Move SchemaMigration model from ManageIQ to ManageIQ::Schema plugin

app/models/schema_migration.rb

@@ -0,0 +1,49 @@
+class SchemaMigration < ActiveRecord::Base
+  def self.up_to_date?
+    begin
+      migrations = missing_db_migrations
+      files      = missing_file_migrations
+      db_ver     = schema_version
+    rescue => err
+      return [false, err]
+    end
+
+    return [false, "database schema is not up to date.  Schema version is [#{db_ver}].  Missing migrations: [#{migrations.join(", ")}]",
+            "database should be migrated to the latest version"] unless migrations.empty?
+    return [false, "database schema is from a newer version of the product and may be incompatible.  Schema version is [#{db_ver}].  Missing files: [#{files.join(", ")}]",
+            "appliance should be updated to match database version"] unless files.empty?
+
+    [true, "database schema version #{db_ver} is up to date"]
+  end
+
+  def self.db_migration_list
+    @db_migration_list ||= SchemaMigration.all.collect { |s| s.version.to_i }.sort
+  end
+
+  def self.file_migration_list
+    @file_migration_list ||= Dir.glob(ManageIQ::Schema::Engine.root.join("db", "migrate", "*.rb")).collect do |f|
+      File.basename(f).split("_")[0].to_i
+    end.sort
+  end
+
+  def self.missing_db_migrations
+    file_migration_list - db_migration_list
+  end
+
+  def self.missing_file_migrations
+    # Ignore migrations prior to the collapsed initial migration
+    db_migration_list.reject { |m| m < initial_migration } - file_migration_list
+  end
+
+  def self.schema_version
+    db_migration_list.last
+  end
+
+  def self.initial_migration
+    file_migration_list.first
+  end
+
+  def self.latest_migration
+    file_migration_list.last
+  end
+end