I figure out my error was a missing proxy settings. I needed to follow the below procedure:
-connect as ssh to my ec2 instance
-add this line to the file /opt/dremio/conf/dremio-env : DREMIO_JAVA_EXTRA_OPTS=”-Dhttp.proxyHost=[host] -Dhttp.proxyPort=[port]”
-restart the service “sudo service dremio restart” for this to take effect