Go Elastic Logger

---

How to use logger package

1. Download the package :

For ElasticSearch 8

    go get github.com/cploutarchou/go-elastic-logger/v8

For ElasticSearch 7

    go get github.com/cploutarchou/go-elastic-logger/v7

2. Import the package :

For ElasticSearch 8

    import github.com/cploutarchou/go-elastic-logger/v8

For ElasticSearch 7

    import github.com/cploutarchou/go-elastic-logger/v8

3. Set the Elasticsearch client:

   cfg := elasticsearch.Config{
    Addresses: []string{"http://localhost:9200"},
    }
    client, err := elasticsearch.NewClient(cfg)
    if err != nil {
        panic(err)
    }
    SetElasticsearchClient(client)

4. Set the index name:

    SetIndex("myindex")

5. Set the log level

    SetLogLevel(DEBUG)

6. Use the log level function

    Debug("Debug message")
    Debugf("Debug message with format: %s", "hello")
    Info("Info message")
    Infof("Info message with format: %d", 123)
    Warning("Warning message")
    Warningf("Warning message with format: %f", 3.14)
    Error("Error message")
    Errorf("Error message with format: %t", true)
    Fatal("Fatal message")
    Fatalf("Fatal message with format: %v", "goodbye")

Notes:

• The package will output logs to stdout and index them in Elasticsearch.
• The package is concurrent safe and the elasticsearch client will be initiated only once.
• If you want to change the timestamp format you can change the format by using the SetTimeFormat()function. Default layout is 2023-01-02 15:04:05
• You can use the SetLogLevel function to filter the logs you want to see based on the log level.

Example:

package main

import (
	"github.com/cploutarchou/go-elastic-logger/v8"
	"github.com/elastic/go-elasticsearch/v8"
)

// setElasticClient sets the elasticsearch client to be used for logging.
func setElasticClient() {
	cnf := elasticsearch.Config{
		Addresses: []string{"http://localhost:9200"},
		Username:  "your_username",
		Password:  "your_password",
	}
	client, err := elasticsearch.NewClient(cnf)
	if err != nil {
		panic(err)
	}
	//sets the client as the Elasticsearch client to be used.
	SetElasticsearchClient(client)

}

func testFnc() {
	// sets the index name to be used for logging.
	SetIndex("logs")
	//sets the log level to debug.
	SetLogLevel(DEBUG)
	//sets the format of the timestamp in the logs.
	SetTimeFormat("2006-01-02 15:04:05")
	//logs a debug message.
	Debug("This is a debug message")
	return
}
func main() {
	//sets the elasticsearch client to be used for logging.
	setElasticClient()
	testFnc()
}

Elastic Doc Example:

{
  "took": 14,
  "timed_out": false,
  "_shards": {
    "total": 1,
    "successful": 1,
    "skipped": 0,
    "failed": 0
  },
  "hits": {
    "total": {
      "value": 1,
      "relation": "eq"
    },
    "max_score": 1.0,
    "hits": [
      {
        "_index": "logs",
        "_id": "mNxvsYUBolkbQeSRmtCN",
        "_score": 1.0,
        "_source": {
          "file": "/Users/christos/workspace/go-elastic-logger/main.go:31",
          "function": "testFnc()",
          "level": "DEBUG",
          "message": "This is a debug message",
          "timestamp": "2023-01-14 19:59:18"
        }
      }
    ]
  }
}