init

A small init/supervisor system for building Docker images (and any other use you may want to put it to)

Installation

To build the software, just run make:

make

This will result in a binary, named init in the current working directory.

If you are on Linux, and want a static binary, try make static instead; the resulting binary will be called init-static, and not link in any libraries -- perfect for using in a Docker image!

Usage

init can determine what processes to supervise via one or more directories (the -d flag), and / or by passing invocations on the command-line, spearated by -- delimiters.

The easiest way is the latter. For example:

init -- /path/to/bin/first-process --foreground \
     -- /path/to/bin/second-process -f -l debug

If you pass init a directory via the -d flag, it lists the contents of said directory, looking for regular, executable files (and symbolic links to the same). Those scripts then get executed, without any arguments:

# ls -l /services.d
total 8
-rwxr-xr-x 1 jhunt staff 2.1k Sep 15 17:43 daemon
-rwxr-xr-x 1 jhunt staff 2.3k Sep 15 17:43 worker

# init -d /services.d

You can freely mix these, assuming you pass all the directory flags first:

init -d /services.d \
     -- /path/to/bin/first-process --foreground \
     -- /path/to/bin/second-process -f -l debug

The init command itself takes the following options:

-h, --help       Print out a help screen.
-v, --version    Print out the version of `init`

-n, --dry-run    Parse and print commands to be run,
                 but do not actually execute them.

-q, --quiet      Suppress output from a --dry-run.

-d, --directory  Process all regular executable files
                 (and symbolic links to the same) in a
                 given directory.  Can be used more
                 than once.

Contributing

Fork it and submit a pull request.

About

Everyone writes a supervisor, right? It's like blog software was in the early aughts. Why did I write this one? RYODI needed something small, compact, and capable.