Shell Compose

Shell Compose is a lightweight background process runner for long-running or scheduled jobs.

Features

Integration with just

just is a command runner with syntax inspired by make. It supports shell commands but also other languages like Python or NodeJS. Tasks can have dependencies and variables loaded from .env files.

Example:

# Simulate data processing
[group('autostart')]
processing:
  #!/usr/bin/env bash
  echo Start processing
  for i in {1..20}; do
    echo processing step $i
    sleep 1
  done
  echo Processing finished

# Serve current directory on port 8000
[group('autostart')]
serve:
  #!/usr/bin/env python3
  import http.server
  server_address = ('localhost', 8000)
  Handler = http.server.SimpleHTTPRequestHandler
  with http.server.HTTPServer(server_address, Handler) as httpd:
      print("Server started at http://%s:%s" % server_address, flush=True)
      httpd.serve_forever()

Running a just recipe:

shell-compose start processing

Running all recipes in a group:

shell-compose up autostart

Similar projects

• PM2: Production process manager for Node.js/Bun applications with a built-in load balancer.

• Pueue: Command-line task management tool for sequential and parallel execution of long-running tasks.

To start tasks in response to file modifications, consider using watchexec.

For interactive background tasks, consider using Pueue or a terminal multiplexer like Zellij, tmux or screen.

Installation

Pre-built binaries

We provide several options to access pre-built binaries for a variety of platforms. If you would like to manually download a pre-built binary, checkout the latest release on GitHub.

Installer scripts

macOS and Linux:

curl --proto '=https' --tlsv1.2 -LsSf https://github.com/pka/shell-compose/releases/latest/download/shell-compose-installer.sh | sh

Windows PowerShell:

powershell -ExecutionPolicy ByPass -c "irm https://github.com/pka/shell-compose/releases/latest/download/shell-compose-installer.ps1 | iex"

Other Options

cargo-binstall

cargo binstall shell-compose

Build From Source

For users who need to install shell-compose on platforms that we do not yet provide pre-built binaries for, you will need to build from source. shell-compose is written in Rust and uses cargo to build. Once you've installed the Rust toolchain (rustup), run:

cargo install shell-compose --locked

Run with systemd and journal logging

Unit file example:

[Unit]
Description=Shell Compose
After=network.target
Requires=network.target

[Service]
Type=exec
User=user
Group=user
WorkingDirectory=/home/user/my-project-justfile-root
ExecStart=/usr/local/bin/shell-composed up autostart
Restart=always

[Install]
WantedBy=multi-user.target

The background process shell-composed supports a subset of the shell-compose command line arguments:

Usage: shell-composed [COMMAND]

Commands:
  run    Execute command
  runat  Execute command with cron schedule
  start  Start service
  up     Start service group
  help   Print this message or the help of the given subcommand(s)

Options:
  -h, --help     Print help
  -V, --version  Print version