func attemptCreateInstance()

in integration_test/gce-testing-internal/gce/gce_testing.go [1342:1412]
52 lines of code
11 McCabe index (conditional complexity)

func attemptCreateInstance(ctx context.Context, logger *log.Logger, options VMOptions) (vmToReturn *VM, errToReturn error) {
	vm := createVMFromVMOptions(options)

	imageFamilyScope := options.ImageFamilyScope

	if imageFamilyScope == "" {
		imageFamilyScope = "global"
	}

	args := []string{
		// "beta" is needed for --max-run-duration.
		"beta", "compute", "instances", "create", vm.Name,
		"--project=" + vm.Project,
		"--zone=" + vm.Zone,
		"--machine-type=" + vm.MachineType,
		"--image-family-scope=" + imageFamilyScope,
		"--network=" + vm.Network,
		"--format=json",
	}

	additionalArgs, err := additionalCreateInstanceArgs(options, vm)
	if err != nil {
		return nil, err
	}
	args = append(args, additionalArgs...)

	output, err := RunGcloud(ctx, logger, "", args)
	if err != nil {
		// Note: we don't try and delete the VM in this case because there is
		// nothing to delete.
		return nil, err
	}

	defer func() {
		if errToReturn != nil {
			// This function is responsible for deleting the VM in all error cases.
			errToReturn = multierr.Append(errToReturn, DeleteInstance(logger, vm))
			// Make sure to never return both a valid VM object and an error.
			vmToReturn = nil
		}
		if errToReturn == nil && vm == nil {
			errToReturn = errors.New("programming error: attemptCreateInstance() returned nil VM and nil error")
		}
	}()

	// Pull the instance ID and external IP address out of the output.
	id, err := extractID(output.Stdout)
	if err != nil {
		return nil, err
	}
	vm.ID = id

	logger.Printf("Instance Log: %v", instanceLogURL(vm))

	ipAddress, err := extractIPAddress(output.Stdout)
	if err != nil {
		return nil, err
	}
	vm.IPAddress = ipAddress

	// This is just informational, so it's ok if it fails. Just warn and proceed.
	if _, err := DescribeVMDisk(ctx, logger, vm); err != nil {
		logger.Printf("Unable to retrieve information about the VM's boot disk: %v", err)
	}

	if err := verifyVMCreation(ctx, logger, vm); err != nil {
		return nil, err
	}

	return vm, nil
}