Response

$ mc access readonly myminio/bucket
Access permission for ‘myminio/bucket’ is set to ‘readonly’
$ mc access myminio/bucket
{"Version":"2012-10-17","Statement":[{"Sid":"","Effect":"Allow","Principal":{"AWS":["*"]},"Action":["s3:GetBucketLocation","s3:ListBucket"],"Resource":["arn:aws:s3:::bucket"]},{"Sid":"","Effect":"Allow","Principal":{"AWS":["*"]},"Action":["s3:GetObject"],"Resource":["arn:aws:s3:::bucket/*"]}]}
Bucket Name: bucket Object Prefix: 
Access permission for ‘myminio/bucket’ is ‘readonly’
$ mc access myminio/bucket/
{"Version":"2012-10-17","Statement":[{"Sid":"","Effect":"Allow","Principal":{"AWS":["*"]},"Action":["s3:GetBucketLocation","s3:ListBucket"],"Resource":["arn:aws:s3:::bucket"]},{"Sid":"","Effect":"Allow","Principal":{"AWS":["*"]},"Action":["s3:GetObject"],"Resource":["arn:aws:s3:::bucket/*"]}]}
Bucket Name: bucket Object Prefix: 
Access permission for ‘myminio/bucket/’ is ‘readonly’