Fix incorrect severity syslog messages (#12079)

Co-authored-by: Evan Culver <eculver@hashicorp.com>

.changelog/12079.txt

@@ -0,0 +1,3 @@
+```release-note:bug
+logging: fix a bug with incorrect severity syslog messages (all messages were sent with NOTICE severity).
+```

.circleci/config.yml

@@ -225,6 +225,8 @@ jobs:
       - image: *GOLANG_IMAGE
     environment:
       <<: *ENVIRONMENT
+      # tput complains if this isn't set to something.
+      TERM: ansi
     steps:
       - checkout
       - run:

logging/logger.go

@@ -77,7 +77,7 @@ func Setup(config Config, out io.Writer) (hclog.InterceptLogger, error) {
 		for i := 0; i <= retries; i++ {
 			syslog, err := gsyslog.NewLogger(gsyslog.LOG_NOTICE, config.SyslogFacility, "consul")
 			if err == nil {
-				writers = append(writers, syslog)
+				writers = append(writers, &SyslogWrapper{l: syslog})
 				break
 			}
 

logging/syslog.go

@@ -3,7 +3,7 @@ package logging
 import (
 	"bytes"
 
-	"github.com/hashicorp/go-syslog"
+	gsyslog "github.com/hashicorp/go-syslog"
 )
 
 // levelPriority is used to map a log level to a
@@ -34,7 +34,7 @@ func (s *SyslogWrapper) Write(p []byte) (int, error) {
 		y := bytes.IndexByte(p[x:], ']')
 		if y >= 0 {
 			level = string(p[x+1 : x+y])
-			afterLevel = p[x+y+2:]
+			afterLevel = bytes.TrimLeft(p[x+y+2:], " ")
 		}
 	}
 

logging/syslog_test.go

@@ -0,0 +1,77 @@
+//go:build linux || darwin || dragonfly || freebsd || netbsd || openbsd || solaris
+// +build linux darwin dragonfly freebsd netbsd openbsd solaris
+
+package logging
+
+import (
+	"testing"
+
+	gsyslog "github.com/hashicorp/go-syslog"
+	"github.com/stretchr/testify/require"
+)
+
+// testSyslogFunc is a wrapper for injecting WriteLevel functionality into a Syslogger
+// implementation; it gives us a way to inject test assertions into a SyslogWrapper.
+type testSyslogWriteLevelFunc func(p gsyslog.Priority, m []byte) error
+
+// Write is a no-op
+func (f testSyslogWriteLevelFunc) Write(p []byte) (int, error) {
+	return 0, nil
+}
+
+// WriteLevel is a wrapper for the identity to be called
+func (f testSyslogWriteLevelFunc) WriteLevel(p gsyslog.Priority, m []byte) error {
+	return f(p, m)
+}
+
+// Close is a no-op
+func (f testSyslogWriteLevelFunc) Close() error {
+	return nil
+}
+
+func TestSyslog_Wrapper(t *testing.T) {
+	expectedMsg := []byte("test message")
+
+	// generator for a writer that expects to be written with expectedPriority
+	writerForPriority := func(expectedPriority gsyslog.Priority) testSyslogWriteLevelFunc {
+		return func(p gsyslog.Priority, m []byte) error {
+			require.Equal(t, expectedPriority, p)
+			require.Equal(t, expectedMsg, m)
+			return nil
+		}
+	}
+	// [TRACE] is mapped to the LOG_DEBUG priority
+	debugw := &SyslogWrapper{l: writerForPriority(gsyslog.LOG_DEBUG)}
+	_, err := debugw.Write([]byte("[TRACE]   " + string(expectedMsg)))
+	require.NoError(t, err)
+
+	// [DEBUG] is mapped to the LOG_INFO priority
+	infow := &SyslogWrapper{l: writerForPriority(gsyslog.LOG_INFO)}
+	_, err = infow.Write([]byte("[DEBUG]     " + string(expectedMsg)))
+	require.NoError(t, err)
+
+	// [INFO] is mapped to the LOG_NOTICE priority
+	noticew := &SyslogWrapper{l: writerForPriority(gsyslog.LOG_NOTICE)}
+	_, err = noticew.Write([]byte("[INFO]     " + string(expectedMsg)))
+	require.NoError(t, err)
+
+	// [WARN] is mapped to the LOG_WARNING priority
+	warnw := &SyslogWrapper{l: writerForPriority(gsyslog.LOG_WARNING)}
+	_, err = warnw.Write([]byte("[WARN]     " + string(expectedMsg)))
+	require.NoError(t, err)
+
+	// [ERROR] is mapped to the LOG_ERR priority
+	errorw := &SyslogWrapper{l: writerForPriority(gsyslog.LOG_ERR)}
+	_, err = errorw.Write([]byte("[ERROR]        " + string(expectedMsg)))
+	require.NoError(t, err)
+
+	// [CRIT] is mapped to the LOG_CRIT priority
+	critw := &SyslogWrapper{l: writerForPriority(gsyslog.LOG_CRIT)}
+	_, err = critw.Write([]byte("[CRIT]  " + string(expectedMsg)))
+	require.NoError(t, err)
+
+	// unknown levels are written with LOG_NOTICE priority
+	defaultw := &SyslogWrapper{l: writerForPriority(gsyslog.LOG_NOTICE)}
+	_, err = defaultw.Write([]byte("[INVALID]     " + string(expectedMsg)))
+	require.NoError(t, err)
+}

logging/syslog_unsupported_test.go

@@ -0,0 +1,20 @@
+//go:build windows || plan9 || nacl
+// +build windows plan9 nacl
+
+package logging
+
+import (
+	"testing"
+
+	gsyslog "github.com/hashicorp/go-syslog"
+	"github.com/stretchr/testify/require"
+)
+
+func TestSyslog_Unsupported(t *testing.T) {
+	// the role of the underlying go-syslog library is primarily to wrap the
+	// default log/syslog package such that when running against an unsupported
+	// OS, a meaningful error is returned, so that's what we'll test here by default.
+	s, err := gsyslog.NewLogger(gsyslog.LOG_NOTICE, "USER", "consul")
+	require.Error(t, err)
+	require.Nil(t, s)
+}