FindLicense: Implement license finding in Go

This change implements the license finding in Go using
github.com/go-enry/go-license-detector.

Issue: https://gitlab.com/gitlab-org/gitaly/-/issues/3078
Changelog: performance

1 files changed, 12 insertions, 0 deletions

diff --git a/cmd/gitaly/main.go b/cmd/gitaly/main.go
index 4304ee970..f9f5baa02 100644
--- a/cmd/gitaly/main.go
+++ b/cmd/gitaly/main.go
@@ -7,6 +7,7 @@ import (
 	"os"
 	"time"
 
+	"github.com/go-enry/go-license-detector/v4/licensedb"
 	"github.com/prometheus/client_golang/prometheus"
 	log "github.com/sirupsen/logrus"
 	"gitlab.com/gitlab-org/gitaly/v14/client"
@@ -110,6 +111,7 @@ func configure(configPath string) (config.Cfg, error) {
 	cfg.Prometheus.Configure()
 	config.ConfigureConcurrencyLimits(cfg)
 	tracing.Initialize(tracing.WithServiceName("gitaly"))
+	preloadLicenseDatabase()
 
 	return cfg, nil
 }
@@ -129,6 +131,16 @@ func verifyGitVersion(cfg config.Cfg) error {
 	return nil
 }
 
+func preloadLicenseDatabase() {
+	// the first call to `licensedb.Detect` could be too long
+	// https://github.com/go-enry/go-license-detector/issues/13
+	// this is why we're calling it here to preload license database
+	// on server startup to avoid long initialization on gRPC
+	// method handling.
+	licensedb.Preload()
+	log.Info("License database preloaded")
+}
+
 func run(cfg config.Cfg) error {
 	ctx, cancel := context.WithCancel(context.Background())
 	defer cancel()