Groom your app’s Node environment with nodenv.

Use nodenv to pick a Node version for your application and guarantee that your development environment matches production. Put nodenv to work with NPM for painless Node upgrades and bulletproof deployments.

Powerful in development. Specify your app's Node version once, in a single file. Keep all your teammates on the same page. No headaches running apps on different versions of Node. Just Works™ from the command line. Override the Node version anytime: just set an environment variable.

Rock-solid in production. Your application's executables are its interface with ops. With nodenv you'll never again need to cd in a cron job or Chef recipe to ensure you've selected the right runtime. The Node version dependency lives in one place—your app—so upgrades and rollbacks are atomic, even when you switch versions.

One thing well. nodenv is concerned solely with switching Node versions. It's simple and predictable. A rich plugin ecosystem lets you tailor it to suit your needs. Compile your own Node versions, or use the node-build plugin to automate the process. See more plugins on the wiki.

How It Works
Installation
Command Reference
Development

How It Works

At a high level, nodenv intercepts Node commands using shim executables injected into your PATH, determines which Node version has been specified by your application, and passes your commands along to the correct Node installation.

Understanding PATH

When you run a command like node, your operating system searches through a list of directories to find an executable file with that name. This list of directories lives in an environment variable called PATH, with each directory in the list separated by a colon:

/usr/local/bin:/usr/bin:/bin

Directories in PATH are searched from left to right, so a matching executable in a directory at the beginning of the list takes precedence over another one at the end. In this example, the /usr/local/bin directory will be searched first, then /usr/bin, then /bin.

Understanding Shims

nodenv works by inserting a directory of shims at the front of your PATH:

~/.nodenv/shims:/usr/local/bin:/usr/bin:/bin

Through a process called rehashing, nodenv maintains shims in that directory to match every Node command across every installed version of Node—node, npm, and so on.

Shims are lightweight executables that simply pass your command along to nodenv. So with nodenv installed, when you run, say, npm, your operating system will do the following:

Search your PATH for an executable file named npm
Find the nodenv shim named npm at the beginning of your PATH
Run the shim named npm, which in turn passes the command along to nodenv

Choosing the Node Version

When you execute a shim, nodenv determines which Node version to use by reading it from the following sources, in this order:

The NODENV_VERSION environment variable, if specified. You can use the nodenv shell command to set this environment variable in your current shell session.
The application-specific .node-version file in the current directory, if present. You can modify the current directory's .node-version file with the nodenv local command.
The first .node-version file found by searching each parent directory until reaching the root of your filesystem, if any.
The global ~/.nodenv/version file. You can modify this file using the nodenv global command. If the global version file is not present, nodenv assumes you want to use the "system" Node—i.e. whatever version would be run if nodenv weren't in your path.

Locating the Node Installation

Once nodenv has determined which version of Node your application has specified, it passes the command along to the corresponding Node installation.

Each Node version is installed into its own directory under ~/.nodenv/versions. For example, you might have these versions installed:

~/.nodenv/versions/0.8.22/
~/.nodenv/versions/0.10.0/

Version names to nodenv are simply the names of the directories in ~/.nodenv/versions.

Installation

Compatibility note: nodenv is incompatible with NVM. Please make sure to fully uninstall NVM and remove any references to it from your shell initialization files before installing nodenv.

If you're on Mac OS X, consider installing with Homebrew. (Coming Soon)

Basic GitHub Checkout

This will get you going with the latest version of nodenv and make it easy to fork and contribute any changes back upstream.

Check out nodenv into ~/.nodenv.

$ git clone git://github.com/OiNutter/nodenv.git ~/.nodenv

Add ~/.nodenv/bin to your $PATH for access to the nodenv command-line utility.
```
$ echo 'export PATH="$HOME/.nodenv/bin:$PATH"' >> ~/.bash_profile
```
Ubuntu note: Modify your ~/.profile instead of ~/.bash_profile.

Zsh note: Modify your ~/.zshrc file instead of ~/.bash_profile.
Add nodenv init to your shell to enable shims and autocompletion.
```
$ echo 'eval "$(nodenv init -)"' >> ~/.bash_profile
```
Same as in previous step, use ~/.profile on Ubuntu, ~/.zshrc for Zsh.
Restart your shell as a login shell so the path changes take effect. You can now begin using nodenv.
```
$ exec $SHELL -l
```
Install node-build, which provides an nodenv install command that simplifies the process of installing new Node versions.
```
$ nodenv install v0.10.0
```
As an alternative, you can download and compile Node yourself into ~/.nodenv/versions/.
Rebuild the shim executables. You should do this any time you install a new Node executable (for example, when installing a new Node version, or when installing a module that provides a command).
```
$ nodenv rehash
```

Upgrading

If you've installed nodenv manually using git, you can upgrade your installation to the cutting-edge version at any time.

