Challenge unsuccessful

[neith00]

Ths script fails every time it arrives to the http challenge.
Seems like nothing stops nginx during the challenge so it cannot bind port 80.
I'm surprised no one encountered this issue.
tried today on GRA5 with ubuntu 18.04

null_resource.provision (remote-exec): Installation succeeded.
null_resource.provision (remote-exec): Saving debug log to /var/log/letsencrypt/letsencrypt.log
null_resource.provision (remote-exec): Plugins selected: Authenticator standalone, Installer None
null_resource.provision (remote-exec): Obtaining a new certificate
null_resource.provision (remote-exec): Performing the following challenges:
null_resource.provision (remote-exec): http-01 challenge for ip232.ip-51-83-106.eu
null_resource.provision (remote-exec): Cleaning up challenges


Error: error executing "/tmp/terraform_856515459.sh": Process exited with status 1