GCP auth issue with registrar

[pisuke]

Running the registrar program, I've run into this issue:

LDNML14RHV2F:udmi francesco.anselmo$ bin/registrar project_name local/project_name
Building validator...
Note: Some input files use or override a deprecated API.
Note: Recompile with -Xlint:deprecation for details.
Note: /Users/username/Documents/Code/Repositories/github/udmi/validator/src/main/java/com/google/daq/mqtt/validator/Validator.java uses unchecked or unsafe operations.
Note: Recompile with -Xlint:unchecked for details.
fatal: No names found, cannot describe anything.
Running tools version
Using gcloud auth:
username@gmail.com
Using cloud project project_name
Using site config dir local/project_name
Using schema root dir bin/../schema
Using device filter
java args project_name local/project_name bin/../schema
Reading Cloud IoT config from /Users/username/Documents/Code/Repositories/github/udmi/local/project_name/cloud_iot_config.json
Initializing with default credentials...
Aug 01, 2020 10:38:57 AM com.google.auth.oauth2.ComputeEngineCredentials runningOnComputeEngine
INFO: Failed to detect whether we are running on Google Compute Engine.
java.lang.RuntimeException: While initializing Cloud IoT project projects/arup-8-fitzroy-st/locations/europe-west1
	at com.google.daq.mqtt.util.CloudIotManager.initializeCloudIoT(CloudIotManager.java:94)
	at com.google.daq.mqtt.util.CloudIotManager.<init>(CloudIotManager.java:61)
	at com.google.daq.mqtt.registrar.Registrar.setSiteConfigPath(Registrar.java:119)
	at com.google.daq.mqtt.registrar.Registrar.main(Registrar.java:75)
Caused by: java.io.IOException: The Application Default Credentials are not available. They are available if running in Google Compute Engine. Otherwise, the environment variable GOOGLE_APPLICATION_CREDENTIALS must be defined pointing to a file defining the credentials. See https://developers.google.com/accounts/docs/application-default-credentials for more information.
	at com.google.auth.oauth2.DefaultCredentialsProvider.getDefaultCredentials(DefaultCredentialsProvider.java:132)
	at com.google.auth.oauth2.GoogleCredentials.getApplicationDefault(GoogleCredentials.java:127)
	at com.google.auth.oauth2.GoogleCredentials.getApplicationDefault(GoogleCredentials.java:100)
	at com.google.daq.mqtt.util.CloudIotManager.initializeCloudIoT(CloudIotManager.java:84)
	... 3 more
Registrar complete, exit 255

It's easy to sort this out by adding the GOOGLE_APPLICATION_CREDENTIALS environment variable as suggested

export GOOGLE_APPLICATION_CREDENTIALS=/path/to/service_account.json

but it would be useful to handle it directly in the code since the service account is already indicated inside local/system.conf

[grafnu]

local/system.conf is for DAQ. UDMI is not likely to follow the same mechanism for doing this, although it might be something similar.

The concept of setting it in the code is fine, we just need to figure out how to do it properly. I think, maybe, there should be a
{site_folder}/local directory that could contain local site-specific information? Or maybe it should be {site_folder}/projects/{project_id}/config?

The reason it's separated out is that the same site folder can apply to different projects, and each project would have different credentials!

[pisuke]

I think I was following an old doc file which was referring to local/system.conf.
Using sites/projects/{project_id}/config sounds good, indeed these creds apply to individual projects.