feat(metrics): add active users, actions queue/running to Prometheus (#42)

Extend the existing /metrics endpoint with 3 new application metrics:
- gitea_active_users_30d: users active in last 30 days
- gitea_actions_queue_length: pending action jobs
- gitea_actions_running_jobs: currently running jobs

No new dependencies — extends existing collector and statistic model.

Closes #42

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

models/activities/statistic.go

@@ -6,6 +6,7 @@ package activities
 import (
 	"context"
 
+	actions_model "code.gitea.io/gitea/models/actions"
 	asymkey_model "code.gitea.io/gitea/models/asymkey"
 	"code.gitea.io/gitea/models/auth"
 	"code.gitea.io/gitea/models/db"
@@ -18,6 +19,7 @@ import (
 	user_model "code.gitea.io/gitea/models/user"
 	"code.gitea.io/gitea/models/webhook"
 	"code.gitea.io/gitea/modules/optional"
+	"code.gitea.io/gitea/modules/timeutil"
 	"code.gitea.io/gitea/modules/setting"
 	"code.gitea.io/gitea/modules/structs"
 )
@@ -37,6 +39,11 @@ type Statistic struct {
 		Branches, Tags, CommitStatus int64
 		IssueByLabel      []IssueByLabelCount
 		IssueByRepository []IssueByRepositoryCount
+
+		// MokoGitea extended metrics
+		ActiveUsers30d     int64
+		ActionsQueueLength int64
+		ActionsRunningJobs int64
 	}
 }
 
@@ -131,5 +138,19 @@ func GetStatistic(ctx context.Context) (stats Statistic) {
 	stats.Counter.Attachment, _ = e.Count(new(repo_model.Attachment))
 	stats.Counter.Project, _ = e.Count(new(project_model.Project))
 	stats.Counter.ProjectColumn, _ = e.Count(new(project_model.Column))
+
+	// MokoGitea extended metrics
+	// Active users in last 30 days (users who performed any action)
+	stats.Counter.ActiveUsers30d, _ = e.Where("last_login_unix > ?",
+		timeutil.TimeStampNow()-30*24*60*60).Count(new(user_model.User))
+
+	// Actions queue and running jobs (if actions enabled)
+	if setting.Actions.Enabled {
+		stats.Counter.ActionsQueueLength, _ = e.Where("status = ?", 1). // StatusWaiting
+										Count(new(actions_model.ActionRunJob))
+		stats.Counter.ActionsRunningJobs, _ = e.Where("status = ?", 2). // StatusRunning
+										Count(new(actions_model.ActionRunJob))
+	}
+
 	return stats
 }

modules/metrics/collector.go

@@ -46,6 +46,11 @@ type Collector struct {
 	Users              *prometheus.Desc
 	Watches            *prometheus.Desc
 	Webhooks           *prometheus.Desc
+
+	// MokoGitea extended metrics
+	ActiveUsers30d     *prometheus.Desc
+	ActionsQueueLength *prometheus.Desc
+	ActionsRunningJobs *prometheus.Desc
 }
 
 // NewCollector returns a new Collector with all prometheus.Desc initialized
@@ -196,6 +201,21 @@ func NewCollector() Collector {
 			"Number of Webhooks",
 			nil, nil,
 		),
+		ActiveUsers30d: prometheus.NewDesc(
+			namespace+"active_users_30d",
+			"Number of active users in the last 30 days",
+			nil, nil,
+		),
+		ActionsQueueLength: prometheus.NewDesc(
+			namespace+"actions_queue_length",
+			"Number of actions jobs waiting to run",
+			nil, nil,
+		),
+		ActionsRunningJobs: prometheus.NewDesc(
+			namespace+"actions_running_jobs",
+			"Number of actions jobs currently running",
+			nil, nil,
+		),
 	}
 }
 
@@ -229,6 +249,9 @@ func (c Collector) Describe(ch chan<- *prometheus.Desc) {
 	ch <- c.Users
 	ch <- c.Watches
 	ch <- c.Webhooks
+	ch <- c.ActiveUsers30d
+	ch <- c.ActionsQueueLength
+	ch <- c.ActionsRunningJobs
 }
 
 // Collect returns the metrics with values
@@ -392,4 +415,21 @@ func (c Collector) Collect(ch chan<- prometheus.Metric) {
 		prometheus.GaugeValue,
 		float64(stats.Counter.Webhook),
 	)
+
+	// MokoGitea extended metrics
+	ch <- prometheus.MustNewConstMetric(
+		c.ActiveUsers30d,
+		prometheus.GaugeValue,
+		float64(stats.Counter.ActiveUsers30d),
+	)
+	ch <- prometheus.MustNewConstMetric(
+		c.ActionsQueueLength,
+		prometheus.GaugeValue,
+		float64(stats.Counter.ActionsQueueLength),
+	)
+	ch <- prometheus.MustNewConstMetric(
+		c.ActionsRunningJobs,
+		prometheus.GaugeValue,
+		float64(stats.Counter.ActionsRunningJobs),
+	)
 }