adds alternate method in comment

create.sh

     sleep 1
 done
 
-COMMAND="mysqladmin \
+PING_MYSQL="mysqladmin \
   ping \
   --host ${DOCKER_PREFIX}-db \
   --port 3306 \
   --silent"
 # weird [: mysqld: unexpected operator when using COMMAND
 #while ! docker exec ${DOCKER_PREFIX}-web /bin/sh -c "mysqladmin ping -h ${DOCKER_PREFIX}-db -P 3306 --protocol=tcp -u user -puser --silent"
-while [ ! $(docker exec ${DOCKER_PREFIX}-web /bin/sh -c "${COMMAND}") ]
+while [ ! $(docker exec ${DOCKER_PREFIX}-web /bin/sh -c "${PING_MYSQL}") ]
+#while [ ! $(${COMMAND}) ]
 do
     echo Waiting for ${DOCKER_PREFIX}-db to accept connections…
     sleep 1