Imports github.com/pkg/errors github.com/prometheus/client_golang/prometheus github.com/prometheus/client_golang/prometheus/collectors github.com/prometheus/client_golang/prometheus/promhttp github.com/tomasen/fcgi_client go.uber.org/zap golang.org/x/sync/errgroup Standard library imports context io/ioutil net net/http net/url os os/signal regexp strconv syscall time