Adding .dockerignore and making docker-entrypoint consider DATABASE_URL (#312)

.dockerignore

@@ -0,0 +1,7 @@
+CTFd/logs/*.log
+CTFd/static/uploads
+CTFd/uploads
+CTFd/*.db
+CTFd/uploads/**/*
+.ctfd_secret_key
+.data

docker-entrypoint.sh

@@ -1,6 +1,8 @@
 #!/bin/sh
 
-# http://stackoverflow.com/questions/25503412/how-do-i-know-when-my-docker-mysql-container-is-up-and-mysql-is-ready-for-taking#29793382
+if [ -n "$DATABASE_URL" ]
+    then
+    # https://stackoverflow.com/a/29793382
     echo "Waiting on MySQL"
     while ! mysqladmin ping -h db --silent; do
         # Show some progress
@@ -10,6 +12,7 @@ done
     echo "Ready"
     # Give it another second.
     sleep 1;
+fi
 
 echo "Starting CTFd"
 gunicorn --bind 0.0.0.0:8000 -w 1 'CTFd:create_app()' --access-logfile '/opt/CTFd/CTFd/logs/access.log' --error-logfile '/opt/CTFd/CTFd/logs/error.log'