hostsd - A simple hosts file manager

hostsd is a simple hosts file manager that allows you to separate your hosts file into multiple files and easily enable or disable them. It's useful for development environments where you need to manage lots of hosts entries, or for managing ad-blocking hosts files.

Dependencies

• Python 3.8 or later (earlier versions may work but are untested)
• Linux or macOS (should work on Windows too but is untested)

Installation

pip install hostsd

Now, to ensure that your existing /etc/hosts contents are retained, you can copy the file to /etc/hosts.d/00-original:

sudo mkdir /etc/hosts.d
sudo cp /etc/hosts /etc/hosts.d/00-original

Usage

To write the contents of /etc/hosts.d/* to /etc/hosts:

sudo hostsd

You can also specify the input and output paths:

hostsd -i /etc/hosts.d -o /etc/hosts

Excluding files

There are several ways to exclude files and directories from being included in the output:

1. You can disable a file or directory by adding a .disabled extension:

mv /etc/hosts.d/10-my-file /etc/hosts.d/10-my-file.disabled

2. Hidden files and directories are ignored as well:

mv /etc/hosts.d/regular-file /etc/hosts.d/.hidden-file

3. You can include the magic string HOSTSD_IGNORE within a file to exclude it from the output, for example as a comment:

echo "# HOSTSD_IGNORE" >> /etc/hosts.d/10-my-file

4. Any binary files are automatically ignored.

Note that files are not currently checked for validity, so your hosts.d directory should only contain valid hosts file entries or files that are excluded using one of the methods above.

Running hostsd automatically

You can run hostsd automatically using a cron job or a systemd timer. Here's an example of a systemd timer (assuming you have installed hostsd globally, for simplicity):

# /etc/systemd/system/hostsd.timer
[Unit]
Description=Update hosts file every minute

[Timer]
OnBootSec=1min
OnUnitActiveSec=1min

[Install]
WantedBy=timers.target

# /etc/systemd/system/hostsd.service
[Unit]
Description=Update hosts file

[Service]
Type=oneshot
ExecStart=/usr/bin/hostsd

sudo systemctl enable hostsd.timer
sudo systemctl start hostsd.timer

This will run hostsd every minute. So you can just drop a new file in /etc/hosts.d and it will be picked up automatically.

You could even combine this with a git repository and you have a simple way to manage your hosts files across multiple machines or share them with others, without needing to set up and manage a full DNS server.

License

hostsd is licensed under the MIT license. See LICENSE for the full license text.