To successfully remove Amazon icon appearing on Ubuntu 17, open the Terminal and type the following:
sudo apt-get remove ubuntu-web-launchers
Type the root password and Amazon icon will disappear.
When you want to reduce the file size of a PDF document, this quick command using convert will shrink the original PDF file.
convert -density 150×150 -quality 60 -compress jpeg -colorspace Gray original.pdf new.pdf
This command is particularly useful against scanned documents, the jpeg quality will be 60% for 150dpi.
Converting an original 300dpi / color PDF to a 150dpi, greyscale PDF can reduce file size up to 50%. There will be some quality loss but in this way you can reduce file size enough to send scanned documents of dozens of pages via e-mail without using third-party services.
On Linux you don’t need to install OpenVPN because it’s already installed. However, configuration especially via the network manager can be tricky.
Install this additional package on your distro to display a new OpenVPN option in the network manager:
sudo apt-get install network-manager-openvpn-gnome
If you’re migrating from Windows and you’ve already a Windows installation of OpenVPN you can copy .key, .crt, .conf and .ovpn files from the OpenVPN location. Copy these files to your Linux home (e.g. ~/openvpn/) and reshape permissions to allow the access only to the owner.
After you’ve the .ovpn, .crt, .key files locally, you can test the connection using these commands:
cd ~/openvpn/; sudo openvpn my-openvpn-file.ovpn
Type the sudo password, wait and the connection should be established successfully. Press Ctrl+C to stop the VPN from command line.
Now you can configure the Network Manager to accept the .ovpn file.
Click on the network icon on the top right corner of the screen and look for VPN Settings.
Click the + icon aside the VPN title and select Import from file…
Select the my-openvpn-file.ovpn you’ve checked before. A form containing user certificate, CA, private key and the gateway will be automatically filled. It’s very important to select .ovpn and not .conf since the latter will not work.
If the private key is password protected you can also type the password and on Advanced you can do some fine tuning but it’s usually unnecessary.
On the Details tab, uncheck the automatic connection option if you don’t want to start the VPN at every login and choose if you want to allow other users to access the connection.
On IPv4 and IPv6 you can disable a specific protocol or limit the connection to “Use this connection only for resources on its network“. This last step is particularly important because using VPN can limit network connection.
Press Apply and you should be able to connect pressing the network icon on the top right corner > VPN > your VPN name.
Tested on Ubuntu 17.
Using Django, and easy_thumbnails coupled with Pillow specifically I’m stumbled upon this error in PIL.ImageFile on PIL/_binary.py:
ord() expected a character, but string of length 0 found
This python error was so frequent I’ve done some research, coming up with nothing.
I’ve checked current Pillow version with:
pip freeze | grep Pillow
Getting:
Pillow==3.0.0
Then I’ve upgraded the Pillow package with this:
pip install Pillow --upgrade
The sofware was updated to the very last version (5.0.0) without any issue on easy_thumbnails backend or frontend.
Consequently, pip freeze returned:
Pillow==5.0.0
and errors are gone.
tl;dr: Update Pillow from 3.0.0 to latest version (5.0.0 by now)
Note: this error can be accompained by others:
Upgrading Pillow also correct these.
If you get the “Failed to start Authorization manager” while booting a Linux OS (e.g. CentOS) most likely you’ve a SELinux misconfiguration.
The main issue is that if you’ve restarted the system, you cannot login since OpenSSH service is not running. If you’ve a virtual server, even the console shipped by your provider is stuck on the Authorization manager error.
The reason behind this in my case was a completely wrong value in SELINUXTYPE.
The example below is valid for a Digital Ocean’s droplet running a CentOS 7 but can be adapted to other providers and distro.
To fix it I had to:
1. Boot the OS with initramfs (also called Recovery Kernel). You can do this on the dashboard provided by your virtual server provider (e.g. on Digital Ocean)
2. Open the console from your provider’s dashboard
3. Mount the root filesystem, e.g.
mkdir /mnt mount /dev/vfsa1 /mnt
Where /dev/vfsa1 is your root partition.
4. Move broken configuration and recreate selinux config file manually with:
mv /mnt/etc/selinux/config /mnt/etc/selinux/config.BROKEN touch /mnt/etc/selinux/config cat > /mnt/etc/selinux/config
Then type these two lines:
SELINUX=disabled SELINUXTYPE=targeted
Go to a new blank line after, then type Ctrl+D to quit. Since initramfs hasn’t a text editor like vi or nano, the simple cat > filename do the trick.
5. From your dashboard, change the kernel version to what you’ve used previously and Power Cycle (reboot) the machine using the dashboard because a reboot from initramfs in this state will restart initramfs itself.
