Virtualenv

Virtualenv adalah aplikasi untuk membuat membuat environment virtual Python terisolasi. Aplikasi ini membuat sebuah environment virtual yang mempunyai direktori instalasi sendiri, yang tidak berbagi library dengan environment Virtualenv lainnya dan dapat dikonfigurasi untuk tidak mengakses library yang diinstal secara global.

Instal pip di sistem operasi masing-masing, contohnya CentOS

sudo yum update -y
sudo yum install -y python-pip

Instal virtualenv menggunakan pip

sudo pip install virtualenv

Buat environment virtual Python menggunakan virtualenv

Let’s Encrypt adalah Certificate Authority (CA) yang gratis dan terotomatisasi yang berjalan untuk kepentingan umum. Let’s Encrypt adalah sebuah layanan yang disediakan oleh Internet Security Research Group (ISRG). Prinsip-prinsip dasar dari Let’s Encrypt adalah gratis, otomatis, aman, transparan, terbuka, dan koperatif.

Instalasi Let’s Encrypt

Instalasi Let’s Encrypt

sudo yum -y install git bc
sudo git clone https://github.com/letsencrypt/letsencrypt /opt/letsencrypt

Buat sertifikat baru untuk domain example.com, sebelumnya hentikan dulu aplikasi Nginx

Setelah kita melakukan instalasi email server, cek skor email server di website Mail Tester. Salah satu contoh hasil pengecekan website tersebut sebagai berikut.

Content:
[Text]
[HTML]
[Source]

SpamAssassin:
[Score]
 The famous spam filter SpamAssassin. A score below -5 is considered spam.

Authentication:
 We check if the server you are sending from is authenticated
[SPF]
 Sender Policy Framework (SPF) is an email validation system designed to prevent email spam by detecting email spoofing, a common vulnerability, by verifying sender IP addresses.
[Sender ID]
 Sender ID is like SPF, but it checks the FROM address, not the bounce address.
[DKIM]
 DomainKeys Identified Mail (DKIM) is a method for associating a domain name to an email message, thereby allowing a person, role, or organization to claim some responsibility for the message.
[DMARC record]
 A DMARC policy allows a sender to indicate that their emails are protected by SPF and/or DKIM, and give instruction if neither of those authentication methods passes. Please be sure you have a DKIM and SPF set before using DMARC.
[PTR record]
 Reverse DNS lookup or reverse DNS resolution (rDNS) is the determination of a domain name that is associated with a given IP address. Some companies such as AOL will reject any message sent from a server without rDNS, so you must ensure that you have one. You cannot associate more than one domain name with a single IP address.
[A record]
 We check if there is a mail server (A Record) behind your hostname.

Errors:
 Checks whether your message is well formatted or not.
[Image alternate tag]
 alt attributes provide a textual alternative to your images. It is a useful fallback for people suffering from sight problems and for cases where your images cannot be displayed.
[HTML elements]
 Checks whether your message contains dangerous html elements such as javascript, iframes, embed content or applet.
[URL shortener]
 Checks whether your message uses URL shortener systems.
[List-Unsubscribe header]
 The List-Unsubscribe header is required if you send mass emails, it enables the user to easily unsubscribe from your mailing list.
[Blacklist]
 Matches your server IP address against 22 of the most common ipv4 blacklists.

Untuk meningkatkan skor, kita bisa memperbaiki konfigurasi email server dengan SPF dan DKIM

Sejak FreeBSD 10.0-RELEASE, hypervisor bhyve (lisensi BSD) sudah menjadi bagian dari base system. Hypervisor adalah aplikasi yang bisa membuat dan menjalankan virtual machine atau yang biasa disebut guest di dalam sebuah sistem operasi. Guest yang didukung oleh bhyve cukup banyak, termasuk FreeBSD, OpenBSD, dan banyak distribusi Linux. Saat ini bhyve hanya mendukung konsol serial dan tidak bisa menampilkan konsol grafik. Bhyve membutuhkan prosesor baru yang mendukung Intel Extended Page Tables (EPT) atau AMD Rapid Virtualization Indexing (RVI), yang dikenal juga sebagai Nested Page Tables (NPT). Untuk Linux atau FreeBSD guest dengan vCPU (virtualCPU) membutuhkan dukungan VMX unrestricted mode (UG). Cara termudah untuk mengecek dukungan prosesor untuk bhyve adalah dengan menjalankan #dmesg# atau melihat isi /var/run/dmesg.boot untuk fitur POPCNT di baris Features dan EPT dan UG di baris VT-x. Panduan yang cukup lengkap untuk menggunakan bhyve dapat diakses di halaman ini

You’ll find this post in your _posts directory. Go ahead and edit it and re-build the site to see your changes. You can rebuild the site in many different ways, but the most common way is to run jekyll serve, which launches a web server and auto-regenerates your site when a file is updated.

To add new posts, simply add a file in the _posts directory that follows the convention YYYY-MM-DD-name-of-post.ext and includes the necessary front matter. Take a look at the source for this post to get an idea about how it works.

Python is one of the programming languages which can claim to be both simple and powerful.

Python is an easy to learn, powerful programming language with efficient high-level data structures and a simple but effective approach to object oriented programming. Python’s elegant syntax and dynamic typing, together with its interpreted nature, make it an ideal language for scripting and rapid application development in many areas in many platforms.

Guido van Rossum, the creator of the Python language, named the language after the BBC show “Monty Python’s Flying Circus”.