config: add logging config options

This commit adds config options so that users can for both the console
logger and the file logger set the following things:

- disable the logger
- omit timestamps from log lines.

build/config.go

@@ -0,0 +1,38 @@
+package build
+
+import "github.com/btcsuite/btclog/v2"
+
+// LogConfig holds logging configuration options.
+//
+//nolint:lll
+type LogConfig struct {
+	Console *LoggerConfig `group:"console" namespace:"console" description:"The logger writing to stdout and stderr."`
+	File    *LoggerConfig `group:"file" namespace:"file" description:"The logger writing to LND's standard log file."`
+}
+
+// DefaultLogConfig returns the default logging config options.
+func DefaultLogConfig() *LogConfig {
+	return &LogConfig{
+		Console: &LoggerConfig{},
+		File:    &LoggerConfig{},
+	}
+}
+
+// LoggerConfig holds options for a particular logger.
+//
+//nolint:lll
+type LoggerConfig struct {
+	Disable      bool `long:"disable" description:"Disable this logger."`
+	NoTimestamps bool `long:"no-timestamps" description:"Omit timestamps from log lines."`
+}
+
+// HandlerOptions returns the set of btclog.HandlerOptions that the state of the
+// config struct translates to.
+func (cfg *LoggerConfig) HandlerOptions() []btclog.HandlerOption {
+	var opts []btclog.HandlerOption
+	if cfg.NoTimestamps {
+		opts = append(opts, btclog.WithNoTimestamp())
+	}
+
+	return opts
+}