Hosts & Environment
Two small editors you would otherwise use a terminal for: your computer's hosts file (which names map to which addresses) and the environment variables that apps in your desktop session receive.
Hosts file#
/etc/hosts maps names to IP addresses before DNS is asked. It is how you make myapp.test open your local development server, or block a site.
Entries#
Each entry shows its IP address, its host names and an optional note. A switch turns the entry on or off without deleting it (an off entry is kept as a commented line). Buttons let you Edit or Delete it.
Add or edit an entry#
Click Add Entry and fill in:
| Field | Rules |
|---|---|
| IP address | An IPv4 or IPv6 address such as 127.0.0.1 or ::1 |
| Host names, separated by spaces | At least one name, with letters, digits, dots and dashes, such as myapp.test |
| Note (optional) | A comment saved with the entry |
Voltkit explains what is wrong if a field is not valid.
Save or discard#
Changes are collected until you click Save Changes (or Discard to drop them). Saving writes /etc/hosts as the administrator through polkit, so you see one password prompt. The new file is written beside the old one, the old one is backed up as /etc/hosts.voltkit-backup, and only then is the new one moved into place, so a failure never leaves a half-written file. The toast tells you where the previous version is.
System entries are protected#
Entries the system relies on (localhost, the IPv6 basics and this computer's own name) are shown as System entry, kept as it is and cannot be changed. If you really need to, turn on Allow editing system entries. Changing localhost or your computer's name can break networking and sudo; a backup is kept either way.
Comments, blank lines and entries you did not touch are written back exactly as they were read.
Environment variables#
Environment variables such as EDITOR or an extra folder in PATH apply to every app in your desktop session. Voltkit keeps yours in ~/.config/environment.d/90-voltkit.conf, a file systemd reads at login, so they reach every app started in the session.
Your variables#
- Add Variable creates one. Name uses letters, digits and underscores and does not start with a digit. Value must fit on one line.
- Filter variables searches the list.
- Edit or delete a variable from its row. Deleting shows an Undo toast.
- After saving, the toast reminds you: Log out and back in to apply it. Running apps keep the environment they started with.
Already in your session#
This list shows variables the session already has. You can Override one to give it a different value from now on. Variables that wire the running session together (bus addresses, display sockets, session IDs) are not offered, because overriding them breaks the session.
Examples: EDITOR=nano, or add a folder to PATH for tools you install in your home directory.
Troubleshooting#
- The password prompt does not appear. Saving the hosts file needs
pkexec(polkit). Installpolkitd/policykit-1for your distribution. - A variable has no effect. Log out and back in; apps read the environment when they start.
- I broke my hosts file. Restore the backup:
sudo cp /etc/hosts.voltkit-backup /etc/hosts.