func buildPrometheusScrapeConfig()

in pkg/operator/apis/monitoring/v1/common_types.go [114:176]
55 lines of code
11 McCabe index (conditional complexity)

func buildPrometheusScrapeConfig(jobName string, discoverCfgs discovery.Configs, httpCfg config.HTTPClientConfig, relabelCfgs []*relabel.Config, limits *ScrapeLimits, ep ScrapeEndpoint) (*promconfig.ScrapeConfig, error) {
	interval, err := prommodel.ParseDuration(ep.Interval)
	if err != nil {
		return nil, fmt.Errorf("invalid scrape interval: %w", err)
	}
	timeout := interval
	if ep.Timeout != "" {
		timeout, err = prommodel.ParseDuration(ep.Timeout)
		if err != nil {
			return nil, fmt.Errorf("invalid scrape timeout: %w", err)
		}
		if timeout > interval {
			return nil, fmt.Errorf("scrape timeout %v must not be greater than scrape interval %v", timeout, interval)
		}
	}
	metricsPath := "/metrics"
	if ep.Path != "" {
		metricsPath = ep.Path
	}

	var metricRelabelCfgs []*relabel.Config
	for _, r := range ep.MetricRelabeling {
		rcfg, err := convertRelabelingRule(r)
		if err != nil {
			return nil, err
		}
		metricRelabelCfgs = append(metricRelabelCfgs, rcfg)
	}

	scrapeCfg := &promconfig.ScrapeConfig{
		// Generate a job name to make it easy to track what generated the scrape configuration.
		// The actual job label attached to its metrics is overwritten via relabeling.
		JobName:                 jobName,
		ServiceDiscoveryConfigs: discoverCfgs,
		MetricsPath:             metricsPath,
		Scheme:                  ep.Scheme,
		Params:                  ep.Params,
		HTTPClientConfig:        httpCfg,
		ScrapeInterval:          interval,
		ScrapeTimeout:           timeout,
		RelabelConfigs:          relabelCfgs,
		MetricRelabelConfigs:    metricRelabelCfgs,
	}
	if limits != nil {
		scrapeCfg.SampleLimit = uint(limits.Samples)
		scrapeCfg.LabelLimit = uint(limits.Labels)
		scrapeCfg.LabelNameLengthLimit = uint(limits.LabelNameLength)
		scrapeCfg.LabelValueLengthLimit = uint(limits.LabelValueLength)
	}
	// The Prometheus configuration structs do not generally have validation methods and embed their
	// validation logic in the UnmarshalYAML methods. To keep things reasonable we don't re-validate
	// everything and simply do a final marshal-unmarshal cycle at the end to run all validation
	// upstream provides at the end of this method.
	b, err := yaml.Marshal(scrapeCfg)
	if err != nil {
		return nil, fmt.Errorf("scrape config cannot be marshalled: %w", err)
	}
	var scrapeCfgCopy promconfig.ScrapeConfig
	if err := yaml.Unmarshal(b, &scrapeCfgCopy); err != nil {
		return nil, fmt.Errorf("invalid scrape configuration: %w", err)
	}
	return scrapeCfg, nil
}