ynh-dev - Yunohost dev environment manager

Please report issues on the following repository: https://github.com/yunohost/issues

Table Of Contents

• ynh-dev - Yunohost dev environment manager
  • Table Of Contents
  • Introduction
    • Local Development Path
    • Remote Development Path
  • Local Development Environment
    • 1. Setup ynh-dev and the development environment
    • 2. Manage YunoHost's dev LXCs
    • 3. Development and container testing
    • 4. Testing the web interface
    • Advanced: using snapshots
    • Troubleshooting
  • Remote Development Environment
    • 1. Setup your VPS and install YunoHost
    • 2. Setup ynh-dev and the development environment
    • 3. Develop and test
  • Further Resources

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Introduction

ynh-dev is a CLI tool to manage your local development environment for YunoHost.

This allow you to develop on the various repositories of the YunoHost project.

In particular, it allows you to:

• Create a directory with a clone of each repository of the YunoHost project
• Replace Yunohost debian packages with symlinks to those git clones

Because there are many diverse constraints on the development of the Yunohost project, there is no "official" one-size-fits-all development environment. However, we do provide documentation for what developers are using now in various circumstances.

Please keep this in mind when reviewing the following options with regard to your capacities and resources when aiming to setup a development environment.

yhn-dev can be used for the following scenarios:

Local Development Path

Yunohost can be developed on using a combination of the following technologies:

• Git (any version is sufficient)
• Incus

Because LXC are containers, they are typically lightweight and quick to start and stop. But you may find the initial setup complex (in particular network configuration). Incus makes managing an LXC ecosystem much simpler.

This local development path allows to work without an internet connection, but be aware that it will not allow you to easily test your email stack or deal with deploying SSL certificates, for example, as your machine is likely to not be exposed on the internet. A remote machine should be used for these cases.

If choosing this path, please keep reading at the local development environment section.

Remote Development Path

Yunohost can be deployed as a typical install on a remote VPS. You can then use ynh-dev to configure a development environment on the server.

This method can potentially be faster than the local development environment assuming you have familiarity with working on VPS machines, if you always have internet connectivity when working, and if you're okay with paying a fee. It is also a good option if the required system dependencies (Incus/LXC, Virtualbox, etc.) are not easily available to you on your distribution.

Please be aware that this method should not be used for a end-user facing production environment.

If choosing this path, please keep reading at the remote development environment section.

Local Development Environment

Here is the development flow:

1. Setup ynh-dev and the development environment
2. Manage YunoHost's development LXCs
3. Develop on your local host and testing in the container

1. Setup ynh-dev and the development environment

First you need to install the system dependencies.

ynh-dev essentially requires Git and the Incus/LXC ecosystem. Be careful that Incus/LXC can conflict with other installed virtualization technologies such as libvirt or vanilla LXCs, especially because they all require a daemon based on DNSmasq and therefore require to listen on port 53.

Incus can be installed on Debian 13 or Ubuntu 24.04 with the following command:

apt install incus

If you have an older distribution, you need to add the Zabbly repository to your package manager.
To do so please follow the installation guide that you can find on https://github.com/zabbly/incus.

You then need to add yourself in the incus-admin group, to run incus without sudo every time:

sudo usermod -a -G incus-admin $(whoami)

Now the group incus-admin should be present when you type the command:

groups

If not you need to create the group first:

newgrp incus-admin
sudo usermod -a -G incus-admin $(whoami)

Then you shall initialize Incus which will ask you a bunch of question. Usually answering the default (just pressing enter) to all questions is fine.

incus admin init

Pre-built images are centralized on https://repo.yunohost.org/incus and we'll download them from there to speed things up:

incus remote add yunohost https://repo.yunohost.org/incus --protocol simplestreams --public

On Archlinux-based distributions (Arch, Manjaro, ...) it was found that it's needed that Incus/LXC will throw some error about "newuidmap failed to write mapping / Failed to set up id mapping" ... It can be fixed with the following :

## N.B.: this is ONLY for Arch-based distros
echo "root:1000000:65536" > /etc/subuid
echo "root:1000000:65536" > /etc/subgid

Then, go into your favorite development folder and deploy ynh-dev with:

curl https://raw.githubusercontent.com/yunohost/ynh-dev/master/deploy.sh | bash

This will create a new ynh-dev folder with everything you need inside.

