Add the ability to set a custom hostname in the config

Fixes papertrail#126

README.md

@@ -273,6 +273,23 @@ destination:
 
 This functionality was introduced in version 0.17
 
+### Choosing hostname name
+
+To override the hostname, which is sent as the system's hostname by default,
+tell remote_syslog to set another hostname name using the `hostname` attribute
+in the configuration file:
+```
+files:
+  - path: /var/log/httpd/access_log
+    hostname: example.com
+destination:
+  host: logs.papertrailapp.com
+  port: 12345
+  protocol: tls
+```
+
+This is not supported by command line configurations.
+
 ## Troubleshooting
 
 ### Generate debug log

config.go

@@ -65,6 +65,7 @@ type Config struct {
 type LogFile struct {
 	Path string
 	Tag  string
+	Hostname string
 }
 
 func init() {
@@ -299,6 +300,8 @@ func decodeLogFiles(f interface{}) ([]LogFile, error) {
 		case string:
 			lf := strings.Split(val, "=")
 			switch len(lf) {
+			case 3:
+				files = append(files, LogFile{Tag: lf[0], Hostname: lf[1], Path: lf[2]})
 			case 2:
 				files = append(files, LogFile{Tag: lf[0], Path: lf[1]})
 			case 1:
@@ -310,17 +313,19 @@ func decodeLogFiles(f interface{}) ([]LogFile, error) {
 		case map[interface{}]interface{}:
 			var (
 				tag  string
+				hostname string
 				path string
 			)
 
 			tag, _ = val["tag"].(string)
+			hostname, _ = val["hostname"].(string)
 			path, _ = val["path"].(string)
 
 			if path == "" {
 				return files, fmt.Errorf("Invalid log file %#v", val)
 			}
 
-			files = append(files, LogFile{Tag: tag, Path: path})
+			files = append(files, LogFile{Tag: tag, Hostname: hostname, Path: path})
 
 		default:
 			panic(vals)

config_test.go

@@ -43,6 +43,11 @@ func TestRawConfig(t *testing.T) {
 			Tag:  "apache",
 			Path: "/var/log/httpd/access_log",
 		},
+		{
+			Tag:	"debian",
+			Path:	"/var/log/syslog",
+			Hostname: "myhost.mydomain.com",
+		},
 	})
 	assert.Equal(c.TcpMaxLineLength, 99991)
 	assert.Equal(c.NewFileCheckInterval, 10*time.Second)

examples/log_files.yml.example.advanced

@@ -6,6 +6,7 @@ files:
     tag: site2/access_log
   - path: /var/log/httpd/site2/error_log
     tag: site2/error_log
+    hostname: example.com
   - /opt/misc/*.log
   - /home/**/*.log
   - /var/log/mysqld.log

remote_syslog.go

@@ -93,7 +93,7 @@ func (s *Server) closing() bool {
 }
 
 // Tails a single file
-func (s *Server) tailOne(file, tag string, whence int) {
+func (s *Server) tailOne(file, tag string, hostname string, whence int) {
 	defer s.registry.Remove(file)
 
 	t, err := follower.New(file, follower.Config{
@@ -111,6 +111,10 @@ func (s *Server) tailOne(file, tag string, whence int) {
 		tag = path.Base(file)
 	}
 
+	if hostname == "" {
+		hostname = s.logger.ClientHostname
+	}
+
 	for {
 		select {
 		case line, ok := <-t.Lines():
@@ -139,7 +143,7 @@ func (s *Server) tailOne(file, tag string, whence int) {
 					Severity: s.config.Severity,
 					Facility: s.config.Facility,
 					Time:     time.Now(),
-					Hostname: s.logger.ClientHostname,
+					Hostname: hostname,
 					Tag:      tag,
 					Token:    s.config.Destination.Token,
 					Message:  l,
@@ -181,6 +185,7 @@ func (s *Server) globFiles(firstPass bool) {
 	for _, glob := range s.config.Files {
 
 		tag := glob.Tag
+		hostname := glob.Hostname
 		files, err := filepath.Glob(utils.ResolvePath(glob.Path))
 
 		if err != nil {
@@ -206,7 +211,7 @@ func (s *Server) globFiles(firstPass bool) {
 				}
 
 				s.registry.Add(file)
-				go s.tailOne(file, tag, whence)
+				go s.tailOne(file, tag, hostname, whence)
 			}
 		}
 	}

remote_syslog_test.go

@@ -77,6 +77,88 @@ func TestNewFileSeek(t *testing.T) {
 
 		packet := <-server.packets
 		assert.Equal(msg, packet.Message)
+		assert.Equal("testhost", packet.Hostname)
+	}
+}
+
+func TestCustomTag(t *testing.T) {
+	assert := assert.New(t)
+
+	// Close any existing channel and restart the testSyslogServer
+	server.closeCh <- struct{}{}
+	go server.serve()
+
+	// Add custom tag
+	config := testConfig()
+	config.Files = []LogFile {
+		{
+			Path: "tmp/*.log",
+			Tag: "customTag",
+		},
+	}
+
+	s := NewServer(config)
+	go s.Start()
+	defer s.Close()
+
+	// just a quick rest to get the server started
+	time.Sleep(1 * time.Second)
+
+	for _, msg := range []string{
+		"welcome to the jungle",
+		"we got alerts and logs",
+		"we got everything you want",
+		"as long as it's alerts and logs",
+	} {
+		file := tmpLogFile()
+		defer file.Close()
+
+		writeLog(file, msg)
+
+		packet := <-server.packets
+		assert.Equal(msg, packet.Message)
+		assert.Equal("customTag", packet.Tag)
+		assert.Equal("testhost", packet.Hostname)
+	}
+}
+
+func TestCustomHostname(t *testing.T) {
+	assert := assert.New(t)
+
+	// Close any existing channel and restart the testSyslogServer
+	server.closeCh <- struct{}{}
+	go server.serve()
+
+	// Add custom hostname
+	config := testConfig()
+	config.Files = []LogFile {
+		{
+			Path: "tmp/*.log",
+			Hostname: "custom.hostname",
+		},
+	}
+
+	s := NewServer(config)
+	go s.Start()
+	defer s.Close()
+
+	// just a quick rest to get the server started
+	time.Sleep(1 * time.Second)
+
+	for _, msg := range []string{
+		"welcome to the jungle",
+		"we got alerts and logs",
+		"we got everything you want",
+		"as long as it's alerts and logs",
+	} {
+		file := tmpLogFile()
+		defer file.Close()
+
+		writeLog(file, msg)
+
+		packet := <-server.packets
+		assert.Equal(msg, packet.Message)
+		assert.Equal("custom.hostname", packet.Hostname)
 	}
 }
 

test/config.yaml

@@ -4,6 +4,9 @@ files:
   - "nginx=/var/log/nginx/nginx.log"
   - path: /var/log/httpd/access_log
     tag: apache
+  - path: /var/log/syslog
+    tag: debian
+    hostname: myhost.mydomain.com
 destination:
   host: logs.papertrailapp.com
   port: 514