ar: plumb error handling into alloc runner hook initialization

client/allocrunner/alloc_runner.go

@@ -185,7 +185,9 @@ func NewAllocRunner(config *Config) (*allocRunner, error) {
 	ar.allocDir = allocdir.NewAllocDir(ar.logger, filepath.Join(config.ClientConfig.AllocDir, alloc.ID))
 
 	// Initialize the runners hooks.
-	ar.initRunnerHooks()
+	if err := ar.initRunnerHooks(); err != nil {
+		return nil, err
+	}
 
 	// Create the TaskRunners
 	if err := ar.initTaskRunners(tg.Tasks); err != nil {

client/allocrunner/alloc_runner_hooks.go

@@ -94,7 +94,7 @@ func (a *allocHealthSetter) SetHealth(healthy, isDeploy bool, trackerTaskEvents
 }
 
 // initRunnerHooks intializes the runners hooks.
-func (ar *allocRunner) initRunnerHooks() {
+func (ar *allocRunner) initRunnerHooks() error {
 	hookLogger := ar.logger.Named("runner_hook")
 
 	// create health setting shim
@@ -110,7 +110,7 @@ func (ar *allocRunner) initRunnerHooks() {
 	}
 
 	// initialize platform specific hooks
-	ar.initPlatformRunnerHooks(hookLogger)
+	return ar.initPlatformRunnerHooks(hookLogger)
 }
 
 // prerun is used to run the runners prerun hooks.

client/allocrunner/alloc_runner_linux.go

@@ -11,13 +11,17 @@ import (
 )
 
 // initialize linux specific alloc runner hooks
-func (ar *allocRunner) initPlatformRunnerHooks(hookLogger hclog.Logger) {
+func (ar *allocRunner) initPlatformRunnerHooks(hookLogger hclog.Logger) error {
 
 	// determine how the network must be created
 	ns := &allocNetworkIsolationSetter{ar: ar}
-	nm, _ := ar.initNetworkManager()
+	nm, err := ar.initNetworkManager()
+	if err != nil {
+		return err
+	}
 
 	ar.runnerHooks = append(ar.runnerHooks, newNetworkHook(ns, hookLogger, ar.Alloc(), nm))
+	return nil
 }
 
 func (ar *allocRunner) initNetworkManager() (nm drivers.DriverNetworkManager, err error) {

client/allocrunner/alloc_runner_nonlinux.go

@@ -5,4 +5,4 @@ package allocrunner
 import hclog "github.com/hashicorp/go-hclog"
 
 // noop for non linux clients
-func (ar *allocRunner) initPlatformRunnerHooks(hookLogger hclog.Logger) {}
+func (ar *allocRunner) initPlatformRunnerHooks(hookLogger hclog.Logger) error { return nil }