# Preparing a build environment

To create builds you will need a build user (`omnibus-build:omnibus-build` in our example).
Preparing the build machine requires sudo access.

## Ubuntu 12.04

```shell
# Get the latest OS updates
sudo apt-get update
sudo apt-get upgrade

# Set up the firewall to only allow inbound SSH traffic
sudo apt-get install ufw
sudo ufw allow ssh
sudo ufw enable

# Check for SSH password logins, they should be disabled; The command below should return no results
grep '^[^#]*PasswordAuthentication' /etc/ssh/sshd_config

# Install dependencies
sudo apt-get install ruby1.9.1 ruby1.9.1-dev git build-essential cmake
sudo gem install --no-ri --no-rdoc bundler

# Create the build user
sudo adduser --gecos 'Omnibus Build' --disabled-password omnibus-build
# Create build directories for use by the build user
sudo mkdir -p /opt/gitlab /var/cache/omnibus
sudo chown omnibus-build:omnibus-build /opt/gitlab /var/cache/omnibus
```

Then, as the build user (omnibus-build):

```shell
# Login as omnibus-build user
sudo su - omnibus-build

# Clone the omnibus repo
git clone https://gitlab.com/gitlab-org/omnibus-gitlab.git

# Install gem dependencies for omnibus-ruby
cd omnibus-gitlab
bundle install --path .bundle --binstubs

# Do a build (and take a break from the computer)
bin/omnibus build project gitlab
```

## Debian 7.4

the steps to build gitlab with omnibus on Debian 7.4 are equal to the ones to build on Ubuntu 12.04

## Centos 6.5

```shell
# Update OS packages
sudo yum update

# Set up the firewall to only allow inbound SSH traffic
sudo lokkit -s ssh

# Check for SSH password logins; they should be disabled
grep '^[^#]*PasswordAuthentication' /etc/ssh/sshd_config

sudo yum groupinstall 'Development Tools'
# Install RedHat Software Collections to get Ruby 1.9.3
sudo yum install centos-release-SCL
sudo yum install ruby193 ruby193-ruby-devel

# Create the build user
sudo adduser -c 'Omnibus Build' omnibus-build
# Create build directories for use by the build user
sudo mkdir -p /opt/gitlab /var/cache/omnibus
sudo chown omnibus-build:omnibus-build /opt/gitlab /var/cache/omnibus
```

As the build user (omnibus-build):

```shell
# Enable Ruby 1.9.3 from Software Collections
echo 'exec scl enable ruby193 bash' >> .bash_profile
# Start a new login shell so we do not have to log out and in
# this one time
bash --login

# Clone the omnibus repo
git clone https://gitlab.com/gitlab-org/omnibus-gitlab.git

# Install gem dependencies for omnibus-ruby
cd omnibus-gitlab
bundle install --path .bundle --binstubs

# Do a build (and take a break from the computer)
bin/omnibus build project gitlab
```

## Usage

### Build

You create a platform-specific package using the `build project` command:

```shell
$ bin/omnibus build project gitlab
```

The platform/architecture type of the package created will match the platform
where the `build project` command is invoked. So running this command on say a
MacBook Pro will generate a Mac OS X specific package. After the build
completes packages will be available in `pkg/`.

### Clean

You can clean up all temporary files generated during the build process with
the `clean` command:

```shell
$ bin/omnibus clean
```

Adding the `--purge` purge option removes __ALL__ files generated during the
build including the project install directory (`/opt/gitlab`) and
the package cache directory (`/var/cache/omnibus/pkg`):

```shell
$ bin/omnibus clean --purge
```

### Help

Full help for the Omnibus command line interface can be accessed with the
`help` command:

```shell
$ bin/omnibus help
```

## Vagrant-based Virtualized Build Lab

Every Omnibus project ships will a project-specific
[Berksfile](http://berkshelf.com/) and [Vagrantfile](http://www.vagrantup.com/)
that will allow you to build your projects on the following platforms:

* CentOS 5 64-bit
* CentOS 6 64-bit
* Ubuntu 10.04 64-bit
* Ubuntu 11.04 64-bit
* Ubuntu 12.04 64-bit

Please note this build-lab is only meant to get you up and running quickly;
there's nothing inherent in Omnibus that restricts you to just building CentOS
or Ubuntu packages. See the Vagrantfile to add new platforms to your build lab.

The only requirements for standing up this virtualized build lab are:

* VirtualBox - native packages exist for most platforms and can be downloaded
from the [VirtualBox downloads page](https://www.virtualbox.org/wiki/Downloads).
* Vagrant 1.2.1+ - native packages exist for most platforms and can be downloaded
from the [Vagrant downloads page](http://downloads.vagrantup.com/).

The [vagrant-berkshelf](https://github.com/RiotGames/vagrant-berkshelf) and
[vagrant-omnibus](https://github.com/schisamo/vagrant-omnibus) Vagrant plugins
are also required and can be installed easily with the following commands:

```shell
$ vagrant plugin install vagrant-berkshelf
$ vagrant plugin install vagrant-omnibus
```

Once the pre-requisites are installed you can build your package across all
platforms with the following command:

```shell
$ vagrant up
```

If you would like to build a package for a single platform the command looks like this:

```shell
$ vagrant up PLATFORM
```

The complete list of valid platform names can be viewed with the
`vagrant status` command.