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Notice: Migration Of This Blog to New Site

Notice: Migration Of This Blog to New Site

First of all, I’d like to thank you for caring about what I write here. I hope the content available through this site has been useful for you in one way or the other. Because of the increasing visitors and size of the content published in this blogging site, I’ve decided to migrate it to a better hosting service. Accordingly, I’ve setup my blog on Amazon Web Services and the updated site address is https://blog.sajjan.com.np. With that said, I request you to expect…

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Docker: Running Apache Web Server In A Container

Docker: Running Apache Web Server In A Container

This is my second post for this blog series on Docker. If you haven’t already read my previous post, I highly recommend you to read that article first. Here, I’m going to dive a little deeper into container management by working on a further complicated application and advanced features of docker. Until now, I’ve already covered the introduction, basic container usage and default networking in docker. So, let’s now get into more advanced concepts in container virtualization. For this post,…

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CubLinux – Yet Another Linux Distribution

CubLinux – Yet Another Linux Distribution

Welcome to my yet another post! If you’re a fan of Linux, then this article is definitely for you. Here, I’m going to write a little review of a new Linux distro that I’ve been using lately. I don’t know about you, but I hadn’t heard about a Linux distro called CubLinux before. It seems CubLinux, as suggested by the name itself (Chrome + Ubuntu + Linux), is a combination of Chrome OS and Ubuntu. That means, it brings the…

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PHP7 – What’s New and Better in PHP?

PHP7 – What’s New and Better in PHP?

In some of my previous posts, I discussed about using PHP as part of LAMP for web application development. Well, if you haven’t noticed it already, when I said PHP, I was talking about PHP version 5 or 5.x. However, now I’m going to specifically talk about PHP7 and what new features it brings to the table. PHP History PHP5, which is the most popular and most widely used PHP version, was introduced in 2004 and immediately after its launch, development of…

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GIT – A Simple Getting Started Guide For Git

GIT – A Simple Getting Started Guide For Git

There is a term called “Git” in IT field, which may not be much familiar to most people despite being one of the most useful and handy tools in the industry. So, in this post, I’m going to cover the introduction and getting started guide for Git so that more people will be able to understand it and leverage its benefits. What is Git? Basically, Git is a distributed version control system. So, what is version control system and why should…

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LAMP-Securing Your Web Server With SSL

LAMP-Securing Your Web Server With SSL

Hello and welcome! In my previous post on LAMP web server, I discussed about its installation and configuration inside CentOS environment. Today, I’m writing on how to setup SSL certificate in our website and other security related configurations as well. Installing SSL Certificate First of all, let’s install mod_ssl package from MOD Security. It’s done in CentOS as follows: Then, let’s create a directory where we’ll keep our SSL certificates. Now, let’s generate self-signed certificate for our web server. Here, openssl is…

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Blocking Mails Based on Subject in Zimbra

Blocking Mails Based on Subject in Zimbra

Welcome back! In this post, let’s talk about tightening our Antispam or Spamassassin in Zimbra. In real-time, there may be a serious reason for filtering and blocking mails based on subject that contain certain structures or words. Here are the steps to achieve this objective in Zimbra 8.5 and later. 1) Create a policy file inside /opt/zimbra/data/spamassassin/rules/ as root user e.g. Here, SUB_ATTACHMENT is a rule that filters the mail header based on the regular expression match of Subject. The describe…

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Restricting Certain Users from Sending/Receiving External Mails in Zimbra

Restricting Certain Users from Sending/Receiving External Mails in Zimbra

Hello! In this post, I’m going to talk about how to configure a Zimbra server to restrict certain users from sending or receiving mails from external domains. In order to achieve this objective, Zimbra provides two alternatives: one using CBPolicyd (web based) and another using MTA restrictions (cli based). Here I’m covering both methods. First, let’s have a look at CBPolicyd. Note: The methods mentioned here are tested successfully in ZCS 8.5 and ZCS 8.6. I cannot confirm its validity…

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Backup/Restore Zimbra LDAP for DR

Backup/Restore Zimbra LDAP for DR

Overview In this post, I’m going to cover the topic on how to backup and restore LDAP database and config in case of disaster. If you’re a Zimbra administrator, this is a must have knowledge. This can be useful for anyone with an interest in system administration and mail servers. The reason I’m writing this blog is to help others in quickly recovering from a disaster, based on my personal experiences. I understand how it feels to have your system damaged or…

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How To Restore Zimbra When LDAP DB Is Corrupted

How To Restore Zimbra When LDAP DB Is Corrupted

A week ago, I received a call from one of our clients to whom we provide system and networking support. They had called me to inform that their Zimbra server had stopped working after an unexpected power outage. So, I asked them to provide me a remote access to their server so that I could analyze the cause of the problem. It didn’t strike me as a big deal then because there had been lots of issues with this server previously…

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