$ cd ~/.nodenv
$ git pull

To use a specific release of nodenv, check out the corresponding tag:

$ cd ~/.nodenv
$ git fetch
$ git checkout v0.3.0

Neckbeard Configuration

Skip this section unless you must know what every line in your shell profile is doing.

nodenv init is the only command that crosses the line of loading extra commands into your shell. Coming from RVM, some of you might be opposed to this idea. Here's what nodenv init actually does:

Sets up your shims path. This is the only requirement for nodenv to function properly. You can do this by hand by prepending ~/.nodenv/shims to your $PATH.
Installs autocompletion. This is entirely optional but pretty useful. Sourcing ~/.nodenv/completions/nodenv.bash will set that up. There is also a ~/.nodenv/completions/nodenv.zsh for Zsh users.
Rehashes shims. From time to time you'll need to rebuild your shim files. Doing this automatically makes sure everything is up to date. You can always run nodenv rehash manually.
Installs the sh dispatcher. This bit is also optional, but allows nodenv and plugins to change variables in your current shell, making commands like nodenv shell possible. The sh dispatcher doesn't do anything crazy like override cd or hack your shell prompt, but if for some reason you need nodenv to be a real script rather than a shell function, you can safely skip it.

Run nodenv init - for yourself to see exactly what happens under the hood.

Uninstalling Node Versions

As time goes on, Node versions you install will accumulate in your ~/.nodenv/versions directory.

To remove old Node versions, simply rm -rf the directory of the version you want to remove. You can find the directory of a particular Node version with the nodenv prefix command, e.g. nodenv prefix 0.10.0.

The node-build plugin provides an nodenv uninstall command to automate the removal process.

Command Reference

Like git, the nodenv command delegates to subcommands based on its first argument. The most common subcommands are:

nodenv local

Sets a local application-specific Node version by writing the version name to a .node-version file in the current directory. This version overrides the global version, and can be overridden itself by setting the NODENV_VERSION environment variable or with the nodenv shell command.

$ nodenv local 0.10.0

When run without a version number, nodenv local reports the currently configured local version. You can also unset the local version:

$ nodenv local --unset

Previous versions of nodenv stored local version specifications in a file named .nodenv-version. For backwards compatibility, nodenv will read a local version specified in an .nodenv-version file, but a .node-version file in the same directory will take precedence.

nodenv global

Sets the global version of Node to be used in all shells by writing the version name to the ~/.nodenv/version file. This version can be overridden by an application-specific .node-version file, or by setting the NODENV_VERSION environment variable.

$ nodenv global 0.8.22

The special version name system tells nodenv to use the system Node (detected by searching your $PATH).

When run without a version number, nodenv global reports the currently configured global version.

nodenv shell

Sets a shell-specific Node version by setting the NODENV_VERSION environment variable in your shell. This version overrides application-specific versions and the global version.

$ nodenv shell 0.9.12

When run without a version number, nodenv shell reports the current value of NODENV_VERSION. You can also unset the shell version:

$ nodenv shell --unset

Note that you'll need nodenv's shell integration enabled (step 3 of the installation instructions) in order to use this command. If you prefer not to use shell integration, you may simply set the NODENV_VERSION variable yourself:

$ export NODENV_VERSION=0.10.0

nodenv versions

Lists all Node versions known to nodenv, and shows an asterisk next to the currently active version.

$ nodenv versions
  0.8.22
  0.9.12
* 0.10.0 (set by /Users/will/.nodenv/version)

nodenv version

Displays the currently active Node version, along with information on how it was set.

$ nodenv version
0.10.0 (set by /Volumes/OiNutter/hubot/.node-version)

nodenv rehash

Installs shims for all Node executables known to nodenv (i.e., ~/.nodenv/versions/*/bin/*). Run this command after you install a new version of Node, or install a module that provides commands.

$ nodenv rehash

nodenv which

Displays the full path to the executable that nodenv will invoke when you run the given command.

$ nodenv which npm
/Users/will/.nodenv/versions/0.10.0/bin/npm

nodenv whence

Lists all Node versions with the given command installed.

$ nodenv whence npm
0.10.0
0.9.12
0.8.22

Development

The nodenv source code is hosted on GitHub. It's clean, modular, and easy to understand, even if you're not a shell hacker.

Tests are executed using Bats:

$ bats test
$ bats test/<file>.bats

Please feel free to submit pull requests and file bugs on the issue tracker.

Credits

Copied from rbenv and modified to work for node.

Version History

0.1.0 (March 18, 2013)

Initial public release. Copied from rbenv

License

(The MIT license)

Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated documentation files (the "Software"), to deal in the Software without restriction, including without limitation the rights to use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is furnished to do so, subject to the following conditions:

The above copyright notice and this permission notice shall be included in all copies or substantial portions of the Software.

THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.

devdiva/nodenv