Fix startuphooks race condition panic

Ensure startup hooks WaitGroup is initialized before starting goroutine that will wait on it

Signed-off-by: Brad Davidson <brad.davidson@rancher.com>

Author: brandond

pkg/cli/server/server.go

@@ -8,6 +8,7 @@ import (
 	"os"
 	"path/filepath"
 	"strings"
+	"sync"
 	"time"
 
 	systemd "github.com/coreos/go-systemd/v22/daemon"
@@ -602,6 +603,9 @@ func run(app *cli.Context, cfg *cmds.Server, leaderControllers server.CustomCont
 
 	go cmds.WriteCoverage(ctx)
 
+	serverConfig.ControlConfig.Runtime.StartupHooksWg = &sync.WaitGroup{}
+	serverConfig.ControlConfig.Runtime.StartupHooksWg.Add(len(serverConfig.StartupHooks))
+
 	go func() {
 		if !serverConfig.ControlConfig.DisableETCD {
 			<-executor.ETCDReadyChan()

pkg/server/server.go

@@ -8,7 +8,6 @@ import (
 	"runtime/debug"
 	"strconv"
 	"strings"
-	"sync"
 	"time"
 
 	helmchart "github.com/k3s-io/helm-controller/pkg/controllers/chart"
@@ -74,19 +73,14 @@ func StartServer(ctx context.Context, config *Config, cfg *cmds.Server) error {
 		return pkgerrors.WithMessage(err, "starting kubernetes")
 	}
 
-	wg := &sync.WaitGroup{}
-	wg.Add(len(config.StartupHooks))
-
-	config.ControlConfig.Runtime.StartupHooksWg = wg
-
 	shArgs := cmds.StartupHookArgs{
 		APIServerReady:       executor.APIServerReadyChan(),
 		KubeConfigSupervisor: config.ControlConfig.Runtime.KubeConfigSupervisor,
 		Skips:                config.ControlConfig.Skips,
 		Disables:             config.ControlConfig.Disables,
 	}
 	for _, hook := range config.StartupHooks {
-		if err := hook(ctx, wg, shArgs); err != nil {
+		if err := hook(ctx, config.ControlConfig.Runtime.StartupHooksWg, shArgs); err != nil {
 			return pkgerrors.WithMessage(err, "startup hook")
 		}
 	}