agent: Adding remote exec configuration

command/agent/config.go

@@ -235,6 +235,10 @@ type Config struct {
 	// agent layer using the standard APIs.
 	Watches []map[string]interface{} `mapstructure:"watches"`
 
+	// DisableRemoteExec is used to turn off the remote execution
+	// feature. This is for security to prevent unknown scripts from running.
+	DisableRemoteExec bool `mapstructure:"disable_remote_exec"`
+
 	// AEInterval controls the anti-entropy interval. This is how often
 	// the agent attempts to reconcile it's local state with the server'
 	// representation of our state. Defaults to every 60s.
@@ -676,6 +680,9 @@ func MergeConfig(a, b *Config) *Config {
 	if len(b.WatchPlans) != 0 {
 		result.WatchPlans = append(result.WatchPlans, b.WatchPlans...)
 	}
+	if b.DisableRemoteExec {
+		result.DisableRemoteExec = true
+	}
 
 	// Copy the start join addresses
 	result.StartJoin = make([]string, 0, len(a.StartJoin)+len(b.StartJoin))

command/agent/config_test.go

@@ -405,6 +405,17 @@ func TestDecodeConfig(t *testing.T) {
 	if !reflect.DeepEqual(out, exp) {
 		t.Fatalf("bad: %#v", config)
 	}
+
+	// remote exec
+	input = `{"disable_remote_exec": true}`
+	config, err = DecodeConfig(bytes.NewReader([]byte(input)))
+	if err != nil {
+		t.Fatalf("err: %s", err)
+	}
+
+	if !config.DisableRemoteExec {
+		t.Fatalf("bad: %#v", config)
+	}
 }
 
 func TestDecodeConfig_Service(t *testing.T) {
@@ -566,6 +577,7 @@ func TestMergeConfig(t *testing.T) {
 				"handler": "foobar",
 			},
 		},
+		DisableRemoteExec: true,
 	}
 
 	c := MergeConfig(a, b)