Linux Server Security Secrets and Administration

Download m3u8 files from command line on linux

2022-03-14T17:13:00.002-03:00

To automate the download of a file, you can do this for m3u8 formats.

ffmpeg -y -loglevel verbose -i "http://example.com/test.m3u8" -c copy -f mpegts test.mp4

Debian LightDm Autologin

2021-09-02T17:41:00.000-03:00

The Autologin is a nice feature, linux starts and do not asks for user/password.

vi /etc/lightdm/lightdm.conf

autologin-user=<your username>
autologin-user-timeout=0

This worked for me

vncserver vncviewer on linux

2021-06-14T15:08:00.003-03:00

On vncserver:

x11vnc -reopen -forever -scale 2/3

From client:

vncviewer hostname-ip

Remove rc packages debian

2021-06-09T19:41:00.002-03:00

apt-get remove --purge $(dpkg -l | grep "^rc" | awk '{print $2}')

rdesktop rdp from Linux to Windows

2021-06-05T18:45:00.004-03:00

rdesktop -r disk:tmp=/home/me/Pictures -g 90% 12.12.12.16

Retropie roms and games

2021-05-27T15:45:00.002-03:00

Testing, games for DOS:

https://www.gamulator.com/es/roms/dos?currentpage=3

Part 1 - Setting up an older Eclipse version

2021-05-25T11:31:00.007-03:00

Like others i have an old device with Android, a Samsung i5500 and some years ago i did developed a game for it to teach my daughter the numbers when she was 3 years. The device is still working, it had Froyo Android 2.2 and upgraded to 2.3 Gingerbeard with Cyanogenmod. There seem to be two problems to resolve, future problems and past problems, because it is incredible difficult if one wants to develop something for an old device how hard it is! Like inventing something new. All versions are deleted, unavailable... may be for that reason i have some hobby of collecting old software and backing up. I hope i help somebody with this.

Download

eclipse-standard-kepler-R-linux-gtk-x86_64.tar.gz

!ENTRY org.eclipse.osgi 4 0 2021-05-24 23:01:22.214
!MESSAGE error loading hook: org.eclipse.osgi.internal.baseadaptor.BaseHookConfigurator
!STACK 0
java.lang.reflect.InaccessibleObjectException: Unable to make protected void java.net.URLClassLoader.addURL(java.net.URL) accessible: module java.base does not "opens java.net" to unnamed module @1c53fd30

Solution:

Download & Uncompress:jre-8u291-linux-x64.tar.gz

Modify / add eclipse.ini:

--launcher.appendVmargs
-vm
~/Android/jre1.8.0_291/bin
-vmargs

eclipse import android.os cannot be resolved

Open Eclipse -> Help -> Install Software -> Add:

ADP Repository

http://dl-ssl.google.com/android/eclipse/

Eclipse restarts

Now Window -> Preferences -> Now appears Android option

I had this:

/home/walter/Desktop/Android/adt-bundle-linux-x86_64-20131030/sdk

Pointed here:

/home/walter/Backup/Android/Android/adt-bundle-linux-x86_64-20131030/sdk

It openeded the SDK Manager and updated few packages:

Important is to add android library to each project:

And with this you are able to do Android apps for Froyo, Gingerbread or old versions.

Error: R cannot be reoslved to a variable (in Eclipse)

Removed gen -> and recreates it.

Check res/values/strings.xml and others, fix, remove gen, recreate.

Bienvenido a mi blog !

2021-04-28T08:30:00.000-03:00

Bienvenido! En este "espacio virtual" comparto de forma pública algunas notas, ideas, proyectos. Aca hay temas en general, de mi profesión ,un hobby o deporte.

Aqui mi pagina web

Some git notes

2021-04-27T08:54:00.011-03:00

Here i am posting some git notes for myself and if useful for somebody else, i appreciate any comment or even a coffee :)

To add something i edited:

git add .; git commit -m "bm"; git push origin master

To remember credentials for 15 minutes:

git config --global credential.helper cache

To modify the timeout:
git config --global credential.helper 'cache --timeout=3600'

Work with modules:

git submodule add https://github.com/wlamagna/datamining
git submodule init
git submodule update

If the submodule changed something and i want to have it point to the latest:
rm -rf datamining; git add .; git commit -m "deleted module"; git push origin master
git submodule add --force https://github.com/wlamagna/datamining
git add .; git commit -m "new module"; git push origin master

