Add gauge metric for number of self-hosted org runners

internal/server/billing_metrics_exporter.go

@@ -8,7 +8,6 @@ import (
 	"github.com/go-kit/log"
 	"github.com/go-kit/log/level"
 	"github.com/google/go-github/v50/github"
-	"golang.org/x/oauth2"
 )
 
 type BillingMetricsExporter struct {
@@ -18,12 +17,7 @@ type BillingMetricsExporter struct {
 }
 
 func NewBillingMetricsExporter(logger log.Logger, opts Opts) *BillingMetricsExporter {
-	ctx := context.Background()
-	ts := oauth2.StaticTokenSource(
-		&oauth2.Token{AccessToken: opts.GitHubAPIToken},
-	)
-	tc := oauth2.NewClient(ctx, ts)
-	client := github.NewClient(tc)
+	client := getGithubClient(opts.GitHubAPIToken)
 
 	return &BillingMetricsExporter{
 		Logger:   logger,

internal/server/github_client.go

@@ -0,0 +1,25 @@
+package server
+
+import (
+	"context"
+
+	"github.com/google/go-github/v50/github"
+	"golang.org/x/oauth2"
+)
+
+var client *github.Client
+
+func getGithubClient(githubToken string) *github.Client {
+	if client != nil {
+		return client
+	}
+
+	ctx := context.Background()
+	ts := oauth2.StaticTokenSource(
+		&oauth2.Token{AccessToken: githubToken},
+	)
+	tc := oauth2.NewClient(ctx, ts)
+	client = github.NewClient(tc)
+
+	return client
+}

internal/server/metrics.go

@@ -63,21 +63,21 @@ var (
 
 	totalMinutesUsedUbuntuActions = prometheus.NewGaugeVec(prometheus.GaugeOpts{
 		Name: "actions_total_minutes_used_ubuntu_minutes",
-		Help: "Total minutes used for Ubuntu type for the GitHub Actions. To be deprecate, use actions_total_minutes_used_by_host_minutes",
+		Help: "Total minutes used for Ubuntu type for the GitHub Actions. To be deprecated, use actions_total_minutes_used_by_host_minutes",
 	},
 		[]string{"org", "user"},
 	)
 
 	totalMinutesUsedMacOSActions = prometheus.NewGaugeVec(prometheus.GaugeOpts{
 		Name: "actions_total_minutes_used_macos_minutes",
-		Help: "Total minutes used for MacOS type for the GitHub Actions. To be deprecate, use actions_total_minutes_used_by_host_minutes",
+		Help: "Total minutes used for MacOS type for the GitHub Actions. To be deprecated, use actions_total_minutes_used_by_host_minutes",
 	},
 		[]string{"org", "user"},
 	)
 
 	totalMinutesUsedWindowsActions = prometheus.NewGaugeVec(prometheus.GaugeOpts{
 		Name: "actions_total_minutes_used_windows_minutes",
-		Help: "Total minutes used for Windows type for the GitHub Actions. To be deprecate, use actions_total_minutes_used_by_host_minutes",
+		Help: "Total minutes used for Windows type for the GitHub Actions. To be deprecated, use actions_total_minutes_used_by_host_minutes",
 	},
 		[]string{"org", "user"},
 	)
@@ -88,6 +88,13 @@ var (
 	},
 		[]string{"org", "user", "host_type"},
 	)
+
+	numberOfSelfHostedRunners = prometheus.NewGaugeVec(prometheus.GaugeOpts{
+		Name: "github_actions_num_self_hosted_org_runners",
+		Help: "Number of self-hosted org runners for the GitHub Actions.",
+	},
+		[]string{"org"},
+	)
 )
 
 func init() {
@@ -104,6 +111,7 @@ func init() {
 	prometheus.MustRegister(totalMinutesUsedMacOSActions)
 	prometheus.MustRegister(totalMinutesUsedWindowsActions)
 	prometheus.MustRegister(totalMinutesUsedByHostTypeActions)
+	prometheus.MustRegister(numberOfSelfHostedRunners)
 }
 
