How can I fix these APT repository errors?

Question

How can I fix these APT repository errors? I'm using Debian GNU/Linux 9.13 (stretch). I'm looking to 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

As Docker is running on my VM is it safe to import the Docker GPG key?

Answer 1

The problem is because Debian 9/stretch moved to archive.debian.org.

See the post Debian stretch repositories 404 Not Found for solutions.

The answer by Luis Herrera recommends these commands :

replace deb.debian.org with archive.debian.org:

sudo sed -i s/deb.debian.org/archive.debian.org/g /etc/apt/sources.list

replace security.debian.org with archive.debian.org/debian-security/:

sudo sed -i 's|security.debian.org|archive.debian.org|g' /etc/apt/sources.list 

remove line that contains source stretch-updates:

sudo sed -i '/stretch-updates/d' /etc/apt/sources.list

You may also do these changes using a text editor.

Answer 2

This worked for me(as root):

echo "deb [trusted=yes] http://archive.debian.org/debian stretch main non-free contrib" > /etc/apt/sources.list
echo "deb-src [trusted=yes] http://archive.debian.org/debian stretch main non-free contrib" >> /etc/apt/sources.list
echo "deb [trusted=yes] http://archive.debian.org/debian-security stretch/updates main non-free contrib" >> /etc/apt/sources.list

You can just copy paste it. It will work even without a text editor installed. Obviously it will overwrite what is in your /etc/apt/sources.list so make sure to save what you had in case you need it.

Now you will be able to:

# apt update
# apt install vim

Answer 3

It worked this way for me.

Edit /etc/apt/sources.list to match following:

deb http://archive.debian.org/debian stretch main
deb http://archive.debian.org/debian-security  stretch/updates main