Certbot: auto-renew LetsEncrypt certificate on cron

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Certificates renewal can be difficult to automate leading to errors that will mark the website as “Insecure”.

Here’s how to automate certificate renewal on CentOS 7 with nginx as webserver:

su -
(root password)
crontab -e

And then add to the crontab these lines pressing A to edit:

37 02 * * * /usr/local/sbin/certbot-auto renew
39 02 * * * /usr/bin/systemctl reload nginx

Every day at 02.37 the certificate will be asked for renewal. Two minutes later nginx will be restarted.

After you’ve typed these lines, type:

:wq

To write and quit. You’ll get this message:

crontab: installing new crontab

Other Linux distributions

If you’re using a different Linux OS you can locate certbot-auto using the following command:

whereis certbot-auto

And then you can use it on the crontab.

You’ve also to use the alternative of systemctl for your system to refresh the certificates on the webserver.

If you’ve to do get your first certificate, here you can get more information about how to install free Let’s Encrypt certificates on nginx.

When auto-renew certificates

Since certificates lasts for about three months, you can tell crontab to run this every week instead every day.

To do so, change the lines on crontab like this:

37 02 * * 0 /usr/local/sbin/certbot-auto renew
39 02 * * 0 /usr/bin/systemctl reload nginx

Adding the 0 on the 5th position will tell crontab to run the command every Sunday at 2 AM (2nd position) and 37 minutes (1st position).

If you find this syntax difficult you can use crontab.guru to easily generate the crontab.

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A screen from JournaKit Followship .ows

A new language for Social Media managers on Twitter

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Last months I looked for a tool to shape my community on Twitter to follow interesting profiles and to increase my followers.

I had bad experiences using integration from third party (app) so I wanted this tool to be able to create my own app on Twitter without 3rd party involvment for better security and privacy.

Since I wanted real new followers and I don’t want to violate Twitter policies I looked for a tool able to select and filter users from my network, choosing only those whom are relevant to follow.

I wasn’t looking for a new, fancy SaaS website with a monthly fee to pay, and I want to handle many accounts at the same time without additional costs.

I wanted a tool able to run on my own PC and with the full access to the source code to avoid my data to be stolen and to understand its inner mechanics.

Well, that tool doesn’t exists at the time.

So I decided to write my own.

The fancy app

When I start to develop a full-featured Twitter app for desktop with a user interface running on my local machine. I started to add icons for the actions, tables to list users, buttons to do actions, a lot of checkboxes to select users and so on.

The result was a good-looking app that works. But when I tried to filter and select users using some criteria it all became clumsy.

As a programmer, I started to feel my own application as a cage.

I wasn’t allowed to search for users on my network for multiple or complex criteria. I wasn’t able to merge, diff or intersect different set of users.

Then I realized that what I was really looking for wasn’t an app but a brand new scripting language to manage social networks.

The programming language

I started to look for open source solutions able to create this new programming language for social media management using Python 3. There is a small bunch of instructions to add to this programming language but I want it to be efficient and well-designed.

Here comes in help TextX by the professor Igor Dejanović, a parser build on top of the Arpeggio PEG. Among all formal languages and parsers, Parsing Expression Language (PEG) seems to me the better for my purpose and the most modern approach to parsers.

The grammar of this new language is written on a single file and can be graphically represented using DOT language. Then TextX use the grammar to parse the language using a Meta-model where the language comes to life.

.ows language grammar

.ows language grammar

To handle the Twitter management I used the solid Tweepy by Joshua Roesslein and to query the social network SQLAlchemy and SQLite.

Scripts are launched by command line and an interactive console with history is available to manage your Twitter account using the scripting language using the Python Prompt Toolkit by Jonathan Slenders.

JournaKit Followship .ows

All these free software / open source tools among others are the construction blocks used to create this bare-bones social media managers’ tool for Twitter.

A simple scripting language to manage and expand your network of followers and friends with complex queries, running on my PC, registered with custom application on Twitter and executable on many accounts at the same time.

