HOWTO Ubuntu 20.04 Setup An APT Caching server

Introduction

When you are running a few Ubuntu servers you may want to think about setting up an APT caching server.  Installs and upgrades will go quicker.  You might save some bandwidth on your internet connection

Setting Up The Base Server (Optional

For a dedicated server start with the base server setup:

HOWTO Ubuntu 20.04 LTS Base Server Setup

Introduction All of our servers will start with this install. This base server is based on Ubuntu 20.04 LTS Server.  I don’t explain much in the howto so if you have a question leave a comment or use Google. Downloading … Continue reading

NOTE: You can choose an existing server to use.  I chose to have a dedicated server.

Install Software

Install apt-cacher-ng
> sudo apt install apt-cacher-ng

Configure and Test the server

Apt-cacher-ng has a web interface.  To test it visit http://<your-ip-address>:3142/acng-report.html

Create /etc/apt/apt.conf.d/00aptproxy with the following
> sudo nano -w /etc/apt/apt.conf.d/00aptproxy

Acquire::http::Proxy "http://<your-ip-address>:3142";

Do a software update to test it out.
> sudo apt update
> sudo apt dist-upgrade

Now reload the server web page.  It should now show that some items have been downloaded.

Configuring Clients

On each client create /etc/apt/apt.conf.d/00aptproxy with the following
> sudo nano -w /etc/apt/apt.conf.d/00aptproxy

Acquire::http::Proxy "http://<your-ip-address>:3142";

Do a software update to test it out.
> sudo apt update
> sudo apt dist-upgrade

Conclusion

Its a nice and easy setup.  The cache will work for several distros.

Howto Ubuntu 20.04 Setting up a DNS Server

Introduction

DNS is a big player on the internet.  It gives us a way to assign names to all those IP addresses out there.  This howto is going to cover installing DNS and 3 configuration examples.  Keep in mind that one server can encompass all three configurations at the same time.

Setup New Server (Optional)

I like to have dedicated DNS servers.  So you can start with a fresh server install.  Follow the HOWTO below to setup a new server.  Otherwise move on to install software.

HOWTO Ubuntu 20.04 LTS Base Server Setup

Introduction All of our servers will start with this install. This base server is based on Ubuntu 20.04 LTS Server.  I don’t explain much in the howto so if you have a question leave a comment or use Google. Downloading … Continue reading

Install Software

We will be using BIND for our DNS server.  Software is a quick install.  Type the following.
> sudo apt-get install bind9 bind9utils bind9-doc

Three DNS Configurations

I’m going to cover 3 common DNS configurations.  They are:

Caching DNS Server:
Usually a local server.  It helps speed up the DNS lookup process by storing a local cache of frequently looked up host names by clients.

Primary DNS Server:
This type of server provides authoritative answers for domains and sub domains.  Zone files contain information about the domain.

Secondary DNS Server:
This type of server is known as a slave server.  It provides redundancy to the primary DNS server.

Caching only DNS Server

Out of the box the Bind package for Ubuntu has been configured as a caching DNS server.  We can speed up lookups by forwarding them to your ISP’s DNS servers, Googles DNS server and / or other fast DNS server.  In this example I’m going to use Google’s DNS server.  We are also going to limit the clients that can use the server.

Make a backup of /etc/bind/named.conf.options
> sudo cp /etc/bind/named.conf.options /etc/bind/named.conf.options.save

Change /etc/bind/named.conf.options to look like the text below.
> sudo nano -w /etc/bind/named.conf.options

// caching only DNS server config
//
acl localclients {
  192.168.0.0/16;
  10.0.0.0/8;
  localhost;
  localnets;
};
options {
  directory "/var/cache/bind";
  recursion yes;
  allow-query { any; };
  allow-query-cache { any; };
  allow-recursion { localclients; };
  forwarders { 
    0.0.0.0;
    8.8.4.4;
  }; 
  dnssec-validation auto;
  auth-nxdomain no; # conform to RFC1035
  listen-on-v6 { any; };
};

Restart bind
> sudo service bind9 restart

Primary DNS Server

This configuration is for providing DNS for your domain name(s).  I’m only going to cover a basic domain setup.  There are a lot of configuration options for zone files.

