FYI, the Grafana repository URL https://packages.grafana.com/oss/deb returns 404 since at least 05 March 2019 00:05:00 +0000 and up to at least 05 March 2019 03:50:00 +0000. I hope it will be fixed quickly since our environment test builds are failing for this reason. Thanks in advance.
The same here:
# apt update ... Ign:6 https://packages.grafana.com/oss/deb stretch InRelease Err:7 https://packages.grafana.com/oss/deb stretch Release 404 Not Found Lecture des listes de paquets... Fait E: The repository 'https://packages.grafana.com/oss/deb stretch Release' does not have a Release file. 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.