CERN Hacks
----------
This Gist is a guide on how to setup your computer at CERN with __Ubuntu 14.04 LTS__. 
Last tested by myself on a brand new computer on __18/11/2014__, proof tested by @[Alea88](https://github.com/Alea88).

### How To Acces AFS 

#### Step 1: install packages


Download the following:

```
sudo apt-get install openafs-client
sudo apt-get install openafs-modules-dkms
sudo apt-get install openafs-krb5
sudo apt-get install krb5-user
sudo apt-get install krb5-config
```

#### Step 2: generate your keytab

Make sure that you don't have any __.keytab__ created yet. If so, erase it. If you want to check whats in your keytab type:

```
$ ktutil
ktutil: read_kt path_to_keytab/name_of_keytab
ktutil: list
```
Execute this commands, with your username:
```
$ ktutil
ktutil: addent -password -p gcampogi@CERN.CH -k 1 -e aes256-cts
ktutil: addent -password -p gcampogi@CERN.CH -k 1 -e arcfour-hmac-md5
ktutil: wkt .keytab
ktutil: q
```

See if your keytab works:
```
kinit -kt .keytab gcampogi
```

If nothing appears in your prompt, it works. Move your __.keytab__ file to __/etc/__ and rename it __krb5.keytab__.

#### Step 3: use "cern.ch" as default AFS cell

Open the file __/etc/openafs/ThisCell__ and add ``cern.ch`` 

#### Step 4: setup kerberos5 authentication

Open the file __/etc/krb5.conf__ and replace it by [this one](http://linux.web.cern.ch/linux/docs/krb5.conf)


#### Step 5: avoiding SSH errors

To avoid problems when connecting to lxplus with:
```
ssh user@lxplus
```
open the file __/etc/ssh/ssh_config__ and make it look like this:

```
HOST lxplus*
    ForwardX11 yes
    ForwardX11Trusted no
    GSSAPITrustDNS yes
    HashKnownHosts yes
    GSSAPIAuthentication yes
    GSSAPIDelegateCredentials yes
```

#### Step 6: renew your token automatically

Open the file __/etc/crontab__ and add the following line:

```
@daily ID=afstoken kinit --renew
```

#### Step 7: time sync

Kerberos only works if your computer clock is in close sync (certainly within 5 minutes) with CERN time servers. 

In a normal computer you can do a one-off clock sync like typing the following:

```
ntpdate ntp.ubuntu.com
```

For CERN you'll need to install the ntp daemon, which will continuously keep your clock in accurate sync with the CERN time servers.

```
apt-get install ntp
```

Then add the following lines to your __/etc/ntp.conf__ file, and comment or erase the lines for ubuntu time servers:
```
# CERN Client
                   
server 137.138.18.69 version 4 #IP-TIME-0
server 137.138.16.69 version 4 #IP-TIME-1
server 137.138.17.69 version 4 #IP-TIME-2
                   
# Disable remote access, but trust sources of time restrict default nomodify #noquery
restrict default nomodify noquery

# Allow hosts to query stats and ask for the time.
# eg restrict 123.123.123.123 nomodify

# Allow localhost to do everything.
restrict 127.0.0.1

#logconfig=all
```

More information [here](http://service-ntp.web.cern.ch/service-ntp/clientconfig.asp). Then restart the ntp service:

```
sudo service ntp restart
```

#### Step 8: automatize identification

My way of obtaining my credentials is adding the following line in my __.bash_aliases__ file: 

```
alias afs="kdestroy && kinit -kt /etc/krb5.keytab gcampogi -l 7d -r 1d ; aklog CERN.CH"
```
Like this I can obtain the credentials only by typping __"afs"__ in the console.

What all of this means:

* The __"kdestroy"__ command deletes a Kerberos credentials cache file. More info [here](http://publib.boulder.ibm.com/infocenter/aix/v7r1/index.jsp?topic=%2Fcom.ibm.aix.cmds%2Fdoc%2Faixcmds3%2Fkdestroy.htm)

* The __"kinit"__ command is used to get a Kerberos ticket. See __"kinit"__'s options [here](http://linux.die.net/man/1/kinit). We are using the keytab we just created to obtain the Kerberos ticket.

