Add custom DNS server on Linux

TODO: the whole document is copied!!!!!!!!!!!!!!!!!!!!

On MacOS, custom DNS entries can be added to the /etc/hosts and will take precedence over the same entries provided by any DNS server.

Table of Contents

local

Assumption

In order to better illustrate the process, we are going to use two projects as an example. See the following table for project directories and env_tld_suffix.

Project directory	TLD_SUFFIX	Project URL	Required DNS name
project-1	`loc`	http://project-1.loc	`project-1.loc`
www.project-1	`loc`	http://www.project-1.loc	`www.project-1.loc`

Docker for Mac

When using Docker for Mac you can use 127.0.0.1 for the IP address.

Open /etc/hosts with admistrative privileges or via sudo with your favorite editor
```
host> sudo vi /etc/hosts
```

Add DNS records for the above listed examples:

127.0.0.1  project-1.loc
127.0.0.1  www.project-1.loc

Safe the file and verify the DNS entries with the ping command

host> ping -c1 project-1.loc

PING project-1.loc (127.0.0.1) 56(84) bytes of data.
64 bytes from localhost (127.0.0.1): icmp_seq=1 ttl=64 time=0.066 ms

host> ping -c1 www.project-1.loc

PING www.project-1.loc (127.0.0.1) 56(84) bytes of data.
64 bytes from localhost (127.0.0.1): icmp_seq=1 ttl=64 time=0.066 ms

Docker Toolbox

When using the Docker Toolbox, you cannot use 127.0.0.1 for DNS entries, but rather need to use the IP address of the Docker Toolbox machine instead.

howto_find_docker_toolbox_ip_address

For this example we will assume the Docker Toolbox IP address is 192.168.99.100.

Open /etc/hosts with admistrative privileges or via sudo with your favorite editor
```
host> sudo vi /etc/hosts
```