DevOps Tip - How to use terraform apply without prompt and input yes for CI/CD?

Problem

Took a memo about integration of CI/CD applied by terraform without prompt to input 'yes'
It is annoying to input yes every time if you already make sure already by `terraform plan`.
On the other hand, I need to integrate with different system for CI/CD. I need a way to approve it automatically.
By tests with commands official documents, I found the correct command and arguments.

Tested Solutions

    terraform apply -input=false -auto-approve

or as my test, you can shorten to the following command

    terraform apply -auto-approve

Test Environments

• Ubuntu 16.04.04 LTS
• OSX 10.14

Reference:

• https://learn.hashicorp.com/terraform/development/running-terraform-in-automation

Extended Reading

• DevOps Tip - How to use shared terraform plugins by -plugin-dir argument?