Leaflet + Datos Abiertos del Servicio Meteorologico Nacional

2021-04-25T15:58:00.004-03:00

Mi intención era tener un mapa con el Rio de la Plata y poder observar exactamente de donde proviene el viento. Curiosamente cuesta mucho hoy en dia encontrar un mapa que incluya la Rosa de los vientos, lo desafio a que encuentre uno ! A mi al menos me resultó imposible. Entonces, quería tener:

* Mapa del Rio de la plata

* Que incluya la Rosa de los Vientos

* Que muestra exactamente la dirección del viento pronosticado.

Para el pronóstico tomé Datos Abiertos del Servicio Meteorologico Nacional y filtrandolos de acuerdo a lo que comparti aca los combine con un mapa y usando la columna de direccion del viento,decodificado segun el angulo de origen en la direccion. El problema es que los pronósticos son para "Buenos Aires" y la provincia es tan pero tan grande que basicamente puede tener todas las direcciones de vientos al mismo tiempo: como suelo decir entre mis familiares, "los de pronóstico siempre la pegan por que digan lo que digan en algún lugar seguro se cumple" jaja.

Armé el mapa, hice el procesamiento de los datos para ser leidos por la página pero los datos del pronóstico no me terminaron de convencer para esta aplicación al menos por ser demasiado generál para una provincia tan grande. De todas formas aca comparto: Aqui la visualizacion:

d3 + Observable : notas post meeting de d3 en Español

2021-04-03T11:48:00.014-03:00

Me invitaron a una meeting virtual de D3, asi que pude asistir y voy a escribir aqui algunas notas publicas.

Aqui comparto la grabación de la reunión:

Me entusiasmé y estuve incursionando en ObservableHQ, el problema ahora es que no sé que datos usar, siempre me pasa lo mismo ! Así que creé un nuevo conjunto de datos :) Entonces les presento datos abiertos del Servicio Meteorológico Nacional.

Paso 1. Obtener los datos y convertirlos a un formato para trabajar con ellos. El parser, datos y una brevísima documentación: aca en github.

El conjunto de datos consta de 5 columnas:

fecha y hora, temperatura, dirección del viento, velocidad del viento en Km/h,probabilidad de precipitaciones.

La dirección del viento es un número que representa los grados, es un "cifrado en grados" y su dirección se decodifica con ésta tabla. Naturalmente para los que realizen deportes náuticos en Argentina, habrá una preferencia por vientos NorEste y Este (entre 0 y 90 grados).

Paso 2. Hacer algo en ObservableHQ

Encontre también este video de una de las personas que organizaron el evento, este video en particular no es el del evento, pero lo agrego aca como recordatorio.

Intro a Observable (como un Notebook de Javascript):

Apagar las luces de pantalla raspberry pi touch

2020-05-07T08:43:00.002-03:00

Queria apagar y encender las luces a la pantalla LCD del Raspberry, con este comando pude hacerlo:

$ sudo sh -c 'echo "1" > /sys/class/backlight/rpi_backlight/bl_power' # apagar luz fondo

$ sudo sh -c 'echo "0" > /sys/class/backlight/rpi_backlight/bl_power' # encender luz fondo

Cacti with lighttpd

2020-04-23T14:11:00.001-03:00

~~I had a VM with jitsi which install nginx, and now i want to test CACTI install on the VM to then do it in the read only usb boot i have at the Firewall.~~

Intially i wanted to install cacti with nginx but did not wanted to struggle with the php setup, so now i have set it up with lighttpd.

Just to first:

1) not copy the VM or creating another (save time).
2) nginx seems lighter than apache so it is a good alternative for the firewall.

So... lets start.

