# Building an ISO from the Source Code for Photon OS
 
 This document describes how to build an ISO from the source code for Photon OS, the open-source minimalist Linux operating system from VMware that is optimized for cloud computing platforms, VMware vSphere deployments, and applications native to the cloud. 
 

 ## Folder Layout

 
 Here is the structure of the directories on GitHub that contain the source code for Photon OS:
 

 ```
 photon/
 ├── Makefile
 ├── README

 ├── Dockerfile
 ├── Vagrantfile
 ├── SPECS        # RPM SPEC files

 ├── common       # Build, packaging config

 ├── docs         # Documentation
 ├── installer    # Installer used at runtime
 ├── support      # Build scripts
 └── tools

 ```
 

 ## How to Build the ISO
 
 The following process for building the ISO assumes that the following prerequisites are in place:

 * A build operating system running the 64-bit version of Ubuntu 14.04 or later
 * Packages: bison, gawk, g++, createrepo, python-aptdaemon, genisoimage, texinfo, python-requests
 * Docker
 * Downloaded the source code from the Photon OS repository on GitHub into `$HOME/workspaces/photon`.
 
 Here's how to install the packages on Ubuntu: 

 
 ```

 sudo apt-get -y install bison gawk g++ createrepo python-aptdaemon genisoimage texinfo python-requests libfuse-dev libssl-dev uuid-dev libreadline-dev kpartx git bc

 ```

 Here's how to get Docker:

 ```
 wget -qO- https://get.docker.com/ | sh
 ```

 Here's how to make the ISO, assuming you checked out the workspace under `$HOME/workspaces/photon`:

 ```
 cd $HOME/workspaces/photon
 sudo make iso
 ```

 The ISO is created at `$HOME/workspaces/photon/stage/photon.iso`
 

 ## How to Use the Cached Toolchain and RPMS

 ```
 mkdir $HOME/photon-cache
 sudo make iso PHOTON_CACHE_PATH=$HOME/photon-cache
 ```
 Directory format of `PHOTON_CACHE_PATH` is as follows.
 ```
 photon-cache/
 ├──tools-build.tar.gz
 ├──RPMS/x86-64/*.rpm
 └──RPMX/noarch/*.rpm
 ```

 ## How to Use Cached Sources

 ```
 mkdir $HOME/photon-sources
 sudo make iso PHOTON_SOURCES_PATH=$HOME/photon-sources
 ```
 Directory format of `PHOTON_SOURCES_PATH` is as follows.
 ```
 photon-sources/
 ├──src1.tar.gz
 ├──src2.tar.gz
 └──...
 ```
 

 ## Where are the Build Logs?

 ```
 $HOME/workspaces/photon/stage/LOGS
 ```
 

 ## Building RPMs from their Source RPMs
 
 For instructions on how to install and build a package on Photon OS from the package's source RPM, see the [Photon OS Administration Guide](https://github.com/vmware/photon/blob/master/docs/photon-admin-guide.md#building-a-package-from-a-source-rpm).
 
 ## Complete Build Environment Using Vagrant
 A `Vagrantfile` is available to ensure a quick standup of a development or build environment for Photon. This Vagrantfile uses a box called `photon-build-machine` that is created through a [Packer](http://packer.io) template available under `support/packer-templates`; see the [README.md](https://github.com/vmware/photon/blob/master/support/packer-templates/README.md) for more information on how to build `photon-build-machine`.

 ## Photon Vagrant Box
 As with the build-machine a Packer template is available under `support/packer-templates` to build a Photon based Vagrant box running Docker, see the [README.md](https://github.com/vmware/photon/blob/master/support/packer-templates/README.md) for more information on how to build it. 

 ## Automated Build Environment and Vagrant Boxes
 Convenience `make` targets also exist to build both the `photon-build-machine` and the `photon` Packer templates as well as building a fresh ISO using the `photon-build-machine`. See the [README.md](https://github.com/vmware/photon/blob/master/support/packer-templates/README.md) for details.