alerting: Address review

build/limits.go

@@ -0,0 +1,6 @@
+package build
+
+var (
+	DefaultFDLimit uint64 = 16 << 10
+	MinerFDLimit   uint64 = 100_000
+)

lib/ulimit/ulimit.go

@@ -3,11 +3,14 @@ package ulimit
 // from go-ipfs
 
 import (
+	"errors"
 	"fmt"
 	"os"
 	"strconv"
 	"syscall"
 
+	"github.com/filecoin-project/lotus/build"
+
 	logging "github.com/ipfs/go-log/v2"
 )
 
@@ -17,7 +20,7 @@ var (
 	supportsFDManagement = false
 
 	// getlimit returns the soft and hard limits of file descriptors counts
-	GetLimit func() (uint64, uint64, error)
+	getLimit func() (uint64, uint64, error)
 	// set limit sets the soft and hard limits of file descriptors counts
 	setLimit func(uint64, uint64) error
 )
@@ -25,8 +28,15 @@ var (
 // minimum file descriptor limit before we complain
 const minFds = 2048
 
-// default max file descriptor limit.
-const maxFds = 16 << 10
+var ErrUnsupported = errors.New("unsupported")
+
+func GetLimit() (uint64, uint64, error) {
+	if getLimit == nil {
+		return 0, 0, ErrUnsupported
+	}
+
+	return getLimit()
+}
 
 // userMaxFDs returns the value of LOTUS_FD_MAX
 func userMaxFDs() uint64 {
@@ -55,7 +65,7 @@ func ManageFdLimit() (changed bool, newLimit uint64, err error) {
 		return false, 0, nil
 	}
 
-	targetLimit := uint64(maxFds)
+	targetLimit := build.DefaultFDLimit
 	userLimit := userMaxFDs()
 	if userLimit > 0 {
 		targetLimit = userLimit

lib/ulimit/ulimit_freebsd.go

@@ -11,7 +11,7 @@ import (
 
 func init() {
 	supportsFDManagement = true
-	GetLimit = freebsdGetLimit
+	getLimit = freebsdGetLimit
 	setLimit = freebsdSetLimit
 }
 

lib/ulimit/ulimit_test.go

@@ -8,6 +8,8 @@ import (
 	"strings"
 	"syscall"
 	"testing"
+
+	"github.com/filecoin-project/lotus/build"
 )
 
 func TestManageFdLimit(t *testing.T) {
@@ -16,7 +18,7 @@ func TestManageFdLimit(t *testing.T) {
 		t.Errorf("Cannot manage file descriptors")
 	}
 
-	if maxFds != uint64(16<<10) {
+	if build.DefaultFDLimit != uint64(16<<10) {
 		t.Errorf("Maximum file descriptors default value changed")
 	}
 }

lib/ulimit/ulimit_unix.go

@@ -8,7 +8,7 @@ import (
 
 func init() {
 	supportsFDManagement = true
-	GetLimit = unixGetLimit
+	getLimit = unixGetLimit
 	setLimit = unixSetLimit
 }
 

node/builder.go

@@ -28,6 +28,7 @@ import (
 	"go.uber.org/fx"
 	"golang.org/x/xerrors"
 
+	"github.com/filecoin-project/lotus/build"
 	"github.com/filecoin-project/lotus/chain/beacon"
 	"github.com/filecoin-project/lotus/chain/types"
 	"github.com/filecoin-project/lotus/extern/sector-storage/stores"
@@ -152,7 +153,7 @@ func defaults() []Option {
 		Override(new(journal.Journal), modules.OpenFilesystemJournal),
 		Override(new(*alerting.Alerting), alerting.NewAlertingSystem),
 
-		Override(CheckFDLimit, modules.CheckFdLimit(16<<10)),
+		Override(CheckFDLimit, modules.CheckFdLimit(build.DefaultFDLimit)),
 
 		Override(new(system.MemoryConstraints), modules.MemoryConstraints),
 		Override(InitMemoryWatchdog, modules.MemoryWatchdog),

node/builder_miner.go

@@ -15,6 +15,7 @@ import (
 	storage2 "github.com/filecoin-project/specs-storage/storage"
 
 	"github.com/filecoin-project/lotus/api"
+	"github.com/filecoin-project/lotus/build"
 	"github.com/filecoin-project/lotus/chain/gen"
 	"github.com/filecoin-project/lotus/chain/gen/slashfilter"
 	sectorstorage "github.com/filecoin-project/lotus/extern/sector-storage"
@@ -74,7 +75,7 @@ func ConfigStorageMiner(c interface{}) Option {
 	return Options(
 		ConfigCommon(&cfg.Common, enableLibp2pNode),
 
-		Override(CheckFDLimit, modules.CheckFdLimit(100_000)), // recommend at least 100k FD limit to miners
+		Override(CheckFDLimit, modules.CheckFdLimit(build.MinerFDLimit)), // recommend at least 100k FD limit to miners
 
 		Override(new(api.MinerSubsystems), modules.ExtractEnabledMinerSubsystems(cfg.Subsystems)),
 		Override(new(stores.LocalStorage), From(new(repo.LockedRepo))),

node/modules/alerts.go

@@ -7,13 +7,14 @@ import (
 
 func CheckFdLimit(min uint64) func(al *alerting.Alerting) {
 	return func(al *alerting.Alerting) {
-		if ulimit.GetLimit == nil {
+		soft, _, err := ulimit.GetLimit()
+
+		if err == ulimit.ErrUnsupported {
+			log.Warn("FD limit monitoring not available")
 			return
 		}
 
 		alert := al.AddAlertType("process", "fd-limit")
-
-		soft, _, err := ulimit.GetLimit()
 		if err != nil {
 			al.Raise(alert, map[string]string{
 				"message": "failed to get FD limit",