initial commit

.gitignore

@@ -0,0 +1,18 @@
+# Binaries for programs and plugins
+*.exe
+*.exe~
+*.dll
+*.so
+*.dylib
+
+# Test binary, built with `go test -c`
+*.test
+
+# Output of the go coverage tool, specifically when used with LiteIDE
+*.out
+
+# Dependency directories (remove the comment below to include it)
+# vendor/
+
+# Go workspace file
+go.work

LICENSE

@@ -0,0 +1,21 @@
+MIT License
+
+Copyright (c) 2023 Karan Jagtiani
+
+Permission is hereby granted, free of charge, to any person obtaining a copy
+of this software and associated documentation files (the "Software"), to deal
+in the Software without restriction, including without limitation the rights
+to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+copies of the Software, and to permit persons to whom the Software is
+furnished to do so, subject to the following conditions:
+
+The above copyright notice and this permission notice shall be included in all
+copies or substantial portions of the Software.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+SOFTWARE.

README.md

@@ -0,0 +1,77 @@
+# go-logstash
+Logstash Logger written in Go that pushes logs directly to [Logstash](https://www.elastic.co/products/logstash). It supports writing outputs to Logstash in JSON format as well as String format.
+
+### **Features**
+
+- Supports TCP and UDP protocols for sending logs to Logstash.
+- Supports writing logs in both JSON and string formats.
+- Provides customisable options for configuring the Logstash connection.
+
+### **Getting Started**
+
+#### 1. Install the package using:
+
+```
+go get github.com/KaranJagtiani/go-logstash
+```
+
+#### 2. Import the package in your Go application:
+
+```go
+import "github.com/KaranJagtiani/go-logstash"
+```
+#### 3. Initialize the **`logstash_logger`** instance with your Logstash server details and connection type:
+
+```go
+logger := logstash_logger.Init("<host>", <port>, "protocol", <timeout>)
+```
+
+The `logstash_logger.Init()` has the following configuration options:
+
+- Host: Logstash server hostname.
+- Port: Logstash server port number.
+- Protocol: Logstash connection protocol, either "tcp" or "udp".
+- Timeout: Connection timeout in seconds.
+
+Example:
+```go
+logger := logstash_logger.Init("logstash", 5228, "udp", 5)
+```
+
+#### 4. Use one of the different methods provided for sending logs to Logstash:
+
+```go
+payload := map[string]interface{}{
+		"message": "test message",
+		"error":   false,
+}
+
+// Generic - For logging the payload as it is
+logger.Log(payload)
+
+// Adds a attribute called "severity": "INFO" to the payload
+logger.Info(payload)
+
+// Adds a attribute called "severity": "DEBUG" to the payload
+logger.Debug(payload)
+
+// Adds a attribute called "severity": "WARN" to the payload
+logger.Warn(payload)
+
+// Adds a attribute called "severity": "ERROR" to the payload
+logger.Error(payload)
+
+// For sending a string message to Logstash
+logger.LogString("String Message")
+```
+
+### **Contribution**
+Contributions to go-logstash are welcome! If you find a bug or want to add a new feature, please create an issue or submit a pull request here on GitHub.
+
+#### Submit a Pull Request
+1. Fork this repository.
+2. Create your feature branch (git checkout -b my-new-feature).
+3. Commit your changes (git commit -am 'Add some feature').
+4. Push to the branch (git push origin my-new-feature).
+5. Create a new Pull Request.
+

