From 05aa5f2d385c85ff8cdf9ffd8ce20149d446ea85 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Ra=C3=BAl=20Kripalani?= <raul@protocol.ai>
Date: Mon, 14 Sep 2020 13:01:03 +0100
Subject: [PATCH] allow customizing disabled journal events + tests.

---
 journal/registry_test.go | 49 ++++++++++++++++++++++++++++++++++++++++
 journal/types.go         | 21 +++++++++++++++++
 node/builder.go          | 15 +++++++++++-
 3 files changed, 84 insertions(+), 1 deletion(-)
 create mode 100644 journal/registry_test.go

diff --git a/journal/registry_test.go b/journal/registry_test.go
new file mode 100644
index 000000000..9d2085c12
--- /dev/null
+++ b/journal/registry_test.go
@@ -0,0 +1,49 @@
+package journal
+
+import (
+	"testing"
+
+	"github.com/stretchr/testify/require"
+)
+
+func TestDisabledEvents(t *testing.T) {
+	req := require.New(t)
+
+	test := func(dis DisabledEvents) func(*testing.T) {
+		return func(t *testing.T) {
+			registry := NewEventTypeRegistry(dis)
+
+			reg1 := registry.RegisterEventType("system1", "disabled1")
+			reg2 := registry.RegisterEventType("system2", "disabled2")
+
+			req.False(reg1.Enabled())
+			req.False(reg2.Enabled())
+			req.True(reg1.safe)
+			req.True(reg2.safe)
+
+			reg3 := registry.RegisterEventType("system3", "enabled3")
+			req.True(reg3.Enabled())
+			req.True(reg3.safe)
+		}
+	}
+
+	t.Run("direct", test(DisabledEvents{
+		EventType{System: "system1", Event: "disabled1"},
+		EventType{System: "system2", Event: "disabled2"},
+	}))
+
+	dis, err := ParseDisabledEvents("system1:disabled1,system2:disabled2")
+	req.NoError(err)
+
+	t.Run("parsed", test(dis))
+
+	dis, err = ParseDisabledEvents("  system1:disabled1 , system2:disabled2  ")
+	req.NoError(err)
+
+	t.Run("parsed_spaces", test(dis))
+}
+
+func TestParseDisableEvents(t *testing.T) {
+	_, err := ParseDisabledEvents("system1:disabled1:failed,system2:disabled2")
+	require.Error(t, err)
+}
diff --git a/journal/types.go b/journal/types.go
index c81fb8c89..56c7d4bc0 100644
--- a/journal/types.go
+++ b/journal/types.go
@@ -1,6 +1,8 @@
 package journal
 
 import (
+	"fmt"
+	"strings"
 	"time"
 
 	logging "github.com/ipfs/go-log"
@@ -20,6 +22,25 @@ var (
 // DisabledEvents is the set of event types whose journaling is suppressed.
 type DisabledEvents []EventType
 
+// ParseDisabledEvents parses a string of the form: "system1:event1,system2:event2[,...]"
+// into a DisabledEvents object, returning an error if the string failed to parse.
+//
+// It sanitizes strings via strings.TrimSpace.
+func ParseDisabledEvents(s string) (DisabledEvents, error) {
+	s = strings.TrimSpace(s) // sanitize
+	evts := strings.Split(s, ",")
+	ret := make(DisabledEvents, 0, len(evts))
+	for _, evt := range evts {
+		evt = strings.TrimSpace(evt) // sanitize
+		s := strings.Split(evt, ":")
+		if len(s) != 2 {
+			return nil, fmt.Errorf("invalid event type: %s", s)
+		}
+		ret = append(ret, EventType{System: s[0], Event: s[1]})
+	}
+	return ret, nil
+}
+
 // EventType represents the signature of an event.
 type EventType struct {
 	System string
diff --git a/node/builder.go b/node/builder.go
index 08c48d408..028c9212e 100644
--- a/node/builder.go
+++ b/node/builder.go
@@ -3,6 +3,7 @@ package node
 import (
 	"context"
 	"errors"
+	"os"
 	"time"
 
 	logging "github.com/ipfs/go-log"
@@ -68,6 +69,10 @@ import (
 	"github.com/filecoin-project/lotus/storage/sectorblocks"
 )
 
+// EnvJournalDisabledEvents is the environment variable through which disabled
+// journal events can be customized.
+const EnvJournalDisabledEvents = "LOTUS_JOURNAL_DISABLED_EVENTS"
+
 //nolint:deadcode,varcheck
 var log = logging.Logger("builder")
 
@@ -157,7 +162,15 @@ type Settings struct {
 func defaults() []Option {
 	return []Option{
 		// global system journal.
-		Override(new(journal.DisabledEvents), journal.DefaultDisabledEvents),
+		Override(new(journal.DisabledEvents), func() journal.DisabledEvents {
+			if env, ok := os.LookupEnv(EnvJournalDisabledEvents); ok {
+				if ret, err := journal.ParseDisabledEvents(env); err == nil {
+					return ret
+				}
+			}
+			// fallback if env variable is not set, or if it failed to parse.
+			return journal.DefaultDisabledEvents
+		}),
 		Override(new(journal.Journal), modules.OpenFilesystemJournal),
 		Override(InitJournalKey, func(j journal.Journal) {
 			journal.J = j // eagerly sets the global journal through fx.Invoke.