Timeout when starting addon should be configurable in config.yaml

[modbus2mqtt]

Describe the problem

In short words:

In the supervisor log, there is the following message:

"2025-03-27 08:32:03.317 WARNING (MainThread) [supervisor.addons.addon] Timeout while waiting for addon Modbus <=> MQTT to start, took more than 120 seconds"

when starting the development version of my addon on a small (Odroid N2+) system.

More detail:

The development version of my addon can take very long to start up, because it does a lot of github download, npm installs ...
The productive version uses a prebuilt docker container. It is much faster. On a powerful developer system, it is acceptable and no timeouts occure.

The development version is very handy, because it builds directly from github source code.
No docker publishing ... is needed. The drawback of longer loading is acceptable in this case.
It has a Dockerfile in the addon directory and a config.yaml w/o image tag.

If I (re)start the addon, the startup takes very long (which is expected, about 5-10 minutes) at some point in time there is a timeout. Anyhow, the addon is available later. So, no functional issue here.

I am not familiar with home assistant development, but If I knew the places which need to be changed, I could try creating pull request(s).

Debug information

1. SSH Addon type

• [ X] Community
• Core
• [ X] Custom

2. Version of the CLI

CLI Version: ??
Add-on: not published yet
Add-on version: not published yet

3. Version of Home Assistant Core & the Home Assistant Supervisor

Core: 2024.12.5
Supervisor: 2025.03.3

Expected behavior

The startup timeout should be configurable in the config.yaml. It can be specific to the addon.

[agners]

What you can do instead is creating a local add-on, and have the long running tasks be part of the Dockerfile. The build does not have a timeout, and a simple restart will be faster for you. See:
https://developers.home-assistant.io/docs/add-ons/tutorial#step-1-the-basics

I am not familiar with home assistant development, but If I knew the places which need to be changed, I could try creating pull request(s).

This change would need a new config entry for add-ons. The change would need to be in Supervisor along with documenting the change in the developer documentation.