add cernvm-launch doc

cpt-context.rst

@@ -1,3 +1,5 @@
+.. _sct_context:
+
 Contextualization
 =================
 

cpt-launch.rst

@@ -1,8 +1,62 @@
-How to Instantiate a CernVM
-===========================
-
-Download the latest images from our
-`downloads page <https://cernvm.cern.ch/portal/downloads>`_.
-The image is generic and available in different file formats for different
-hypervisors. The image needs to be contextualized to become either a graphical
-development VM or a batch virtual machine for the cloud.
+CernVM Launch
+=============
+
+**Note**: CernVM Launch does currently not work with VirtualBox 6.1. We are working on a fix. Please use VirtualBox 6.0 for the time being.
+
+The ``cernvm-launch`` utility is a single binary for `Windows <https://ecsft.cern.ch/dist/cernvm/launch/bin/Win/cernvm-launch.exe>`_, `Linux <https://ecsft.cern.ch/dist/cernvm/launch/bin/Linux/cernvm-launch>`_, and `Mac <https://ecsft.cern.ch/dist/cernvm/launch/bin/Mac/cernvm-launch>`_ that creates, lists, and destroys (interactive) CernVMs on `VirtualBox <https://www.virtualbox.org/>`_. It works similar to the vagrant and docker command line utilities. It is meant to be used for interactive (graphical) CernVM instances on a local workstation or laptop.
+
+Installation
+------------
+
+As a one time preparation you need to:
+
+  * Install `VirtualBox <https://www.virtualbox.org/>`_.
+  * `Download the CernVM-Launch binary <https://ecsft.cern.ch/dist/cernvm/launch/bin/>`_ for your operating system and put it in your ``PATH`` environment (see below).
+
+Once installed, you can manage CernVM instances using different ":ref:`context <sct_context>`" ASCII files, which you can store on your computer.
+
+The installation process depends on the platform. For instructions how to install VirtualBox, please visit the `official VirtualBox page <https://www.virtualbox.org/wiki/Downloads>`_.
+
+
+Linux/Mac Installation
+~~~~~~~~~~~~~~~~~~~~~~
+
+Run the following commands in your terminal:
+
+::
+
+    # Download
+    if [ "x$(uname -s)" = "xLinux" ]; then
+      curl -o cernvm-launch https://ecsft.cern.ch/dist/cernvm/launch/bin/Linux/cernvm-launch
+    else
+      curl -o cernvm-launch https://ecsft.cern.ch/dist/cernvm/launch/bin/Mac/cernvm-launch
+    fi
+    chmod +x cernvm-launch  # make it executable
+    # As root user, place it in a directory from the $PATH environment
+    sudo cp cernvm-launch /usr/local/bin
+
+You can pick a different directory from your ``$PATH`` environment. Use ``echo $PATH`` to see all possible directories.
+
+
+Windows
+~~~~~~~
+
+Download the `cernvm-launch executable <https://ecsft.cern.ch/dist/cernvm/launch/bin/Win/cernvm-launch.exe>`_. Open a Windows prompt as an Administrator
+
+  * Click the Start icon
+  * Type ``cmd``
+  * Right-click on "cmd.exe" and click "Run as administrator"
+
+Go to the directory where you have the downloaded binary, e.g.
+
+::
+
+    cd C:\Users\sftnight\Downloads
+
+From there, copy the binary in a directory, which is a default path for executable, e.g.
+
+::
+
+    copy cernvm-launch.exe C:\Windows
+
+You can see your path directories with ``echo %PATH%``.