Always color output and fold settled values into constants

system.go

@@ -62,13 +62,12 @@ type ethtoolCoalesce struct {
 	rateSampleInterval       uint32
 }
 
-type systemConfig struct {
-	governor string
-	rxUsecs  uint32
-	txUsecs  uint32
-	rxRing   uint32
-	txRing   uint32
-}
+const (
+	wantGovernor      = "performance"
+	wantCoalesceUsecs = 25
+	wantRxRing        = 8160
+	wantTxRing        = 4096
+)
 
 type checkResult struct {
 	item  string
@@ -311,15 +310,15 @@ func withIoctlSocket(fn func(fd int) []checkResult) []checkResult {
 	return fn(fd)
 }
 
-func configureSystem(cfg systemConfig, ifnames []string) []checkResult {
+func configureSystem(ifnames []string) []checkResult {
 	return withIoctlSocket(func(fd int) []checkResult {
-		out := []checkResult{checkGovernor(cfg.governor)}
+		out := []checkResult{checkGovernor(wantGovernor)}
 		for _, ifname := range ifnames {
 			out = append(out, checkLinkUp(fd, ifname))
-			out = append(out, checkCoalesce(fd, ifname, cfg.rxUsecs, cfg.txUsecs))
+			out = append(out, checkCoalesce(fd, ifname, wantCoalesceUsecs, wantCoalesceUsecs))
 
 			carrierWait := 3 * time.Second
-			r, reset := checkRings(fd, ifname, cfg.rxRing, cfg.txRing)
+			r, reset := checkRings(fd, ifname, wantRxRing, wantTxRing)
 			out = append(out, r)
 			if reset {
 				carrierWait = 10 * time.Second