Difference between revisions of "Server"
m (→LAMP: rm red link)
|Line 36:||Line 36:|
==== SSH ====
==== SSH ====
SSH stands for '''S'''ecure '''Sh'''ell. SSH enables you to log on to your server through an SSH client, presenting you with a recognizable terminal-like interface.Users available on the system can be given access to log on remotely though SSH, thereby
SSH stands for '''S'''ecure '''Sh'''ell. SSH enables you to log on to your server through an SSH client, presenting you with a recognizable terminal-like interface.Users available on the system can be given access to log on remotely though SSH, thereby remote administration of your server.
The [[SSH|Arch wiki SSH page]] covers Installation and Configuration nicely.
The [[SSH|Arch wiki SSH page]] covers Installation and Configuration nicely.
Revision as of 14:22, 11 June 2013
This guide will give you an overview for the most common server options in existence and will outline some administration and security guidelines.
- 1 Preface
- 2 Requirements
- 3 Basic set-up
- 4 Additional web-services
- 5 Local Network Services
- 6 Security
- 7 Administration and maintenance
- 8 Extras
- 9 More Resources
What is a server?
In essence, a server is a computer that runs services that involve clients working on remote locations. All computers run services of some kind, for example: when using Arch as a desktop you will have a network service running to connect to a network. A server will, however, run services that involve external clients, for example: a webserver will run a website to be viewed via the internet or elsewhere on a local network.
Arch Linux as a server OS
You may have seen the comments or claims: Arch Linux was never intended as a server operating system! This is correct: there is no server installation disc available, per se, such as those you may find for other distributions. This is because Archlinux comes as a minimal (but solid) base system, with very few desktop or server features pre-installed. This does not mean you should not use Archlinux as a server; quite the contrary. Arch's core installation is a secure and capable foundation. Since only a small number of features come pre-installed, this core installation can easily be used as a basis for a Linux Server. All the most popular server software (Apache, MySQL, PHP, Samba, and plenty more) is available in the official repository, and even more is available on the AUR. The wiki also contains much detailed documentation regarding how to get set up with this software.
For using Arch Linux on a server you will need to have an Arch Linux installation ready.
In most Linux server Operating Systems you have two options:
- A 'text' version of the OS (where everything is done from the command line)
- A GUI version of the OS (where you get a desktop interface such as GNOME/KDE etc).
So what is a "basic" set-up:
- Remote access to the server.
We want to be able to remotely log-on to our server to perform several administrative tasks. When your server is located elsewhere or does not have a monitor attached: removing or adding files, changing configuration options and server rebooting are all tasks which are impossible to do without a way to log on to your server remotely. SSH nicely provides this functionality.
- Your Linux server.
- A http server (Apache), required for serving webpages.
- A database server (MySql), often required for storing data of address book-, forum- or blog scripts.
- The PHP scripting language, a highly popular internet scripting language used in blogs, forums, content management systems and many other web-scripts.
As the bold letters suggest, there is a name for this combination of applications: LAMP.
The following sections will guide you through the installation and configuration of the above mentioned basic set-up features.
SSH stands for Secure Shell. SSH enables you to log on to your server through an SSH client, presenting you with a recognizable terminal-like interface.Users available on the system can be given access to log on remotely though SSH, thereby enabling remote administration of your server.
The Arch wiki SSH page covers Installation and Configuration nicely.
A LAMP server is a reasonably standard webserver.
There are often disputes as to what the 'P' stands for, some people say it is PHP some people say it is Perl while others say it's Python. For the purposes of this guide I am going to make it PHP, although there are some nice Perl and Python modules for Linux so you may wish to install Perl or Python as well.
Having said that, LAMP is a reasonably standard webserver, it is by no means simple so there may be a lot to take in here.
Please refer to the LAMP wiki page for instructions on installation and configuration.
Please refer to pages in Category:Mail Server for instructions on mail server installation and configuration.
FTP stands for File Transfer Protocol. FTP is a service that can provide access to the filesystem from a remote location through an FTP client (FileZilla, gftp etc.) or FTP-capable browser. Through FTP, you are able to add or remove files from a remote location, as well as apply some chmod commands to these files to set certain permissions.
FTP access will be related to user accounts available on the system, allowing simple rights management. FTP is a much used tool for adding files to a webserver from a remote locations.
There are several FTP daemons available, here follows a list of Arch Linux Wiki pages on a few:
- vsFTPd: Very Secure FTP Daemon (often the standard)
- glFTPd: GreyLine FTP daemon (highly configurable, no system accounts required)
- proFTPd: Article is incomplete.
