support JSON output for kolide logs (#1026)

cli/serve.go

@@ -47,15 +47,19 @@ binary (which you're executing right now). Use the options below to customize
 the way that the kolide server works.
 `,
 		Run: func(cmd *cobra.Command, args []string) {
-			var (
-				ctx    = context.Background()
-				logger kitlog.Logger
-			)
-
+			ctx := context.Background()
 			config := configManager.LoadConfig()
 
-			logger = kitlog.NewLogfmtLogger(os.Stderr)
-			logger = kitlog.NewContext(logger).With("ts", kitlog.DefaultTimestampUTC)
+			var logger kitlog.Logger
+			{
+				output := os.Stderr
+				if config.Logging.JSON {
+					logger = kitlog.NewJSONLogger(output)
+				} else {
+					logger = kitlog.NewLogfmtLogger(output)
+				}
+				logger = kitlog.NewContext(logger).With("ts", kitlog.DefaultTimestampUTC)
+			}
 
 			var ds kolide.Datastore
 			var err error

server/config/config.go

@@ -68,6 +68,7 @@ type OsqueryConfig struct {
 // LoggingConfig defines configs related to logging
 type LoggingConfig struct {
 	Debug         bool
+	JSON          bool
 	DisableBanner bool
 }
 
@@ -129,6 +130,7 @@ func (man Manager) addConfigs() {
 
 	// Logging
 	man.addConfigBool("logging.debug", false)
+	man.addConfigBool("logging.json", false)
 	man.addConfigBool("logging.disable_banner", false)
 }
 
@@ -177,6 +179,7 @@ func (man Manager) LoadConfig() KolideConfig {
 		},
 		Logging: LoggingConfig{
 			Debug:         man.getConfigBool("logging.debug"),
+			JSON:          man.getConfigBool("logging.json"),
 			DisableBanner: man.getConfigBool("logging.disable_banner"),
 		},
 	}