How to fix Fix the APT repository errors I'm using Debian GNU/Linux 9.13 (stretch), how can i fix this update error ?and import the Docker GPG key?
root@test:~# apt-get update
Ign:1 http://security.debian.org stretch/updates InRelease
Err:2 http://security.debian.org stretch/updates Release
404 Not Found [IP: 111.73.1113.145 90]
Get:3 https://download.docker.com/linux/debian stretch InRelease [44.8 kB]
Ign:4 http://ftp.de.debian.org/debian stretch InRelease
Err:5 http://ftp.de.debian.org/debian stretch Release
404 Not Found
Err:3 https://download.docker.com/linux/debian stretch InRelease
The following signatures couldn't be verified because the public key is not available: NO_PUBKEY 7PB0A8C2F192FFDM
Reading package lists... Done
E: The repository 'http://security.debian.org stretch/updates Release' does no longer 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.
E: The repository 'http://ftp.de.debian.org/debian stretch Release' does no longer 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.
W: An error occurred during the signature verification. The repository is not updated and the previous index files will be used. GPG error: https://download.docker.com/linux/debian stretch InRelease: The following signatures couldn't be verified because the public key is not available: NO_PUBKEY 7PB0A8C2F192FFDM
root@test:~# apt-get install tree
Reading package lists... Done
Building dependency tree
Reading state information... Done
The following NEW packages will be installed:
tree
0 upgraded, 1 newly installed, 0 to remove and 0 not upgraded.
Need to get 46.1 kB of archives.
After this operation, 106 kB of additional disk space will be used.
Err:1 http://ftp.de.debian.org/debian stretch/main amd64 tree amd64 1.7.0-5
404 Not Found
E: Failed to fetch http://ftp.de.debian.org/debian/pool/main/t/tree/tree_1.7.0-5_amd64.deb 404 Not Found
E: Unable to fetch some archives, maybe run apt-get update or try with --fix-missing?
I have this sources.list
root@test:~# cat /etc/apt/sources.list
# deb http://ftp.de.debian.org/debian stretch main
deb http://ftp.de.debian.org/debian stretch main contrib non-free
deb-src http://ftp.de.debian.org/debian stretch main contrib non-free
deb http://security.debian.org/ stretch/updates main
deb-src http://security.debian.org/ stretch/updates main
# deb http://packages.dotdeb.org stretch all
# deb-src http://packages.dotdeb.org stretch all
Any short of help would be appreciated .