use gosu and usermod to ensure data permissions

docker-entrypoint.sh

@@ -0,0 +1,19 @@
+#!/bin/sh
+
+USER=metube
+
+echo "---Setup Timezone to ${TZ}---"
+echo "${TZ}" > /etc/timezone
+echo "---Checking if UID: ${UID} matches user---"
+usermod -o -u ${UID} ${USER}
+echo "---Checking if GID: ${GID} matches user---"
+groupmod -o -g ${GID} ${USER} > /dev/null 2>&1 ||:
+usermod -g ${GID} ${USER}
+echo "---Setting umask to ${UMASK}---"
+umask ${UMASK}
+
+mkdir -p ${DOWNLOAD_DIR} ${STATE_DIR}
+
+chown -R ${UID}:${GID} /app ${DOWNLOAD_DIR} ${STATE_DIR}
+
+gosu ${USER} python3 app/main.py