Refactoring SMS credentials to be multi-tenant and persisted in database

Gemfile.lock

@@ -192,5 +192,8 @@ DEPENDENCIES
   unicorn
   webmock
 
+RUBY VERSION
+   ruby 2.2.3p173
+
 BUNDLED WITH
-   1.10.6
+   1.15.1

app/models.rb

@@ -83,6 +83,7 @@ module Models
 require 'app/models/city'
 require 'app/models/event'
 require 'app/models/publisher'
+require 'app/models/sms_credentials'
 require 'app/models/subscription'
 
 # access model class constants without qualifying namespace

app/models/publisher.rb

@@ -2,6 +2,7 @@ module Citygram::Models
   class Publisher < Sequel::Model
     one_to_many :subscriptions
     one_to_many :events
+    many_to_one :sms_credentials
 
     plugin :url_validation
     plugin :serialization, :pg_array, :tags
@@ -19,6 +20,9 @@ def active
         where(active: true)
       end
     end
+
+    delegate :credential_name, :from_number, :account_sid, :auth_token, to: :sms_credentials
+
 
     def validate
       super

app/models/sms_credentials.rb

@@ -0,0 +1,12 @@
+module Citygram::Models
+  class SmsCredentials < Sequel::Model
+    dataset_module do
+    end
+
+    def validate
+      super
+      validates_presence [:from_number, :account_sid, :auth_token]
+      validates_unique :account_sid
+    end
+  end
+end

app/models/subscription.rb

@@ -112,6 +112,8 @@ def last_notification
     def last_notification_date
       self.last_notification.strftime("%b %d, %Y")
     end
+
+    delegate :credential_name, :from_number, :account_sid, :auth_token, to: :publisher
 
     def validate
       super

app/modules/sms_sender.rb

@@ -0,0 +1,15 @@
+module Citygram
+  module SmsSender
+
+    def send_sms(subscription, body)
+      Citygram::App.logger.info("Sending SMS via #{subscription.credential_name}")
+      Citygram::Services::Channels::SMS.sms(
+        subscription.account_sid, 
+        subscription.auth_token, {
+        from: subscription.from_number,
+        to:   subscription.phone_number,
+        body: body
+      })
+    end
+  end
+end

app/services/channels.rb

@@ -21,6 +21,7 @@ class NotificationFailure < StandardError; end
   end
 end
 
+require 'app/modules/sms_sender'
 require 'app/services/channels/base'
 require 'app/services/channels/email'
 require 'app/services/channels/sms'

app/services/channels/sms.rb

@@ -1,27 +1,22 @@
 module Citygram::Services::Channels
   class SMS < Base
-    FROM_NUMBER = ENV.fetch('TWILIO_FROM_NUMBER').freeze
+
+    include ::Citygram::SmsSender
 
-    TWILIO_ACCOUNT_SID = ENV.fetch('TWILIO_ACCOUNT_SID').freeze
-    TWILIO_AUTH_TOKEN  = ENV.fetch('TWILIO_AUTH_TOKEN').freeze
 
     UNSUBSCRIBE_ERROR_CODES = [
       21211, # number cannot exist - https://www.twilio.com/docs/errors/21211
       21610, # user replied with a stop word - https://www.twilio.com/docs/errors/21610
       21614, # not a valid mobile number - https://www.twilio.com/docs/errors/21614
     ].freeze
 
-    def self.sms(*args)
-      client = Twilio::REST::Client.new(TWILIO_ACCOUNT_SID, TWILIO_AUTH_TOKEN)
+    def self.sms(sid, token, *args)
+      client = Twilio::REST::Client.new(sid, token)
       client.account.messages.create(*args)
     end
 
     def call
-      self.class.sms(
-        from: FROM_NUMBER,
-        to: subscription.phone_number,
-        body: event.title
-      )
+      send_sms(subscription, event.title)
     rescue Twilio::REST::RequestError => e
       Citygram::App.logger.error(e)
 

app/workers.rb

@@ -5,12 +5,14 @@ module Workers
   end
 end
 
+require 'app/modules/sms_sender'
 require 'app/workers/publisher_poll'
 require 'app/workers/notifier'
 require 'app/workers/subscription_confirmation'
 require 'app/workers/reminder_notification'
 require 'app/workers/middleware/database_connections'
 
+
 Sidekiq.configure_server do |config|
   config.server_middleware do |chain|
     chain.add Citygram::Workers::Middleware::DatabaseConnections, Sequel::Model.db

app/workers/reminder_notification.rb

@@ -1,6 +1,7 @@
 module Citygram::Workers
   class ReminderNotification
     include Sidekiq::Worker
+    include ::Citygram::SmsSender
     sidekiq_options retry: 5
 
     def reminder_url(subscription)
@@ -23,11 +24,7 @@ def perform(subscription_id)
       # ...but if there is an error sending this message, tomorrow's might work
       subscription.remind!
       [body_1, body_2].each do |body|
-        Citygram::Services::Channels::SMS.sms(
-          from: Citygram::Services::Channels::SMS::FROM_NUMBER,
-          to: subscription.phone_number,
-          body: body
-        )
+        send_sms(subscription, body)
       end
     rescue Twilio::REST::RequestError => e
       Citygram::App.logger.error(e)

app/workers/subscription_confirmation.rb

@@ -1,6 +1,8 @@
 module Citygram::Workers
   class SubscriptionConfirmation
     include Sidekiq::Worker
+    include ::Citygram::SmsSender
+
     sidekiq_options retry: 5
 
     def digest_url(subscription)
@@ -15,12 +17,7 @@ def perform(subscription_id)
       case subscription.channel
       when 'sms'
         body = "Welcome! You are now subscribed to #{publisher.title} in #{publisher.city}. To see current Citygrams please visit #{digest_url(subscription)}. To unsubscribe from all messages, reply REMOVE."
-
-        Citygram::Services::Channels::SMS.sms(
-          from: Citygram::Services::Channels::SMS::FROM_NUMBER,
-          to: subscription.phone_number,
-          body: body
-        )
+        send_sms(subscription, body)
       when 'email'
         body = <<-BODY.dedent
           <p>Thank you for subscribing! <a href="#{digest_url(subscription)}">View Citygrams</a> in a browser.</p>

db/migrations/031_create_sms_credentials.rb

@@ -0,0 +1,17 @@
+Sequel.migration do
+  up do
+    create_table :sms_credentials do
+      primary_key :id
+      String :credential_name
+      String :from_number
+      String :account_sid
+      String :auth_token
+      DateTime :updated_at
+      DateTime :created_at
+    end
+  end
+
+  down do
+    drop_table :sms_credentials
+  end
+end

db/migrations/032_add_sms_credentials_to_publisher.rb

@@ -0,0 +1,13 @@
+Sequel.migration do
+  up do
+    alter_table(:publishers) do
+      add_foreign_key :sms_credentials_id, :sms_credentials
+    end
+  end
+
+  down do
+    alter_table(:publishers) do
+      drop_foreign_key :sms_credentials_id
+    end
+  end
+end