D8 reinstallation script by patrickd http://dropbucket.org/node/657. Resets settings.php, removes config and php cache, deletes all tables of a database.

d8_uninstall.sh

#!/bin/bash

# Put this into your drupal root as uninstall.sh
# Make it executable with $ chmod +x uninstall.sh
# Add it to your .gitignore $ echo uninstall.sh >> .gitignore 

# To disable sudo to demand a password for executing this script:
# execute $ visudo
# and add the following lines with the correct paths and your own username:
#  Cmnd_Alias D8_UNINSTALL_SCRIPT = /var/www/drupal/uninstall.sh
#  patrickd ALL=(ALL) NOPASSWD: D8_UNINSTALL_SCRIPT


# MySQL username
MUSER="root"
# MySQL password
MPASS="root"
# Database to delete all tables from
MDB="drupal"


echo "Removing files..."
sudo rm -rf sites/default/files/*

echo "Resetting settings.php..."
rm sites/default/settings.php
cp sites/default/default.settings.php sites/default/settings.php
chmod 777 sites/default/settings.php

MYSQL=$(which mysql)
AWK=$(which awk)
GREP=$(which grep)

TABLES=$($MYSQL -u $MUSER -p$MPASS $MDB -e 'show tables' | $AWK '{ print $1}' | $GREP -v '^Tables' )

for t in $TABLES
do
  echo "Deleting $t table from $MDB database..."
  $MYSQL -u $MUSER -p$MPASS $MDB -e "drop table $t"
done