Auto-upgrade homebrew's PostgreSQL data directory

brew-pgupgrade.sh

#!/usr/bin/env bash

old=$1
new=$2
if ! [ "$new" ]; then
  new=`psql -V | cut -d' ' -f3`
fi

if ! [ "$old" ]; then
  echo "Usage: pgupgrade.sh <old-version> [new-version]"
  echo
  echo "Please specify complete old version (i.e. 9.6.5)"
  echo "Assumption is that the new psql ($new) is already active in path, if not please indicate it in arguments"
  exit
fi

echo Upgrading PostgreSQL data directory from $old to $new

echo "=== Stopping postgresql ==============================="
brew services stop postgresql
echo "=== Making new data directory ========================="
initdb /usr/local/var/postgres$new -E utf8
echo "=== Upgrading data ===================================="
pg_upgrade -d /usr/local/var/postgres -D /usr/local/var/postgres$new -b /usr/local/Cellar/postgresql/$old/bin -B /usr/local/Cellar/postgresql/$new/bin -v
echo "=== Moving old data aside ============================="
mv /usr/local/var/postgres /usr/local/var/postgres$old
echo "=== Moving new data in place =========================="
mv /usr/local/var/postgres$new /usr/local/var/postgres
echo "=== Start postgresql =================================="
brew services start postgresql

Usage:

./pgupgrade.sh 9.6.5

Let me know if there are issues.