func gatherBlockIOMetrics()

in plugins/inputs/docker/docker.go [423:531]
95 lines of code
20 McCabe index (conditional complexity)

func gatherBlockIOMetrics(
	stat *types.StatsJSON,
	acc telegraf.Accumulator,
	tags map[string]string,
	now time.Time,
	id string,
	perDevice bool,
	total bool,
) {
	blkioStats := stat.BlkioStats
	// Make a map of devices to their block io stats
	deviceStatMap := make(map[string]map[string]interface{})

	for _, metric := range blkioStats.IoServiceBytesRecursive {
		device := fmt.Sprintf("%d:%d", metric.Major, metric.Minor)
		_, ok := deviceStatMap[device]
		if !ok {
			deviceStatMap[device] = make(map[string]interface{})
		}

		field := fmt.Sprintf("io_service_bytes_recursive_%s", strings.ToLower(metric.Op))
		deviceStatMap[device][field] = metric.Value
	}

	for _, metric := range blkioStats.IoServicedRecursive {
		device := fmt.Sprintf("%d:%d", metric.Major, metric.Minor)
		_, ok := deviceStatMap[device]
		if !ok {
			deviceStatMap[device] = make(map[string]interface{})
		}

		field := fmt.Sprintf("io_serviced_recursive_%s", strings.ToLower(metric.Op))
		deviceStatMap[device][field] = metric.Value
	}

	for _, metric := range blkioStats.IoQueuedRecursive {
		device := fmt.Sprintf("%d:%d", metric.Major, metric.Minor)
		field := fmt.Sprintf("io_queue_recursive_%s", strings.ToLower(metric.Op))
		deviceStatMap[device][field] = metric.Value
	}

	for _, metric := range blkioStats.IoServiceTimeRecursive {
		device := fmt.Sprintf("%d:%d", metric.Major, metric.Minor)
		field := fmt.Sprintf("io_service_time_recursive_%s", strings.ToLower(metric.Op))
		deviceStatMap[device][field] = metric.Value
	}

	for _, metric := range blkioStats.IoWaitTimeRecursive {
		device := fmt.Sprintf("%d:%d", metric.Major, metric.Minor)
		field := fmt.Sprintf("io_wait_time_%s", strings.ToLower(metric.Op))
		deviceStatMap[device][field] = metric.Value
	}

	for _, metric := range blkioStats.IoMergedRecursive {
		device := fmt.Sprintf("%d:%d", metric.Major, metric.Minor)
		field := fmt.Sprintf("io_merged_recursive_%s", strings.ToLower(metric.Op))
		deviceStatMap[device][field] = metric.Value
	}

	for _, metric := range blkioStats.IoTimeRecursive {
		device := fmt.Sprintf("%d:%d", metric.Major, metric.Minor)
		deviceStatMap[device]["io_time_recursive"] = metric.Value
	}

	for _, metric := range blkioStats.SectorsRecursive {
		device := fmt.Sprintf("%d:%d", metric.Major, metric.Minor)
		deviceStatMap[device]["sectors_recursive"] = metric.Value
	}

	totalStatMap := make(map[string]interface{})
	for device, fields := range deviceStatMap {
		fields["container_id"] = id
		if perDevice {
			iotags := copyTags(tags)
			iotags["device"] = device
			acc.AddFields("docker_container_blkio", fields, iotags, now)
		}
		if total {
			for field, value := range fields {
				if field == "container_id" {
					continue
				}

				var uintV uint64
				switch v := value.(type) {
				case uint64:
					uintV = v
				case int64:
					uintV = uint64(v)
				default:
					continue
				}

				_, ok := totalStatMap[field]
				if ok {
					totalStatMap[field] = totalStatMap[field].(uint64) + uintV
				} else {
					totalStatMap[field] = uintV
				}
			}
		}
	}
	if total {
		totalStatMap["container_id"] = id
		iotags := copyTags(tags)
		iotags["device"] = "total"
		acc.AddFields("docker_container_blkio", totalStatMap, iotags, now)
	}
}