Tutorials Index Page 8


Backup mongodb with crontab

In this tutorial we are going to explain how to do daily backups of mongodb using cron.


Install go in raspberrypi steps

Follow this steps to install go on the raspberry pi. We don't use apt to install go and instead we download the latest version from https://golang.org.


Mongoengine: How to use filefield for storing images and files

Check here an example on how to use mongoengine filefield. Mongoengine FieldField uses GridFS to store the files, check here how to use it in your project.


Javascript http request: No 'Access-Control-Allow-Origin' header is present on the requested resource error

When you try to fetch data from a different domain using javascript you will get the error: No 'Access-Control-Allow-Origin' header is present on the requested resource. This is a security feature of web browsers. The proper solution is to use CORS, check here for full solution. Alterntive you can code a custom proxy or use JSONP.


How to check internet speed on a Linux server from the terminal using cli?

We explain how to use speedtest python project to check internet speed via the terminal. We will also explain how to save historical network speed on your linux server with a very cron line. Finally we explain how to plot the generated csv data.


Steps to disable root login in phpMyAdmin

To disable root login in phpMyAdmin set AllowRoot to false like this example: $cfg['Servers'][$i]['AllowRoot'] = FALSE;. If you want more details check our tutorial.

How to Generate md5 checksum for all Files in a Directory

In this small tutorial we are going to explain how to calculate the md5 sum of all the files in a directory. Example find . -exec md5sum "{}" ; > md5sum_current_directory will save the md5 sums in the file called md5sum_current_directory. Check this article for more details


Introduction to MapReduce with MongoDB

MapReduce is a programming model and an associated implementation for processing and generating large data sets. In this tutorial we are going to explain how to use MapReduce with MongoDB and python. We explain how to use the MapReduce query and then with an example we show examples using pymongo en mongoengine.


Linux Coding style for coding in C

In this tutorial we are going to explain some C code style and why developers have to follow good practices. This is a very good beginner article.


Bash: How to Check if a directory exists?

If you need to check if directory exists use: if [ -d "$DIR" ];. Check here for details when you have symbolic links.