Open the provider’s console on boot to see your system working again. Wait the services to start and then connect with your SSH client to see again your files and get again the control of your server.
Be careful when configuring SELinux again and create a shapshot and/or backup after you’ve restored your server…and before changing SELinux again.
HTTPS is a great improvement to a website security. However, HTTPS comes in different flavours and among these there are very weak ones.
Among protocols, SSL have to be avoided because it is not secure. Its successor, TLS, comes in different versions and supports different ciphers. To be short, the cipher is the encryption method/algorihms the website and the client use to talk each other.
The combination of protocols and ciphers available to implement HTTPS will limits the type of clients capable to access the website.
To be sure your website will not lose traffic, you have to balance the strongest ciphers available with the most compatible but still secure, dropping all weaker ciphers.
If you’ve already implemented HTTPS on your website, first you’ve to check ist current security status of protocols and ciphers.
Check your hostname on Qualys SSL Labs pasting the HTTPS protected domain on the Test your server section. It’s a fast method with a very detailed output for public websites.
The report will give your hostname a rank, a detailed list of issues, browser support, and the complete list of supported ciphers. Among these ciphers, you can get some ciphers highlighted in yellow. You have to get the rid of these no matter what.
The list of ciphers actually differs from a typical cipher declaration on nginx because nginx can use the OpenSSL naming and Qualys uses IANA naming.
Here’s an helpful conversion table by Mozilla where you can convert IANA to OpenSSL and the other way round. Take note of the weak ciphers but wait before start to cut your cipher declaration on nginx.
You’ve to check how many visitors you’ll lose after the cut first.
Using Google Analytics or similar services and software, go to the Audience > Technology > Browser to get a list of your visitors’ browsers. Select a timespan like the last year or less.
You can add Browser version or OS version as secondary dimension to match the list of supported browsers from SSL Labs. You’ll get something similar:
Well, someone is still using Internet Explorer 9.0 in 2018.
Since Internet Explorer running on old Windows versions (like XP) is one of the most troublesome combination, check how many visitors use this legacy software.
On Google Analytics type on the search box “Internet Explorer” and you’ll get the browser usage of this legacy browser. Select OS version as secondary dimension to get a list of OSes using IE.
Compare this list with the report from SSL Labs and with the conversion table from Mozilla cited above and count the number of visitors you want to cut off from your website in the sake of security.
Trimming down the ciphers declaration on nginx conf you’ll get something like this:
ssl_ciphers ‘ECDHE-RSA-AES128-GCM-SHA256:ECDHE-ECDSA-AES128-GCM-SHA256:ECDHE-RSA-AES256-GCM-SHA384:ECDHE-ECDSA-AES256-GCM-SHA384:DHE-RSA-AES128-GCM-SHA256:DHE-DSS-AES128-GCM-SHA256:kEDH+AESGCM:ECDHE-RSA-AES128-SHA256:ECDHE-ECDSA-AES128-SHA256:ECDHE-RSA-AES128-SHA:ECDHE-ECDSA-AES128-SHA:ECDHE-RSA-AES256-SHA384:ECDHE-ECDSA-AES256-SHA384:ECDHE-RSA-AES256-SHA:ECDHE-ECDSA-AES256-SHA:DHE-RSA-AES128-SHA256:DHE-RSA-AES128-SHA:DHE-DSS-AES128-SHA256:DHE-RSA-AES256-SHA256:DHE-DSS-AES256-SHA:DHE-RSA-AES256-SHA:DES-CBC3-SHA:!aNULL:!eNULL:!EXPORT:!DES:!RC4:!MD5:!PSK:!aECDH:!EDH-DSS-DES-CBC3-SHA:!EDH-RSA-DES-CBC3-SHA:!KRB5-DES-CBC3-SHA:!3DES’;
Each cipher is separated by a ‘:’ and at the end some elements (typically using OpenSSL naming) are forbidden with a ‘!’.
Here’s the context:
server {
# the port your site will be served on
listen 443 ssl;
# the domain name it will serve for
# substitute your machine's IP address or FQDN
server_name example.com www.example.com;
ssl_certificate /path/to/fullchain.pem;
ssl_certificate_key /path/to/privkey.pem;
ssl_protocols TLSv1 TLSv1.1 TLSv1.2;
ssl_prefer_server_ciphers on;
ssl_dhparam /etc/ssl/certs/dhparam.pem;
# cfr. ........................................
ssl_ciphers ** PASTE CIPHERS HERE **;
ssl_session_timeout 1d;
ssl_session_cache shared:SSL:50m;
ssl_stapling on;
ssl_stapling_verify on;
add_header Strict-Transport-Security max-age=15768000;
charset utf-8;
# This is for Let's Encrypt
location ^~ /.well-known {
alias /path/to/.well-known;
allow all;
}
# max upload size
client_max_body_size 75M; # adjust to taste
location /webpath {
alias /path/to/web;
}
}
Change the conf file, reload nginx (on CentOS 7 systemctl reload nginx) and then re-run the SSL Labs test.
