feat: Add Public APIs for API Channel (#2375)

db/migrate/20210602182058_add_hmac_to_api_channel.rb

@@ -0,0 +1,19 @@
+class AddHmacToApiChannel < ActiveRecord::Migration[6.0]
+  def change
+    add_column :channel_api, :identifier, :string
+    add_index :channel_api, :identifier, unique: true
+    add_column :channel_api, :hmac_token, :string
+    add_index :channel_api, :hmac_token, unique: true
+    add_column :channel_api, :hmac_mandatory, :boolean, default: false
+    add_column :channel_web_widgets, :hmac_mandatory, :boolean, default: false
+    set_up_existing_api_channels
+  end
+
+  def set_up_existing_api_channels
+    ::Channel::Api.find_in_batches do |api_channels_batch|
+      Rails.logger.info "migrated till #{api_channels_batch.first.id}\n"
+      api_channels_batch.map(&:regenerate_hmac_token)
+      api_channels_batch.map(&:regenerate_identifier)
+    end
+  end
+end