There is also the option of FTP over SSH, or SFTP
Local Network Services
CUPS, or Common UNIX Printing System, can provide a central point via which a number of users can print. For instance, you have several (say 3) printers and several people on a local network that wish to print. You can either add all these printers to every user's pc, or add all printers to a server running CUPS, and then simply adding the server to all clients. This allows for a central printing system that can be online 24/7, especially nice for printers that do not have networking capabilities.
Please refer to the CUPS wiki page for instructions on installation and configuration.
Samba (windows compatible file- and printer sharing)
Samba is an open source implementation of SBM/CIFS networking protocols, effectively allowing you to share files and printers between Linux and Windows systems. Samba can provide public shares or require several forms of authentication.
Please refer to the Samba wiki page for instructions on installation and configuration.
Refer to Firewalls for details regarding available firewall software.
The Linux kernel includes iptables as a built-in firewall solution. Configuration may be managed directly through the userspace utilities or by installing one of several GUI configuration tools.
# ufw allow SSH/tcp # ufw allow WWW/tcp # ufw enable
You can also allow only specific ip addresses and ranges. Should you have a static ip address, this can be a convenient way to limit ssh access. To only allow SSH access from 188.8.131.52:
# ufw allow 184.108.40.206 to any app SSH
To view other preconfigured services and apps run
# ufw app list
A GUI frontend to UFW is available providing simple management of your iptables rules and settings. It is available in the
community repository. To install and run use the following commands:
# pacman -S gufw # gufw
Allowing remote log-on through SSH is good for administrative purposes, but can pose a threat to your server's security. Often the target of brute force attacks, SSH access needs to be limited properly to prevent third parties gaining access to your server.
- Use non-standard account names and passwords
- Only allow incoming SSH connections from trusted locations
- Use fail2ban or sshguard to monitor for brute force attacks, and ban brute forcing IPs accordingly
Protecting against brute force attacks
Brute forcing is a simple concept: One continuously tries to log in to a webpage or server log-in prompt like SSH with a high number of random username and password combinations. You can protect yourself from brute force attacks by using an automated script that blocks anybody trying to brute force their way in, for example fail2ban or sshguard.
Deny root login
It is generally considered bad practice to allow the user root to log in over SSH: The root account will exist on nearly any Linux system and grants full access to the system, once login has been achieved. Sudo provides root rights for actions requiring these and is the more secure solution, third parties would have to find a username present on the system, the matching password and the matching password for sudo to get root rights on your system. More barriers to be breached before full access to the system is reached.
Configure SSH to deny remote logins with the root user by editing (as root) /etc/ssh/sshd_config and look for this section:
# Authentication: #LoginGraceTime 2m #PermitRootLogin yes #StrictModes yes #MaxAuthTries 6 #MaxSessions 10
Now simply change #PermitRootLogin yes to no, and uncomment the line:
Next, restart the SSH daemon:
# systemctl restart sshd
You will now be unable to log in through SSH under root, but will still be able to log in with your normal user and use su - or sudo to do system administration.
Please refer to the SELinux wiki page for instructions on installation and configuration, the page is only a stub, if you use SELinux you are on your own.
Administration and maintenance
SSH is the Secure SHell, it allows you to remotely connect to your server and administer commands as if you were physically at the computer. Combined with Screen, SSH can become an invaluable tool for remote maintenance and administration while on-the-move. Please note that a standard SSH install is not very secure and some configuration is needed before the server can be considered locked-down. This configuration includes disabling root login, disabling password based login and setting up firewall rules. In addition, you may supplement the security of your SSH daemon by utilizing daemons such as sshguard or fail2ban which constantly monitor the log files for any suspicious activity and ban IP addresses with too many failed logins.
X Forwarding is forwarding your X session via SSH so you can login to the desktop GUI remotely. Use of this feature will require SSH and an X server to be installed on the server. You will also need to have a working X server installed on the client system you will be using to connect to the server with. More information can be found in the X Forwarding section of the SSH guide.
phpMyAdmin is a free software tool written in PHP intended to handle the administration of MySQL over the World Wide Web. phpMyAdmin supports a wide range of operations with MySQL. The most frequently used operations are supported by the user interface (managing databases, tables, fields, relations, indexes, users, permissions, etc), while you still have the ability to directly execute any SQL statement." http://www.phpmyadmin.net/home_page/index.php