Can I load a Vagrantfile that loads another Vagrantfile? - vagrant

Question

I'm trying to set up an inheritance structure in my forest of Vagrantfiles. Basically I wanted something like this:
/base
Vagrantfile
/testvm
Vagrantfile
/nginx-test
Vagrantfile
The testvm/Vagrantfile would load the base/Vagrantfile and the nginx-test/Vagrantfile would load the testvm/Vagrantfile. In my test case, the base Vagrantfile specifies one box type (eg bento/ubuntu-18.04) and sets 1GB of memory for the VM and some other stuff. The testvm Vagrantfile loads that and overrides the box to bento/ubuntu-22.04 and sets a different hostname. The nginx-test Vagrantfile loads that last file and sets its own hostname plus adds another provisioning block to install nginx.
I've tried this but I get this SystemStackError: stack level too deep error:
$ vagrant up
Vagrant failed to initialize at a very early stage:
There was an error loading a Vagrantfile. The file being loaded
and the error message are shown below. This is usually caused by
a syntax error.
Path: /Users/donseiler/vagrant_test/testvm/nginx-test/Vagrantfile
Line number: 5
Message: SystemStackError: stack level too deep
I've been searching but haven't found anyone attempting multiple layers of loading yet. I can run vagrant up just fine from the base and testvm directories to bring those machines up. I can't run any vagrant commands from the nginx-test directory (not even vagrant status, etc)
Here are the file contents:
/base/Vagrantfile:
VAGRANTFILE_API_VERSION = "2"
NAME = "basevm"
Vagrant.configure(VAGRANTFILE_API_VERSION) do |config|
# Default to bento bionic box
config.vm.box = "bento/ubuntu-18.04"
config.vm.hostname = NAME
# Set default virtualbox provider settings
config.vm.provider :virtualbox do |vb|
vb.name = NAME
vb.memory = "1024"
vb.gui = false
end
config.vm.provision "shell", inline: "DEBIAN_FRONTEND=noninteractive apt-get update"
end
/base/testvm/Vagrantfile:
# Load parent Vagrantfile
load "../Vagrantfile"
# define hostname
NAME = "testvm"
Vagrant.configure(VAGRANTFILE_API_VERSION) do |config|
# Change to jammy
config.vm.box = "bento/ubuntu-22.04"
config.vm.provision "shell", inline: <<-SHELL
export DEBIAN_FRONTEND=noninteractive
apt-get -y install curl
SHELL
end
/base/testvm/nginx-test/Vagrantfile:
# Load parent Vagrantfile
load "../Vagrantfile"
# define hostname
NAME = "nginx-test"
Vagrant.configure(VAGRANTFILE_API_VERSION) do |config|
config.vm.provision "shell", inline: <<-SHELL
export DEBIAN_FRONTEND=noninteractive
apt-get -y install nginx
SHELL
end
UPDATE: It looks like I can do multiple loading just fine as long as I use absolute file paths to the Vagrantfiles (or only use relative paths in the pwd's Vagrantfile, or if all Vagrantfiles are in the same directory). The relative path apparently is relative to the pwd, so when ../Vagrantfile also tries to load ../Vagrantfile, it does so from pwd and not from the parent dir. Then it becomes somewhat of an infinite loop as the parent dir's Vagrantfile keeps trying to load itself from the child dir until vagrant short-circuits itself.
Basically, it loads Vagrantfiles from wherever but the commands in them are executed from the pwd, so relative paths are always relative to the pwd, NOT relative to where the Vagrantfile lives.
Not being able to use relative paths makes things a little less flexible but at least it's a working alternative.