sandboxd

Speed up your bashrc / zshrc: avoids running (slow) setup commands until you actually need them.

Why?

Having installed nvm, rvm, virtualenvwrapper and other similar gubbins over time, my shell starts horrifically slowly. By running these setup scripts on-demand, my time-to-first-prompt is nice and fast again. On top of this, I rarely need all of these tools enabled at the same time...

How?

sandboxd creates a placeholder shell function for each command you specify (e.g. rvm). When this command gets run for the first time, the following happens:

• the cmd placeholder function (plus all associated placeholders) gets removed
• the setup you have associated with cmd gets run,
• cmd gets run with the original arguments

Usage

To 'sandbox' a setup, wrap it in a function named sandbox_init_[name]:

# in ~/.bashrc / your shell rc file
source /path/to/sandboxd


# in ~/.sandboxrc
sandbox_init_nvm(){
  source $(brew --prefix nvm)/nvm.sh #long running setup command
}

# create hooks for commands 'nvm', 'node' and 'nodemon'
sandbox_hook nvm node
sandbox_hook nvm nodemon
# this one not needed: it's created automatically based on the sandbox name
# sandbox_hook nvm nvm

The sandbox setup gets run once, when either nvm, nodemon or node is used for the first time:

[20:45:44 ~] echo 'console.log("hi")' | node
sandboxing nvm ...
hi
[20:45:53 ~] echo 'console.log("hi")' | node
hi

Manually calling the sandbox command

To manually run a specific sandbox setup, run sandbox [name]

This might be useful if you want to run a sandbox that doesn't have an associated command, or to create "feature flags" in your rc file:

#uncomment to enable features

# sandbox virtualenv
sandbox rvm
sandbox nvm

Shims

Tools like pyenv, rbenv, nodenv etc use the concept of 'shims', which are helper scripts created when installed packages create command line utilities (e.g. installing the AWS CLI via Pip creates the aws command). To make it easy for sandboxd to lazy-load these environments when any of these 'shims' are called, use the function sandbox_hook_shims {<name>} [<dir>]. See sandboxrc.example.pyenv for more information.

Example: Shims created under ~/.pyenv/shims/

$ ls -l ~/.pyenv/shims
ansible
ansible-config
aws
flask
[...]

To automatically add them all as a sandboxd hook, simply add the following to .sandboxrc:

# in ~/.sandboxrc

sandbox_init_pyenv() {
  export PYENV_ROOT="$HOME/.pyenv"
  export PATH="$PYENV_ROOT/bin:$PATH"
  export VIRTUAL_ENV_DISABLE_PROMPT=1
  eval "$(pyenv init -)"
  eval "$(pyenv virtualenv-init -)"
}

sandbox_hook_shims pyenv

Here, the pyenv argument of sandbox_hook_shims matches the function name defined above (sandbox_init_pyenv). sandbox_hook_shims assumes the shim directory to be ~/.<name>/shims where <name> is the first argument. If the diretory is different, pass it as an argument:

sandbox_hook_shims pyenv /path/to/shim/directory