Up default Podman rlimits to avoid max open files

Every port we open consumes an open FD. This can easily consume
all available FDs for the podman process. Set rlimits to resolve
this.

Signed-off-by: Matthew Heon <matthew.heon@gmail.com>

Closes: #1437
Approved by: rhatdan

cmd/podman/main.go

@@ -138,6 +138,17 @@ func main() {
 			logrus.SetLevel(level)
 		}
 
+		// Only if not rootless, set rlimits for open files.
+		// We open numerous FDs for ports opened
+		if os.Geteuid() == 0 {
+			rlimits := new(syscall.Rlimit)
+			rlimits.Cur = 1048576
+			rlimits.Max = 1048576
+			if err := syscall.Setrlimit(syscall.RLIMIT_NOFILE, rlimits); err != nil {
+				return errors.Wrapf(err, "error setting new rlimits")
+			}
+		}
+
 		if logLevel == "debug" {
 			debug = true