1) Install
apt-get install snmpd

Add this to sources, you may add something different:

deb http://ftp.ro.debian.org/debian/ stretch main contrib non-freedeb-src http://ftp.ro.debian.org/debian/ stretch main deb http://security.debian.org/debian-security stretch/updates main contrib non-freedeb-src http://security.debian.org/debian-security stretch/updates main

Then:
apt-get install snmp-mibs-downloader

2) Configure SNMPD
Edit /etc/default/snmpd, find the following line:

#export MIBS=/usr/share/mibs/netsnmp/
Replace it with:
export MIBS=ALL

Then add or uncomment the following line to the ACCESS CONTROL area of /etc/snmp/snmpd.conf:

rocommunity public localhost # Full access from localhost

3) Restart snmp
service snmpd restart

4) Installing Cacti:
apt-get install cacti cacti-spine

5) Yes, and put a password:

Reference:
https://notblog.org/cacti-with-nginx/
https://www.paveltashev.com/blog/how-to-install-cacti-monitoring-server-with-nginx/

Pi Hole Linux on a Raspberry PI

2020-04-19T14:43:00.002-03:00

First i installed the Pi-Hole on a VM, and it worked very well! So now i installed it on the PI.
It can not be more easy. I did some videos to share the easy it is.

From:

https://github.com/pi-hole/pi-hole/#one-step-automated-install

git clone --depth 1 https://github.com/pi-hole/pi-hole.git Pi-hole

Step 1: run from command line:

Step 2: also i modified my dhcp server to give the new DNS instead of 8.8.8.8 or whathever.
https://github.com/walt3rminer/perl/tree/master/dhcpserver

Step 3: Continue the installation

Step 4: It provides a password and you can start using it.

Arduino ser_open "can't open device" ttyACM0

2020-04-03T14:38:00.003-03:00

chmod a+rw /dev/ttyACM0

Compress or uncompress safely

2020-04-02T17:57:00.000-03:00

gpg --batch --passphrase-file /usb/pepe -o something.tgz --decrypt something.gpg

gpg --batch --passphtase-file /usb/pepe -c something.tgz -o something.tgz

Arduino notes #1

2020-04-02T17:26:00.004-03:00

Download Arduino here: https://www.arduino.cc/en/Main/Donate

uncompress the package, move to home.

home/walter/arduino-1.8.12# ./install.sh
Adding desktop shortcut, menu item and file associations for Arduino IDE...

touch: cannot touch '/root/.config/mimeapps.list': No such file or directory
/usr/bin/xdg-mime: 848: /usr/bin/xdg-mime: cannot create /root/.config/mimeapps.list.new: Directory nonexistent

done!

Back to user:
arduino starts the IDE

Hacking games / Internet Puzzles

2019-09-28T20:01:00.003-03:00

Playing is fun, and if you can learn something new, much better ! It is a good way to know people with similar interests also.
Here are two platforms to resolve complex problems that also guide you in the world of internet puzzles.
Rootme: Even its design may not be so heavy, eye catching, or call it how you want, i like it very much because it has many categories of problems.
HackTheBox: is another one, a coworker talked me about this one, to enter you have to resolve a problem that depending on your experience and knowledge could be hard or medium... or easy ?

What other puzzle games do you know similar to these ones ?

In Spanish: Arduino + 3 proximity sensors + Shield v5.1 from Keystudio

2019-09-08T14:10:00.001-03:00

Mounting on linux an xhci_hcd android phone

2019-09-08T14:09:00.003-03:00

I want to copy pictures or videos taken on my Android Phone to my Linux machine but mounting it as a regular pendrive do not works. I had to use another method.

When i connect my phone i get something like this:

[ 2695.481431] usb 1-2: new high-speed USB device number 5 using xhci_hcd
[ 2695.623882] usb 1-2: New USB device found, idVendor=271d, idProduct=4008
[ 2695.623891] usb 1-2: New USB device strings: Mfr=2, Product=3, SerialNumber=4
[ 2695.623897] usb 1-2: Product: Ultra
[ 2695.623903] usb 1-2: Manufacturer: TARAN
[ 2695.623909] usb 1-2: SerialNumber: S...6
[ 2718.973332] usb 1-2: USB disconnect, device number 5
[ 2719.509605] usb 1-2: new high-speed USB device number 6 using xhci_hcd
[ 2719.650726] usb 1-2: New USB device found, idVendor=271d, idProduct=4008
[ 2719.650735] usb 1-2: New USB device strings: Mfr=2, Product=3, SerialNumber=4
[ 2719.650742] usb 1-2: Product: Ultra
[ 2719.650747] usb 1-2: Manufacturer: TARAN
[ 2719.650753] usb 1-2: SerialNumber: S...6

And to mount i had to do this:

apt-get install jmtpfs
jmtpfs /mnt

3.5 Inch 480x320 TFT Display with Touch Screen for Raspberry Pi

2019-08-27T09:51:00.003-03:00

Hello my Linux Friend, how are you ? Hope well, from the part of this world you are certainly if you use Linux you are supporting Open Source and part of Free Software also... do not forget to contribute to the community because the great change that Open Source has meant to the society is priceless. The same happens with Open Hardware.

