I'm developing an app engine application using the "go111" runtime. According to Migrating your App Engine app from Go 1.9 to Go 1.11 accessing the datastore should be done using package datastore. However, calling google.FindDefaultCredentials fails with "could not find default credentials". Any ideas how to access the datastore using default credentials?
Set the GOOGLE_APPLICATION_CREDENTIALS environment variable before starting your application.
With the second generation runtime, if you aren't using any google.golang.org/appengine APIs, you do not need to use dev_appserver.py -- you can build and start your application normally (go build and/or go run).
Also, it's very uncommon to explicitly pass the credentials. cloud.google.com/go APIs should all automatically find your credentials for you. When you're running locally, setting the GOOGLE_APPLICATION_CREDENTIALS and GOOGLE_CLOUD_PROJECT environment variables should be enough to get running. See https://cloud.google.com/docs/authentication/production#obtaining_credentials_on_app_engine_standard_environment (note the comment about this being uncommon).
I just got it working using local app engine SDK by ..
--support_datastore_emulator=true to dev_appserver.py--datastore_emulator_port=9090 to dev_appserver.pyDATASTORE_EMULATOR_HOST to localhost:9090 in app.yamlDATASTORE_PROJECT_ID to my project id in app.yamlIn my Go 1.11 code, I simply create a new cloud.google.com/go/datastore client using datastore.NewClient(ctx, ""), which picks up the environment variables and connects to the local datastore emulator (running as part of dev_appserver.py).