki.rules.kubernetes "local" {
    address = "loki:3100"
    tenant_id = "team-a"

    rule_namespace_selector {
        match_labels = {
            agent = "yes",
        }
    }

    rule_selector {
        match_labels = {
            agent = "yes",
        }
    }
}

This example creates a loki.rules.kubernetes component that loads discovered rules to Grafana Cloud.

Alloy Copy

loki.rules.kubernetes "default" {
    address = "GRAFANA_CLOUD_URL"
    basic_auth {
        username = "GRAFANA_CLOUD_USER"
        password = "GRAFANA_CLOUD_API_KEY"
        // Alternatively, load the password from a file:
        // password_file = "GRAFANA_CLOUD_API_KEY_PATH"
    }
}

The following example is an RBAC configuration for Kubernetes. It authorizes Grafana Agent to query the Kubernetes REST API:

YAML Copy

apiVersion: v1
kind: ServiceAccount
metadata:
  name: grafana-agent
  namespace: default
---
apiVersion: rbac.authorization.k8s.io/v1
kind: ClusterRole
metadata:
  name: grafana-agent
rules:
- apiGroups: [""]
  resources: ["namespaces"]
  verbs: ["get", "list", "watch"]
- apiGroups: ["monitoring.coreos.com"]
  resources: ["prometheusrules"]
  verbs: ["get", "list", "watch"]
---
apiVersion: rbac.authorization.k8s.io/v1
kind: ClusterRoleBinding
metadata:
  name: grafana-agent
subjects:
- kind: ServiceAccount
  name: grafana-agent
  namespace: default
roleRef:
  kind: ClusterRole
  name: grafana-agent
  apiGroup: rbac.authorization.k8s.io