The goal of this step is for you to get confident with the ESC working environment and check that everything is correctly set up for the school exercises.

If something doesn’t work as expected, please ask one of the organizers.

Wi-Fi access

Make sure you are using the INFN-Captive WiFi or eduroam networks and not the CEUB WiFi network. Only the INFN-Captive or eduroam networks will allow to connect to the ESC computers.

SSH access to school computers

You have been assigned a personal account, with a username of the form studentNM, where NM is a number between 01 and 30. In the following, when you see studentNM, replace it with your personal account. You should also have received the corresponding password.

Similarly you have been assigned a computer, named esc-XY, where XY is a number between 01 and 60. In the following, when you see esc-XY, replace it with the name of the host assigned to you.

To log on esc-XY you have to first log into a gateway server, named esc-gw.pd.infn.it, with the username and password of studentNM.

[myself@mylaptop ~]$ ssh -X studentNM@esc-gw.pd.infn.it

The -X option forwards the X11 display.

From there you can log into esc-XY in a password-less way, thanks to an SSH key already generated for you and available in the .ssh directory (files id_rsa and id_rsa.pub).

[studentNM@esc-gw ~]$ ssh esc-XY

If you want you can do it in one step.

[myself@mylaptop ~]$ $ ssh -tX studentNM@esc-gw.pd.infn.it ssh esc-XY

Your shell is bash.

Your home directory is shared between esc-gw and esc-XY, but please don’t use esc-gw but to log into esc-XY.

IMPORTANT NOTE: The student computers will be uninstalled on Friday evening and all data on them will be destroyed. Please make sure you make a copy of everything valuable by the end of the Friday session!

School material

All the school material is included in a git repository. Get it using:

git clone https://github.com/infn-esc/esc15.git

Testing the environment

Log into esc-XY.

Check the following commands and the respective outputs.

 [studentNM@esc-XY ~]$ c++ -dumpversion
 5.2.0
 [studentNM@esc-XY ~]$ valgrind --version
 valgrind-3.10.0
 [studentNM@esc-XY ~]$ igprof -h
 igprof [options] program [options]
	
 Options to igprof:
 -h, --help                  	this help message
 ...
 [studentNM@esc-XY ~]$ which igprof-navigator
 /usr/bin/igprof-navigator

Create a web area where you will put output from some exercises:

 mkdir -p ~/public_html/cgi-bin/data
 cp $(which igprof-navigator) ~/public_html/cgi-bin/igprof-navigator.py
 echo "<html><body><a href='cgi-bin/igprof-navigator.py'>My igprof reports</a></body></html>" > ~/public_html/index.html
 chmod 755 ~/public_html/cgi-bin

View http://esc-gw.pd.infn.it:61100/~studentNM/ in your web browser; you should see the basic page you created above. Click on the link to profiles, it should produce some output – for now it will in fact display an error message due to lack of profiles.

Editing source code

Editing locally

On esc-XY you can find several editors available, such as vim, emacs, gedit, nano. If the X display is available, graphical editors will open a window on your laptop; the network latency however may not be good enough to give you a fine experience.

Editing remotely

Alternatively you could edit the source code for the exercises on your laptop, synchronizing the files with esc-XY. Some options are presented below.

First of all you should simplify your use of SSH to connect to ESC resources.

If you run Linux, you could for example copy the SSH credentials available on esc-gw onto your laptop and configure SSH to use them when logging into esc-gw.

mkdir esc_ssh
scp studentNM@esc-gw.pd.infn.it:.ssh/id_rsa esc_ssh
scp studentNM@esc-gw.pd.infn.it:.ssh/id_rsa.pub esc_ssh
chmod 600 esc_ssh/id_rsa
cat >> .ssh/config <<EOF

Host esc-gw
HostName esc-gw.pd.infn.it
User studentNM
IdentityFile ~/esc_ssh/id_rsa
ForwardX11 yes
EOF
ssh esc-gw

Using scp

You can copy files remotely using scp, in both directions.

scp exercise.cc @esc-gw:
scp @esc-gw:exercise2.cc .

Using sshfs

You can mount your ESC home directory on your laptop via sshfs.

mkdir esc_workspace
sshfs esc-gw: esc_workspace

Using rsync

You can synchronize your local workspace with the one you keep on the ESC system using rsync. The synchronization can work in both directions, so you can use it for example to save all your work on your laptop at the end of the week.

To synchronize the remote workspace on the ESC system with your locally-modified one you can do:

mkdir esc_workspace
vi esc_workspace/exercise.cc
rsync -av -e ssh esc_workspace esc-gw:

Similarly, if you make modifications to the remote ESC workspace you can synchronize your local one:

rsync -av -e ssh esc-gw:esc_workspace .

Please refer to the rsync manual to fully understand the meaning of the different options, so to avoid mistakes that could cause loss of data.

School exercise environment