From b8740b62daca01b4a7f7c1d136752b90e81fd280 Mon Sep 17 00:00:00 2001
From: Ryan Uber <ru@ryanuber.com>
Date: Mon, 5 Jan 2015 12:30:03 -0800
Subject: [PATCH 1/2] agent: reject config with invalid options

---
 command/agent/config.go      | 12 ++++++++++--
 command/agent/config_test.go |  9 +++++++++
 2 files changed, 19 insertions(+), 2 deletions(-)

diff --git a/command/agent/config.go b/command/agent/config.go
index 707cd43ade76..cecaf7c4a183 100644
--- a/command/agent/config.go
+++ b/command/agent/config.go
@@ -335,6 +335,13 @@ type Config struct {
 
 	// WatchPlans contains the compiled watches
 	WatchPlans []*watch.WatchPlan `mapstructure:"-" json:"-"`
+
+	// Allow the following fields to be present in configuration files without
+	// mapstructure erroring on them.
+	_ interface{} `mapstructure:"services"`
+	_ interface{} `mapstructure:"checks"`
+	_ interface{} `mapstructure:"service"`
+	_ interface{} `mapstructure:"check"`
 }
 
 type dirEnts []os.FileInfo
@@ -463,8 +470,9 @@ func DecodeConfig(r io.Reader) (*Config, error) {
 	// Decode
 	var md mapstructure.Metadata
 	msdec, err := mapstructure.NewDecoder(&mapstructure.DecoderConfig{
-		Metadata: &md,
-		Result:   &result,
+		Metadata:    &md,
+		Result:      &result,
+		ErrorUnused: true,
 	})
 	if err != nil {
 		return nil, err
diff --git a/command/agent/config_test.go b/command/agent/config_test.go
index 13e8634ce44f..f0bbd9e61c3d 100644
--- a/command/agent/config_test.go
+++ b/command/agent/config_test.go
@@ -7,6 +7,7 @@ import (
 	"os"
 	"path/filepath"
 	"reflect"
+	"strings"
 	"testing"
 	"time"
 )
@@ -591,6 +592,14 @@ func TestDecodeConfig(t *testing.T) {
 	}
 }
 
+func TestDecodeConfig_invalidKeys(t *testing.T) {
+	input := `{"bad": "no way jose"}`
+	_, err := DecodeConfig(bytes.NewReader([]byte(input)))
+	if err == nil || !strings.Contains(err.Error(), "invalid keys") {
+		t.Fatalf("should have rejected invalid config keys")
+	}
+}
+
 func TestDecodeConfig_Services(t *testing.T) {
 	input := `{
 		"services": [

From 42ace3a6b5fae1f0af5a6e7bbb63d4a432c6f229 Mon Sep 17 00:00:00 2001
From: Ryan Uber <ru@ryanuber.com>
Date: Mon, 5 Jan 2015 14:41:19 -0800
Subject: [PATCH 2/2] agent: use mapstructure's Metadata.Unused to detect
 extraneous config

---
 command/agent/config.go | 26 ++++++++++++++++----------
 1 file changed, 16 insertions(+), 10 deletions(-)

diff --git a/command/agent/config.go b/command/agent/config.go
index cecaf7c4a183..e9846786644b 100644
--- a/command/agent/config.go
+++ b/command/agent/config.go
@@ -335,13 +335,6 @@ type Config struct {
 
 	// WatchPlans contains the compiled watches
 	WatchPlans []*watch.WatchPlan `mapstructure:"-" json:"-"`
-
-	// Allow the following fields to be present in configuration files without
-	// mapstructure erroring on them.
-	_ interface{} `mapstructure:"services"`
-	_ interface{} `mapstructure:"checks"`
-	_ interface{} `mapstructure:"service"`
-	_ interface{} `mapstructure:"check"`
 }
 
 type dirEnts []os.FileInfo
@@ -470,9 +463,8 @@ func DecodeConfig(r io.Reader) (*Config, error) {
 	// Decode
 	var md mapstructure.Metadata
 	msdec, err := mapstructure.NewDecoder(&mapstructure.DecoderConfig{
-		Metadata:    &md,
-		Result:      &result,
-		ErrorUnused: true,
+		Metadata: &md,
+		Result:   &result,
 	})
 	if err != nil {
 		return nil, err
@@ -482,6 +474,20 @@ func DecodeConfig(r io.Reader) (*Config, error) {
 		return nil, err
 	}
 
+	// Check unused fields and verify that no bad configuration options were
+	// passed to Consul. There are a few additional fields which don't directly
+	// use mapstructure decoding, so we need to account for those as well.
+	allowedKeys := []string{"service", "services", "check", "checks"}
+	var unused []string
+	for _, field := range md.Unused {
+		if !strContains(allowedKeys, field) {
+			unused = append(unused, field)
+		}
+	}
+	if len(unused) > 0 {
+		return nil, fmt.Errorf("Config has invalid keys: %s", strings.Join(unused, ","))
+	}
+
 	// Handle time conversions
 	if raw := result.DNSConfig.NodeTTLRaw; raw != "" {
 		dur, err := time.ParseDuration(raw)