Migrate: handle NotFound via resource matching and during conflicts

This change fixes two issues with the migrate command:

1. It updates isNotFoundForInfo to compare the error's kind to the
info's resource as well as its kind.  The server error's use the
resource value in places where the kind should be used.  We simply
accept both now.
2. It updates DefaultRetriable to not fail on conflict errors if
they were caused by the deletion of the given resource.

The following shell based tests were used to stress the edge cases
that this change fixes.  The migrate command will readily fail in
these tests without the fixes from this change.

In one shell we continuously create service accounts with random
names as fast as possible.  The resource type is not relevant.

N=8
while true; do
    ((i=i%N)); ((i++==0)) && wait
    oc create serviceaccount $((1 + RANDOM % 10000000)) &
done

In a second shell we try to continuously delete all service
accounts:

while true; do
    oc delete sa --all
done

In a third shell we try to continuously migrate service accounts:

while true; do
    oc adm migrate storage --include='serviceaccount' --confirm
done

Bug 1537751

Signed-off-by: Monis Khan <[email protected]>

Author: enj

pkg/oc/admin/migrate/migrator.go

@@ -503,6 +503,11 @@ func DefaultRetriable(info *resource.Info, err error) error {
 		return ErrNotRetriable{err}
 	case errors.IsConflict(err):
 		if refreshErr := info.Get(); refreshErr != nil {
+			// tolerate the deletion of resources during migration
+			// report unchanged since we did not actually migrate this object
+			if isNotFoundForInfo(info, refreshErr) {
+				return ErrUnchanged
+			}
 			return ErrNotRetriable{err}
 		}
 		return ErrRetriable{err}
@@ -526,11 +531,14 @@ func isNotFoundForInfo(info *resource.Info, err error) bool {
 	if details == nil {
 		return false
 	}
-	// get schema.GroupKind from the mapping since the actual object may not have type meta filled out
+	// get schema.GroupKind and Resource from the mapping since the actual object may not have type meta filled out
 	gk := info.Mapping.GroupVersionKind.GroupKind()
+	mappingResource := info.Mapping.Resource
 	// based on case-insensitive string comparisons, the error matches info iff
-	// the name and kind match
-	// the group match, but only if both the error and info specify a group
-	return strings.EqualFold(details.Name, info.Name) && strings.EqualFold(details.Kind, gk.Kind) &&
+	// the names match
+	// the error's kind matches the mapping's kind or the mapping's resource
+	// the groups match, but only if both the error and info specify a group
+	return strings.EqualFold(details.Name, info.Name) &&
+		(strings.EqualFold(details.Kind, gk.Kind) || strings.EqualFold(details.Kind, mappingResource)) &&
 		(len(details.Group) == 0 || len(gk.Group) == 0 || strings.EqualFold(details.Group, gk.Group))
 }

pkg/oc/admin/migrate/migrator_test.go

@@ -334,6 +334,72 @@ func TestIsNotFoundForInfo(t *testing.T) {
 			},
 			want: false,
 		},
+		{
+			name: "case-insensitive match due to different kinds but same resource",
+			args: args{
+				info: &resource.Info{
+					Mapping: &meta.RESTMapping{
+						Resource: "KIND2",
+						GroupVersionKind: schema.GroupVersionKind{
+							Group: "group1",
+							Kind:  "kind1",
+						},
+					},
+					Name: "NOTname",
+				},
+				err: errors.NewNotFound(schema.GroupResource{
+					Group:    "GROUP1",
+					Resource: "kind2", // this is the kind
+				},
+					"notNAME",
+				),
+			},
+			want: true,
+		},
+		{
+			name: "case-insensitive match due to different resource but same kinds",
+			args: args{
+				info: &resource.Info{
+					Mapping: &meta.RESTMapping{
+						Resource: "kind1",
+						GroupVersionKind: schema.GroupVersionKind{
+							Group: "group1",
+							Kind:  "KIND2",
+						},
+					},
+					Name: "NOTname",
+				},
+				err: errors.NewNotFound(schema.GroupResource{
+					Group:    "GROUP1",
+					Resource: "kind2", // this is the kind
+				},
+					"notNAME",
+				),
+			},
+			want: true,
+		},
+		{
+			name: "case-insensitive not match due to different resource and different kinds",
+			args: args{
+				info: &resource.Info{
+					Mapping: &meta.RESTMapping{
+						Resource: "kind1",
+						GroupVersionKind: schema.GroupVersionKind{
+							Group: "group1",
+							Kind:  "kind3",
+						},
+					},
+					Name: "NOTname",
+				},
+				err: errors.NewNotFound(schema.GroupResource{
+					Group:    "GROUP1",
+					Resource: "kind2", // this is the kind
+				},
+					"notNAME",
+				),
+			},
+			want: false,
+		},
 	}
 	for _, tt := range tests {
 		t.Run(tt.name, func(t *testing.T) {