Update ar_internal_metadata after remote restore

This change updates the local development restore operation to update the
`ar_internal_metadata` table if it's present, setting the environment
value to `development`.

If the table is not present (either for older Rails applications or
non-Rails applications), this anonymous PG function will no-op.

Fix #147

lib/parity/backup.rb

@@ -40,6 +40,7 @@ def restore_to_development
       wipe_development_database
       restore_from_local_temp_backup
       delete_local_temp_backup
+      delete_rails_production_environment_settings
     end
 
     def wipe_development_database
@@ -81,6 +82,17 @@ def delete_local_temp_backup
       Kernel.system("rm tmp/latest.backup")
     end
 
+    def delete_rails_production_environment_settings
+      Kernel.system(
+        "psql #{development_db} -c "\
+          "\"DO $$ BEGIN IF EXISTS "\
+          "(SELECT 1 FROM pg_tables WHERE tablename = 'ar_internal_metadata') "\
+          "THEN UPDATE ar_internal_metadata "\
+          "SET value = 'development' "\
+          "WHERE key = 'environment'; ELSE END IF; END $$;\"",
+      )
+    end
+
     def restore_to_remote_environment
       reset_remote_database
       Kernel.system(

spec/parity/backup_spec.rb

@@ -1,52 +1,79 @@
 require File.join(File.dirname(__FILE__), '..', '..', 'lib', 'parity')
 
 describe Parity::Backup do
-  it "restores backups to development (after dropping the development DB)" do
-    allow(IO).to receive(:read).and_return(database_fixture)
-    allow(Kernel).to receive(:system)
-    allow(Etc).to receive(:nprocessors).and_return(number_of_processes)
-
-    Parity::Backup.new(from: "production", to: "development").restore
-
-    expect(Kernel).
-      to have_received(:system).
-      with(make_temp_directory_command)
-    expect(Kernel).
-      to have_received(:system).
-      with(download_remote_database_command)
-    expect(Kernel).
-      to have_received(:system).
-      with(drop_development_database_drop_command)
-    expect(Kernel).
-      to have_received(:system).
-      with(restore_from_local_temp_backup_command)
-    expect(Kernel).
-      to have_received(:system).
-      with(delete_local_temp_backup_command)
-  end
-
-  it "restores backups to development with Rubies that do not support Etc.nprocessors" do
-    allow(IO).to receive(:read).and_return(database_fixture)
-    allow(Kernel).to receive(:system)
-    allow(Etc).to receive(:respond_to?).with(:nprocessors).and_return(false)
-
-    Parity::Backup.new(from: "production", to: "development").restore
-
-    expect(Kernel).
-      to have_received(:system).
-      with(make_temp_directory_command)
-    expect(Kernel).
-      to have_received(:system).
-      with(download_remote_database_command)
-    expect(Kernel).
-      to have_received(:system).
-      with(drop_development_database_drop_command)
-    expect(Kernel).
-      to have_received(:system).
-      with(restore_from_local_temp_backup_command(cores: 2))
-    expect(Kernel).
-      to have_received(:system).
-      with(delete_local_temp_backup_command)
+  context "restoring to the local development environment" do
+    it "restores backups to development (after dropping the development DB)" do
+      allow(IO).to receive(:read).and_return(database_fixture)
+      allow(Kernel).to receive(:system)
+      allow(Etc).to receive(:nprocessors).and_return(number_of_processes)
+
+      Parity::Backup.new(from: "production", to: "development").restore
+
+      expect(Kernel).
+        to have_received(:system).
+        with(make_temp_directory_command)
+      expect(Kernel).
+        to have_received(:system).
+        with(download_remote_database_command)
+      expect(Kernel).
+        to have_received(:system).
+        with(drop_development_database_drop_command)
+      expect(Kernel).
+        to have_received(:system).
+        with(restore_from_local_temp_backup_command)
+      expect(Kernel).
+        to have_received(:system).
+        with(delete_local_temp_backup_command)
+    end
+
+    it "restores backups to development with Rubies that do not support Etc.nprocessors" do
+      allow(IO).to receive(:read).and_return(database_fixture)
+      allow(Kernel).to receive(:system)
+      allow(Etc).to receive(:respond_to?).with(:nprocessors).and_return(false)
+
+      Parity::Backup.new(from: "production", to: "development").restore
+
+      expect(Kernel).
+        to have_received(:system).
+        with(make_temp_directory_command)
+      expect(Kernel).
+        to have_received(:system).
+        with(download_remote_database_command)
+      expect(Kernel).
+        to have_received(:system).
+        with(drop_development_database_drop_command)
+      expect(Kernel).
+        to have_received(:system).
+        with(restore_from_local_temp_backup_command(cores: 2))
+      expect(Kernel).
+        to have_received(:system).
+        with(delete_local_temp_backup_command)
+    end
+
+    it "drops the 'ar_internal_metadata' table if it exists" do
+      allow(IO).to receive(:read).and_return(database_fixture)
+      allow(Kernel).to receive(:system)
+      allow(Etc).to receive(:nprocessors).and_return(number_of_processes)
+
+      Parity::Backup.new(from: "production", to: "development").restore
+
+      expect(Kernel).
+        to have_received(:system).
+        with(make_temp_directory_command)
+      expect(Kernel).
+        to have_received(:system).
+        with(download_remote_database_command)
+      expect(Kernel).
+        to have_received(:system).
+        with(drop_development_database_drop_command)
+      expect(Kernel).
+        to have_received(:system).
+        with(restore_from_local_temp_backup_command)
+      expect(Kernel).
+        to have_received(:system).
+        with(delete_local_temp_backup_command)
+      expect(Kernel).to have_received(:system).with(set_db_metadata_sql)
+    end
   end
 
   it "restores backups to staging from production" do
@@ -156,4 +183,13 @@ def additional_argument_pass_through
   def default_db_name
     "parity_development"
   end
+
+  def set_db_metadata_sql
+    "psql parity_development -c "\
+      "\"DO $$ BEGIN IF EXISTS "\
+      "(SELECT 1 FROM pg_tables WHERE tablename = 'ar_internal_metadata') "\
+      "THEN UPDATE ar_internal_metadata "\
+      "SET value = 'development' "\
+      "WHERE key = 'environment'; ELSE END IF; END $$;\""
+  end
 end