The Qualys’ tool will show you the new incompatibility with legacy browsers in the Handshake Simulation section:
Modern protocols and ciphers implemented using the above declaration on nginx cut off IE 8 on XP and IE 6, the report explain.
According to the technology used by visitors of the analyzed website, few visits are sacrificed for better security for both visitors and host.
Tune these settings according to your needs, keep monitoring the tecnology used by site visitors and dropping legacy system progressively, with Modern compatibility as a (not so) long term objective.
I’ve started using Drupal on 2007. For about 9 years I visits drupal.org almost on daily basis, I released a module, I suggested some patches, participated to local events and so on. I’ve started working on Drupal with Drupal 5 and I ended on Drupal 7 with a long time on Drupal 6.
In the meantime, Acquia was created to support Drupal development and make some money from the project and for the project in a typical open source scheme, free software accompained to paid services.
This is my report based on those years.
On my journey to Drupal and beyond, I enjoyed the community but I’ve seen many issues in those years:
The result of these issues together is that you cannot use Drupal without a dedicated Drupal team to take care of fixing components. Even two people are not enough to develop and follow couples of Drupal websites, not to mention a lone developer.
I’ve talked with other developers that used Drupal and other applications to design and publish websites and their assumption is easy: if you have a small team, you cannot use Drupal. Not anymore. Maintainance would be overwhelming.
Following this fondness for big teams, the release of Drupal 8 confirmed how low is the power of the community become compared to core contributors and Acquia (where many of them now works). They deliberately moved this open source software from a multipurpose Content Management System usable from small and big firm to a software that has the Enterprise world in his mind and forget the others.
This was a shock for many small developers and enthusiasts.
I’ve read about Drupal enthusiasts that suffers the same uneasiness of mine after long-time Drupal and PHP development.
Here’s a list of theirs experiences along with the number of years they used this software:
Some of them migrated to Django like me. During this journey I’ve discovered a wonderful language like Python and his tools and documentation. I’ve also discovered how deep you can customize the framework to do the job, concentrating on the important things.
You cannot tell the difference without using another framework like Django or WordPress, just to pick some very different beasts. You need to compare Drupal with others to try the difference.
While Drupal try to overcome PHP language, Django uses only a fraction of the power of Python and it’s not the best tool on the Earth for building website like I supposed Drupal was.
This means that I can move for example to Flask when I have to build small of focused web applications, or to Kivy when I have to make a desktop and mobile app using the same language, the same Python packages, building my own classes to share when needed.
This is actually a change of perspective, to choose a language before the framework to easily switch from one to another in case the project go wild.
Upgrading an existing application using a well designed framework is straightforward compared to the major versions migration on Drupal. During the last 7 years, Django preserved much of his structure making simple the maintainance and the upgrade of websites. Virtualenvs surely helps, but the whole design supports the developer in his duties. This is not an unique feature of Python and Django, but it’s what it lacks to PHP/Drupal.
Here’s and example of how a framework built in Python can scale and how to migrate between major versions of the language here, even a very big website can be feasible when the framework design works in your same team:
Another reason to think about leaving Drupal is his decreasing popularity. It seems naif but it’s a very important matter for open source software since a weak community leaves bugs unfixed and create less contrib modules.
Here’s the popularity in Google Trends of Drupal compared to Django between May 1st, 2007 and December 31st, 2017:
Golden age for Drupal was long time ago, at the time of Drupal 6 and early 7. Decline followed the effort to build Drupal 8 in 2012 and the outcome of this transition is better described by this graph:
Drupal was a credible WordPress competitor back on 2008 scoring a 1:3 ratio in Trends at the time of Drupal 5. On January 2018 with Drupal 8 as major version it’s passed to 1:10.
Drupal failed to become the alternative for WordPress and actually was surpassed by niche, low-level alternatives like Django. Because by now:
If it’s not enough, here’s the TIOBE index for PHP language compared to Python from 2002 to 2018:
These are simple indexes, but you can find other evidences about the usage crisis of the couple Drupal/PHP. Take another index like PyPL, read some of the experiences listed above or read this good picture of Drupal development cycle. Find as many sources as you want, the conclusion is the same: Drupal is now a declining framework written in a declining language. Who still uses PHP go for the winner WordPress.
If you read this, probably you’re asking yourself how to leave Drupal. Start to use another language and framework to suit your needs and then try the difference. If you still want to use Drupal, using another language and framework will surely help you to write better code.