In particular, you shall notice that there are clones or the various git repositories. In the next step, we shall start a LXC and 'link' those folders between the host and the LXC.

2. Manage YunoHost's dev LXCs

When ran on the host, the ./ynh-dev command allows you to manage YunoHost's dev LXCs.

Start your actual dev LXC using :

cd ynh-dev  # if not already done
./ynh-dev start

This should automatically download from https://repo.yunohost.org/incus a pre-build ynh-dev LXC image running Yunohost unstable, and create a fresh container from it.

After starting the LXC, your terminal will automatically be attached to it. If you later disconnect from the LXC, you can go back in with ./ynh-dev attach. Later, you might want to destroy the LXC. You can do so with ./ynh-dev destroy.

If you container doesn't have an ip address nor access to internet, this is likely because you either have a conflict with another virtualization system or that a program running on the host is using the port 53 and therefore prevent Incus's dnsmasq to run correctly (as stated before in the setup section.)

3. Development and container testing

After SSH-ing inside the container, you should notice that the directory /ynh-dev is a shared folder with your host. In particular, it contains the various git clones yunohost, yunohost-admin and so on - as well as the ./ynh-dev script itself.

Most of the time, the first thing you'll want to do is to start by running yunohost tools postinstall as the first command (except if you are working on something that happens before the postinstall).

Inside the container, ./ynh-dev can be used to link the git clones living in the host to the code being ran inside the container.

For instance, after running:

./ynh-dev use-git yunohost

The code of the git clone 'yunohost' will be directly available inside the container. Which mean that running any yunohost command inside the container will use the code from the host... This allows to develop with any tool you want on your host, then test the changes in the container.

The use-git action can be used for any package among yunohost, yunohost-admin, moulinette and ssowat with similar consequences. You might want to run use-git several times depending on what you want to develop precisely.

When using use-git on package yunohost, please do it also on its dependency package moulinette. Both packages should be on branch bookworm.

Note: The use-git operation can't be reverted now. Do not do this in production.

4. Testing the web interface

You should be able to access the web interface via the IP address of the container. The IP can be known from inside the container using either from ip a or with ./ynh-dev ip.

If you want to access to the interface using the domain name, you shall tweak your /etc/hosts and add a line such as:

111.222.333.444 yolo.test

Note that ./ynh-dev use-git yunohost-admin has a particular behavior: it starts a gulp watcher that shall re-compile automatically any changes in the javascript code. Hence this particular use-git will keep running until you kill it after your work is done.

Advanced: using snapshots

You can check incus snapshot --help to learn how to manage incus snapshots.

Troubleshooting

If you experiment network issues with your incus during rebuild container steps. Probably your container are not able to get a local IP with DHCP.

It could be due to bridge conflict (for example if you have incus installed too) or dnsmasq port already used.

This ticket could help.

If you have docker and incus, and your dns resolution inside incus container does not work at all, you can try:

sudo iptables -I DOCKER-USER -i incusbr0 -o eno1 -j ACCEPT

Remote Development Environment

Here is the development flow:

1. Setup your VPS and install YunoHost
2. Setup ynh-dev and the development environment
3. Develop and test

1. Setup your VPS and install YunoHost

Setup a VPS somewhere (e.g. Scaleway, Digital Ocean, etc.) and install YunoHost following the usual instructions.

Depending on what you want to achieve, you might want to run the postinstall right away - and/or setup a domain with an actually working DNS.

2. Setup ynh-dev and the development environment

Deploy a ynh-dev folder at the root of the filesystem with:

cd /
curl https://raw.githubusercontent.com/yunohost/ynh-dev/master/deploy.sh | bash
cd /ynh-dev

3. Develop and test

Inside the VPS, ./ynh-dev can be used to link the git clones to actual the code being ran.

For instance, after running:

./ynh-dev use-git yunohost

Any yunohost command will run from the code of the git clone.

The use-git action can be used for any package among yunohost, yunohost-admin, moulinette and ssowat with similar consequences.

Further Resources

• yunohost.org/dev