Refactor collectors

Signed-off-by: Jan-Otto Kröpke <mail@jkroepke.de>

pkg/collector/cpu_info/cpu_info.go

@@ -0,0 +1,125 @@
+//go:build windows
+
+package cpu_info
+
+import (
+	"errors"
+	"strconv"
+	"strings"
+
+	"github.com/alecthomas/kingpin/v2"
+	"github.com/go-kit/log"
+	"github.com/go-kit/log/level"
+	"github.com/prometheus-community/windows_exporter/pkg/types"
+	"github.com/prometheus-community/windows_exporter/pkg/wmi"
+	"github.com/prometheus/client_golang/prometheus"
+)
+
+const (
+	Name = "cpu_info"
+	// If you are adding additional labels to the metric, make sure that they get added in here as well. See below for explanation.
+	win32ProcessorQuery = "SELECT Architecture, DeviceId, Description, Family, L2CacheSize, L3CacheSize, Name FROM Win32_Processor"
+)
+
+type Config struct{}
+
+var ConfigDefaults = Config{}
+
+// A collector is a Prometheus collector for a few WMI metrics in Win32_Processor
+type collector struct {
+	logger log.Logger
+
+	CpuInfo *prometheus.Desc
+}
+
+func New(logger log.Logger, _ *Config) types.Collector {
+	c := &collector{}
+	c.SetLogger(logger)
+	return c
+}
+
+func NewWithFlags(_ *kingpin.Application) types.Collector {
+	return &collector{}
+}
+
+func (c *collector) GetName() string {
+	return Name
+}
+
+func (c *collector) SetLogger(logger log.Logger) {
+	c.logger = log.With(logger, "collector", Name)
+}
+
+func (c *collector) GetPerfCounter() ([]string, error) {
+	return []string{}, nil
+}
+
+func (c *collector) Build() error {
+	c.CpuInfo = prometheus.NewDesc(
+		prometheus.BuildFQName(types.Namespace, "", Name),
+		"Labeled CPU information as provided provided by Win32_Processor",
+		[]string{
+			"architecture",
+			"device_id",
+			"description",
+			"family",
+			"l2_cache_size",
+			"l3_cache_size",
+			"name",
+		},
+		nil,
+	)
+
+	return nil
+}
+
+type win32_Processor struct {
+	Architecture uint32
+	DeviceID     string
+	Description  string
+	Family       uint16
+	L2CacheSize  uint32
+	L3CacheSize  uint32
+	Name         string
+}
+
+// Collect sends the metric values for each metric
+// to the provided prometheus Metric channel.
+func (c *collector) Collect(_ *types.ScrapeContext, ch chan<- prometheus.Metric) error {
+	if desc, err := c.collect(ch); err != nil {
+		_ = level.Error(c.logger).Log("msg", "failed collecting cpu_info metrics", "desc", desc, "err", err)
+		return err
+	}
+	return nil
+}
+
+func (c *collector) collect(ch chan<- prometheus.Metric) (*prometheus.Desc, error) {
+	var dst []win32_Processor
+	// We use a static query here because the provided methods in wmi.go all issue a SELECT *;
+	// This results in the time-consuming LoadPercentage field being read which seems to measure each CPU
+	// serially over a 1 second interval, so the scrape time is at least 1s * num_sockets
+	if err := wmi.Query(win32ProcessorQuery, &dst); err != nil {
+		return nil, err
+	}
+	if len(dst) == 0 {
+		return nil, errors.New("WMI query returned empty result set")
+	}
+
+	// Some CPUs end up exposing trailing spaces for certain strings, so clean them up
+	for _, processor := range dst {
+		ch <- prometheus.MustNewConstMetric(
+			c.CpuInfo,
+			prometheus.GaugeValue,
+			1.0,
+			strconv.Itoa(int(processor.Architecture)),
+			strings.TrimRight(processor.DeviceID, " "),
+			strings.TrimRight(processor.Description, " "),
+			strconv.Itoa(int(processor.Family)),
+			strconv.Itoa(int(processor.L2CacheSize)),
+			strconv.Itoa(int(processor.L3CacheSize)),
+			strings.TrimRight(processor.Name, " "),
+		)
+	}
+
+	return nil, nil
+}