terraform: fix some issues around filtering single counts

terraform/state_filter.go

@@ -36,7 +36,7 @@ func (f *StateFilter) Filter(fs ...string) ([]*StateFilterResult, error) {
 
 	// If we werent given any filters, then we list all
 	if len(fs) == 0 {
-		as = append(as, &ResourceAddress{})
+		as = append(as, &ResourceAddress{Index: -1})
 	}
 
 	// Filter each of the address. We keep track of this in a map to
@@ -94,6 +94,11 @@ func (f *StateFilter) filterSingle(a *ResourceAddress) []*StateFilterResult {
 					continue
 				}
 
+				if a.Index >= 0 && key.Index != a.Index {
+					// Index doesn't match
+					continue
+				}
+
 				// Build the address for this resource
 				addr := &ResourceAddress{
 					Path:  m.Path[1:],

terraform/state_filter_test.go

@@ -51,6 +51,15 @@ func TestStateFilterFilter(t *testing.T) {
 				"*terraform.InstanceState: module.bootstrap.aws_route53_zone.oasis-consul-bootstrap",
 			},
 		},
+
+		"single count index": {
+			"complete.tfstate",
+			[]string{"module.consul.aws_instance.consul-green[0]"},
+			[]string{
+				"*terraform.ResourceState: module.consul.aws_instance.consul-green[0]",
+				"*terraform.InstanceState: module.consul.aws_instance.consul-green[0]",
+			},
+		},
 	}
 
 	for n, tc := range cases {