ubuntu


Lubuntu LVM Encrypted

While trying to setup a lubuntu GNU/Linux that would use an encrypted LVM file-system we run into several problems that should have not been there.
For example, the installer would not continue as swap memory was not encrypted and it was blocking the operation.
An other issue was that the LVM support package was not installed by default although it is needed by the installer.

Our solution requires an active internet connection so that you can install the lvm2 package.

Methodology

After booting into the live session, before we started the installation process, we opened a terminal from the main menu (Start Menu) and executed the following two commands:

sudo apt-get install lvm2 -y;

sudo swapoff --all;

These two commands disabled all swap (so that we do not get the error that swap is not encrypted) and it installed the lvm2 package that is needed by the installer to create our LVM setup.

The following video presents the full successful installation procedure by making the changes before starting the procedure.

The next video, shows our attempts to fix the installation after encountering the errors instead of fixing them beforehand.

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CloudFlare does not allow port 22 (usual SSH port) on domain 2

When you try to connect via ssh on a domain for which you are using CloudFlare as a HTTP proxy, you will get the following error:

$ ssh [email protected]
 ssh_exchange_identification: Connection closed by remote host

You have a few options to resolve for this issue:

  1. Either connect directly to the IP of the machine.
  2. Or, setup a CNAME record with no HTTP proxy for the SSH (so that you do not need to remember the IP).
    This solution does not offer any additional benefits than connecting directly to the IP of the server.
    To do that, you need to visit the configure DNS page for your site: e.g. https://www.cloudflare.com/a/dns/example.com,
    then create the CNAME named ssh, use as target your domain (e.g. example.com) and disable HTTP proxy by clicking on the orange cloud and making it gray before pressing the Add Record button.

    Then, you will be able to connect via ssh [email protected].
  3. Last solution but not least is configuring your server to listen for SSH on one of the ports of CloudFlare that are open.
    When this post was written, the following ports were available/open for any site in CloudFlare:
    For requests made via HTTP:

    80
    8080
    8880
    2052
    2082
    2086
    2095

    For requests made via HTTPS:

    443
    2053
    2083
    2087
    2096
    8443

    At the time, we were using an Ubuntu GNU/Linux server, to instruct Ubuntu SSHD to listen to multiple ports we edited the file /etc/ssh/sshd_config and right after the lines:

    # What ports, IPs and protocols we listen for
    Port 22

    we added another line with the new port we wanted to use:

    # What ports, IPs and protocols we listen for
    Port 22
    Port 2053

    After restarting the service
    service ssh restart;
    we were able to connect to our page as follows:
    ssh -p 2053 [email protected];

 


Lubuntu: “Do Nothing” when I close the laptop’s lid 1

A few days ago we setup a server on a laptop with lubuntu. We wanted to make sure that once the screen lid is off, the PC would not shut down (or hibernate or sleep) and it would continue to accept requests.

We tried to configure the PC through the system settings that are available with the GUI but we could not get it to work right. Anyhow, what we did in the end and worked was the following:

In the file /etc/systemd/logind.conf we set the variable HandleLidSwitch to ignore. So after the change, the following line was in logind.conf:

HandleLidSwitch=ignore

If the above line is commented out (i.e. starts with the character #, be sure to uncomment it by removing the # character).
After that, we had to restart the systemd-logind service as follows:

service systemd-logind restart;

Finally, to test we closed the lid and the server was operating as expected.

Note

If you have a power manager such as xfce4-power-manager-settings, it is a good practice to make sure it is configure properly first before doing the change above. (e.g. Set Lock screen or Switch off display in When laptop lid is closed option).

If you start xfce4-power-manager after you do the change above, you might have to restart the service again as the solution seems to stop.


Compiling openbts-umts on Ubuntu 15.04

Below are the steps we followed to compile OpenBTS-UMTS on Ubuntu 15.04.
There could be a chance that we installed a couple of extra system packages while troubleshooting the installation but it works and we did not include some heavy system service as well so it should be OK.

sudo apt-get install build-essential libuhd autoconf libtool libdevel libzmq-dev libzmq libzmq-dev libzmq-dev libosip2-dev libortp-dev libusb-dev libusb-1.0 libtool-bin libsqlite3-dev libboost-dev libreadline-dev;
git clone https://github.com/RangeNetworks/OpenBTS-UMTS;
cd OpenBTS-UMTS/;
git submodule init;
git submodule update;
#First we need to setup ASN1C compiler
tar -xf asn1c-0.9.23.tar.gz;
cd vlm-asn1c-0959ffb/;
./configure;
make;
make check;
sudo make install;
cd ..;
#Finally, we can proceed with compiling openbts-umts
./autogen.sh;
./configure;
make;
sudo make install;


Compiling gr-gsm on Ubuntu 14.04 LTS

Below are the steps that we followed to compile gr-gsm on Ubuntu 14.04 LTS.

sudo apt-get update;
sudo apt-get install build-essential python-dev git python-pip;
sudo pip install PyBOMBS;
sudo pybombs prefix init /usr/local -a default_prx;
sudo pybombs config default_prefix default_prx;
sudo pybombs recipes add gr-recipes git+https://github.com/gnuradio/gr-recipes.git;
sudo pybombs recipes add gr-etcetera git+https://github.com/gnuradio/gr-etcetera.git;
sudo pybombs install gr-gsm;
sudo ldconfig;