check if accessConfig is not nil before deleting

model/gcp_vm.rb

@@ -72,25 +72,25 @@ def swap_ip(vm)
     gcp_client = Hosting::GcpApis.new
     zone1 = "#{location}-a"
     zone2 = "#{vm.location}-a"
-    vm_info1 = gcp_client.get_vm(name, zone1)
-    vm_info2 = gcp_client.get_vm(vm.name, zone2)
+    access_configs1 = gcp_client.get_vm(name, zone1)["networkInterfaces"][0]["accessConfigs"] || []
+    access_configs2 = gcp_client.get_vm(vm.name, zone2)["networkInterfaces"][0]["accessConfigs"] || []
 
-    if vm_info1["networkInterfaces"][0]["accessConfigs"].find { _1["name"] == "External NAT" }
+    if access_configs1.find { _1["name"] == "External NAT" }
       gcp_client.delete_ephermal_ipv4(name, zone1)
     end
 
-    if vm_info2["networkInterfaces"][0]["accessConfigs"].find { _1["name"] == "External NAT" }
+    if access_configs2.find { _1["name"] == "External NAT" }
       gcp_client.delete_ephermal_ipv4(vm.name, zone2)
     end
 
     # we are explicitly checking if ip is already assigned
     # because the operation can be terminated while running
     # and on next retry we will have error that the external ip is already assigned
-    if !vm_info1["networkInterfaces"][0]["accessConfigs"].find { _1["natIP"] == vm.sshable.host }
+    if !access_configs1.find { _1["natIP"] == vm.sshable.host }
       gcp_client.assign_static_ipv4(name, vm.sshable.host, zone1)
     end
 
-    if !vm_info2["networkInterfaces"][0]["accessConfigs"].find { _1["natIP"] == sshable.host }
+    if !access_configs2.find { _1["natIP"] == sshable.host }
       gcp_client.assign_static_ipv4(vm.name, sshable.host, zone2)
     end
 

spec/model/gcp_vm_spec.rb

@@ -91,6 +91,24 @@
       expect { gcp_vm.swap_ip(vm2) }.not_to raise_error
     end
 
+    it "does not delete if no access config" do
+      api = instance_double(Hosting::GcpApis)
+      expect(api).to receive(:assign_static_ipv4).with("vm1", "ip2", "us-central1-a")
+      expect(api).to receive(:assign_static_ipv4).with("vm2", "ip1", "us-central1-a")
+      expect(api).to receive(:get_vm).and_return({"networkInterfaces" => [{"accessConfigs" => nil}]}).at_least(:once)
+      expect(Hosting::GcpApis).to receive(:new).and_return(api)
+      vm2 = instance_double(described_class, name: "vm2", address_name: "vm2-addr", location: "us-central1", sshable: instance_double(Sshable, host: "ip2"))
+      expect(gcp_vm).to receive(:sshable).and_return(instance_double(Sshable, host: "ip1")).at_least(:once)
+      expect(gcp_vm.sshable).to receive(:invalidate_cache_entry)
+      expect(vm2.sshable).to receive(:invalidate_cache_entry)
+      expect(gcp_vm.sshable).to receive(:update).with(host: "temp_vm1")
+      expect(gcp_vm.sshable).to receive(:update).with(host: "ip2")
+      expect(vm2.sshable).to receive(:update).with(host: "ip1")
+      expect(gcp_vm).to receive(:update).with(address_name: "vm2-addr")
+      expect(vm2).to receive(:update).with(address_name: "vm1-addr")
+      expect { gcp_vm.swap_ip(vm2) }.not_to raise_error
+    end
+
     it "does not delete if no public ip" do
       api = instance_double(Hosting::GcpApis)
       expect(api).to receive(:assign_static_ipv4).with("vm1", "ip2", "us-central1-a")