We are sitting on our computer somewhere and are in the need of an ISO.
Maybe we want to create a virtual machine or have some other need like flashing said ISO to a usb stick.
Sometimes it is too much hassle to mount our NAS share or we are on a totally different device which is not ours.
I’ve had quite some situations in which I was working on a PC/Laptop that a friend gave me on which I did not want to mount my network share.

So, what can we do?

The answer is simple. We serve our ISO’s via HTTP!

Webserver

Which one do we chose?
This is personal preference. But for a simple task like this I personally like Lighttpd which is easy to set up and works well.

First, we need to install lighttpd.

$ sudo pkg install -y lighttpd

After the installation is finished we enable the service.

$ sudo sysrc lighttpd_enable="YES"

Before we start Lighttpd we should first configure it.

Configuration fun

First things first. We want to access our ISO’s over a custom DNS name - A so called A Record in DNS parlence.
To do that we will first create a directory that holds our configuration file.

$ $ sudo mkdir /usr/local/etc/lighttpd/vhost

After that is done we need to edit the Lighttpd configuration file.

$ sudo vim /usr/local/etc/lighttpd/lighttpd.annotated.conf

Add the following lines at the end of the file.

...
# Include custom vhost config directory
include conf_dir + "/vhost/*.conf"

This will make it possible to add config snippets to Lighttpd without editing the main configuration file. Technically, the line we’ve added specifies that Lighttpd should read in configuration files from the vhost directory (The files need to end in *.conf - Keep that in mind!)

Let’s move on to the actual config of our site. Create a new file under the vhost directory and paste in the following contents.

$ sudo vim /usr/local/etc/lighttpd/vhost/iso.conf

$HTTP["host"] =~ "iso\.void\.lan" {
        server.document-root = "/data/iso"
        dir-listing.activate = "enable"
}

Let me explain a little.
This snippet specifies that when a request enters our webserver with the hostname iso.void.lan it should set the Document Root to /data/iso and it should enable Directory Listings.
Note: /data/iso is my local ISO directory where all my files are stored. You need to change this to the location where your ISO’s are saved!

To check if our configuration was successful we can run Lighttpd with certain flags - this will dump all configuration parameters to stdout for us to inspect.

$ sudo lighttpd -p -f lighttpd.annotated.conf | less

You should see the above config snippet at the end of the output.

Note on DNS: You can select whatever hostname fits your bill - there are no limits. However, you need to make sure that the given A Record or CNAME entry is resolveable! Configruing a DNS server is out of the scope of this text - Bind is a popular DNS server for example.

Quick and dirty: If you just want to test out that it works you can of course make a simple entry in your /etc/hosts file. Simple and quick!

Give me permission

The final step before starting Lighttpd is to check the permissions of the files we want to serve - and the directories for that matter!

In my case I need to chown the directories in question to make it able for the user www (Which Lighttpd runs as) to read files inside these directories.

$ sudo chown :www /data
$ sudo chown :www /data/iso

Note: Make sure your permissions are correctly set! To read a file you will need r and x for traversing directories!

Let the show begin!

It is now time to start Lighttpd.

$ sudo service lighttpd start

The moment of truth is here, finally. Let’s fire up or browser of choice.

$ firefox http://iso.void.lan

Et voila, the site works and we can now access our ISO’s over HTTP in case we need something quickly!

Last words

Sure, Lighttpd can do much more - that is a fact. We’ve barely scratched the surface here.
But: We don’t need more than that. In the end, the task at hand is simple. Simple tasks need simple solutions after all!

Have a look at the documentation and MAN pages for further configuration.

Enjoy!

…and as always:

Stay Open!