Chapter 3. OTLP data ingestion in Loki

When using the Loki Operator in openshift-logging mode, attribute mapping follow OpenShift default values, but you can configure custom mappings to adjust default values. In the openshift-logging mode, you can configure custom attribute mappings globally for all tenants or for individual tenants as needed. When you define custom mappings, they are appended to the OpenShift default values. If you do not need default labels, you can disable them in the tenant configuration.

Within LokiStack, attribute mapping configuration is managed through the limits setting. See the following example LokiStack configuration:

# ...
spec:
  limits:
    global:
      otlp: {} 
    tenants:
      application:
        otlp: {} 

# ...
spec:
  limits:
    global:
      otlp: {} 

    tenants:
      application:
        otlp: {} 

Stream labels derive only from resource-level attributes, which the LokiStack resource structure reflects. See the following LokiStack example configuration:

spec:
  limits:
    global:
      otlp:
        streamLabels:
          resourceAttributes:
          - name: "k8s.namespace.name"
          - name: "k8s.pod.name"
          - name: "k8s.container.name"

spec:
  limits:
    global:
      otlp:
        streamLabels:
          resourceAttributes:
          - name: "k8s.namespace.name"
          - name: "k8s.pod.name"
          - name: "k8s.container.name"

You can drop attributes of type resource, scope, or log from the log entry.

# ...
spec:
  limits:
    global:
      otlp:
        streamLabels:
# ...
        drop:
          resourceAttributes:
          - name: "process.command_line"
          - name: "k8s\\.pod\\.labels\\..+"
            regex: true
          scopeAttributes:
          - name: "service.name"
          logAttributes:
          - name: "http.route"

# ...
spec:
  limits:
    global:
      otlp:
        streamLabels:
# ...
        drop:
          resourceAttributes:
          - name: "process.command_line"
          - name: "k8s\\.pod\\.labels\\..+"
            regex: true
          scopeAttributes:
          - name: "service.name"
          logAttributes:
          - name: "http.route"

You can use regular expressions by setting regex: true to apply a configuration for attributes with similar names.

Attributes that are not explicitly set as stream labels or dropped from the entry are saved as structured metadata by default.

In the openshift-logging mode, certain attributes are required and cannot be removed from the configuration due to their role in OpenShift functions. Other attributes, labeled recommended, might be dropped if performance is impacted. For information about the attributes, see OpenTelemetry data model attributes.

When using the openshift-logging mode without custom attributes, you can achieve immediate compatibility with OpenShift tools. If additional attributes are needed as stream labels or some attributes need to be dropped, use custom configuration. Custom configurations can merge with default configurations.

To reduce default attributes in the openshift-logging mode, disable recommended attributes:

# ...
spec:
  tenants:
    mode: openshift-logging
    openshift:
      otlp:
        disableRecommendedAttributes: true 

# ...
spec:
  tenants:
    mode: openshift-logging
    openshift:
      otlp:
        disableRecommendedAttributes: true