Installing the cqlsh security packages

To use cqlsh with a Kerberized cluster, you must install the PyKerberos and python-pure-sasl packages. The PyKerberos package is a high-level wrapper for Kerberos (GSSAPI) operations. The python-pure-sasl package is a pure Python client-side SASL (Simple Authentication and Security Layer) implementation.

RHEL-based installs

From root:

Make sure that the DataStax repository has been added. See Installing DataStax Enterprise on RHEL-based systems.
Check which version of Python is installed:
```
python -V
```

Add the Python module:

# yum install python26-pure-sasl ## for Python 2.6.x

# yum install python27-pure-sasl ## for Python 2.7.x

Add the Kerberos module:

# yum install python26-kerberos ## for Python 2.6.x

# yum install python27-kerberos ## for Python 2.7.x

Debian-based installs

Make sure that the DataStax repository has been added. See Installing DataStax Enterprise on Debian-based systems.
Add the modules:
```
$ sudo apt-get install python-pure-sasl
```
This command installs both the Python and Kerberos modules.

Tarball installs

Attention: DataStax recommends using APT or Yum because installing the dependencies can be difficult, time consuming, and requires a high level of Linux expertise.

Ensure all dependencies are properly installed:
- Debian-based systems: $ apt-cache show python-kerberos
- RHEL-based systems: $ yum deplist python-kerberos
Look at the Depends field and update your system to meet any dependencies, such as gcc, g++, python-dev, and libkrb5-dev.

Download the PyKerberos tarball:

$ curl -OL http://username:password@downloads.datastax.com/enterprise/kerberos-1.1.2+DSE1.tar.gz

Extract the tarball:
```
$ tar -xzf kerberos-1.1.2+DSE1.tar.gz
```
From the directory where you untarred PyKerberos:
```
$ python setup.py build
```
From the install directory:
```
$ python setup.py install
```

Download the pure-sasl module tarball:

$ curl -OL http://pypi.python.org/packages/source/p/pure-sasl/pure-sasl-0.1.3.tar.gz

Extract the tarball:
```
$ tar -xzf pure-sasl-0.1.3.tar.gz
```
From the install directory:
```
$ sudo python setup.py install
```