Return network error when logging in and the network connection fails

[marktheunissen]

Displays "unable to login due to network error" to the user when a network error is encountered.

• Works with scenarios where the DNS does not resolve, or the port is closed or there is a timeout, etc.
• We have InsecureSkipVerify set on the http.Client now, so certificate errors are no longer detected by our http client as errors.

@harshavardhana Up to you, I know MINIO_SERVER_URL is deprecated but it looks like people still use it and get into trouble with DNS.

Fixes: #3427

[harshavardhana]

=== NAME  Test_PolicyListGroupsAPI
    policy_test.go:740: 
        	Error Trace:	/home/runner/work/console/console/integration/policy_test.go:740
        	Error:      	Not equal: 
        	            	expected: "[\"testgroup12345\"]\n"
        	            	actual  : "[\"testgroup12345\",\"testgroup12345\"]\n"
        	            	
        	            	Diff:
        	            	--- Expected
        	            	+++ Actual
        	            	@@ -1,2 +1,2 @@
        	            	-["testgroup12345"]
        	            	+["testgroup12345","testgroup12345"]
        	            	 
        	Test:       	Test_PolicyListGroupsAPI
=== RUN   Test_PolicyListGroupsAPI/List_Users_for_Policy_-_Invalid
--- FAIL: Test_PolicyListGroupsAPI (0.05s)

This looks like some duplicate groups are being listed @marktheunissen - needs a fix on the minio upstream side.

[marktheunissen]

@harshavardhana I've tracked this error down to a specific location, this integration test is adding groups and then when getting them back, the duplicates are being introduced.

The group name testgroup12345 is appended here: https://github.com/minio/minio/blob/master/cmd/iam-store.go#L995

And then the same group name testgroup12345 is appended again here: https://github.com/minio/minio/blob/master/cmd/iam-store.go#L1005

The function was modified and no longer does if store.getUsersSysType() == LDAPUsersSysType { so I wonder if that would be the issue?

I can keep working on it but I thought you might be able to find the issue faster than me since it's the first time I've looked at this.

[marktheunissen]

Made a simpler test that is easy to work with and reached out to a few people here: https://github.com/minio/minio/pull/20388/files

[bexsoft]

Please review my comment

[bexsoft]

LGTM