Its name is JournaKit Followship .ows and it’s available on Gumroad. The complete application, the source code and a comprehensive user manual are provided allowing you to master the .ows language.

This is the first application of the JournaKit suite aiming to help journalists and writers whom use the web to share their works and to discover new sources and contacts.

Comment this article or contact me privately if you want to know more about it.

Elementary OS (Loki)

10 essentials steps to use Elementary OS as media station

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I was looking for an easy and good alternative for Windows 7 on a laptop used as a media station to watch Netflix and Crunchyroll and I choose Elementary OS.

This GNU/Linux distribution is based on Ubuntu and it’s relatively easy to install. Anyway, it needs some steps to work great as media station. Here we go:

  1. Make AppCenter Work
    1. Click on Applications on the top left corner of the screen
    2. Click on Terminal
    3. On the console type these commands: 
      sudo dpkg --configure -a
sudo apt update
  2. Update your system
    1. Open the AppCenter moving the mouse at the bottom on the screen, then click on the store icon
    2. Click on Updates on the top of the window
    3. Click on Update All and wait until all packages are installed
    4. When finished, click on the Power icon in top right corner of the screen and restart
  3. Update language (if different than English)
    1. Go to the System settings on the bottom bar
    2. Choose Language & Region
    3. A yellow box should appear telling the language installation is not complete: click on Complete installation
    4. Type the user password you’ve choosen during the installation
    5. Click on Unlock
    6. Select your language, region and format
    7. Log out using the top right power button and log in again. The OS is now translated.
    8. Click on Update names to change home directories names according to the selected language (or keep it in the English version)
  4. Install VLC
    1. Go to AppCenter
    2. On the top right corner of the AppCenter search “vlc”
    3. Click Install
  5. Install your preferred browser
    1. On the top right corner of the AppCenter look for your favourite browser:
      1. If you’re looking for Firefox, type “firefox” and install it
      2. If you’re looking for Chrome, type “chromium” and install it. It’s the open source alternative of Chrome.
  6. Make your browsers ready to watch streaming shows:
    1. If you’re using Firefox, go to Menu > Preferences > Content > and flag Play DRM content checkbox. It will allow services using this meh technology.
    2. Optional: Install Flash Player for Linux if needed (automatically installed in Firefox):
      https://get.adobe.com/it/flashplayer/otherversions/
  7. Optional: Translate your browser
    1. On Firefox, type about:addons in the address bar
    2. Search for your language and install
      1. Language pack
      2. Dictionary
  8. Optional: Install Office Productivity Tools:
    1. On AppCenter, search for LibreOffice, LibreOffice Writer and LibreOffice calc and install them (one by one) to open Word and Excel files or Open Office files.
  9. Optional: get new wallpapers automatically
    1. In the AppCenter search for “Variety“
    2. Install and configure it
    3. You can add nice quotes and a clock to the desktop editing Preferences
  10. Switch the sound to the TV when the HDMI cable is plugged into the port:
    1. By default, when you plug the HDMI cable to the PC you can hear the sound coming from PC speakers
    2. To solve this issue open the Terminal and type 
      sudo bash

      And type your password.

    3. Follow this howto to automatically redirect sound to the TV when it’s plugged in. To create or edit files you can use: 
      nano /path/to/file

With these steps your brand new media station is ready for watching streaming relying on the strong security implemented in GNU/Linux systems.

10 steps to install LyX on Windows

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Here the steps to install LyX on Windows:

  1. Download MiKTeX to provide LaTeX (usually the 64bit version)
  2. Select the installation directory and remember the path
    mikitex
  3. Complete the installation procedure
  4. Download and install LyXWinInstaller
  5. Press Next until a dictionary list is presented: add dictionaries for your languages
  6. Before installing the MiKTeX will be shown:
    lyxwin
  7. Click Install and proceed.
  8. You should get an Update popup for MiKTeX, check the connection settings and then proceed and click Next to update all packages
  9. After the update close the MiKTeX popup and wait to LyX installation to finish: it should take minutes, to see progress click “See details” so you can see it’s not hanged up but it’s simply fetching different templates you can use later.
  10. Select Launch LyX and start using LyX

Now you can enjoy LyX for Windows to create PDF using LaTeX without having to deal with the usual formatting hassles of a WYSIWYG editor.

