restore.sh

#! /bin/sh

set -u # `-e` omitted intentionally, but i can't remember why exactly :'(
set -o pipefail

source ./env.sh

s3_uri_base="s3://${S3_BUCKET}/${S3_PREFIX}"

if [ -z "$PASSPHRASE" ]; then
  file_type=".dump"
else
  file_type=".dump.gpg"
fi

OIFS="$IFS"
IFS=','
for DB in $POSTGRES_DATABASE
do
  IFS="$OIFS"

  if [ $# -eq 1 ]; then
    timestamp="$1"
    key_suffix="${DB}_${timestamp}${file_type}"
  else
    echo "Finding latest backup..."
    key_suffix=$(
      aws $aws_args s3 ls "${s3_uri_base}/${DB}" \
        | sort \
        | tail -n 1 \
        | awk '{ print $4 }'
    )
  fi

  echo "Fetching backup from S3..."
  aws $aws_args s3 cp "${s3_uri_base}/${key_suffix}" "db${file_type}"

  if [ -n "$PASSPHRASE" ]; then
    echo "Decrypting backup..."
    gpg --decrypt --batch --passphrase "$PASSPHRASE" db.dump.gpg > db.dump
    rm db.dump.gpg
  fi

  conn_opts="-h $POSTGRES_HOST -p $POSTGRES_PORT -U $POSTGRES_USER -d $DB"

  echo "Restoring from backup..."
  pg_restore $conn_opts --clean --if-exists db.dump
  rm db.dump
done

echo "Restore complete."