debconf: unable to initialize frontend: Dialog

Question

I am building my own ubuntu VM with packer to host on Atlas and I'm using the packer build template.json to test if it will be a success if I was to use packer push template.json I am getting this error when the I run the mysql.sh script.

virtualbox-iso: debconf: unable to initialize frontend: Dialog
    virtualbox-iso: debconf: (Dialog frontend will not work on a dumb terminal, an emacs shell buffer, or without a controlling terminal.)
    virtualbox-iso: debconf: falling back to frontend: Readline
    virtualbox-iso: Configuring mysql-server-5.6
    virtualbox-iso: ----------------------------
    virtualbox-iso:
    virtualbox-iso: While not mandatory, it is highly recommended that you set a password for the
    virtualbox-iso: MySQL administrative "root" user.
    virtualbox-iso:
    virtualbox-iso: If this field is left blank, the password will not be changed.
    virtualbox-iso:

What is it that I'm missing with debconf:

Thanks.

Answer 1

can you add

export DEBIAN_FRONTEND="noninteractive"

before you run your script