From 437e16ca71a709dbc08495934fae7be63f302c02 Mon Sep 17 00:00:00 2001
From: Ivan Kozlovic <ivan@synadia.com>
Date: Thu, 30 May 2019 15:24:39 -0600
Subject: [PATCH 1/2] Added a function to allow ignoring top-level unknown
 config option

This will be required for NATS Streaming server since streaming
allows user to have NATS and Streaming specific options in same
file.

Signed-off-by: Ivan Kozlovic <ivan@synadia.com>
---
 server/opts.go      | 16 +++++++++++++++-
 server/opts_test.go | 41 +++++++++++++++++++++++++++++++++++++++++
 2 files changed, 56 insertions(+), 1 deletion(-)

diff --git a/server/opts.go b/server/opts.go
index b799c18a..904cf295 100644
--- a/server/opts.go
+++ b/server/opts.go
@@ -27,6 +27,7 @@ import (
 	"regexp"
 	"strconv"
 	"strings"
+	"sync/atomic"
 	"time"
 
 	"github.com/nats-io/jwt"
@@ -34,6 +35,19 @@ import (
 	"github.com/nats-io/nkeys"
 )
 
+var allowUnknownTopLevelField = int32(0)
+
+// AllowUnknownTopLevelConfigurationField sets if the processing of a
+// configuration file returns an error if it finds an unknown top-level
+// configuration option.
+func AllowUnknownTopLevelConfigurationField(allow bool) {
+	var val int32
+	if allow {
+		val = int32(1)
+	}
+	atomic.StoreInt32(&allowUnknownTopLevelField, val)
+}
+
 // ClusterOpts are options for clusters.
 // NOTE: This structure is no longer used for monitoring endpoints
 // and json tags are deprecated and may be removed in the future.
@@ -693,7 +707,7 @@ func (o *Options) ProcessConfigFile(configFile string) error {
 		case "reconnect_error_reports":
 			o.ReconnectErrorReports = int(v.(int64))
 		default:
-			if !tk.IsUsedVariable() {
+			if au := atomic.LoadInt32(&allowUnknownTopLevelField); au == 0 && !tk.IsUsedVariable() {
 				err := &unknownConfigFieldErr{
 					field: k,
 					configErr: configErr{
diff --git a/server/opts_test.go b/server/opts_test.go
index 070acd8e..95bb05b1 100644
--- a/server/opts_test.go
+++ b/server/opts_test.go
@@ -1819,3 +1819,44 @@ func TestLargeMaxPayload(t *testing.T) {
 		t.Fatalf("Expected an error from too large of a max_payload entry")
 	}
 }
+
+func TestHandleUnknownTopLevelConfigurationField(t *testing.T) {
+	conf := createConfFile(t, []byte(`
+		port: 1234
+		streaming {
+			id: "me"
+		}
+	`))
+	defer os.Remove(conf)
+
+	// Verify that we get an error because of unknown "streaming" field.
+	opts := &Options{}
+	if err := opts.ProcessConfigFile(conf); err == nil || !strings.Contains(err.Error(), "streaming") {
+		t.Fatal("Expected error, got none")
+	}
+
+	// Verify that if that is set, we get no error
+	AllowUnknownTopLevelConfigurationField(true)
+	defer AllowUnknownTopLevelConfigurationField(false)
+
+	if err := opts.ProcessConfigFile(conf); err != nil {
+		t.Fatalf("Unexpected error: %v", err)
+	}
+	if opts.Port != 1234 {
+		t.Fatalf("Port was not parsed correctly: %v", opts.Port)
+	}
+
+	// Verify that ignore works only on top level fields.
+	changeCurrentConfigContentWithNewContent(t, conf, []byte(`
+		port: 1234
+		cluster {
+			non_top_level_unknown_field: 123
+		}
+		streaming {
+			id: "me"
+		}
+	`))
+	if err := opts.ProcessConfigFile(conf); err == nil || !strings.Contains(err.Error(), "non_top_level") {
+		t.Fatal("Expected error, got none")
+	}
+}

From 451d4bb05c4633b9157fa401ec79279c31c6b536 Mon Sep 17 00:00:00 2001
From: Ivan Kozlovic <ivan@synadia.com>
Date: Thu, 30 May 2019 16:25:37 -0600
Subject: [PATCH 2/2] Change name of public function

Signed-off-by: Ivan Kozlovic <ivan@synadia.com>
---
 server/opts.go      | 11 ++++++-----
 server/opts_test.go |  4 ++--
 2 files changed, 8 insertions(+), 7 deletions(-)

diff --git a/server/opts.go b/server/opts.go
index 904cf295..33d48a06 100644
--- a/server/opts.go
+++ b/server/opts.go
@@ -37,12 +37,13 @@ import (
 
 var allowUnknownTopLevelField = int32(0)
 
-// AllowUnknownTopLevelConfigurationField sets if the processing of a
-// configuration file returns an error if it finds an unknown top-level
-// configuration option.
-func AllowUnknownTopLevelConfigurationField(allow bool) {
+// NoErrOnUnknownFields can be used to change the behavior the processing
+// of a configuration file. By default, an error is reported if unknown
+// fields are found. If `noError` is set to true, no error will be reported
+// if top-level unknown fields are found.
+func NoErrOnUnknownFields(noError bool) {
 	var val int32
-	if allow {
+	if noError {
 		val = int32(1)
 	}
 	atomic.StoreInt32(&allowUnknownTopLevelField, val)
diff --git a/server/opts_test.go b/server/opts_test.go
index 95bb05b1..5986e889 100644
--- a/server/opts_test.go
+++ b/server/opts_test.go
@@ -1836,8 +1836,8 @@ func TestHandleUnknownTopLevelConfigurationField(t *testing.T) {
 	}
 
 	// Verify that if that is set, we get no error
-	AllowUnknownTopLevelConfigurationField(true)
-	defer AllowUnknownTopLevelConfigurationField(false)
+	NoErrOnUnknownFields(true)
+	defer NoErrOnUnknownFields(false)
 
 	if err := opts.ProcessConfigFile(conf); err != nil {
 		t.Fatalf("Unexpected error: %v", err)