DB OPS (DUMP & RESTORE)

docker-entrypoint.sh

#!/bin/bash

VALID_MODES=("dump" "restore")

if [[ ! " ${VALID_MODES[*]} " =~ " ${MODE} " ]]; then
    printf "\nError: Invalid value for \`MODE\`"
    exit 1
fi

if [[ -z "$MYSQL_DUMP_FILE" ]]; then
    printf "\nError: Required environment variable not set: \`MYSQL_DUMP_FILE\`"
    exit 1
fi

if [[ "$MODE" == "dump" ]]; then
  mysqldump -u $MYSQL_USER -h $MYSQL_HOST -p $MYSQL_DATABASE --no-tablespaces > $MYSQL_DUMP_FILE
else
  mysql -u $MYSQL_USER -h $MYSQL_HOST $MYSQL_DATABASE < $MYSQL_DUMP_FILE
fi

Dockerfile

FROM mysql:8.0

# MODE can be restore or dump
ENV MODE=dump

ENV MYSQL_DATABASE=ghostdb
ENV MYSQL_PWD=password    
ENV MYSQL_USER=ghost_admin
ENV MYSQL_HOST=127.0.0.1  

COPY docker-entrypoint.sh ./docker-entrypoint.sh
RUN chmod +x ./docker-entrypoint.sh

ENTRYPOINT ["./docker-entrypoint.sh"]

The Dockerfile can be used in a containerized environment to take database backup and to do database restore. The docker-entrypoint.sh file can also be independently used to do backup and restores as well.