util: Add a pprof helper package

As it turns out, there are other helper packages out there. I wrote this
before I realized that, and it didn't take me that long anyways.

main.go

@@ -43,7 +43,8 @@ import (
 	_ "github.com/purpleidea/mgmt/lang/gapi"         // import so the gapi registers
 	_ "github.com/purpleidea/mgmt/puppet"            // import so the gapi registers
 	_ "github.com/purpleidea/mgmt/puppet/langpuppet" // import so the gapi registers
-	_ "github.com/purpleidea/mgmt/yamlgraph"         // import so the gapi registers
+	"github.com/purpleidea/mgmt/util/pprof"
+	_ "github.com/purpleidea/mgmt/yamlgraph" // import so the gapi registers
 	"go.etcd.io/etcd/server/v3/etcdmain"
 )
 
@@ -76,6 +77,16 @@ func main() {
 		return              // for safety
 	}
 
+	// Run profiling if it's activated.
+	// TODO: Should we pass a logger into this?
+	ctx, cancel := context.WithCancel(context.Background())
+	if err := pprof.Run(ctx); err != nil {
+		fmt.Println(err)
+		os.Exit(1)
+		//return // redundant
+	}
+	defer cancel()
+
 	cliUtil.LogSetup(debug)
 	data := &cliUtil.Data{
 		Program: program,