func getImageIDFromConfig(computeClient *gophercloud.ServiceClient, d *schema.ResourceData) (string, error) {
	// If block_device was used, an Image does not need to be specified.
	// If an Image was specified, ignore it
	if _, ok := d.GetOk("block_device"); ok {
		return "", nil
	}

	if imageId := d.Get("image_id").(string); imageId != "" {
		return imageId, nil
	} else {
		// try the OS_IMAGE_ID environment variable
		if v := os.Getenv("OS_IMAGE_ID"); v != "" {
			return v, nil
		}
	}

	imageName := d.Get("image_name").(string)
	if imageName == "" {
		// try the OS_IMAGE_NAME environment variable
		if v := os.Getenv("OS_IMAGE_NAME"); v != "" {
			imageName = v
		}
	}

	if imageName != "" {
		imageId, err := images.IDFromName(computeClient, imageName)
		if err != nil {
			return "", err
		}
		return imageId, nil
	}

	return "", fmt.Errorf("Neither a boot device, image ID, or image name were able to be determined.")
}

// Create requests a server to be provisioned to the user in the current tenant.
func Create(client *gophercloud.ServiceClient, opts CreateOptsBuilder) CreateResult {
	var res CreateResult

	reqBody, err := opts.ToServerCreateMap()
	if err != nil {
		res.Err = err
		return res
	}

	// If ImageRef isn't provided, use ImageName to ascertain the image ID.
	if reqBody["server"].(map[string]interface{})["imageRef"].(string) == "" {
		imageName := reqBody["server"].(map[string]interface{})["imageName"].(string)
		if imageName == "" {
			res.Err = errors.New("One and only one of ImageRef and ImageName must be provided.")
			return res
		}
		imageID, err := images.IDFromName(client, imageName)
		if err != nil {
			res.Err = err
			return res
		}
		reqBody["server"].(map[string]interface{})["imageRef"] = imageID
	}
	delete(reqBody["server"].(map[string]interface{}), "imageName")

	// If FlavorRef isn't provided, use FlavorName to ascertain the flavor ID.
	if reqBody["server"].(map[string]interface{})["flavorRef"].(string) == "" {
		flavorName := reqBody["server"].(map[string]interface{})["flavorName"].(string)
		if flavorName == "" {
			res.Err = errors.New("One and only one of FlavorRef and FlavorName must be provided.")
			return res
		}
		flavorID, err := flavors.IDFromName(client, flavorName)
		if err != nil {
			res.Err = err
			return res
		}
		reqBody["server"].(map[string]interface{})["flavorRef"] = flavorID
	}
	delete(reqBody["server"].(map[string]interface{}), "flavorName")

	_, res.Err = client.Post(listURL(client), reqBody, &res.Body, nil)
	return res
}

func getImageIDFromConfig(computeClient *gophercloud.ServiceClient, d *schema.ResourceData) (string, error) {
	// If block_device was used, an Image does not need to be specified, unless an image/local
	// combination was used. This emulates normal boot behavior. Otherwise, ignore the image altogether.
	if vL, ok := d.GetOk("block_device"); ok {
		needImage := false
		for _, v := range vL.([]interface{}) {
			vM := v.(map[string]interface{})
			if vM["source_type"] == "image" && vM["destination_type"] == "local" {
				needImage = true
			}
		}
		if !needImage {
			return "", nil
		}
	}

	if imageId := d.Get("image_id").(string); imageId != "" {
		return imageId, nil
	} else {
		// try the OS_IMAGE_ID environment variable
		if v := os.Getenv("OS_IMAGE_ID"); v != "" {
			return v, nil
		}
	}

	imageName := d.Get("image_name").(string)
	if imageName == "" {
		// try the OS_IMAGE_NAME environment variable
		if v := os.Getenv("OS_IMAGE_NAME"); v != "" {
			imageName = v
		}
	}

	if imageName != "" {
		imageId, err := images.IDFromName(computeClient, imageName)
		if err != nil {
			return "", err
		}
		return imageId, nil
	}

	return "", fmt.Errorf("Neither a boot device, image ID, or image name were able to be determined.")
}