[feature] Make log format configurable (#2130)

* [feature] Don't emit timestamp in log lines

When running gotosocial with a service manager like systemd, or a
container runtime, the associated log driver usually emits timestamps
itself. In those cases, having the extra timestamp from our own log
lines ends up being a bit noisy and when centrally ingesting logs is
duplicate information.

This introduces a configuration flag that allows disabling emitting the
timestamp. It's only wired up for "daemonised" processes, meaning server
and testrig.

* [chore] Add docs for log-timestamp

* [feature] Simplify timestamp handling

Co-Authored-By: kim <89579420+NyaaaWhatsUpDoc@users.noreply.github.com>

* [chore] Less escaped double-quotes

* [chore] Fix help string

---------

Co-authored-by: kim <89579420+NyaaaWhatsUpDoc@users.noreply.github.com>

1 files changed, 16 insertions, 0 deletions

diff --git a/internal/log/syslog_test.go b/internal/log/syslog_test.go
index e7e82ec58..7432e61b3 100644
--- a/internal/log/syslog_test.go
+++ b/internal/log/syslog_test.go
@@ -71,6 +71,22 @@ func (suite *SyslogTestSuite) TestSyslog() {
 	suite.Regexp(regexp.MustCompile(`timestamp=.* func=.* level=INFO msg="this is a test of the emergency broadcast system!"`), entry["content"])
 }
 
+func (suite *SyslogTestSuite) TestSyslogDisableTimestamp() {
+	// Get the current format.
+	timefmt := log.TimeFormat()
+
+	// Set an empty timestamp.
+	log.SetTimeFormat("")
+
+	// Set old timestamp on return.
+	defer log.SetTimeFormat(timefmt)
+
+	log.Info(nil, "this is a test of the emergency broadcast system!")
+
+	entry := <-suite.syslogChannel
+	suite.Regexp(regexp.MustCompile(`func=.* level=INFO msg="this is a test of the emergency broadcast system!"`), entry["content"])
+}
+
 func (suite *SyslogTestSuite) TestSyslogLongMessage() {
 	log.Warn(nil, longMessage)