Installation

ssh-tunnel-swarm ships as one executable Bash script named ssh-tunnel-swarm, attached to every GitHub release. It runs on Linux, macOS or any other Unix-like system with the tools below.

Requirements

To run it:

  • bash 4 or newer. The script uses associative arrays, which the Bash 3.2 that macOS ships does not have.
  • ssh, the OpenSSH client.
  • mktemp, date and pgrep, which come with any normal system.

To use the downloader, also:

  • jq, to read the GitHub releases API.
  • wget, to fetch the downloader and the release asset.

Download the latest release 

wget -qO- https://raw.githubusercontent.com/psyb0t/ssh-tunnel-swarm/master/tools/downloader.sh | bash

tools/downloader.sh checks that jq and wget exist and exits with a message if one is missing. It then asks the GitHub API for the repository’s releases, takes the first one in the list (the newest), downloads its ssh-tunnel-swarm asset into the current directory and makes it executable. You can run it right there with ./ssh-tunnel-swarm.

Put it on your PATH

For all users:

sudo mv ssh-tunnel-swarm /usr/local/bin/

For the current user only:

mkdir -p ~/bin
mv ssh-tunnel-swarm ~/bin/

~/bin has to be on your PATH for that to work. Check:

echo "$PATH" | grep -q "$HOME/bin" && echo "on PATH" || echo "not on PATH"

If it is not, add it to your shell profile and reload it. For Bash:

echo 'export PATH="$HOME/bin:$PATH"' >> ~/.bashrc
source ~/.bashrc

For zsh:

echo 'export PATH="$HOME/bin:$PATH"' >> ~/.zshrc
source ~/.zshrc

Build from source 

git clone https://github.com/psyb0t/ssh-tunnel-swarm.git
cd ssh-tunnel-swarm
make build

make build writes build/ssh-tunnel-swarm, the same single file a release carries. Development explains how it is put together. Copy it onto your PATH as above.

You can also run the sources directly with make run or bash main.sh, but only from the repository root: the source files load each other with relative source lines. The built script has no such limit.

Upgrade

Run the downloader again and move the new file over the old one. There is no state to migrate: the only inputs are your rules file and the environment variables. The changelog lists what changed in each release.

Remove

Stop any running instance (see Running the swarm), then delete the script:

sudo rm /usr/local/bin/ssh-tunnel-swarm

or rm ~/bin/ssh-tunnel-swarm for a per-user install. Apart from a temporary file for each ssh attempt, which it deletes afterwards, the only file it writes is the log you point LOG_FILE at.