improve resilience

cmd/nuke.go

@@ -211,8 +211,8 @@ func (n *Nuke) Scan() error {
 
 	for _, region := range n.Config.Regions {
 		sess := n.sessions[region]
-		scanner := Scan(sess)
-		for item := range scanner.Items {
+		items := Scan(sess)
+		for item := range items {
 			if !n.Parameters.WantsTarget(item.Service) {
 				continue
 			}
@@ -221,12 +221,8 @@ func (n *Nuke) Scan() error {
 			n.Filter(item)
 			item.Print()
 		}
-		if scanner.Error != nil {
-			fmt.Printf("Scanner found an error %s \n", scanner.Error)
-			return scanner.Error
-		}
-
 	}
+
 	fmt.Printf("Scan complete: %d total, %d nukeable, %d filtered.\n\n",
 		queue.CountTotal(), queue.Count(ItemStateNew), queue.Count(ItemStateFiltered))
 

cmd/scan.go

@@ -1,27 +1,29 @@
 package cmd
 
 import (
+	"fmt"
+	"runtime/debug"
+
 	"github.com/aws/aws-sdk-go/aws/session"
 	"github.com/rebuy-de/aws-nuke/resources"
 )
 
-type Scanner struct {
-	Items <-chan *Item
-	Error error
-}
-
-func Scan(sess *session.Session) *Scanner {
-	var err error
+func Scan(sess *session.Session) <-chan *Item {
 	items := make(chan *Item, 100)
 
 	go func() {
 		listers := resources.GetListers(sess)
 
 		for _, lister := range listers {
-			var r []resources.Resource
-			r, err = lister()
+			r, err := safeLister(lister)
 			if err != nil {
-				break
+				LogErrorf(fmt.Errorf("\n=============\n\n"+
+					"Listing with %T failed:\n\n"+
+					"%v\n\n"+
+					"Please report this to https://github.com/rebuy-de/aws-nuke/issues/new.\n\n"+
+					"=============",
+					lister, err))
+				continue
 			}
 
 			for _, r := range r {
@@ -38,5 +40,16 @@ func Scan(sess *session.Session) *Scanner {
 		close(items)
 	}()
 
-	return &Scanner{items, err}
+	return items
+}
+
+func safeLister(lister resources.ResourceLister) (r []resources.Resource, err error) {
+	defer func() {
+		if r := recover(); r != nil {
+			err = fmt.Errorf("%v\n\n%s", r.(error), string(debug.Stack()))
+		}
+	}()
+
+	r, err = lister()
+	return
 }

cmd/scan_test.go

@@ -0,0 +1,22 @@
+package cmd
+
+import (
+	"strings"
+	"testing"
+
+	"github.com/rebuy-de/aws-nuke/resources"
+)
+
+func TestSafeLister(t *testing.T) {
+	nilLister := func() ([]resources.Resource, error) {
+		var ptr *string = nil
+		_ = *ptr
+
+		return nil, nil
+	}
+
+	_, err := safeLister(nilLister)
+	if !strings.Contains(err.Error(), "runtime error: invalid memory address or nil pointer dereference") {
+		t.Fatalf("Got unexpected error: %v", err)
+	}
+}