To setup the 3.5 inch screen, after installing Raspbian this works:

git clone https://github.com/Elecrow-keen/Elecrow-LCD35.git

cd Elecrow-LCD35

sudo ./Elecrow-LCD35

Reseteando niveles de tinta L210 Epson

2019-08-20T23:31:00.002-03:00

How to reset Ink Levels in Epson L series – L120, L210 etc

I found this useful a night after filling the ink and needing to do some urgent copies. Since i only use Linux, this has saved the moment.

1. You can use Ink Codes that come on Ink Bottles.
2. You can reset Ink Levels in L100, L200, L800 printers by WIC Reset Utility.
3. You can follow this instruction to reset Ink Levels in all Epson L-series printers such as:
L100, L110, L111, L120, L130, L200, L210, L211, L220, L300, L301, L310, L350, L351, L353, L355, L358, L360, L365, L455, L550, L551, L555, L558, L565, L800, L810, L850, L1300, L1800
With turned printer ON – press Power button – printer will turn OFF.
Wait 10 seconds.
Hold Paper button, then press and release Power button- the printer will turn ON and Power Green light will start to blink.
Release Paper button and press again for 10 seconds.
After 10 second release Paper button, then press for 1-2 seconds again and release. Thats all.
This works for all Epson L-series.

source: https://www.wic.support/how-to-reset-ink-levels-in-epson-l-series-l120-l210-etc/

Another guide with pictures: https://support.printerpotty.com/2017/reset-ink-level-epson-ecotank-l-series

I am not sure if this only works once.. so the next time i had to follow this step:

Format pendrive on linux for a generic device

2019-08-19T20:06:00.002-03:00

To format a pendrive for any device like the car, a tv, a digital photo viewer is easy. But from linux you have to choose a filesystem that has more chances to be interpreted. The most read filesystem is FAT32 or exFAT.

fdisk /dev/sdb
new filesystem -> type : b W95 FAT32
mkdosfs -F 32 -I /dev/sdb1

I am back

2019-08-16T16:57:00.003-03:00

Hello Linux Friends, i am back. After 4 years i just returned. The only think that we can be sure of is that everything changes. I had to try another blogging system but just found that i missed this one all the time. Finally i decided to return to this platform.

This time, how to detect a fake usb and know its real storage ? Well, i fall in the temptation of cheap usb and huge storage from ebay!! Oh yes!! How smart i am, i can purchase it cheaper and not paying so much!! But well... reality always wins and the 128GB usb was just not working... after researching a little bit i found this tool for linux to detect the real storage for an USB. Obseve, it tells it is from 125GB but the real size is 30GB.

f3probe --destructive --time-ops /dev/sdb
F3 probe 6.0
Copyright (C) 2010 Digirati Internet LTDA.
This is free software; see the source for copying conditions.

WARNING: Probing normally takes from a few seconds to 15 minutes, but
         it can take longer. Please be patient.

Bad news: The device `/dev/sdb' is a counterfeit of type limbo

You can "fix" this device using the following command:
f3fix --last-sec=64897023 /dev/sdb

Device geometry:
             *Usable* size: 30.95 GB (64897024 blocks)
            Announced size: 125.00 GB (262144000 blocks)
                    Module: 128.00 GB (2^37 Bytes)
    Approximate cache size: 0.00 Byte (0 blocks), need-reset=no
       Physical block size: 512.00 Byte (2^9 Bytes)

Probe time: 3'08"
Operation: total time / count = avg time
      Read: 253.0ms / 2156 = 117us
     Write: 3'08" / 2151 = 87.5ms
     Reset: 0us / 0 = 0us

2015-07-22T13:04:00.003-03:00

After 10 years i started this blog, now i decided to keep going on a private domain and hosting. I hope the many people who was there to read or comment could keep on reading in the other site, i will be much more motivated knowing that the content will not be used to be copied or translated, leaving me without that coffee :-)

Do you wish to keep reading my blog but under my terms of use ? Change please the link for this one:

http://blog.wallves.com

Thanks.
Walter