Troubleshooting a homebrew installed postgres

fixmacpostgres.sh

# How did you discover the issue?

  # Elixir
  # 15:22:11.284 [error] GenServer #PID<0.3763.0> terminating
  #** (DBConnection.ConnectionError) tcp connect (localhost:5432): connection refused - :econnrefused

  # psql
  # psql -h 127.0.0.1 -d postgres -U postgres -d crowbar_test

# Hunches about what went wrong. Homebrew upgrade or OS upgrade corrupted the data. We did something foolish?
> brew services
# Probably indicates that postgres is working fine
# Name       Status  User  Plist
# postgresql started me /Users/me/Library/LaunchAgents/homebrew.mxcl.postgresql.plist

> postgres -D /usr/local/var/postgres
# 2020-10-20 15:56:44.132 EDT [27460] FATAL:  database files are incompatible with server
# 2020-10-20 15:56:44.132 EDT [27460] DETAIL:  The data directory was initialized by PostgreSQL version 12, which is not compatible with this version 13.0.
# That was useful!

# Solutions - rollback our version, upgrade the data? or wipe everything and start new :)
# 1. Start Fresh
> rm -rf /usr/local/var/postgres 
> initdb /usr/local/var/postgres -E utf8
> /usr/local/bin/createuser -s postgres

# 2. Upgrade the files
> brew info postgresql
> brew postgresql-upgrade-database