MongoHealtIndicator fails without sufficient privileges

[laurikimmel]

MongoHealtIndicator uses command { serverStatus: 1 } to check MongoDB connection status. This command fails in case user has insufficient privileges in database.

For example if MongoDB user account has only built in roles read and/or readWrite assigned. As result misleading message is shown in /health output:

"mongo":{"status":"DOWN","error":"java.lang.IllegalArgumentException: Data must not be null"}

Proposed solution: use MongoDB command { buildInfo: 1 } to get server version. This command is working with built in roles read, readWrite, userAdmin.

MongoDB version used: 2.6.3.
Not tested with other versions.
Not tested with all built in roles.

[laurikimmel]

As it turned out command { buildInfo:1 } works even for anonymous user or user without any roles.

[cdupuis]

Thanks for the report. I'll change the command in MongoHealthIndicator asap.