Terraform module composer

tfcompose.py

#!/usr/bin/python3

import json
import os
from subprocess import run

combined_statefile = 'terraform.tfstate'
state_dir = "statefiles"

run(['terraform', 'init'])

with open("main.tf.json", "r") as tf:
    wrapper = json.load(tf)

modules_from_tf = [k for k in wrapper['module']]
modules_from_statefiles = [f.removesuffix('.tfstate') for f in os.listdir(state_dir) if f.endswith('.tfstate')]
modules = set(modules_from_tf + modules_from_statefiles)

for module in modules:
    statefile = os.path.join(state_dir, f'{module}.tfstate')
    if os.path.exists(statefile):
        states = run(['terraform', 'state', 'list', '-state', statefile], capture_output=True)
        state_ids = [state_id for state_id in states.stdout.decode('utf-8').split('\n') if state_id]
        for state in state_ids:
            dest_state_id = f'module.{module}.{state}'
            run(['terraform', 'state', 'mv', '-state', statefile, '-state-out', combined_statefile, state, dest_state_id])

run(['terraform', 'plan', '-out', 'tf.plan'])
run(['terraform', 'apply', 'tf.plan'])

state = run(['terraform', 'state', 'list'], capture_output=True)
state_ids = state.stdout.decode('utf-8').split('\n')
for state in state_ids:
    for module in modules:
        module_prefix = f'module.{module}.'
        if state.startswith(module_prefix):
            run(['terraform', 'state', 'mv', '-state', combined_statefile, '-state-out', os.path.join(state_dir, f'{module}.tfstate'), state, state.removeprefix(module_prefix)])