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Linux Sad Servers YouTube CCESTE

Sad Servers 15 – 😵 Failed 😵 Melbourne : WSGI with Gunicorn

Type: Fix
Description: There is a Python WSGI web application file at /home/admin/wsgi.py , the purpose of which is to serve the string “Hello, world!”.
This file is served by a Gunicorn server which is fronted by an nginx server (both servers managed by systemd).
So the flow of an HTTP request is: Web Client (curl) – Nginx – Gunicorn – wsgi.py.
The objective is to be able to curl the localhost (on default port :80) and get back “Hello, world!”, using the current setup.

Efectivamente este desafío me superó y no pude en el primer intento, vamos por otra oportunidad

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Linux Sad Servers YouTube CCESTE

Sad Servers 14 : Oaxaca – Close an Open File – A investigar !

Level: Medium

Type: Fix

Access: Email

Description: The file /home/admin/somefile is open for writing by some process. Close this file without killing the process.

Personalmente me superó – pero nada que no se pueda investigar un poco – estaba casi casi en lo cierto 😀

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Linux Sad Servers YouTube CCESTE

Sad Servers 13 – Venice : Am I in a container?

Level: Medium

Description: Try and figure out if you are inside a container (like a Docker one for example) or inside a Virtual Machine (like in the other scenarios).

Explorando diferentes maneras de chequear si estamos en un contenedor, honestamente muchas no las conocía

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Linux Sad Servers YouTube CCESTE

Sad Servers 12 – Salta : Docker container won’t start

Level: Medium

Description: There’s a “dockerized” Node.js web application in the /home/admin/app directory. Create a Docker container so you get a web app on port :8888 and can curl to it. For the solution to be valid, there should be only one running Docker container.

Muy divertido en mi caso, toco Docker de oído pero nada que no se pueda solucionar con un poco de Google y sentido común

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Linux Sad Servers YouTube CCESTE

Sad Servers 10 – 😵 Failed 😵 Tokyo : can’t serve web file

Level: Medium

Type: Fix

Access: Public

Description: There’s a web server serving a file /var/www/html/index.html with content “hello sadserver” but when we try to check it locally with an HTTP client like curl 127.0.0.1:80, nothing is returned. This scenario is not about the particular web server configuration and you only need to have general knowledge about how web servers work.

No logré terminarlo en este intento pero creo que estamos cerca !!

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Linux Sad Servers YouTube CCESTE

Sad Servers 11 – Cape Town : Borked Nginx

Level: Medium

Type: Fix

Access: Public

Description: There’s an Nginx web server installed and managed by systemd. Running curl -I 127.0.0.1:80 returns curl: (7) Failed to connect to localhost port 80: Connection refused , fix it so when you curl you get the default Nginx page.

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Linux Sad Servers YouTube CCESTE

Sad Servers 10 – Tokyo : can’t serve web file – Resuelto en el 2do intento

Level: Medium

Type: Fix

Access: Public

Description: There’s a web server serving a file /var/www/html/index.html with content “hello sadserver” but when we try to check it locally with an HTTP client like curl 127.0.0.1:80, nothing is returned. This scenario is not about the particular web server configuration and you only need to have general knowledge about how web servers work.

Al fin de cuentas no estaba tan lejos de la solución!
De paso aprendemos bien la sintaxis de iptables

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Linux Sad Servers Uncategorized YouTube CCESTE

Sad Servers 09 – Manhattan : can’t write data into database.

Level: Medium

Type: Fix

Access: Public

Description: Your objective is to be able to insert a row in an existing Postgres database. The issue is not specific to Postgres and you don’t need to know details about it (although it may help).

Helpful Postgres information: it’s a service that listens to a port (:5432) and writes to disk in a data directory, the location of which is defined in the data_directory parameter of the configuration file /etc/postgresql/14/main/postgresql.conf. In our case Postgres is managed by systemd as a unit with name postgresql.

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Linux Sad Servers Uncategorized YouTube CCESTE

Sad Servers 07 – Lhasa : Easy Math

Type: Do

Access: Email

Description: There’s a file /home/admin/scores.txt with two columns (imagine the first number is a counter and the second one is a test score for example).

Find the average (more precisely; the arithmetic mean: sum of numbers divided by how many numbers are there) of the numbers in the second column (find the average score).

Use exaclty two digits to the right of the decimal point. i. e., use exaclty two “decimal digits” without any rounding. Eg: if average = 21.349 , the solution is 21.34. If average = 33.1 , the solution is 33.10.

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Linux Sad Servers Uncategorized YouTube CCESTE

Sad Servers 05 – Taipei : Come a-knocking

Level: Easy

Type: Hack

Description: There is a web server on port :80 protected with Port Knocking. Find the one “knock” needed (sending a SYN to a single port, not a sequence) so you can curl localhost.

Test: Executing curl localhost returns a message with md5sum fe474f8e1c29e9f412ed3b726369ab65. (Note: the resulting md5sum includes the new line terminator: echo $(curl localhost))

La versión del Pelado Nerd la encontrás acá https://www.youtube.com/watch?v=45E_RChOfz0

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