jacobat

Jacobs dual architecture setup

This document is for people using an Apple MacBook based on the Apple ARM architecture, ie. M1 or newer, who wants to run Ruby on Rails applications that does not work on the ARM architecture. The current use case is applications using Oracles instant client libraries which are not ARM compatible.

Overview

jacobat

Enum.reduce_while(list, [], fn x, acc ->
  if Enum.member?(acc, x), do: {:halt, x}, else: {:cont, [x | acc]}
end)

jacobat

$ docker build .
Sending build context to Docker daemon  95.05MB

...
Step 16/42 : WORKDIR /app
 ---> Using cache
 ---> 6169e33fecef
Step 17/42 : RUN apt-get update
 ---> Running in 4805303d6953
Get:1 http://security.debian.org/debian-security buster/updates InRelease [65.4 kB]

jacobat

I, [2020-03-07T14:40:36.587947 #90282]  INFO -- : *** Threaded ***
I, [2020-03-07T14:40:36.588335 #90282]  INFO -- : Still running
I, [2020-03-07T14:40:36.588399 #90282]  INFO -- : Start Nokogiri
I, [2020-03-07T14:40:36.588566 #90282]  INFO -- : Start Nokogiri
I, [2020-03-07T14:40:36.589041 #90282]  INFO -- : Start Nokogiri
I, [2020-03-07T14:40:36.589079 #90282]  INFO -- : Start Nokogiri
I, [2020-03-07T14:40:36.589113 #90282]  INFO -- : Start Nokogiri
I, [2020-03-07T14:40:36.589138 #90282]  INFO -- : Start Nokogiri
I, [2020-03-07T14:40:36.589157 #90282]  INFO -- : Start Nokogiri
I, [2020-03-07T14:40:36.589175 #90282]  INFO -- : Start Nokogiri

jacobat

# The prepare stage extracts the versions of some heavy gems into
# individual files enabling us to preinstall these gems in the build stage
# below. Thus we won't have to install the heavy gems everytime the
# Gemfile.lock changes, only when heavy gem versions are changed.
FROM ruby:2.6.3 AS prepare

RUN mkdir /gem_versions
COPY Gemfile.lock /gem_versions/Gemfile.lock
RUN grep "^    nokogiri " /gem_versions/Gemfile.lock | awk -F '[()]' '{print $2}' > /gem_versions/nokogiri.version
RUN grep "^    sassc " /gem_versions/Gemfile.lock | awk -F '[()]' '{print $2}' > /gem_versions/sassc.version

jacobat

### Keybase proof

I hereby claim:

  * I am jacobat on github.
  * I am jacobatz (https://keybase.io/jacobatz) on keybase.
  * I have a public key ASCXkgitadJqqAAfP8ZVs_g0deD4gxDnw03ggDjKquZclQo

To claim this, I am signing this object:

jacobat

With the new multiple database support in Rails 6 connecting to more than one database from Rails becomes easier. There is a small gotcha to be aware of though. Take the following configuration:

development:
  primary:
    adapter: postgresql
    encoding: unicode
    pool: <%= ENV.fetch("RAILS_MAX_THREADS") { 5 } %>
 host: &lt;%= ENV["PG_HOST"] || "/tmp" %&gt;

jacobat

def a(name:, email:)
  ...
end

def b(email:, phone:)
  ...
end

def f(name:, email:, phone:)
  a(...)

jacobat

def group_continuous(io)
  result = []
  range_start = nil
  offset = 0

  io.each_line do |line|
    id = line.to_i
    puts "#{id}\t#{range_start}\t#{offset}"
    if !range_start.nil? && id == range_start + offset + 1
      offset = offset + 1

jacobat

Macros and the quick list in vim

The problem

Yesterday I was looking at some Ruby code that I wanted to change. For context here is the gist of it:

module UserInstrumentation