Sprinter Tutorial

In this tutorial, you will learn:

  • How to write a sprinter manifest file
  • How to ask for user input (username, password, etc)
  • How to use user input


First, you need to install sprinter. You can find install instructions in the sprinter readme here.

Build a sprinter configuration file

Each sprinter environment is completely defined by a sprinter configuration file. Think of this file as your main way of managing your sprinter environment: any changes you make here will be picked up next time you update your environment. Here’s a good starting point for a sprinter config:

namespace = myenvironment

formula = sprinter.formula.package
apt-get = git-core
brew = git

formula = sprinter.formula.ssh
keyname = github.com
nopassphrase = true
type = rsa
host = github.com
user = git
hostname = github.com

What does this do? Well, give it a shot! Write this to a file called myenvironment.cfg (you should replace myenvironment with your username or whatever makes sense to describe your own personal environment), and install it with:

sprinter install myenvironment.cfg

When you run the above command, you will first be prompted to configure sprinter if you haven’t already.

The next thing sprinter will do is install the ‘myenvironment’ environment. As defined above, this consists of:

  • install brew if you don’t have it already (OSX Users)
  • use brew or apt-get to install git
  • create an ssh key just for github, and add it to the ssh configuration file

Now you just add the ssh key to github, and you’re done! (you can find the path to the ssh file in your ~/.ssh/config file) (Unfortunately it’s not possible to add the key to github programatically)

This outlines a lot of the basic functionality that sprinter provides:

  • Multiple environments can be installed at the same time, with different specific names. In this case, we chose to name our environment ‘myenvironment’

  • adding environment configuration through ‘features’. a feature is decribed by a section in the configuration file (besides ‘config’). In this example, we have two features:

    • ‘git’, which installs git
    • ‘github’, which generates an ssh key

Now that’s not super difficult, so let’s try something more complicated.

sub is a command namespacing tool that allows the creation of subcommands. (e.g. moving to your workspace directory or running your server). Let’s try adding this to our configuration.

Every feature needs a formula to define what the actual feature is going to do. sprinter.formula.ssh, as shown above, generates ssh keys. sprinter.formula.package installs packages from the appropriate package managers. So how about cloning git repositories? Luckily, sprinter has a formula for this as well: sprinter.formula.git. We can add a new feature by adding it’s configuration into the environment config. We’ll add a section to myenvironment.cfg now:

namespace = myenvironment

formula = sprinter.formula.package
apt-get = git-core
brew = git

formula = sprinter.formula.ssh
keyname = github.com
nopassphrase = true
type = rsa
host = github.com
user = git
hostname = github.com

formula = sprinter.formulas.git
depends = github
url = git://github.com/mygithub/sub.git
branch = mybranch
rc = eval "$(%(sub:root_dir)/bin/sub init -)"

The git formula clones a git repository into sprinter’s directory (typically ~/.sprinter). In the sub feature, we then evaluate sub’s init script by injecting ‘eval “$(%(sub:root_dir)/bin/sub init -)”’ into one’s .bashrc or .zshrc file.

You can get more information about each of the formulas, and what they do, on the List of existing sprinter formulas page.

Now remember at this point, sprinter already knows that you have an environment ‘myenvironment’ installed. Instead of running an install again, you can run an ‘update’ command on the environment:

sprinter update myenvironment

The environment ‘myenvironment’ knows where it found the file last time, and will record it’s location for updating in the future. Although storing it locally is perfectly fine, it makes more sense to throw it online somewhere where all of your machines can access it. as an example, check out github user toumorokoshi’s environment configuration file:


variables in sprinter and referencing other formulas

In the above example, you’ll see that you can reference variables and information about other formulas in the values set. In the ‘sub’ example, the value %(sub:root_dir)s in the ‘rc’ option gets replaced with the directory of the sub feature during execution. This can make it very easy to perform operations that rely on information about other features, or the global configuration.

Here’s some examples of variables that are set in the above environment:

  • %(sub:url)s resolves to git://github.com/mygithub/sub.git
  • %(config:namespace)s resolves to ‘myenvironment’

Grabbing user input

Sprinter also provides the capability to prompt the installer for input when installing a sprinter environment. Some common examples are:

  • getting a username
  • getting passwords for various services
  • getting configuration options (version control root directories, workspaces)

You can grab user input by adding an ‘inputs’ option to any feature. Here’s an example of getting a user’s username, password, and git root then using it to make the git root and upload an ssh key through a rest api:

inputs = gitroot==~/git/

formula = sprinter.formula.command
install = mkdir -p %(config:gitroot)s
env = export GITROOT=%(config:gitroot)s

inputs = username
formula = sprinter.formula.ssh
depends = curl
keyname = mygithost.com
nopassphrase = true
type = rsa
user = git
hostname = mygithost.com
install_command = curl -k -u '%(config:username)s:%(config:githostpassword)s' -X POST -H "Accept: application/json" -H "Content-Type: application/json" https://mygithost.com/rest/ssh/1.0/keys -d '{"text":"{{ssh}}"}'
use_global_ssh = False

Note the section ‘inputs’ has specific syntax:

gitroot==~/git/  # the == provides a default to the parameter ~/git/
username   # this is a standard, just asks for a username
githostpassword?  # the question mark makes it a hidden parameter on input, for passwords and other sensitive data

If you run a sprinter install of this configuration, you would be prompted to enter the variables specified:

$ sprinter install sshexample.cfg
Checking and setting global parameters...
Installing environment sshexample...
please enter your gitroot (default ~/git/):
please enter your username:
please enter your githostpassword:

All prompted variables in the sprinter configuration are added to the config section, and can be used with %(config:MYVAR)s. In the example above, %(config:username)s will resolve to whatever the username parameter was.

When you update the environment in the future, you don’t have to enter the parameters again. This is because sprinter environments remember parameters (except passwords/secret parameters. Sprinter stores values in plaintext, so it’s never a good idea to store passwords that way.). If you want to re-enter parameters, you have to do an update with a –reconfigure:

$ sprinter update sshexample --reconfigure

rc and env

If you look at the configuration above, two parameters can be applied to almost all commands. Those are ‘rc’ and ‘env’. rc and env handle the actual content that is injected into your shell (e.g. what goes in your .bashrc or .zshrc). For example, a GoLang installation requires some environment variables set. You can do so like this:

systems = debian
formula = sprinter.formula.unpack
executable = bin/go
symlink = go
remove_common_prefix = true
url = https://go.googlecode.com/files/go1.1.linux-amd64.tar.gz
type = tar.gz
env = export GOROOT=%(golang-debian:root_dir)s
rc = function go() {
         go version

(the sprinter.formula.unpack formula handles unpacking of tar.gz, zip, (and dmg files for OSX)). Here we set an environment variables in ‘env’, and put functions in ‘rc’. This ensures that environment variables are available for graphical applications, while function are available for shells.

It’s ok not to get into specifics, most of the time just follow these rules:

  • environment variables go into ‘env’
  • everything else goes into ‘rc’

What next?

Congratulations! You know a majority of the functionality you need in sprinter. If you have questions about how to do specific things, try the FAQ or look at one of the doc pages, or post a question at our Google Group

Also check out the snippets section. This is a set of snippets that describe how to install common things like node.js