em um servidor Ubuntu 16.04 recebo as seguintes mensagens ao executar 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.
O servidor está por trás de um proxy que funciona, por exemplo eu executei wget -q -O - https://pkg.jenkins.io/debian/jenkins.io.key | sudo apt-key add - e ele apenas imprimiu OK . Mas ao executar sudo apt-get update , os mesmos erros mostrados acima são impressos.
Como corrijo isso?
Ok, corrigi-lo com a ajuda de dino99 . Os repositórios do Google e Jenkins precisavam de https. Para corrigir o repositório de Segurança, substituí http://security.ubuntu.com/ubuntu xenial-security Release por http://de.archive.ubuntu.com/ubuntu xenial-security main restricted universe multiverse .
Não sei qual é o problema exato, mas funcionou.