An interesting incident happened on the server after a global update CentOS 7.1.1503 to version 7.2.1511. Usually when you upgrade CentOS anything happened with SELinux. Somewhere something changed contexts somewhere else something. But in this case, after you upgrade CentOS, daemon logging syslog-ng stopped writing logs. Not all logs, and most of that was getting through syslog.
As it turned out, the system logging ceased publishing send copies of logs to syslog. But the fix is quite easy, to do this, run the following commands:
$ nano -w /etc/systemd/journald.conf
$ systemctl restart systemd-journald.service
$ systemctl restart syslog-ng.service
Installing RoundCube webmail
First of all install the RoundCube and driver for MySQL:
$ yum -y install php-pear-MDB2-Driver-mysqli roundcubemail
Now SELinux allow network connections to the Web server:
$ setsebool -P httpd_can_network_connect=on
First install the required packages:
$ yum -y install dspam dspam-mysql dspam-web
It is assumed that you have already installed and configured Apache, PHP/MySQL and MariaDB. Instructions for setting up can be read at this link.
LAMP is an acronym denoting the set of (complex) server software, widely used in the World Wide Web. LAMP is named after the first letters of its constituent components:
- Linux is the Linux operating system;
- Apache is a Web server;
- Mariadb/MySQL is a database management system;
- PHP is a programming language used to create Web applications (other than PHP can mean other languages such as Perl and Python).
OpenVPN is a free implementation of the technology of virtual private network (VPN) with open source software to create encrypted channels, point-to-point or server-to-client between computers. It allows you to establish connections between computers behind a NAT firewall, without having to change their settings.
In a nutshell, the SSL/TLS certificate (SSL: Secure Sockets Layer, TLS: Transport Layer Security) is a unique digital signature for the secure connection between the client and the server.
Creating SSL certificate can be divided into the following steps:
- create a personal key (Private Key);
- create a query to retrieve the certificate (Certificate Signing Request);
- creating a self-signed (Self-Signed Certificate).
Bind (Berkeley Internet Name Daemon) is also known as the default – this is the best known and most used DNS server on the Internet. I will try to describe how to install and configure the service in the chrooted environment (chroot operation changes the root directory in Unix-like operating systems. program started with altered root directory will only have access to the files contained in this directory, so if you want to allow the program to access other directories or file systems (for example,
/proc), it is necessary to mount the necessary directories in the target directory or device.).
For a number of reasons, rsyslog is installed in the default CentOS, I do not like. I love when the logs are sorted by year, month, facility, priorities. So the first thing I change rsyslog in syslog-ng. To do this, do the following:
A couple of words, why still CentOS, and not something else. General familiarity with Linux started in the year 2000 with some version of RedHat. Then there was the BlackCat Linux (because of its better support of the Russian language). Then came the Gentoo and I found it ideal for that due to the USE flags you only what you need. Oh and for the optimization of the more or less normal to watch movies on a computer with an AMD K6-2-300 can be only under Gentoo. After the Gentoo at work was Ubuntu, but it just didn’t go. Even after moving to any other Gentoo Linux is difficult. It’s like after OS X Windows back on land. In Gentoo and the boot process, and many other things are beautiful from the aesthetic point of view, in Ubuntu by default in a console only white on a black background.
Then there were courses on RHEL and certificate RHCSA. I find that stupid not to use knowledge – therefore decided to install CentOS onto a couple of servers to work under different services. In the process of so doing that even your own personal server is changed from Gentoo to CentOS. First there was the CentOS 5, then CentOS 6, and CentOS 7 is now.
Upgrade to CentOS has become much less time to leave on server maintenance time, as running the command:
$ yum -y update
runs faster than executing a command
$ emerge sync && emerge -upvND world
Yes, and many surprises during the update, the system has become less. Although Gentoo, I am grateful for this experience.