Add apt collector

cmd/server/main.go

@@ -11,6 +11,7 @@ import (
 	"git.faercol.me/monitoring/sys-exporter/registry"
 	"github.com/prometheus/client_golang/prometheus/promhttp"
 
+	_ "git.faercol.me/monitoring/sys-exporter/collector/apt"
 	_ "git.faercol.me/monitoring/sys-exporter/collector/loadavg"
 	_ "git.faercol.me/monitoring/sys-exporter/collector/meminfo"
 	_ "git.faercol.me/monitoring/sys-exporter/collector/pacman"

collector/apt/apt.go

@@ -0,0 +1,105 @@
+package apt
+
+import (
+	"context"
+	"fmt"
+	"os/exec"
+	"strings"
+	"time"
+
+	"git.faercol.me/monitoring/sys-exporter/registry"
+	"github.com/prometheus/client_golang/prometheus"
+	"go.uber.org/zap"
+)
+
+type AptCollector struct {
+	installedPackages int
+	pendingUpdates    int
+
+	promExporter *prometheus.GaugeVec
+	updateFreq   time.Duration
+
+	l *zap.SugaredLogger
+}
+
+func (c *AptCollector) Collect() interface{} {
+	return nil
+}
+
+func (c *AptCollector) updateInstalledPackages() error {
+	cmd := exec.Command("/usr/bin/apt", "list", "--installed")
+	out, err := cmd.CombinedOutput()
+	if err != nil {
+		return fmt.Errorf("failed to run apt list: %w (%s)", err, string(out))
+	}
+
+	c.installedPackages = len(strings.Split(strings.TrimSpace(string(out)), "\n"))
+	return nil
+}
+
+func (c *AptCollector) updatePendingUpdates() error {
+	updateCmd := exec.Command("/usr/bin/apt", "update")
+	out, err := updateCmd.CombinedOutput()
+	if err != nil {
+		return fmt.Errorf("failed to run apt update: %w (%s)", err, string(out))
+	}
+
+	listCmd := exec.Command("/usr/bin/apt", "list", "--upgradable")
+	out, err = listCmd.CombinedOutput()
+	if err != nil {
+		return fmt.Errorf("failed to run apt list: %w (%s)", err, string(out))
+	}
+
+	c.pendingUpdates = len(strings.Split(strings.TrimSpace(string(out)), "\n"))
+	return nil
+}
+
+func (c *AptCollector) update() error {
+	if err := c.updateInstalledPackages(); err != nil {
+		return fmt.Errorf("failed to update count of installed packages: %w", err)
+	}
+	if err := c.updatePendingUpdates(); err != nil {
+		return fmt.Errorf("failed to update count of pending updates: %w", err)
+	}
+
+	c.promExporter.WithLabelValues("total").Set(float64(c.installedPackages))
+	c.promExporter.WithLabelValues("updates").Set(float64(c.pendingUpdates))
+	return nil
+}
+
+func (c *AptCollector) Run(ctx context.Context, l *zap.SugaredLogger) {
+	c.l = l
+
+	c.l.Debug("Initializing collector")
+	if err := c.update(); err != nil {
+		c.l.Errorf("Failed to init collector: %s\n", err)
+	}
+
+	for {
+		select {
+		case <-ctx.Done():
+			c.l.Debug("Stopping collector")
+			return
+		case <-time.After(c.updateFreq):
+			c.l.Debug("Updating collector")
+			if err := c.update(); err != nil {
+				c.l.Errorf("Failed to update collector: %s\n", err)
+			}
+		}
+	}
+}
+
+func (c *AptCollector) PromCollector() prometheus.Collector {
+	return c.promExporter
+}
+
+func New() *AptCollector {
+	return &AptCollector{
+		updateFreq:   30 * time.Minute,
+		promExporter: prometheus.NewGaugeVec(prometheus.GaugeOpts{Namespace: "packages", Subsystem: "apt", Name: "packages_count", Help: "Count of apt packages"}, []string{"status"}),
+	}
+}
+
+func init() {
+	registry.R.MustRegisterCollector("packages.apt", New())
+}

debian/sys-exporter/etc/sys-exporter/config.yml

@@ -6,3 +6,4 @@ collectors:
   - services.systemd
   - system.uptime
   - system.info
+  - packages.apt