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 and 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. Specify per-application environment variables with nodenv-vars. See more plugins on the wiki.

How It Works
Installation
Command Reference
Environment variables
Development
Credits

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 or npm, 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 first .node-version file found by searching the directory of the script you are executing and each of its parent directories until reaching the root of your filesystem.
The first .node-version file found by searching the current working directory and each of its parent directories until reaching the root of your filesystem. You can modify the .node-version file in the current working directory with the nodenv local command.
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/0.10.36/
~/.nodenv/versions/0.12.0/
~/.nodenv/versions/iojs-1.0.0/

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

Installation

If you're on Mac OS X, consider installing with Homebrew.

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 https://github.com/nodenv/nodenv.git ~/.nodenv
```
Optionally, try to compile dynamic bash extension to speed up nodenv. Don't worry if it fails; nodenv will still work normally:
```
$ cd ~/.nodenv && src/configure && make -C src
```
Add ~/.nodenv/bin to your $PATH for access to the nodenv command-line utility.
```
$ echo 'export PATH="$HOME/.nodenv/bin:$PATH"' >> ~/.bash_profile
```
Ubuntu Desktop note: Modify your ~/.bashrc instead of ~/.bash_profile.

Zsh note: Modify your ~/.zshrc file instead of ~/.bash_profile.
Run ~/.nodenv/bin/nodenv init for shell-specific instructions on how to initialize nodenv to enable shims and autocompletion.
Restart your shell so that PATH changes take effect. (Opening a new terminal tab will usually do it.) Now check if nodenv was set up:
```
$ type nodenv
#=> "nodenv is a function"
```
(Optional) Install node-build, which provides the nodenv install command that simplifies the process of installing new Node versions.

Homebrew on Mac OS X

As an alternative to installation via GitHub checkout, you can install nodenv and node-build using the Homebrew package manager on Mac OS X:

$ brew update
$ brew install nodenv
$ nodenv init

Note: node-build is installed with nodenv by default. To skip node-build, pass --without-node-build.

You'll only ever have to run nodenv init once.

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

Alternatively, check out the nodenv-update plugin which provides a command to update nodenv as well as all installed plugins.

$ nodenv update

If you've installed via Homebrew, then upgrade via its brew command:

$ brew update
$ brew upgrade nodenv node-build

How nodenv hooks into your shell

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. 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.

Installing Node versions

The nodenv install command doesn't ship with nodenv out of the box, but is provided by the node-build project. If you installed it as part of GitHub checkout process outlined above you should be able to:

# list all available versions:
$ nodenv install -l

# install a Node version:
$ nodenv install 0.10.26

Alternatively to the install command, you can download and compile Node manually as a subdirectory of ~/.nodenv/versions/. An entry in that directory can also be a symlink to a Node version installed elsewhere on the filesystem. nodenv doesn't care; it will simply treat any entry in the versions/ directory as a separate Node version.

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 0.8.22.

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

Uninstalling nodenv

The simplicity of nodenv makes it easy to temporarily disable it, or uninstall from the system.

To disable nodenv managing your Node versions, simply remove the nodenv init line from your shell startup configuration. This will remove nodenv shims directory from $PATH, and future invocations like node will execute the system Node version, as before nodenv.

nodenv will still be accessible on the command line, but your Node apps won't be affected by version switching.

To completely uninstall nodenv, perform step (1) and then remove its root directory. This will delete all Node versions that were installed under `nodenv root`/versions/ directory:
```
 rm -rf `nodenv root`
```
If you've installed nodenv using a package manager, as a final step perform the nodenv package removal. For instance, for Homebrew:
```
 brew uninstall nodenv
```

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

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 0.10.26

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 0.11.11

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=0.10.26

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 /Users/OiNutter/.nodenv/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 an npm package that provides an executable binary.

$ nodenv rehash

note: the package-rehash plugin automatically runs nodenv rehash whenever an npm package is installed globally

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/0.10.26/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

Environment variables

You can affect how nodenv operates with the following settings:

name	default	description
`NODENV_VERSION`		Specifies the Node version to be used. Also see `nodenv shell`
`NODENV_ROOT`	`~/.nodenv`	Defines the directory under which Node versions and shims reside. Also see `nodenv root`
`NODENV_DEBUG`		Outputs debug information. Also as: `nodenv --debug <subcommand>`
`NODENV_HOOK_PATH`	see wiki	Colon-separated list of paths searched for nodenv hooks.
`NODENV_DIR`	`$PWD`	Directory to start searching for `.node-version` files.

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

Forked from Sam Stephenson's rbenv by Will McKenzie and modified for node.

gauravmehla / nodenv Goto Github PK

nodenv's Introduction