nguyeness

[nguyeness]

Building Vim from source

Get the latest ruby and python installation. At the time of this post, ruby is at v2.7 and python is at v3.8.

shell git clone https://github.com/vim/vim.git ~/.config/vim cd ~/.config/vim ./configure --with-features=huge \ --without-x \ --enable-multibyte \ --enable-rubyinterp=yes \ --enable-python3interp=yes \ --with-python3-config-dir=$(python3-config --configdir) \ --enable-perlinterp=yes \ --enable-luainterp=yes \ --enable-cscope \ --prefix=/usr/local sudo make sudo make install sudo make clean

[nguyeness]

Missing respond_to method in Rails 6 API only app

For Rails 6 API mode only, the respond_to method is missing. Say you wanted to use Devise for user authentication; you'll need to have it respond to the json format.

# config/routes.rb scope :api, defaults { format: :json } do devise_for :users end

There we have the routes scoped to the /api namespace and restricting the format to only json requests.

In the controller is there we'll set the respond_to :json.

# app/controllers/application_controller.rb class ApplicationController < ActionController::API respond_to :json end

This will complain about the missing respond_to method. Resolving this issue is by simply inlcuding the MimeResponds class.

# app/controllers/application_controller.rb class ApplicationController < ActionController::API include ActionController::MimeResponds respond_to :json end

This was documentated in the Rails API.

[nguyeness]

Enabling cookie sessions for Rails 6 api only

As referenced in the guide:

4.4 Other Middleware

Rails ships with a number of other middleware that you might want to use in an API application, especially if one of your API clients is the browser:

Rack::MethodOverride ActionDispatch::Cookies ActionDispatch::Flash For session management ActionDispatch::Session::CacheStore ActionDispatch::Session::CookieStore ActionDispatch::Session::MemCacheStore

We'll need to add these back in manually.

# config/application.rb ... module App class Application < Rails::Application config.load_defaults 6.0 config.api_only = true config.middleware.use ActionDispatch::Cookies config.middleware.use ActionDispatch::Session::CookieStore, key: "custom_cookie_session_name", expires_after: 14.days end end

For more details regarding the session cookie store, check out the API documentation. That will reference the rack session abstract persisted class for the available options to use when instantiating the session cookie store.

[nguyeness]

Wiping a disk with zeros or random data with `dd`

Wiping a disk with zeros:

dd if=/dev/zero of=/dev/sdX bs=8M

Wiping a disk with random data:

dd if=/dev/urandom of=/dev/sdX bs=8M

Note: X in sdX needs to be replaced with the drive to be wiped. The usual case is a. Another thing to note is that bs should be close to the disk cache size for optimial performance.

To determine optimial speed, run:

dd if=/dev/urandom of=zero bs=512K; rm zero; dd if=/dev/urandom of=zero bs=1M; rm zero; dd if=/dev/urandom of=zero bs=8M; rm zero; dd if=/dev/urandom of=zero bs=32M; rm zero; dd if=/dev/urandom of=zero bs=1G; rm zero;

Add as many different block size (bs) variants to test for optimial speeds.

[nguyeness]

Implementing Rails STI and organizing subclasses

I won’t be talking about why or when to use Single Table Inheritance–this article is about how to implement and organize your files.

Let’s start off by creating a base class:

bin/rails genereate model Fruit name:string origin:string amount:integer type:string

For instance, a Gala apple–the name would be Gala and the type would be apple.

Let's create the Apple subclass:

bin/rails generate model Fruit::Apple --parent Fruit

By default rails will use the type column in Fruit to identify which subclass it should use; but since I'm namespacing our subclasses with Fruit:: I'll need to update the Fruit base class to know how to identify it's subclasses.

# app/models/fruit.rb ... def self.find_sti_class(type_name) type_name = if type_name =~ /fruit/i "#{self}::#{self.name}" else self.name end super end ...

Then in the subclasses, in this case the Apple class:

# app/models/fruit/apple.rb class Fruit::Apple < Fruit def self.sti_name 'Apple' end end

Now, define the scopes in the base model for ease of querying via the base model, Fruit:

# app/models/fruit.rb ... scope :apples, -> { where(type: 'Apple') } ...

That's pretty much it.