Backup of all postgres and mariadb docker containers using native dump methods

docker_datatabase_backup.sh

#!/bin/bash

######################################################################
# Bash script for backing up varying docker database containers
#
# This will search for containers using common database image names
# Currently supports postgrest and mariadb
# This uses the common pg_dump and mysqldump methods of backup
# It will also gzip the results if the -c flag is passed
# Note: This is built with linuxserver MariaDB container but should
#       work with MariaDB official if using the MYSQL_* env variables.
#
# TODO
# - Check if volume is docker volume or bind
# - Add archiving feature to create unique backups and not clobber (personally not needed)
#
# Last update: 2022-06-19
# Author: kernelkaribou@github
######################################################################

# Leave as local to have the backups at the same directory level of the container volume. 
# otherwise change to a path where you want all db dumps to be placed 
backup_dir="LOCAL"  

Help()
{
   # Display Help
   echo
   echo "Script for backing up Postgres and MariaDB containers."
   echo
   echo "Syntax: scriptName.sh [-a|p|m|c|h]"
   echo
   echo "options:"
   echo "-a    Backup all database containers"
   echo "-p    Backup only Postgres containers"
   echo "-m    Backup only MariaDB containers"
   echo "-c    Compress the backups with gzip (Default no)"
   echo "-h    Display this help information"
   echo
}

dbDump()
{
  
  db_type=$1

  # Backup Postgres Containers
  for container in $(sudo docker ps --format '{{.Names}} {{.Image}}' | grep "$db_type" | awk '{print $1}') #search for containers using db_type image
  do
    
    echo "$(date +"%Y-%m-%d %T") - Starting database dump ($db_type) for $container"

    # Get container environment details
    container_env=$(sudo docker inspect --format='{{range .Config.Env}}{{println .}}{{end}}' $container)

    if [ "$backup_dir" = "LOCAL" ]; then
        # Get container mount volume for data, should only be one
        # TODO (if the container is using a docker volume this could be an issue and needs to be revisited)
        container_path=$(sudo docker inspect --format='{{range .Mounts}}{{println .Source}}{{end}}' $container)
        db_backup_dir="${container_path%/*}/db_backup"
    else
        db_backup_dir="$backup_dir/$container"
        
    fi
    db_backup_file="$db_backup_dir/$container.sql"

    # Create directory for the database backup 
    mkdir -p $db_backup_dir 

    # Performing database dump based upon type of db engine
    if [ "$db_type" = "postgres" ]; then
        db_name=$(echo $container_env | sed 's/.*POSTGRES_DB=//' | cut -d ' ' -f1)
        db_user=$(echo $container_env | sed 's/.*POSTGRES_USER=//' | cut -d ' ' -f1)
        $(sudo docker exec -i $container /usr/bin/pg_dump -U $db_user $db_name > $db_backup_file)
    elif [ "$db_type" = "mariadb" ]; then
        db_name=$(echo $container_env | sed 's/.*MYSQL_DATABASE=//' | cut -d ' ' -f1)
        db_pass=$(echo $container_env | sed 's/.*MYSQL_ROOT_PASSWORD=//' | cut -d ' ' -f1)
        $(sudo docker exec $container /usr/bin/mysqldump -uroot -p${db_pass} $db_name > $db_backup_file)
    fi
   
    
	# Compress the .sql file if -c flag was passed
	if [[ $compress ]]; then
	  echo "$(date +"%Y-%m-%d %T") - Compressing $container.sql"
	  gzip -f $db_backup_file
	  db_backup_file+=".gz"
    fi

    echo  "$(date +"%Y-%m-%d %T") - Database dump ($db_type) of $container completed. Backup Size: $(ls -lh $db_backup_file | awk '{print  $5}')"

  done

}

# Compress flag was set
if grep -q 'c' <<< ${@}; then compress=true; fi

# Get the options
while getopts ":hapmcv" option; do
   case $option in
      h) # display Help
         Help
         exit;;
	  a) # backup all databases
         echo "$(date +"%Y-%m-%d %T") - Backing up all database containers"
	     dbDump "postgres"
         dbDump "mariadb"
		 exit;;
	  p) # backup postgres containers
         echo "$(date +"%Y-%m-%d %T") - Backing up Postgres database containers"
	     dbDump "postgres"
		 exit;;
	  m) # backup mariadb containers
         echo "$(date +"%Y-%m-%d %T") - Backing up MariaDB database containers"
	     dbDump "mariadb"
		 exit;;
	  \?) # Invalid option
         echo "Error: Invalid option, -h for help"
         exit;;
   esac
done

echo "Missing option, -h for help"