Fix range issue over gcp iam policy bindings.

- When a binding got removed the first time, it would actually shorten
the loop. The next binding to be removed would cause a slice bounds out
of range issue. Instead of using golang's range, used a traditional for
loop to maintain the integrity of the "length" of the loop.

Fixes #73

gcp/iam/service_account.go

@@ -55,32 +55,23 @@ func (s ServiceAccount) removeBindings() error {
 		return fmt.Errorf("Get Project IAM Policy: %s", err)
 	}
 
-	toRemove := []binding{}
+	for j := len(p.Bindings) - 1; j >= 0; j-- {
+		b := p.Bindings[j]
 
-	for j, b := range p.Bindings {
 		for i, m := range b.Members {
 			if strings.Contains(m, s.email) {
-				toRemove = append(toRemove, binding{
-					ServiceAccount: s.email,
-					Member:         m,
-					Role:           b.Role,
-				})
-
 				// Remove this member from the binding
 				b.Members = append(b.Members[:i], b.Members[i+1:]...)
 			}
 		}
 
 		if len(b.Members) == 0 {
-			// If there are no more members for the role, remove the whole binding
 			p.Bindings = append(p.Bindings[:j], p.Bindings[j+1:]...)
+		} else {
+			p.Bindings[j] = b
 		}
 	}
 
-	for _, binding := range toRemove {
-		s.logger.Printf("gcloud iam service-accounts remove-iam-policy-binding %s --member %s --role %s\n", binding.ServiceAccount, binding.Member, binding.Role)
-	}
-
 	_, err = s.client.SetProjectIamPolicy(p)
 	if err != nil {
 		return fmt.Errorf("Set Project IAM Policy: %s", err)

gcp/iam/service_account_test.go

@@ -67,11 +67,6 @@ var _ = Describe("ServiceAccount", func() {
 				err := serviceAccount.Delete()
 				Expect(err).NotTo(HaveOccurred())
 
-				Expect(logger.PrintfCall.Receives.Message).To(Equal("gcloud iam service-accounts remove-iam-policy-binding %s --member %s --role %s\n"))
-				Expect(logger.PrintfCall.Receives.Arguments[0]).To(Equal("[email protected]"))
-				Expect(logger.PrintfCall.Receives.Arguments[1]).To(Equal("serviceAccount:[email protected]"))
-				Expect(logger.PrintfCall.Receives.Arguments[2]).To(Equal("roles/some-role"))
-
 				Expect(client.SetProjectIamPolicyCall.CallCount).To(Equal(1))
 				Expect(client.SetProjectIamPolicyCall.Receives.Input).To(Equal(updatedPolicy))
 			})
@@ -107,6 +102,14 @@ var _ = Describe("ServiceAccount", func() {
 								Members: []string{"user:apple", "serviceAccount:[email protected]"},
 								Role:    "roles/some-other-role",
 							},
+							{
+								Members: []string{"serviceAccount:[email protected]"},
+								Role:    "roles/some-third-role",
+							},
+							{
+								Members: []string{"serviceAccount:[email protected]"},
+								Role:    "roles/some-fourth-role",
+							},
 						},
 					}
 					updatedPolicy = &gcpcrm.Policy{
@@ -115,6 +118,10 @@ var _ = Describe("ServiceAccount", func() {
 								Members: []string{"user:apple"},
 								Role:    "roles/some-other-role",
 							},
+							{
+								Members: []string{"serviceAccount:[email protected]"},
+								Role:    "roles/some-third-role",
+							},
 						},
 					}
 				})