postgres-log

#!/bin/sh

# postgres: tail postgresql logs, ensuring logging is enabled (with optional
# restart and restore).

conf=/var/lib/postgres/data/postgresql.conf

log_statement="log_statement = 'all'"
if ! sudo grep -Eq "^(# )?$log_statement" "$conf"; then
  echo "Expected log_statement line in $conf not found."
  exit 1
fi

_on() {
  if sudo grep -q "^# $log_statement" "$conf"; then
    echo "Enabling log_statement."
    sudo sed -i "s/# $log_statement/$log_statement/" "$conf"
    sudo systemctl restart postgresql.service
    return 1
  fi
  return 0
}
_off() {
  if sudo grep -q "^$log_statement" "$conf"; then
    echo "Disabling log_statement."
    sudo sed -i "s/$log_statement/# $log_statement/" "$conf"
    sudo systemctl restart postgresql.service
    return 1
  fi
  return 0
}

if [ -n "$1" ]; then
  if [ "$1" = 0 ] || [ "$1" = off ]; then
    _off
  else
    _on
  fi
  exit 0
fi

restore=0
_restore() {
  [ "$restore" = 1 ] && _off
}
trap '_restore && exit $?' INT

_on
restore=$?

sudo journalctl -t postgres -f