Template for contab job about dumping mysql database for django applications

midnight_db_dump.sh

#!/usr/bin/env bash
# -*- encoding: utf-8 -*-

# Script makes a backup of mysql database by retieving settings from .env file.
#
# 'stdout' stream can be logged but script itself has no logging logic.
#
# If everything goes right, exit code will be equal to zero so you can use this
# for builing wrappers around it to infrom that backup failed execution.

# Write help string if there is not enough parameters
if [[ $1 == '-h' || $1 == '--help' || $# -ne 3 ]]
then
  echo "Usage: $(basename $0) <project_dir> <project_name> <dump_dir>"
  exit 1
fi

echo "[$(date -I)] dumping db"

PROJECT_ROOT=$1
PROJECT_NAME=$2
DUMP_ROOT=$3
DOT_ENV="$PROJECT_ROOT/$PROJECT_NAME/.env"

# Create directory for dump files
if $( mkdir -p $DUMP_ROOT 2>/dev/null )
then
  echo "[+] '$DUMP_ROOT' exists"
else
  echo "[-] '$DUMP_ROOT' cannot be created"
  exit 1
fi

# Ensure in existance of file with db connection settings
if [ -f $DOT_ENV ]
then
  echo "[+] '.env' exists"
else
  echo "[-] '.env' exists"
  exit 1
fi

# Extract database connection infromation from '.env' file
DB_NAME=$(     awk -F '=' '/DB_NAME/ {print $2}'     $DOT_ENV | sed -e "s/'//g" )
DB_USER=$(     awk -F '=' '/DB_USER/ {print $2}'     $DOT_ENV | sed -e "s/'//g" )
DB_HOST=$(     awk -F '=' '/DB_HOST/ {print $2}'     $DOT_ENV | sed -e "s/'//g" )
DB_PASSWORD=$( awk -F '=' '/DB_PASSWORD/ {print $2}' $DOT_ENV | sed -e "s/'//g" )

# Make database dump
DUMP_SQL_NAME="dump-$(date -I).sql"
DUMP_SQL_PATH="$DUMP_ROOT/$DUMP_SQL_NAME"
mysqldump -u $DB_USER -p$DB_PASSWORD -h $DB_HOST $DB_NAME > $DUMP_SQL_PATH 2>/dev/null
if [[ $? -eq 0 ]]
then
  echo "[+] '$DUMP_SQL_PATH' created"
else
  echo "[-] 'mysqldump' failed"
  exit 1
fi

# Create sha1 sum for backup
DUMP_SQL_SHA_PATH="$DUMP_SQL_PATH.sha1"
sha1sum $DUMP_SQL_PATH > $DUMP_SQL_SHA_PATH 2>/dev/null
if [[ $? -eq 0 ]]
then
  echo "[+] sha1 sum created"
else
  echo "[-] sha1 sum was not created"
  exit 1
fi

# Archive backup with a sha1 sum for it
DUMP_SQL_TAR_GZ_PATH="$DUMP_SQL_PATH.tar.gz"
cd $DUMP_ROOT
tar -czvf "$DUMP_SQL_NAME.tar.gz" "$DUMP_SQL_NAME" "$DUMP_SQL_NAME.sha1" &>/dev/null
if [[ $? -eq 0 ]]
then
  echo "[+] archive created"
  # Clean up temporary and stale fils
  rm $DUMP_SQL_PATH $DUMP_SQL_SHA_PATH && find $DUMP_ROOT -mtime +6 -delete
else
  echo "[-] archiving failed"
  exit 1
fi

# Return status code of clean up step
exit $?