Heroku to RDS migration script from single to multi-tenant

schema.sh

#/bin/sh

usage() { echo "Usage: $0 APP_NAME DESTINATION SCHEMA_NAME" 1>&2; exit 1; }

if [ "$#" -ne 3 ]; then
	usage
fi

function pathParts() {
	url=$1
	proto="`echo $url | grep '://' | sed -e's,^\(.*://\).*,\1,g'`"
	# remove the protocol
	url=`echo $url | sed -e s,$proto,,g`

	# extract the user and password (if any)
	userpass="`echo $url | grep @ | cut -d@ -f1`"
	pass=`echo $userpass | grep : | cut -d: -f2`
	if [ -n "$pass" ]; then
	    user=`echo $userpass | grep : | cut -d: -f1`
	else
	    user=$userpass
	fi

	# extract the host -- updated
	hostport=`echo $url | sed -e s,$userpass@,,g | cut -d/ -f1`
	port=`echo $hostport | grep : | cut -d: -f2`
	if [ -n "$port" ]; then
	    host=`echo $hostport | grep : | cut -d: -f1`
	else
	    host=$hostport
	fi

	# extract the path (if any)1
	path="`echo $url | grep / | cut -d/ -f2-`"
}


APP_NAME=$1
DEST=$2
SCHEMA_NAME=$3

pathParts $DEST
DESTINATION_DB_NAME="$path"
DATE=$(date +"%Y-%m-%d-%H%M")

echo "Backing up $APP_NAME"
backup_filename="$APP_NAME-$DATE.backup.dump"
heroku run 'pg_dump $DATABASE_URL --format custom --no-owner' -a $APP_NAME > "$backup_filename"

echo "ALTER SCHEMA public RENAME TO $SCHEMA_NAME in source"
schema_dump_filename="$SCHEMA_NAME-$APP_NAME-$DATE.schema.dump"

heroku pg:psql -c "ALTER SCHEMA public RENAME TO $SCHEMA_NAME" -a $APP_NAME

echo "CREATE SCHEMA IF NOT EXISTS $SCHEMA_NAME in destination"
psql -d $DEST -c "CREATE SCHEMA IF NOT EXISTS $SCHEMA_NAME"

echo "Backup source to $schema_dump_filename"
heroku run "pg_dump \$DATABASE_URL --format custom --schema $SCHEMA_NAME --no-owner" -a $APP_NAME > "$schema_dump_filename"

echo "put source schema back to public"
heroku pg:psql -c "ALTER SCHEMA $SCHEMA_NAME RENAME TO public" -a $APP_NAME

echo "Restore $SCHEMA_NAME to $DEST"
/usr/lib/postgresql/10/bin/pg_restore --format custom --schema $SCHEMA_NAME -d $DEST "$schema_dump_filename"

echo "Creating Tenant row"
psql -d $DEST -c "INSERT INTO public.tenants (name, created_at, updated_at) VALUES ('$SCHEMA_NAME', now(), now())"