An own database for every branch - escape the migration hell

branch_database.sh

#!/bin/bash

# An own database for every branch
#
# 1) put this script somewhere, make it executable (chmod +x)
# 2) modify your database.yml:
#     development:
#       adapter: postgresql
#       database: "<%= `path/to/stored_script development` %>"
#   You can specify another environment as first arg.
# 3) If you want a separate db for your branch, follow the instructions on STDERR on environment startup


PREFIX=$(basename $(pwd))
echoerr() { echo "$@" 1>&2; }
BRANCH=$(git rev-parse --abbrev-ref HEAD)

ENV=${1:-development}
DATABASE="${PREFIX}~${BRANCH}~${ENV}"
DEFAULT_DATABASE="${PREFIX}_${ENV}"

if [ $(psql -l | grep "\b${DATABASE}\b" | wc -l) -eq 1 ]; then
  echoerr "using branch specific database: ${DATABASE}"
else
  echoerr "falling back to default database: ${DEFAULT_DATABASE}"
  echoerr "run \`createdb ${DATABASE}\` for profit"
  DATABASE="${DEFAULT_DATABASE}"
fi


echo -n $DATABASE