Plesk upgrade fails: Public key for <package_name> is not installed

Symptoms

• Updating Plesk fails the following error:
  

  Note: the affected package's name may vary

  CONFIG_TEXT: warning: /var/cache/yum/x86_64/7/PLESK_18_0_39-dist/packages/sw-engine-cli-3.39-3.39.1-1centos.7.210924.1832.x86_64.rpm: Header V4 DSA/SHA1 Signature, key ID 914bdf7e: NOKEY
  Fatal error during packages installation: Public key for sw-engine-cli-3.39-3.39.1-1centos.7.210924.1832.x86_64.rpm is not installed

• The "Plesk Team" gpg-pubkey-914bdf7e-55c05220 key is indeed missing:
  

  # rpm -q gpg-pubkey --qf '%{NAME}-%{VERSION}-%{RELEASE}\t%{SUMMARY}\n' | grep gpg-pubkey-914bdf7e-55c05220
  <empty output>

Cause

RPM database corruption

Resolution

Warning: the steps below are potentially dangerous and should be executed by the server administrator

1. Create a server snapshot in the hosting panel or on the hardware node.
2. Connect to the server via SSH
3. Back up the RPM database files:
   

   # cp -a /var/lib/rpm /root/rpm_backup

4. Remove corrupted RPM database files:
   

   # rm -rf /var/lib/rpm/__db.*

5. Rebuild RPM database:
   

   # rpm --rebuilddb

6. Verify the database:
   

   # rpm --verifydb

7. Check for package duplicates:
   

   # yum install yum-utils
   # package-cleanup --dupes
   # package-cleanup --cleandupes
   # rpm -e gpg-pubkey-914bdf7e-55c05220 --allmatches

8. Update the system:

   # yum clean all
   # yum makecache
   # yum update

9. Re-import the Plesk key again:
   

   # rpm --import http://autoinstall.plesk.com/plesk.gpg