In my /etc/hosts/ file on Linux/OSX, how do I do a wildcard subdomain?

Install dnsmasq (I do this on all my Linux desktops as a DNS cache anyways). In dnsmasq.conf add the line:

address=/localhost.com/127.0.0.1

It is not possible to specify wildcards in the /etc/hosts file. Either specify the required hostnames explicitly or alternatively set up a local name server with the appropriate rules.

I have written a dns proxy in Python. It will read wildcard entries in /etc/hosts. See here: https://github.com/hubdotcom/marlon-tools/blob/master/tools/dnsproxy/dnsproxy.py

You need to set up a DNS server and have each client use it for resolution. The server itself can be something as "light" as dnsmasq or as heavy as BIND.

Simple Workflow (no need to install anything)

I personally like to create a PAC file for that and make my browser just use it.

Step 1: create a file e.g.: *.proxy.pac* somewhere (I use my $home folder)

Step 2: paste this code (example is with port 8000):

function FindProxyForURL(url, host) {
  if (shExpMatch(host, "*localhost")) {
    return "PROXY localhost:8000";
  }
  return "DIRECT";
}

Step 3: Make your Browser use this PAC file.

Youtube Video for PAC & Firefox

Step 4: Now you can test your app by accessing: http://mysubdomain.localhost/

Step 5: Enjoy :)

I've tidied up an old project of mine:

https://github.com/airtonix/avahi-aliases

requirements:

• linux where avahi and python-avahi are installable
• you're ok with .local domains (avahi doesn't support any other kind)

Advantages over using dnsmasq or the python dns proxy:

• other avahi/bonjour users on your local network can resolve the aliases you create and announce to the network ( providing you're allowing access to port 5353 )

You cannot use a wildcard in /etc/hosts.

Have a look here for a good walkthrough on how to accomplish on OS X using BIND, the built-in but inactive DNS server, and Apache.

This DNS based solution worked perfectly in my case, without need to install anything : https://gist.github.com/fedir/04e60d679d5657d1f9f9aa10b3168282 (Mac OSX 10.9)

If you want to use dnsmasq with NetworkManager you can (or even must?) start dnsmasq from NetworkManager by adding

dns=dnsmasq

to /etc/NetworkManager/NetworkManager.conf. Then the dnsmasq config goes to /etc/NetworkManager/dnsmasq.conf or /etc/NetworkManager/dnsmasq.d/ resp.

Copying from this blog here is how to do it on mac:

https://hedichaibi.com/how-to-setup-wildcard-dev-domains-with-dnsmasq-on-a-mac/

~ brew install dnsmasq

~ vim /usr/local/etc/dnsmasq.conf

# This file will be added to the configuration
conf-file=/Users/your_user_name/.dnsmasq/dnsmasq.conf

~ vim /Users/your_user_name/.dnsmasq/dnsmasq.conf

# example.localhost will be resolved as 127.0.0.1, including subdomains
address=/example.localhost/127.0.0.1
listen-address=127.0.0.1

~ sudo brew services stop dnsmasq

~ sudo brew services start dnsmasq

We need to tell macOS to use 127.0.0.1 as the first DNS resolver.