Make a backup of /etc/bind/named.conf.options
> sudo cp /etc/bind/named.conf.options /etc/bind/named.conf.options.save

Change /etc/bind/named.conf.options to look like the text below.
> sudo nano -w /etc/bind/named.conf.options

// caching only DNS server config
//
acl localclients {
  192.168.0.0/16;
  10.0.0.0/8;
  localhost;
  localnets;
};
options {
  directory "/var/cache/bind";
  recursion yes;
  allow-query { any; };
  allow-query-cache { any; };
  allow-recursion { localclients; };
  forwarders { 
    0.0.0.0;
    8.8.4.4;
  }; 
  dnssec-validation auto;
  auth-nxdomain no; # conform to RFC1035
  listen-on-v6 { any; };
  allow-transfer { none; };
};

Edit /etc/bind/named.conf.local and add the text below.
> sudo nano -w /etc/bind/named.conf.local

zone "example.com" {
  type master;
  file "/etc/bind/db.example.com";
};

Now create /etc/bind/db.example.com and use the text below.
> sudo nano -w /etc/bind/db.example.com

$TTL 604800
@ IN SOA dns1.example.com. admin.example.com. (
          10   ; Serial
      604800   ; Refresh
       86400   ; Retry
     2419200   ; Expire
      604800 ) ; Negative Cache TTL
;

; Name servers
example.com.    IN   NS   dns1.example.com.

; A records for name servers
dns1            IN   A    192.168.1.1

; Other A records
@               IN   A    192.168.1.2
www             IN   A    192.168.1.2

Restart bind
> sudo service bind9 restart

Secondary DNS Server

This configuration is for providing DNS for your domain name(s).  I’m only going to cover a basic domain setup.  There are a lot of configuration options for zone files.

Make a backup of /etc/bind/named.conf.options
> sudo cp /etc/bind/named.conf.options /etc/bind/named.conf.options.save

Change /etc/bind/named.conf.options to look like the text below.
> sudo nano -w /etc/bind/named.conf.options

// caching only DNS server config
//
acl localclients {
  192.168.0.0/16;
  10.0.0.0/8;
  localhost;
  localnets;
};
options {
  directory "/var/cache/bind";
  recursion yes;
  allow-query { any; };
  allow-query-cache { any; };
  allow-recursion { localclients; };
  forwarders { 
    0.0.0.0;
    8.8.4.4;
  }; 
  dnssec-validation auto;
  auth-nxdomain no; # conform to RFC1035
  listen-on-v6 { any; };
  allow-transfer { none; };
};

Edit /etc/bind/named.conf.local and add the text below.
> sudo nano -w /etc/bind/named.conf.local

zone "example.com" {
  type slave;
  file "db.example.com";
  masters { 192.168.1.1; }
};

Restart bind
> sudo service bind9 restart

Conclusion

This howto was focused on configuring Bind on Ubuntu.  You will need to do research on all the options that Bind offers.

HOWTO Ubuntu 20.04 LTS Base Server Setup

Introduction

All of our servers will start with this install. This base server is based on Ubuntu 20.04 LTS Server.  I don’t explain much in the howto so if you have a question leave a comment or use Google.

Downloading the ISO

Visit the Ubuntu website and download the ubuntu 20.04 server ISO.

Initial Install

The install screens are straight forward.  I’m not going to cover them in much detail.  Unless you need to customize a setting, just choose the default settings.  Boot the install DVD.

Click ‘Reboot’ when it appears.

