Find user locations by IP address

I need to demonstrate testing interactions with external HTTP services.
Add support for locating users based on IP addresses, and store the
found location as a string on the user object. Add a dependency on the
Geocoder gem to handle this.

Author: ruralocity

Gemfile

@@ -34,3 +34,4 @@ gem 'bootstrap-sass'
 gem 'jquery-rails'
 gem 'devise'
 gem 'paperclip'
+gem 'geocoder'

Gemfile.lock

@@ -81,6 +81,7 @@ GEM
     faker (1.7.3)
       i18n (~> 0.5)
     ffi (1.9.18)
+    geocoder (1.4.4)
     globalid (0.4.0)
       activesupport (>= 4.2.0)
     i18n (0.8.1)
@@ -212,6 +213,7 @@ DEPENDENCIES
   coffee-rails (~> 4.2)
   devise
   faker
+  geocoder
   jbuilder (~> 2.5)
   jquery-rails
   listen (>= 3.0.5, < 3.2)

app/models/user.rb

@@ -17,6 +17,17 @@ def name
     [first_name, last_name].join(" ")
   end
 
+  geocoded_by :last_sign_in_ip do |user, result|
+    if !user.local? && geocode = result.first
+      user.location = "#{geocode.city}, #{geocode.state}, #{geocode.country}"
+      user.save
+    end
+  end
+
+  def local?
+    ["localhost", "127.0.0.1", "0.0.0.0"].include? last_sign_in_ip
+  end
+
   private
 
   def ensure_authentication_token

db/migrate/20170829013421_add_location_to_users.rb

@@ -0,0 +1,5 @@
+class AddLocationToUsers < ActiveRecord::Migration[5.1]
+  def change
+    add_column :users, :location, :string
+  end
+end

db/schema.rb

@@ -10,7 +10,7 @@
 #
 # It's strongly recommended that you check this file into your version control system.
 
-ActiveRecord::Schema.define(version: 20170519014052) do
+ActiveRecord::Schema.define(version: 20170829013421) do
 
   create_table "notes", force: :cascade do |t|
     t.text "message"
@@ -61,6 +61,7 @@
     t.string "first_name"
     t.string "last_name"
     t.string "authentication_token"
+    t.string "location"
     t.index ["email"], name: "index_users_on_email", unique: true
     t.index ["reset_password_token"], name: "index_users_on_reset_password_token", unique: true
   end