Error while configuring relabel-configs for Lokiclient logger

[rajmohanram]

Describe the bug
Following error observed while configuing relabel-config for Loki logger. Loki logger configuration as follows:

  loggers:
    - name: loki
      lokiclient:
        server-url: "https://grafana-loki.example.com/loki/api/v1/push"
        job-name: "dnscollector"
        mode: "flat-json"
        tls-insecure: true
        tenant-id: fake
        relabel-configs:
          - source_labels: ["__dns_qtype"]
            target_label: "qtype"

Error observed while starting the go-dnscollector:

config error: unknown YAML key `source_labels` in configuration
config error: unknown YAML key `source_labels` in configuration

To Reproduce
Configure the Loki logger as above.

Expected behavior
Relabel configuration accepted and send logs to the Loki with the required labels.

Additional context

• version: v0.41.0

[rajmohanram]

configchecker is not loading the keys related to relabel-configs in defaultKeywords and hence comparison with userKeywords failing.

Can we set a default value for LokiClient RelabelConfigs here, something like this

	c.LokiClient.RelabelConfigs = []*relabel.Config{
		{
			SourceLabels: model.LabelNames{"__dns_qtype"},
			TargetLabel: "qtype",
			Separator: ",",
			Regex: relabel.Regexp{},
			Modulus: 3,
			Replacement: "{$1}",
			Action: "replace",
		},
	}

[dmachard]

Thank for the report. I prefer to kept backward compatibility for default values.

But you can add this relabeling config part here.

Feel free to do a pull request :)