jaeyson

#!/bin/bash
# Script to update a firewall rule in a Hetzner Firewall with your current IP address.
# Good if you would like to restrict SSH access only for your current IP address (secure).

#################
# WARNING: This script will overwrite all rules in the firewall rules, so make sure you 
# added all the required rules.
# I use a separate firewall rule just for SSH access.
#################

jaeyson

Using OTP's observer (appmon replacement) remotely

$ ssh remote-host "epmd -names"
epmd: up and running on port 4369 with data:
name some_node at port 58769

Note the running on port for epmd itself and the port of the node you're interested in debugging. Reconnect to the remote host with these ports forwarded:

$ ssh -L 4369:localhost:4369 -L 58769:localhost:58769 remote-host

jaeyson

PostgreSQL is Enough

• Simplify: move code into database functions
• Just Use Postgres for Everything
• PostgreSQL is the worlds’ best database
• Postgres is eating the database world
• Hacker News discussion

Background and Cron Jobs

jaeyson

defmodule SchemaChecker do
  def find_field_discrepancies do
    schema_modules()
    |> Enum.map(fn mod -> 
      {mod.__schema__(:source), check_module(mod)}
    end)
  end

  defp schema_modules do
    {:ok, modules} = :application.get_key(:core, :modules)