log-keys(&optional (log-bucket *log-bucket*))Return a list of #S(log-key).
log-lines(log-key &key (bucket *log-bucket*))Return a list of #S(log-line).
make-elb-log(credentials bucket-name)Return #S(elb-log credentials bucket-name).
CREDENTIALS should be (cons "AWS_ACCESS_KEY" "AWS_SECRET_KEY").
BUCKET-NAME should be bucket name of ELB log.
make-log-bucket(&optional (elb-log *elb-log*) (date *log-date*) max-keys)Return #S(log-bucket).
ELB-LOG should be #S(elb-log).
DATE should be an instance of loca-time:timestamp.