Google Cloud Datastore Emulator

To develop and test your application locally, you can use the Google Cloud Datastore Emulator , which provides local emulation of the production Google Cloud Datastore environment. You can start the Google Cloud Datastore emulator using the gcloud command-line tool.

When you run the Cloud Datastore emulator you will see a message similar to the following printed:

 If you are using a library that supports the DATASTORE_EMULATOR_HOST
environment variable, run:

  export DATASTORE_EMULATOR_HOST=localhost:8978

Now you can connect to the emulator using the DATASTORE_EMULATOR_HOST environment variable:

 require 
  
 "google/cloud/datastore" 
 # Make Datastore use the emulator 
 ENV 
 [ 
 "DATASTORE_EMULATOR_HOST" 
 ] 
  
 = 
  
 "localhost:8978" 
 datastore 
  
 = 
  
 Google 
 :: 
 Cloud 
 :: 
 Datastore 
 . 
 new 
  
 project 
 : 
  
 "emulator-project-id" 
 task 
  
 = 
  
 datastore 
 . 
 entity 
  
 "Task" 
 , 
  
 "emulatorTask" 
  
 do 
  
 | 
 t 
 | 
  
 t 
 [ 
 "type" 
 ] 
  
 = 
  
 "Testing" 
  
 t 
 [ 
 "done" 
 ] 
  
 = 
  
 false 
  
 t 
 [ 
 "priority" 
 ] 
  
 = 
  
 5 
  
 t 
 [ 
 "description" 
 ] 
  
 = 
  
 "Use Datastore Emulator" 
 end 
 datastore 
 . 
 save 
  
 task

Or by providing the emulator_host argument:

 require 
  
 "google/cloud/datastore" 
 datastore 
  
 = 
  
 Google 
 :: 
 Cloud 
 :: 
 Datastore 
 . 
 new 
  
 emulator_host 
 : 
  
 "localhost:8978" 
 task 
  
 = 
  
 datastore 
 . 
 entity 
  
 "Task" 
 , 
  
 "emulatorTask" 
  
 do 
  
 | 
 t 
 | 
  
 t 
 [ 
 "type" 
 ] 
  
 = 
  
 "Testing" 
  
 t 
 [ 
 "done" 
 ] 
  
 = 
  
 false 
  
 t 
 [ 
 "priority" 
 ] 
  
 = 
  
 5 
  
 t 
 [ 
 "description" 
 ] 
  
 = 
  
 "Use Datastore Emulator" 
 end 
 datastore 
 . 
 save 
  
 task