If you’re a beginner or you want to jog your memory about LyX select Help > Tutorial.

To export to PDF you can user File > Export and then select PDF LuaTeX or PDF XeTeX. In my case LuaTeX generate larger document than XeTeX but both are nicer than those generated by ps2pdf.

Note: If you get some error by MiKTeX regarding SOMETHING.sty, close LyX and in the Windows application finder search MiKTeX Package Manager and run it as Admin. Then look for SOMETHING and install it. This will fix the issue!

Spellcheck web page by address

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Looking for error in web pages can be very boring. I’ve tried some online tools but they seems too old, unsatisfying or premium only so I go to a 3 days programming marathon and I put online a brand new tool to do the job I need.

Go to Spellcheck This! and paste the URL address of the page you want to check and get the page checked for Deutsch, US English, Español, Français and Italiano.

The tool try to understand the language of the page and then return the result highlighting in different ways typing errors, names and acronyms on paragraphs, heading tags, tables and blockquotes.

spellcheck-result.jpg

It’s very far from perfect but it speeds up the spell check job. I’ve already spotted and fixed some minor errors on Wikisource and Wikipedia on very long texts.

Comment if you use and like it!

Programming note: Spellcheck This! is build with Python upon Flask and PyEnchant on the backend and Dust.js, jQuery and Foundation 6 Essential for the frontend.

Linux: MySQLdb on virtualenv with –no-site-packages

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In the past it was difficult to get MySQL working on virtualenv without using system packages. Now you can have a real separated environment with simple steps:

  1. Follow this guide to install virtualenv using this command: 
    virtualenv myproject --no-site-packages

    This command will install a new virtualenv inside a new directory myproject created by the command itself.

  2. Activate virtualenv: 
    source myproject/bin/activate
  3. Upgrade setuptools 
    pip install pip --upgrade
  4. You can now install MySQLdb, inside the package MySQL-python: 
    pip install MySQL-python
  5. Now do a simple test trying to connect to an existing database: 
    python
import MySQLdb
db = MySQLdb.connect(host="localhost",   # your host, usually localhost
                     user="chirale",         # your username
                     passwd="ITSASECRET",    # your password
                     db="chiraledb")         # name of the database
cursor = conn.cursor()
cursor.execute("SELECT VERSION()")
row = cursor.fetchone()
print "server version:", row[0]
cursor.close()
conn.close()

Tested on CentOS 7, Python 2.7

Tip: If you are starting to create a database doing all the dirty work alone you’ve to give SQLAlchemy a try. You can use like an ORM or a lower level as you wish.

See also

The Hitchhiker’s Guide to Python
Simple MySQLdb connection tutorial

About the same topic

Python: MySQLdb on Windows virtualenv (w. figures)

Python: MySQLdb on Windows virtualenv (w. figures)

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If you have a virtualenv on Windows and you want to add MySQLdb support via mysql-python, read this before spending hours of your life to figure why it doesn’t and it will never work.

1) Install MySQL for Python selecting the same Python version of the virtualenv

python-mysql-win

2) From site-packages directory above, copy the selected files:

python-mysql-mysqldb

3) (optional) On PyCharm, look for virtualenv site-packages inside the path marked with the arrow:

pycharm-virtualenv

4) Open your virtualenv console ad do:

import MySQLdb

MySQL for Python is now installed on your virtualenv.

About the same topic
How to Install MySQLdb in PyCharm, Windows
Linux: MySQLdb on virtualenv with –no-site-packages