How to Update dnscrypt proxy in Debian with Minimal Downtime

Scripted Method

1. Save this script to /opt/dnscrypt-proxy/dnscrypt-proxy-update.sh
2. Make the script executable by running chmod +x /opt/dnscrypt-proxy/dnscrypt-proxy-update.sh
3. Execute the script by running sudo ./dnscrypt-proxy-update.sh in /opt/dnscrypt-proxy/

Automatic Method

1. Complete Scripted Method steps above to set up the script and ensure it works on your system
2. Open the crontab editor with sudo crontab -e
3. In the crontab editor that pops up, append a descriptive comment describing the entry, e.g. # Daily dnscrypt-proxy update
4. Add a crontab entry that performs the update on the desired schedule, e.g. @daily /opt/dnscrypt-proxy/dnscrypt-proxy-update.sh. See crontab syntax for more scheduling options
5. Hit Ctrl O to save your changes
6. Hit Enter
7. Hit Ctrl X to exit the crontab editor

Manual Method

1. Start your preferred GUI file manager with sudo, e.g. sudo krusader on Debian or sudo pcmanfm on Raspbian.
2. Download the new version's linux_Platform-VersionNumber.tar.gz archive
3. Extract the archive
4. Use the GUI file manager to transfer the extracted files to /opt
5. Copy the current dnscrypt-proxy folder into an *-old folder
6. Navigate to /opt in the terminal using cd /opt/dnscrypt-proxy
7. Stop the dnscrypt-proxy service in the terminal using sudo ./dnscrypt-proxy -service stop
8. Use the GUI file manager to transfer the new files to to the dnscrypt-proxy folder
9. Start the dnscrypt-proxy service in the terminal using sudo ./dnscrypt-proxy -service start
10. If everything is working, delete the *-old and extracted tar.gz folders

Source: https://www.reddit.com/r/dnscrypt/comments/9ypenw/how_does_one_update_dnscryptproxy_to_a_new/ea48wkh/