Errata for Articles on www.rubyplus.com

DK Smith has offered me his time to point out some errors, spelling mistakes etc. This page will document his findings.

Linode Box Images

git prompts for passphrase after mac os upgrade

Solution

1. Create (or edit if it exists) the following ~/.ssh/config file:
   

   Host *
     UseKeychain yes
     AddKeysToAgent yes
     IdentityFile ~/.ssh/id_rsa

2. eval "$(ssh-agent -s)" 

3. ssh-add -K ~/.ssh/id_rsa

Installing Rugged on Mac OS

Check if Mac is 64 bit: 

getconf LONG_BIT

ERROR: CMake is required to build Rugged

cat /Users/bparanj/.rvm/gems/ruby-2.3.1@headache/extensions/x86_64-darwin-17/2.3.0/rugged-0.25.1.1/gem_make.out

ERROR: CMake is required to build Rugged.

brew install cmake

Must be superuser to create this extension.

ALTER ROLE SUPERUSER;

createuser --superuser postgres2

gpg: keyserver receive failed: No route to host

Solution:

gpg-connect-agent --dirmngr 'keyserver --hosttable'

BYE

gpg --keyserver hkp://b4ckbone.de --recv-keys 409B6B1796C275462A1703113804BB82D39DC0E3 7D2BAF1CF37B13E2069D6956105BD0E739499BDB

When to Apply Memoization

Apply memoization, when two conditions are met:

1. Optimal sub structure
2. Overlapping sub problems

Make sure that `gem install libv8 -v '3.16.14.19' --source 'https://rubygems.org/'` succeeds before bundling.

This happened on Mac OS 10.10.5. I needed a specific version of libv8, so I used the -v flag in gem install.

Resolution

gem install libv8 -v 3.16.14.19 -- --with-system-v8

bundle config build.libv8 --with-system-v8

SSL Notes

git clone https://github.com/letsencrypt/letsencrypt
cd letsencrypt
./letsencrypt-auto --apache --rsa-key-size 4096


./letsencrypt-auto --apache -d example.com -d www.example.com -d foo.example.com -d bar.example.com -d baz.example.com


SSL with Let's Encrypt in Apache