Ubuntu – How to fix not signed repos which worked before

16.04aptJenkinspackage-managementupdates

on an Ubuntu 16.04 server I get the following messages when running sudo apt-get update:

E: The repository 'http://dl.google.com/linux/chrome/deb stable
Release' is no longer signed. N: Updating from such a repository can't
be done securely, and is therefore disabled by default. N: See
apt-secure(8) manpage for repository creation and user configuration
details. E: The repository 'http://security.ubuntu.com/ubuntu
xenial-security Release' is no longer signed. N: Updating from such a
repository can't be done securely, and is therefore disabled by
default. N: See apt-secure(8) manpage for repository creation and user
configuration details. W: The repository
'http://pkg.jenkins.io/debian-stable binary/ Release' is not signed.
N: Data from such a repository can't be authenticated and is therefore
potentially dangerous to use. N: See apt-secure(8) manpage for
repository creation and user configuration details.

The server is behind a proxy which works, for example I ran wget -q -O - https://pkg.jenkins.io/debian/jenkins.io.key | sudo apt-key add - and it just printed OK. But when running sudo apt-get update the same errors as shown above are printed.

How do I fix this?

Best Answer

Okay, I fixed it with the help of dino99. The Google and Jenkins repositories needed https. To fix the Security repository I replaced http://security.ubuntu.com/ubuntu xenial-security Release with http://de.archive.ubuntu.com/ubuntu xenial-security main restricted universe multiverse. Not sure what the exact issue is, but it worked.