anonymous user (i.e. with an empty password) fails

[dicksnippe]

I was trying to create an anonymous user, by specifying an empty passwd:
$ etcdctl user add anonymous:''
(the idea being to limit the anonymous user through RBAC to only some basic read operations)

Creating the user works, but retrieving data does not:
$ etcdctl --user anonymous: get foo
{"level":"warn","ts":"2024-11-26T17:13:40.985591+0100","logger":"etcd-client","caller":"v3@v3.5.17/retry_interceptor.go:63","msg":"retrying of unary invoker failed","target":"etcd-endpoints://0xc0004b4000/test0wa00:9966","attempt":0,"error":"rpc error: code = InvalidArgument desc = etcdserver: user name is empty"} Error: etcdserver: user name is empty

I think I understand why (etcd-io/etcd#9590) But it would be nice to point this out explicitly in the documentation.