First boot

Reboot the machine when the install finishes.
The OS will boot. Log in. All the commands need to be run as root so lets start a shell with root privilleges.
> sudo bash

Get everything updated and install a couple of items.
> sudo apt update
> sudo apt dist-upgrade

Install and enable ssh.
> sudo apt install ssh
> sudo systemctl enable –now ssh

WARNING: My server isn’t directly connected to the internet. The firewall is disabled to help with installation, configuration and testing easier. Once everything is working, turn on the firewall and configure it. I wil remind you to secure your server at the end of this howto.

now reboot the server.

The Second Boot – Installing Additional Packages

We need quite a few other packages. In this howto I’m installing packages regardless if they were already installed by another dependency. This guards against package changes that could cause a package to not be installed. Once again log in to your server.

We need the webmin repo. Create webmin.repo with the text below.
> sudo nano -w /etc/apt/sources.list.d/webmin.list

deb http://download.webmin.com/download/repository sarge contrib

Install the webmin key.
> wget http://www.webmin.com/jcameron-key.asc
> sudo apt-key add jcameron-key.asc

Now bring everything up to date.
> sudo apt update

Install the following packages. Multiple lines to make cut and paste easier.
> sudo apt install make screen snmp composer libcurl3 unzip net-tools
> sudo apt install apache2 libapache2-mod-php7.4 mysql-server mysql-client
> sudo apt install libapache2-mod-fcgid php-opcache php-apcu

Install some extra PHP libraries.
> sudo apt install php7.4-gd php7.4-snmp php7.4-mbstring php7.4-mysql
> sudo apt install php7.4-odbc php7.4-imap
> sudo apt install php7.4-xmlrpc php7.4-dba
> sudo apt install php7.4-soap php7.4-zip php7.4-intl php7.4-curl

Now lets install webmin.
> sudo apt install webmin
> sudo systemctl enable webmin
> sudo service webmin start

Configure Apache and PHP

Enable the rewrite module.
> sudo a2enmod rewrite actions fcgid alias proxy_fcgi expires headers

Enable Apache.
> sudo systemctl enable apache2.service

Reload apache.
> sudo systemctl restart apache2.service

Configuring MySQL

Configure mysql.
> sudo mysql_secure_installation

Installing and Configuring phpMyAdmin

I prefer to phpMyAdmin to manage my MySQL databases.

Now install phpMyAdmin.
> sudo apt install phpmyadmin

Restart Apache.
> sudo systemctl restart apache2.service

Installing Postfix

Lets install postfix.
> sudo apt install postfix

When prompted select internet site. Next set the mail server name.

Installing cockpit

I’m trying cockpit as my server admin tool.  Do the following to set it up.
> sudo apt install cockpit
> sudo systemctl start cockpit
> sudo systemctl enable cockpit.socket

You can now login to https://yourserver.tld:9090 to administer your server.

Getting root’s and other’s mail

You need to get some local system user’s mail. We’ll use postfix’s virtual file to get the emails to the right place.

Add the following to /etc/postfix/virtual

root admin@yourdomain.tld
postmaster admin@yourdomain.tld
abuse admin@yourdomain.tld

Now add the configuration option to main.cf
> sudo postconf -e “virtual_alias_maps = hash:/etc/postfix/virtual”
Just a couple commands to wrap everything up.
> sudo postmap /etc/postfix/virtual
> sudo systemctl restart postfix
> sudo systemctl enable postfix

Remove Cloud Init

Our server won’t be using cloud-init.  To keep from causing you trouble in the future we will remove it now.

Type:
> sudo apt remove cloud-init cloud-initramfs-copymods cloud-initramfs-dyn-netconf

Final Settings

You may want to enable the linux firewall.
Set your timezone in /etc/php.ini

Conclusion

That’s it for the basic server setup. This is an example of a standard linux server setup. Be sure to use cockpit or webmin to set which services you want to start at boot time. See the other pages for info on configuring servers for virtual webhosting or virtual email hosting. Remember to configure the firewall on the server.