// check reachability for a single host, and take any necessary action func checkHostReachability(host host.Host, settings *evergreen.Settings) error { evergreen.Logger.Logf(slogger.INFO, "Running reachability check for host %v...", host.Id) // get a cloud version of the host cloudHost, err := providers.GetCloudHost(&host, settings) if err != nil { return fmt.Errorf("error getting cloud host for host %v: %v", host.Id, err) } // get the cloud status for the host cloudStatus, err := cloudHost.GetInstanceStatus() if err != nil { return fmt.Errorf("error getting cloud status for host %v: %v", host.Id, err) } // take different action, depending on how the cloud provider reports the host's status switch cloudStatus { case cloud.StatusRunning: // check if the host is reachable via SSH reachable, err := cloudHost.IsSSHReachable() if err != nil { return fmt.Errorf("error checking ssh reachability for host %v: %v", host.Id, err) } // log the status update if the reachability of the host is changing if host.Status == evergreen.HostUnreachable && reachable { evergreen.Logger.Logf(slogger.INFO, "Setting host %v as reachable", host.Id) } else if host.Status != evergreen.HostUnreachable && !reachable { evergreen.Logger.Logf(slogger.INFO, "Setting host %v as unreachable", host.Id) } // mark the host appropriately if err := host.UpdateReachability(reachable); err != nil { return fmt.Errorf("error updating reachability for host %v: %v", host.Id, err) } case cloud.StatusTerminated: evergreen.Logger.Logf(slogger.INFO, "Host %v terminated externally; updating db status to terminated", host.Id) // the instance was terminated from outside our control if err := host.SetTerminated(); err != nil { return fmt.Errorf("error setting host %v terminated: %v", host.Id, err) } } // success return nil }