This is documentation for the next version of Grafana Alloy Documentation. For the latest stable release, go to the latest version.

Documentation Grafana Alloy Reference Components loki 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

You can use the following arguments with loki.rules.kubernetes:

At most, one of the following can be provided:

• authorization block
• basic_auth block
• bearer_token_file argument
• bearer_token argument
• 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 the Loki 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 Alloy deployments across your infrastructure. You should set the prefix to a unique value for each deployment.

Blocks

You can use the following blocks with 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.

authorization

basic_auth

extra_query_matchers

The extra_query_matchers block has no attributes. It contains zero or more matcher blocks. These blocks allow you to add extra label matchers to all queries that are discovered by the loki.rules.kubernetes component. The algorithm for adding the label matchers to queries is the same as the one used by the promtool promql label-matchers set command. It’s adapted to work with the LogQL parser.

matcher

The matcher block describes a label matcher that’s added to each query found in PrometheusRule CRDs.

The following arguments are supported:

rule_selector and rule_namespace_selector

The rule_selector and rule_namespace_selector blocks describe a Kubernetes label selector for rule or namespace discovery.

The following arguments are supported:

When the match_labels argument is empty, all resources are matched.

match_expression

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"

oauth2

tls_config

Exported fields

loki.rules.kubernetes doesn’t 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 alloy label set to yes are included.

alloy Copy

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

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

    rule_selector {
        match_labels = {
            alloy = "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>"
    }
}

Replace the following:

• <GRAFANA_CLOUD_URL>: The Grafana Cloud URL.
• <GRAFANA_CLOUD_USER>: Your Grafana Cloud user name.
• <GRAFANA_CLOUD_API_KEY>: Your Grafana Cloud API key.
• <GRAFANA_CLOUD_API_KEY_PATH>: The path to the Grafana Cloud API key.

This example adds label matcher {cluster=~"prod-.*"} to all the queries discovered by loki.rules.kubernetes.

alloy Copy

loki.rules.kubernetes "default" {
    address = "loki:3100"
    extra_query_matchers {
        matcher {
            name = "cluster"
            match_type = "=~"
            value = "prod-.*"
        }
    }
}

If a query in the form of {app="my-app"} is found in PrometheusRule CRDs, it will be modified to {app="my-app", cluster=~"prod-.*"} before sending it to Loki.

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

YAML Copy

apiVersion: v1
kind: ServiceAccount
metadata:
  name: alloy
  namespace: default
---
apiVersion: rbac.authorization.k8s.io/v1
kind: ClusterRole
metadata:
  name: alloy
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: alloy
subjects:
- kind: ServiceAccount
  name: alloy
  namespace: default
roleRef:
  kind: ClusterRole
  name: alloy
  apiGroup: rbac.authorization.k8s.io