connection.go

@@ -0,0 +1,37 @@
+package logstash_logger
+
+import (
+	"fmt"
+	"log"
+	"net"
+	"time"
+)
+
+func (l *logstash) initLoggerConnection() {
+	logstashAddr := fmt.Sprintf("%s:%d", l.host, l.port)
+	if l.connectionType == "udp" {
+		netConnTemp, err := net.Dial("udp", logstashAddr)
+		if err != nil {
+			log.Printf("[Logstash Logger] Failed to connect to Logstash: %s\n", err)
+		}
+		l.connection = netConnTemp
+	} else if l.connectionType == "tcp" {
+		netConnTemp, err := net.Dial("tcp", logstashAddr)
+		if err != nil {
+			log.Printf("[Logstash Logger] Failed to connect to Logstash: %s\n", err)
+		}
+		l.connection = netConnTemp
+	} else {
+		log.Println("[Logstash Logger] Invalid 'ConnectionType' provided. Please provide one of the following: tcp, udp")
+		return
+	}
+
+	l.setTimeout()
+}
+
+func (l *logstash) setTimeout() {
+	deadline := time.Now().Add(time.Duration(l.timeout) * time.Second)
+	l.connection.SetDeadline(deadline)
+	l.connection.SetWriteDeadline(deadline)
+	l.connection.SetReadDeadline(deadline)
+}

go-logstash.go

@@ -0,0 +1,33 @@
+package logstash_logger
+
+func (l *logstash) Log(payload map[string]interface{}) {
+	l.pushJsonMessage(payload)
+}
+
+func (l *logstash) Info(payload map[string]interface{}) {
+	payload["severity"] = "INFO"
+	l.pushJsonMessage(payload)
+	delete(payload, "severity")
+}
+
+func (l *logstash) Debug(payload map[string]interface{}) {
+	payload["severity"] = "DEBUG"
+	l.pushJsonMessage(payload)
+	delete(payload, "severity")
+}
+
+func (l *logstash) Warn(payload map[string]interface{}) {
+	payload["severity"] = "WARN"
+	l.pushJsonMessage(payload)
+	delete(payload, "severity")
+}
+
+func (l *logstash) Error(payload map[string]interface{}) {
+	payload["severity"] = "ERROR"
+	l.pushJsonMessage(payload)
+	delete(payload, "severity")
+}
+
+func (l *logstash) LogString(stringMsg string) {
+	l.pushStringMessage(stringMsg)
+}

go.mod

@@ -0,0 +1,3 @@
+module github.com/KaranJagtiani/go-logstash
+
+go 1.18

init-logstash.go

@@ -0,0 +1,10 @@
+package logstash_logger
+
+func Init(hostname string, port int, connection_type string, timeout int) *logstash {
+	l := logstash{}
+	l.host = hostname
+	l.port = port
+	l.connectionType = connection_type
+	l.timeout = timeout
+	return &l
+}

init.go

@@ -0,0 +1,7 @@
+package logstash_logger
+
+import "log"
+
+func init() {
+	log.Printf("[Logstash Logger] initializing...")
+}

push-message.go

@@ -0,0 +1,44 @@
+package logstash_logger
+
+import (
+	"encoding/json"
+	"log"
+)
+
+func (l *logstash) pushJsonMessage(jsonMsg map[string]interface{}) {
+	l.initLoggerConnection()
+
+	if l.connection == nil {
+		log.Println("[Logstash Logger] Logger was not initialized properly, could not push message.")
+		return
+	}
+
+	jsonData, err := json.Marshal(jsonMsg)
+
+	if err != nil {
+		log.Printf("[Logstash Logger] Failed to parse JSON object: %s\n", err)
+	}
+
+	_, connWriteError := l.connection.Write(jsonData)
+	if connWriteError != nil {
+		log.Printf("[Logstash Logger] Failed to send log JSON message: %s\n", connWriteError)
+	}
+
+	l.connection.Close()
+}
+
+func (l *logstash) pushStringMessage(stringMsg string) {
+	l.initLoggerConnection()
+
+	if l.connection == nil {
+		log.Println("[Logstash Logger] Logger was not initialized properly, could not push message.")
+		return
+	}
+
+	_, connWriteError := l.connection.Write([]byte(stringMsg))
+	if connWriteError != nil {
+		log.Printf("[Logstash Logger] Failed to send log String message: %s\n", connWriteError)
+	}
+
+	l.connection.Close()
+}

type.go

@@ -0,0 +1,11 @@
+package logstash_logger
+
+import "net"
+
+type logstash struct {
+	host           string
+	port           int
+	connectionType string
+	timeout        int
+	connection     net.Conn
+}