Certificate verification failed: The certificate is NOT trusted | Jenkins installation Error Fix | Jenkins Installation on Ubuntu 18.0.4 | Jenkins Installation on Ubuntu 20.0.4

If you try to install Jenkins on Ubuntu 18.0.4/20.0.4 instance, you may experience this problem.

Running sudo apt-get update on my AWS EC2 Ubuntu 18.04.01 LTS instance fails because Certificate verification failed: The certificate is NOT trusted.

Err:6 https://pkg.jenkins.io/debian-stable binary/ Release

Certificate verification failed: The certificate is NOT trusted. The certificate chain uses expired certificate.  Could not handshake: Error in the certificate verification. [IP: 199.232.66.133 443]

Fix for the above error

You need to install certificates to overcome this error:

sudo apt install ca-certificates

sudo apt-get update

Now try installing Jenkins

sudo apt install jenkins -y