Caution
Grafana Alloy is the new name for our distribution of the OTel collector. Grafana Agent has been deprecated and is in Long-Term Support (LTS) through October 31, 2025. Grafana Agent will reach an End-of-Life (EOL) on November 1, 2025. Read more about why we recommend migrating to Grafana Alloy.
Important: This documentation is about an older version. It's relevant only to the release noted, many of the features and functions have been updated or replaced. Please view the current version.
loki.rules.kubernetes
EXPERIMENTAL: This is an experimental component. Experimental components are subject to frequent breaking changes, and may be removed with no equivalent replacement.
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
andPrometheusRule
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.
Note
This component requires [Role-based access control (RBAC)][] to be set up in Kubernetes for Grafana Agent to access it via the Kubernetes REST API.
Role-based access control (RBAC)]: https://kubernetes.io/docs/reference/access-authn-authz/rbac/
Usage
loki.rules.kubernetes "LABEL" {
address = LOKI_RULER_URL
}
Arguments
loki.rules.kubernetes
supports the following arguments:
Name | Type | Description | Default | Required |
---|---|---|---|---|
address | string | URL of the Loki ruler. | yes | |
tenant_id | string | Loki tenant ID. | no | |
use_legacy_routes | bool | Whether to use deprecated ruler API endpoints. | false | no |
sync_interval | duration | Amount of time between reconciliations with Loki. | “30s” | no |
loki_namespace_prefix | string | Prefix used to differentiate multiple Grafana Agent deployments. | “agent” | no |
bearer_token | secret | Bearer token to authenticate with. | no | |
bearer_token_file | string | File containing a bearer token to authenticate with. | no | |
proxy_url | string | HTTP proxy to proxy requests through. | no | |
follow_redirects | bool | Whether redirects returned by the server should be followed. | true | no |
enable_http2 | bool | Whether HTTP2 is supported for requests. | true | no |
At most, one of the following can be provided:
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
:
Hierarchy | Block | Description | Required |
---|---|---|---|
rule_namespace_selector | label_selector | Label selector for Namespace resources. | no |
rule_namespace_selector > match_expression | match_expression | Label match expression for Namespace resources. | no |
rule_selector | label_selector | Label selector for PrometheusRule resources. | no |
rule_selector > match_expression | match_expression | Label match expression for PrometheusRule resources. | no |
basic_auth | basic_auth | Configure basic_auth for authenticating to the endpoint. | no |
authorization | authorization | Configure generic authorization to the endpoint. | no |
oauth2 | oauth2 | Configure OAuth2 for authenticating to the endpoint. | no |
oauth2 > tls_config | tls_config | Configure TLS settings for connecting to the endpoint. | no |
tls_config | tls_config | 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.
label_selector block
The label_selector
block describes a Kubernetes label selector for rule or namespace discovery.
The following arguments are supported:
Name | Type | Description | Default | Required |
---|---|---|---|---|
match_labels | map(string) | Label keys and values used to discover resources. | {} | yes |
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:
Name | Type | Description | Default | Required |
---|---|---|---|---|
key | string | The label name to match against. | yes | |
operator | string | The operator to use when matching. | yes | |
values | list(string) | The values used when matching. | no |
The operator
argument should be one of the following strings:
"in"
"notin"
"exists"
basic_auth block
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
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
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
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
andca_file
cert_pem
andcert_file
key_pem
andkey_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
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
Metric Name | Type | Description |
---|---|---|
loki_rules_config_updates_total | counter | Number of times the configuration has been updated. |
loki_rules_events_total | counter | Number of events processed, partitioned by event type. |
loki_rules_events_failed_total | counter | Number of events that failed to be processed, partitioned by event type. |
loki_rules_events_retried_total | counter | Number of events that were retried, partitioned by event type. |
loki_rules_client_request_duration_seconds | histogram | Duration of requests to the Loki API. |
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.
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.
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:
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