Mention Invalid Login error on MINIO_SERVER_URL

[ecerulm]

The MinIO Console currently does not warn the user if the MinIO server is not reachable. MinIO Console will just say "Invalid Login" when the MINIO_SERVER_URL is not reachable which is misleading in the sense that will make think most people that the username/password/access key is incorrect so I think it should be mentioned in the documentation that Invalid Login could be just due to connectivity between console and server.

Related to minio/console#3428 and minio/console#3427

@marktheunissen

[harshavardhana]

It isn't done in vain, it was an ask by the customer to avoid reporting "login errors" to avoid brute force attacks on the login vector in the name of security by (obscurity)

We used to be more descriptive in the past but it was implemented to make it vague on purpose.

[ecerulm]

It isn't done in vain, it was an ask by the customer to avoid reporting "login errors" to avoid brute force attacks on the login vector in the name of security by (obscurity)

Yeah, I suspected that was on purpose, but mentioning on the documentation (this PR) I hope it's ok. I guess that the wait for 10 seconds before getting the "invalid login" already gives away (in hindsight) that is a communication problem between MinIO Console and MinIO Server, but mentioning in the documentation will make it easier to find in an internet serarch.

I wrote another issue minio/console#3427 about actually changing the "Invalid Login" for "Server unreachable" in that specific case.

[ravindk89]

Thanks for your patience @ecerulm and your contribution!