further yak shaving

internal/log/log.go

@@ -0,0 +1,58 @@
+/*
+   GoToSocial
+   Copyright (C) 2021 GoToSocial Authors admin@gotosocial.org
+
+   This program is free software: you can redistribute it and/or modify
+   it under the terms of the GNU Affero General Public License as published by
+   the Free Software Foundation, either version 3 of the License, or
+   (at your option) any later version.
+
+   This program is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+   GNU Affero General Public License for more details.
+
+   You should have received a copy of the GNU Affero General Public License
+   along with this program.  If not, see <http://www.gnu.org/licenses/>.
+*/
+
+package log
+
+import (
+	"bytes"
+	"os"
+
+	"github.com/sirupsen/logrus"
+)
+
+// New returns a new logrus logger with the specified level,
+// or an error if that level can't be parsed
+func New(level string) (*logrus.Logger, error) {
+	log := logrus.New()
+	log.SetOutput(&outputSplitter{})
+	return setLogLevel(level, log)
+}
+
+// outputSplitter implements the io.Writer interface for use with Logrus, and simply
+// splits logs between stdout and stderr depending on their severity.
+// See: https://github.com/sirupsen/logrus/issues/403#issuecomment-346437512
+type outputSplitter struct{}
+
+func (splitter *outputSplitter) Write(p []byte) (n int, err error) {
+	if bytes.Contains(p, []byte("level=error")) {
+		return os.Stderr.Write(p)
+	}
+	return os.Stdout.Write(p)
+}
+
+// setLogLevel will try to set the logrus log level to the
+// desired level specified by the user with the --log-level flag
+func setLogLevel(level string, logger *logrus.Logger) (*logrus.Logger, error) {
+	log := logrus.New()
+	logLevel, err := logrus.ParseLevel(level)
+	if err != nil {
+		return nil, err
+	}
+	log.SetLevel(logLevel)
+	return log, nil
+}