nickpoorman

# node.js #
###########
lib-cov
*.seed
*.log
*.csv
*.dat
*.out
*.pid
*.gz

nickpoorman

# node.js #
###########
lib-cov
*.seed
*.log
*.csv
*.dat
*.out
*.pid
*.gz

nickpoorman

/**
 * simple repl for the database
 */
var r = require('rethinkdb');
var inspect = require('util').inspect;

var connectOpts = {
  host: process.HOST || '127.0.0.1',
  port: process.PORT || 28015,
};

nickpoorman

Keybase proof

I hereby claim:

• I am nickpoorman on github.
• I am nickpoorman (https://keybase.io/nickpoorman) on keybase.
• I have a public key whose fingerprint is F54D 717B 258B F44B A8F3 893B 59CC 07EF B0FC 5E29

To claim this, I am signing this object:

nickpoorman

# app/controllers/application_controller.rb
class ApplicationController < ActionController::API
  include Pundit
  
  # set current_user from token
  include DeviseTokenAuth::Concerns::SetUserByToken

  # For this example we will stub out `current_user`
  # For Pundit, you may want to override `pundit_user`
  def current_user

nickpoorman

# app/graph/application_schema.rb
ApplicationSchema = GraphQL::Schema.define do
  query QueryType
  mutation MutationType

  resolve_type -> (object, _ctx) { ApplicationSchema.types[object.class.name] }

  # These are used by relay
  object_from_id -> (id, ctx) { decode_object(id, ctx) }
  id_from_object -> (obj, type, ctx) { encode_object(obj, type, ctx) }

nickpoorman

# app/controllers/graphql_controller.rb
class GraphqlController < ApplicationController
  def create
    query_string = params[:query]
    query_variables = ensure_hash(params[:variables])
    context = { current_user: current_user, pundit: self }
    result = ApplicationSchema.execute(query_string, variables: query_variables, context: context)
    render json: result
  end
  

nickpoorman

# app/graph/fields/fetch_field.rb
class FetchField < GraphQL::Field
  def initialize(model:, type:)
    self.type = type
    @model = model
    self.description = 'Find a #{model.name} by ID'
    self.arguments = {
      'id' => GraphQL::Argument.define do
        name 'id'
        type !GraphQL::INT_TYPE

nickpoorman

# app/graph/mutations/post_mutations/create.rb
module PostMutations
  Create = GraphQL::Relay::Mutation.define do
    # Used to name derived types, eg `"CreatePostInput"`:
    name 'CreatePost'
    description 'Create post with a title and return a post'

    # Define input parameters
    # Accessible from `input` in the resolve function:
    input_field :title, !types.String

nickpoorman

Scaling your API with rate limiters

The following are examples of the four types rate limiters discussed in the accompanying blog post. In the examples below I've used pseudocode-like Ruby, so if you're unfamiliar with Ruby you should be able to easily translate this approach to other languages. Complete examples in Ruby are also provided later in this gist.

In most cases you'll want all these examples to be classes, but I've used simple functions here to keep the code samples brief.

Request rate limiter

This uses a basic token bucket algorithm and relies on the fact that Redis scripts execute atomically. No other operations can run between fetching the count and writing the new count.