MySQL 8 apt Error The following signatures were invalid

When trying to install MySQL 8 on Ubuntu 18.04, i get following error

root@ssdnodes-45790:~# apt update
Ign:1 http://download.webmin.com/download/repository sarge InRelease
Hit:2 http://download.webmin.com/download/repository sarge Release                  
Get:3 http://repo.mysql.com/apt/ubuntu bionic InRelease [16.9 kB]                                              
Hit:5 http://archive.ubuntu.com/ubuntu cosmic InRelease                                                            
Hit:6 http://archive.ubuntu.com/ubuntu cosmic-security InRelease
Err:3 http://repo.mysql.com/apt/ubuntu bionic InRelease
  The following signatures were invalid: EXPKEYSIG 8C718D3B5072E1F5 MySQL Release Engineering 
Hit:7 http://archive.ubuntu.com/ubuntu cosmic-updates InRelease
Reading package lists... Done                     
W: GPG error: http://repo.mysql.com/apt/ubuntu bionic InRelease: The following signatures were invalid: EXPKEYSIG 8C718D3B5072E1F5 MySQL Release Engineering 
E: The repository 'http://repo.mysql.com/apt/ubuntu bionic InRelease' is not 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.
root@ssdnodes-45790:~# 

To fix this error, run

apt-key adv --keyserver keys.gnupg.net --recv-keys 8C718D3B5072E1F5

Now apt update will work.

To list keys, run

root@ssdnodes-45790:~# apt-key list
/etc/apt/trusted.gpg
--------------------
pub   dsa1024 2003-02-03 [SCA] [expires: 2022-02-16]
      A4A9 4068 76FC BD3C 4567  70C8 8C71 8D3B 5072 E1F5
uid           [ unknown] MySQL Release Engineering 

pub   dsa1024 2002-02-28 [SCA]
      1719 003A CE3E 5A41 E2DE  70DF D97A 3AE9 11F6 3C51
uid           [ unknown] Jamie Cameron 
sub   elg1024 2002-02-28 [E]

/etc/apt/trusted.gpg.d/ondrej_ubuntu_php.gpg
--------------------------------------------
pub   rsa1024 2009-01-26 [SC]
      14AA 40EC 0831 7567 56D7  F66C 4F4E A0AA E526 7A6C
uid           [ unknown] Launchpad PPA for Ondřej Surý

/etc/apt/trusted.gpg.d/ubuntu-keyring-2012-archive.gpg
------------------------------------------------------
pub   rsa4096 2012-05-11 [SC]
      790B C727 7767 219C 42C8  6F93 3B4F E6AC C0B2 1F32
uid           [ unknown] Ubuntu Archive Automatic Signing Key (2012) 

/etc/apt/trusted.gpg.d/ubuntu-keyring-2012-cdimage.gpg
------------------------------------------------------
pub   rsa4096 2012-05-11 [SC]
      8439 38DF 228D 22F7 B374  2BC0 D94A A3F0 EFE2 1092
uid           [ unknown] Ubuntu CD Image Automatic Signing Key (2012) 

/etc/apt/trusted.gpg.d/ubuntu-keyring-2018-archive.gpg
------------------------------------------------------
pub   rsa4096 2018-09-17 [SC]
      F6EC B376 2474 EDA9 D21B  7022 8719 20D1 991B C93C
uid           [ unknown] Ubuntu Archive Automatic Signing Key (2018) 

root@ssdnodes-45790:~#