 type WorkflowObserver interface {

internal/server/runner_metrics.go

@@ -0,0 +1,61 @@
+package server
+
+import (
+	"context"
+	"time"
+
+	"github.com/go-kit/log"
+	"github.com/go-kit/log/level"
+	"github.com/google/go-github/v50/github"
+)
+
+type RunnerMetricsExporter struct {
+	GHClient *github.Client
+	Logger   log.Logger
+	Opts     Opts
+}
+
+func NewRunnerMetricsExporter(logger log.Logger, opts Opts) *RunnerMetricsExporter {
+	client := getGithubClient(opts.GitHubAPIToken)
+
+	return &RunnerMetricsExporter{
+		GHClient: client,
+		Logger:   logger,
+		Opts:     opts,
+	}
+}
+
+func (e *RunnerMetricsExporter) StartOrgRunnerMetricsCollection(ctx context.Context) {
+	if e.Opts.GitHubOrg == "" {
+		_ = level.Info(e.Logger).Log("msg", "Github org is not set, no org runner metrics will be collected.")
+		return
+	}
+	if e.Opts.GitHubAPIToken == "" {
+		_ = level.Info(e.Logger).Log("msg", "Github token is not set, no org runner metrics will be collected.")
+		return
+	}
+
+	ticker := time.NewTicker(time.Duration(e.Opts.RunnersAPIPollSeconds) * time.Second)
+	go func() {
+		for {
+			select {
+			case <-ticker.C:
+				e.collectOrgRunnerMetrics(ctx)
+			case <-ctx.Done():
+				ticker.Stop()
+				_ = level.Info(e.Logger).Log("msg", "Stopped polling for org runner metrics.")
+				return
+			}
+		}
+	}()
+}
+
+func (e *RunnerMetricsExporter) collectOrgRunnerMetrics(ctx context.Context) {
+	runners, _, err := e.GHClient.Actions.ListOrganizationRunners(ctx, e.Opts.GitHubOrg, nil)
+
+	if err != nil {
+		_ = e.Logger.Log("msg", "Failed to retrieve org runners for org ", e.Opts.GitHubOrg, " ", err)
+	}
+
+	numberOfSelfHostedRunners.WithLabelValues(e.Opts.GitHubOrg).Set(float64(runners.TotalCount))
+}

internal/server/server.go

@@ -27,6 +27,9 @@ type Opts struct {
 	GitHubOrg             string
 	GitHubUser            string
 	BillingAPIPollSeconds int
+
+	GitHubRunnersRepos    []string
+	RunnersAPIPollSeconds int
 }
 
 type Server struct {
@@ -55,6 +58,9 @@ func NewServer(logger log.Logger, opts Opts) *Server {
 		_ = level.Info(logger).Log("msg", fmt.Sprintf("not exporting user billing: %v", err))
 	}
 
+	runnerMetricsExporter := NewRunnerMetricsExporter(logger, opts)
+	runnerMetricsExporter.StartOrgRunnerMetricsCollection(context.TODO())
+
 	muxIngress := http.NewServeMux()
 	httpServerIngress := &http.Server{
 		Handler:           muxIngress,

main.go

@@ -27,6 +27,8 @@ var (
 	gitHubOrg                   = kingpin.Flag("gh.github-org", "GitHub Organization.").Envar("GITHUB_ORG").Default("").String()
 	gitHubUser                  = kingpin.Flag("gh.github-user", "GitHub User.").Default("").String()
 	gitHubBillingPollingSeconds = kingpin.Flag("gh.billing-poll-seconds", "Frequency at which to poll billing API.").Default("5").Int()
+	gitHubRunnersRepos          = kingpin.Flag("gh.runners-repos", "The name of the repositories where runners are configures.").Default("").Strings()
+	gitHubRunnersPollingSeconds = kingpin.Flag("gh.runners-poll-seconds", "Frequency at which to poll runners API.").Default("5").Int()
 )
 
 func init() {
@@ -62,6 +64,8 @@ func main() {
 		GitHubUser:            *gitHubUser,
 		GitHubOrg:             *gitHubOrg,
 		BillingAPIPollSeconds: *gitHubBillingPollingSeconds,
+		GitHubRunnersRepos:    *gitHubRunnersRepos,
+		RunnersAPIPollSeconds: *gitHubRunnersPollingSeconds,
 	})
 	go func() {
 		err := srv.Serve(context.Background())