svgen

A small utility to generate runit services from templates.

Usage

This tool looks for service templates in the directory /etc/svgen/templates/ and instantiates them using instance descriptions in /etc/svgen/instances. A template is a directory containing at least a run file and optionally other files. Each line in the instances file must be of the form <template-name>@<instance-name>. Instantiation means that the files from the template are read, the string __INSTANCE__ is replaced with the instance name and then a new service directory under /etc/sv/generated/<instance-line> is created. The processed files from the template directory are then written to the service directory while an existing log file is handled specially and installed as log/run. Afterwards the service is symlinked in /service/ to activate it.

Example

In this example we build a template for [wg-quick], a simple program to setup wireguard VPN connections. This is a good example, since we usually have a bunch of VPN interfaces we want to set up and all the corresponding runit services would look nearly identical. Create a new directory /etc/svgen/templates/wg-quick/ and put the following into the run file:

#!/bin/sh

wg-quick up "__INSTANCE__"
exec chpst -b "wg-quick@__INSTANCE__" pause

The __INSTANCE__ string will get replaced upon instantiation of this template and takes the role of the interface name. In order to tear-down the network when the service is stopped, we also need a finish script:

#!/bin/sh

wg-quick down "__INSTANCE__"

Now, let's imagine you have configured two wireguard networks, wg-net1 and wg-net2. In order to create services for them create the following /etc/svgen/instances file:

# wireguard
wg-quick@wg-net1
wg-quick@wg-net2

Now run

chmod +x run finish
svgen

This will generate two services under /etc/sv/generated/ and symlink to them from /service/.

Installation

To build the program, run

cargo build --release

and afterwards run as root:

bash
./install.sh

Full operational description

See the documentation for a full description on how this program operates.

License

This project is licensed under the GNU AGPL version 3 or later, see the LICENSE file for more information.