The following signatures couldn't be verified because the public key is not available: NO_PUBKEY

Question

I am trying to install previous version of ubuntu, i.e. 3.0. I am giving below command

$echo "deb http://repo.mongodb.org/apt/ubuntu trusty/mongodb-org/3.0 multiverse" | sudo tee /etc/apt/sources.list.d/mongodb-org-3.0.list

After that I am giving command

$sudo apt-get update

It throws below error.

The following signatures couldn't be verified because the public key is not available: NO_PUBKEY

Kindly help.

Answer 1

Solution given below helped me.

Execute the following commands in terminal

sudo apt-key adv --keyserver keyserver.ubuntu.com --recv-keys <PUBKEY>

where <PUBKEY> is your missing public key for repository, e.g. 8BAF9A6F.

Then update

sudo apt-get update