* The __"aklog"__ command is used to obtain tokens for authentication to AFS. More info [here](http://docs.openafs.org/Reference/1/aklog.html).


#### Debugging

* Restart the console so your alias will work.
* Restart the AFS client: ``sudo service openafs-client restart``.
* Login with the alias you chose (make sure you get ticket and token).
* Make sure the clocks are synced.

__NOTE__

With the kernel upgrade from 3.13.0-45-generic to 3.13.0-46-generic AFS stops working: [read more](https://bugs.launchpad.net/ubuntu/+source/openafs/+bug/1423151)

Type this to check your kernel version:

```uname -r```

To revert the change in your system, type:

```
sudo apt-get remove 3.13.0-46-generic
sudo update-grub
```

Then restart your computer.

#### References

* [Ome Gak](https://gist.github.com/OmeGak/9530124)
* [linux.web.cern.ch](http://linux.web.cern.ch/linux/docs/kerberos-access.shtml)
* [akorneev.web.cern.ch](http://akorneev.web.cern.ch/akorneev/howto/openafs.txt)
* [Yngve's blog](http://eothred.wordpress.com/2011/05/09/cern-and-kerberos-tokens/)


### How To Install a CERN Printer
- Open the printer settings on your local computer.
- Click "Add"
- Select "Network printer" --> "LPD/LPR Host or printer"
- Look for the name of your printer [here](https://printservice.web.cern.ch/printservice/UserTools/PrinterStatus.aspx)
- Write __name.print.cern.ch__ in the field "Host" and __name__ in "Queue" and press "Forward"
- Select brand and model of the printer
- Select the duplexer if it can print both sides of the paper
- Change the name of the printer to the original name provided by the CERN page provided above
- Print a test page
- Done!

### How to install Spotify
Follow this [link](https://www.evernote.com/shard/s364/sh/d9ac7567-f789-42ec-b6a9-0f323d9928d9/806834de8e8ca12bc4220251ac3ce101) to my Evernote snippet about it.

### Setting up Git

- Install it
``
sudo apt-get install git
``
- Activate the colors 
``
git config --global color.ui auto
``
- Create your SSH key following this [link](https://help.github.com/articles/generating-ssh-keys/)

### Setting up Python

- Download Python
```
wget http://python.org/ftp/python/2.7.8/Python-2.7.8.tgz
```

- Untar it, acces the folder and
```
./configure
make
sudo make install
```

- Install important things

```
sudo apt-get install python-numpy python-scipy python-matplotlib ipython ipython-notebook python-pandas python-sympy python-nose
```

- Install pip
```
sudo apt-get install python-pip
```

- Instal virtual environments (click [here](https://gist.github.com/KFubuki/17d724d224bd97a0f20f#virtual-environment) to see how it works)

```
sudo pip install virtualenv
```

### Installing Adobe Reader and setting it as default

Download Adobe Reader (32 bit) from the Adobe site: ftp://ftp.adobe.com/pub/adobe/reader/unix/9.x/9.5.5/enu/AdbeRdr9.5.5-1_i386linux_enu.deb
```
sudo dpkg -i --force-architecture AdbeRdr9.5.5-1_i386linux_enu.deb
sudo apt-get -f install
sudo apt-get install libxml2:i386 lib32stdc++6
```
To set it as the default program to open pdfs:
``
mimeopen -d *.pdf
``

Open a document for the first time:
``
acroread <path>/<MyDocument>.pdf
``

### Things to install

- Chrome
- Dropbox
- Emacs (click [here](https://github.com/KFubuki/dotfiles/tree/master/emacs) for my emacs configuration)
- Atom (click [here](https://www.computersnyou.com/3254/install-atom-editor-ubuntu-14-04/))
- Subversion
- Terminator
- Pdflatex

```
sudo apt-get install texlive-latex-bas
```

- TexLive
``
https://github.com/scottkosty/install-tl-ubuntu
``