doc/packaging_apps.md

App packaging

This document aimed to learn you how to package an application for YunoHost.

Requirements

To package an application, here are the requirements:

• An account on a git server as GitHub to publish the application;
• Control a minimum git, Shell and other programming stuffs;
• A testing virtual machine or a distant server to package and test the package.

Content

A YunoHost package is composed of:

• A manifest.json file
• A scripts directory, which contains five Shell scripts: install, remove, upgrade, backup and restore
• Optional directories, containing sources or conf files
• A LICENSE file containing the license of the package
• A presentation page of your package in a README.md file

 A basic package feel free to use it as a framework.

Manifest

Manifest

Scripts

For now, a YunoHost package must contain five Shell scripts: install, remove, upgrade, backup and restore. These scripts will be executed as admin on the YunoHost instances.

Here is an example:

# Retrieve arguments
domain=$1
path=$2

# Check domain/path availability
sudo yunohost app checkurl $domain$path -a roundcube
if [[ ! $? -eq 0 ]]; then
    exit 1
fi

# Generate random DES key & password
deskey=$(dd if=/dev/urandom bs=1 count=200 2> /dev/null | tr -c -d '[A-Za-z0-9]' | sed -n 's/\(.\{24\}\).*/\1/p')
db_pwd=$(dd if=/dev/urandom bs=1 count=200 2> /dev/null | tr -c -d '[A-Za-z0-9]' | sed -n 's/\(.\{24\}\).*/\1/p')

# Use 'roundcube' as database name and user
db_user=roundcube

# Initialize database and store mysql password for upgrade
sudo yunohost app initdb $db_user -p $db_pwd -s $(readlink -e ../sources/SQL/mysql.initial.sql)
sudo yunohost app setting roundcube mysqlpwd -v $db_pwd

# Copy files to the right place
final_path=/var/www/roundcube
sudo mkdir -p $final_path
sudo cp -a ../sources/* $final_path
sudo cp ../conf/main.inc.php $final_path/config/
sudo cp ../conf/db.inc.php $final_path/config/
sudo mv $final_path/plugins/managesieve/config.inc.php.dist $final_path/plugins/managesieve/config.inc.php

# Change variables in Roundcube configuration
sudo sed -i "s/rcmail-ynhDESkeyTOchange/$deskey/g" $final_path/config/main.inc.php
sudo sed -i "s/yunouser/$db_user/g" $final_path/config/db.inc.php
sudo sed -i "s/yunopass/$db_pwd/g" $final_path/config/db.inc.php
sudo sed -i "s/yunobase/$db_user/g" $final_path/config/db.inc.php

# Set permissions to roundcube directory
sudo chown -R www-data: $final_path

# Modify Nginx configuration file and copy it to Nginx conf directory
sed -i "s@PATHTOCHANGE@$path@g" ../conf/nginx.conf
sed -i "s@ALIASTOCHANGE@$final_path/@g" ../conf/nginx.conf
sudo cp ../conf/nginx.conf /etc/nginx/conf.d/$domain.d/roundcube.conf

# Reload nginx and regenerate SSOwat conf
sudo service nginx reload
sudo yunohost app ssowatconf

Usage

You have to put everything in the install script in order to get the app to install without issue. It means that you have to install dependencies, create required repositories, initialize potential databases, copy sources and configure everything in the single install script (and of course do the reverse process in the remove script).

Be careful: for security reasons, the script is executed as the admin user in YunoHost. Be sure to test it as admin and prepend sudo to commands that require it.

Architecture and arguments

Since YunoHost has a unified architecture, you will be able to guess most of the settings you need. But if you need variable ones, like the domain or web path, you will have to ask the administrator at installation (see arguments section in the manifest above).

Arguments management

Nginx configuration

Nginx configuration

Hooks

YunoHost provides a hook system, which is accessible via the packager's script callbacks in moulinette (CLI). The scripts have to be placed in the hooks repository at the root of the YunoHost package, and must be named priority-hook_name, for example: hooks/50-post_user_create will be executed after each user creation.

Note: priority is optional, default is 50.

Take a look at the ownCloud package for a working example.

Helpers

The CLI moulinette provides a few tools to make the packager's work easier:

sudo yunohost app checkport <port>

This helper checks the port and returns an error if the port is already in use.

sudo yunohost app setting <id> <key> [ -v <value> ]

This is the most important helper of YunoHost. It allows you to store some settings for a specific app, in order to be either reused afterward or used for YunoHost configuration (**e.g.** for the SSO).

It sets the value if you append ```-v ```, and gets it otherwise.

** Some useful settings **

skipped_uris

Remove the protection on the uris list provided separated by commas.

protected_uris

Protects the uris list provided separated by commas. Only logged in users will have access.

There are also skipped_regex, protected_regex, unprotected_uris, unprotected_regex.

Be careful : you must run yunohost app ssowatconf to apply the effect. URIs will be converted into URLs and written to the file /etc/ssowat/conf.json.

Example:
yunohost app setting myapp unprotected_urls -v "/"
yunohost app ssowatconf
These commands will disable the SSO on the root of the aplication like domain.tld/myapp This is useful for public application.

sudo yunohost app checkurl <domain><path> -a <id>

This helper is useful for web apps and allows you to be sure that the web path is not taken by another app. If not, it "reserves" the path.

**Note**: do not prepend `http://` or `https://` to the ``.

sudo yunohost app initdb <db_user> [ -p <db_pwd> ] [ -s <SQL_file> ]

This helper creates a MySQL database. If you do not append a password, it generates one and returns it. If you append a SQL file, it initializes your database with the SQL statements inside.

sudo yunohost app ssowatconf

This helper reloads the SSO configuration. You have to call it at the end of the script when you are packaging a web app.

Test it!

In order to test your package, you can execute your script standalone as admin (do not forget to append required arguments):

su - admin -c "/bin/bash /path/to/my/script my_arg1 my_arg2"

Or you can use moulinette:

yunohost app install /path/to/my/app/package

Note that it also works with a Git URL:

yunohost app install https://github.com/author/my_app_package.git

Enhance package

You will find points to verify quality of your scripts:

• scripts should use sudo cp -a ../sources/. $final_path instead of sudo cp -a ../sources/* $final_path;
• install script must contain support in case of script errors to delete residuals files thanks to set -e and trap;
• install script should use command line method instead of curl call through web install form;
• install script should save install answers;
• application sources should be checked with a control sum (sha256, sha1 or md5) or a PGP signature;
• scripts had been tested on Debian Wheezy and Jessie as well as 32 bits, 64 bits and ARM architectures;
• backup and restore scripts are present and functional.

Publish and ask for testing your application

• Publishing a post on the Forum with the App integration category, to ask tests and returns on your application.

• Ask to add your application in the app repository to be displayed in the non-official apps list. Precise his progress state: notworking, inprogress, or working.

Officalization of an application

To become an official application, it must be enough tested, stable and should works on 64 bits, 32 bits et ARM processors architectures and on Debian Wheezy and Jessie. If you think thoses conditions are gather, ask for official integration of your application.