I have Home Assistant Supervised. In order for it to be a supported install, I am required to run Network Manager. I have it installed and set up like here: Network Manager - Home Assistant
The one difference is that I have assigned a static IP address. So my /etc/network/interfaces file look like this:
The problem is every time I reboot the network manger is clearing the /etc/resolv.conf file and leaving it empty. Then if i try to execute a sudo apt-get update, it cannot find any of the locations.
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I found it by googling NetworkManager in order to fix a problem I recently experienced.