codesync

A tiny CLI that mirrors local code to remote systems with rsync over SSH, driven by codesync.yaml. Connection details — host, user, and a pointer to your SSH key — live in the config (no ~/.ssh/config needed). The key never leaves disk; codesync just passes its path to ssh -i.

# codesync.yaml
systems:
  perlmutter:                        # system id
    host: perlmutter-p1.nersc.gov    # IP or hostname
    user: myuser
    key: ~/.ssh/id_nersc             # pointer to your private key (-> ssh -i)
    locations:
      my_repo:                       # location id
        local: ~/code/myproj
        remote: code/myproj

Setup

./setup.sh

Installs everything under $HOME/.codesync and puts codesync on your PATH:

• $HOME/.codesync/env/ — a virtualenv (Python + PyYAML)
• $HOME/.codesync/bin/codesync — linked to this repo's launcher
• ~/.local/bin/codesync — symlink on your PATH (the dir is added to your ~/.zshrc or ~/.bashrc)
• ~/.config/codesync/codesync.yaml — the default config, seeded once (edit it to define your systems)

Then open a new terminal (or source ~/.zshrc) and run codesync from anywhere — no venv activation needed; it re-execs itself under $HOME/.codesync/env. You also need rsync and ssh on your PATH.

codesync reads the first config it finds: ./codesync.yaml (project-local), then ~/.config/codesync/codesync.yaml.

Usage

codesync <system> <location>          # push (local -> remote) — the default
codesync push <system> <location>     # explicit push
codesync pull <system> <location>     # remote -> local
#   add --dry-run to preview, -v for progress

codesync perlmutter my_repo → rsync -e 'ssh -i ~/.ssh/id_nersc' … ~/code/myproj/ myuser@perlmutter-p1.nersc.gov:code/myproj/.

Omit <location> if the system has only one; omit <system> too if there's only one. The exact rsync command is printed before it runs.

Before a push, codesync creates the remote directory inside rsync's own SSH connection — via --rsync-path='mkdir -p … && rsync' — so you authenticate once, not twice (rsync otherwise only creates the final path component, not missing parents). Before a pull it creates the local directory. --dry-run skips this — it changes nothing.

Reusing values

codesync.yaml supports YAML anchors (&name) and aliases (*name), resolved natively — e.g. define a key path once and reuse it across systems (see the sample). exclude / rsync_flags can be set in defaults, per-system, or per-location; the most specific wins.

Layout

• codesync — thin launcher: re-exec into the venv, then dispatch to the package
• codesync_core/config.py — find/validate codesync.yaml, resolve a (system, location)
• codesync_core/rsync.py — build the rsync + ssh -i command and exec it
• codesync_core/cli.py — argument parsing and top-level error handling
• setup.sh — create the venv and seed the default config

Note for HPC/Shared systems

If you have loaded modules in your .bashrc or .zshrc, make sure to add this to the top your code, so that during non-interactive sessions, modules are not loaded.

  case $- in
    *i*) ;;        # interactive shell — keep going
    *) return ;;   # non-interactive (ssh/rsync) — stop here, stay silent
  esac