From 87d7d84db2b53d3df55254a0b4e4cdfb3ba8156e Mon Sep 17 00:00:00 2001
From: Ludwik Grodzki <ludwik@improbable.io>
Date: Fri, 30 Aug 2019 15:47:53 +0100
Subject: [PATCH] InstanceGroups refactor and fn for extracting zones

---
 plugin/authorizer_client_gcp.go      | 33 +++++++++++++++------------
 plugin/authorizer_client_gcp_test.go | 34 ++++++++++++++++++++++++++++
 2 files changed, 52 insertions(+), 15 deletions(-)
 create mode 100644 plugin/authorizer_client_gcp_test.go

diff --git a/plugin/authorizer_client_gcp.go b/plugin/authorizer_client_gcp.go
index d4ea0acf..eb70fdd5 100644
--- a/plugin/authorizer_client_gcp.go
+++ b/plugin/authorizer_client_gcp.go
@@ -19,6 +19,23 @@ type gcpClient struct {
 	iamSvc     *iam.Service
 }
 
+func genExtractZonesFn(igz map[string][]string, boundInstanceGroups []string) func(*compute.InstanceGroupAggregatedList) error {
+	return func(l *compute.InstanceGroupAggregatedList) error {
+		for k, v := range l.Items {
+			zone, err := zoneFromSelfLink(k)
+			if err != nil {
+				return err
+			}
+			for _, g := range v.InstanceGroups {
+				if strutil.StrListContains(boundInstanceGroups, g.Name) {
+					igz[zone] = append(igz[zone], g.Name)
+				}
+			}
+		}
+		return nil
+	}
+}
+
 func (c *gcpClient) InstanceGroups(ctx context.Context, project string, boundInstanceGroups []string) (map[string][]string, error) {
 	// map of zone names to a slice of instance group names in that zone.
 	igz := make(map[string][]string)
@@ -26,21 +43,7 @@ func (c *gcpClient) InstanceGroups(ctx context.Context, project string, boundIns
 	if err := c.computeSvc.InstanceGroups.
 		AggregatedList(project).
 		Fields("items/*/instanceGroups/name").
-		Pages(ctx, func(l *compute.InstanceGroupAggregatedList) error {
-			for k, v := range l.Items {
-				zone, err := zoneFromSelfLink(k)
-				if err != nil {
-					return err
-				}
-
-				for _, g := range v.InstanceGroups {
-					if strutil.StrListContains(boundInstanceGroups, g.Name) {
-						igz[zone] = append(igz[zone], g.Name)
-					}
-				}
-			}
-			return nil
-		}); err != nil {
+		Pages(ctx, genExtractZonesFn(igz, boundInstanceGroups)); err != nil {
 		return nil, err
 	}
 
diff --git a/plugin/authorizer_client_gcp_test.go b/plugin/authorizer_client_gcp_test.go
new file mode 100644
index 00000000..bc934f15
--- /dev/null
+++ b/plugin/authorizer_client_gcp_test.go
@@ -0,0 +1,34 @@
+package gcpauth
+
+import (
+	"testing"
+	"google.golang.org/api/compute/v1"
+)
+
+func TestInstanceGroups(t *testing.T) {
+
+	igz := make(map[string][]string)
+	boundInstanceGroups := []string{"foo-us1-baz-group"}
+
+	extractZonesFn := genExtractZonesFn(igz, boundInstanceGroups)
+
+
+	InstanceGroupAggregatedList := compute.InstanceGroupAggregatedList{
+		Items: map[string]compute.InstanceGroupsScopedList{
+			"zones/us-central1-c": compute.InstanceGroupsScopedList{
+				InstanceGroups: []*compute.InstanceGroup{&compute.InstanceGroup{Name: "foo-us1-bar-group"}, &compute.InstanceGroup{Name: "foo-us1-baz-group"}},
+			},
+			"regions/us-central1": compute.InstanceGroupsScopedList{},
+		},
+	}
+
+	err := extractZonesFn(&InstanceGroupAggregatedList)
+
+	if err != nil {
+		t.Fatal("error not expected")
+	}
+
+	if igz["us-central1-c"][0] != "foo-us1-baz-group" {
+		t.Fatal("expected value not found")
+	}
+}
\ No newline at end of file