Noodlog

Summary

Noodlog is a Golang JSON parametrized and highly configurable logging library.

It allows you to:

• print go structs as JSON messages;
• print JSON strings and raw strings messages as pure JSONs;
• obscure some sensitive params from your logging;
• chain objects or strings in your logs;
• apply string templates to your logs;
• choose to trace the caller file and function and fine tune the settings;
• apply pretty printing or not;
• apply colors to your logging;
• customize colors per log level.

Import

go get github.com/gyozatech/noodlog

Usage

Let's assume you have Go 1.16+ istalled on your computer. Execute the following:

$ mkdir example && cd example
$ go mod init example
$ go get github.com/gyozatech/noodlog
$ touch main.go

Open main.go and paste the following code:

package main

import (
    "github.com/gyozatech/noodlog"
)

var log *noodlog.Logger

func init() {
   log = noodlog.NewLogger().SetConfigs(
      noodlog.Configs{
         LogLevel: noodlog.LevelTrace,
         JSONPrettyPrint: noodlog.Enable,
         TraceCaller: noodlog.Enable,
         Colors: noodlog.Enable,
         CustomColors: &noodlog.CustomColors{ Trace: noodlog.Cyan },
         ObscureSensitiveData: noodlog.Enable,
         SensitiveParams: []string{"password"},
      },
    )
}

func main() {
    // simple string message (with custom color)
    log.Trace("Hello world!")
    
    // chaining elements
    log.Info("You've reached", 3, "login attemps")
    
    // using string formatting
    log.Warn("You have %d attempts left", 2)
    
    // logging a struct with a JSON
    log.Error(struct{Code int; Error string}{500, "Generic Error"})
    
    // logging a raw JSON string with a JSON (with obscuring "password")
    log.Info(`{"username": "gyozatech", "password": "Gy0zApAssw0rd"}`)
    
    // logging a JSON string with a JSON (with obscuring "password")
    log.Info("{\"username\": \"nooduser\", \"password\": \"N0oDPasSw0rD\"}")
}

Running this example with:

$ go run main.go

You'll get the following output:

Settings

Noodlog allows you to customize the logs through various settings. You can use various facility functions or the SetConfigs function which wraps all the configs together.

LogLevel

To set the logging level, after importing the library with:

import (
    "github.com/gyozatech/noodlog"
)

var log *noodlog.Logger

func init() {
   log = noodlog.NewLogger()
}

you can use the facility method:

log.LogLevel("warn")

or the SetConfigs function:

log.SetConfigs(
    noodlog.Configs{
        LogLevel: noodlog.LevelWarn,
    },
)

log.LevelWarn is a pre-built pointer to the string "warn".

The default log level is info.

JSON Pretty Printing

After importing the library with:

import (
    "github.com/gyozatech/noodlog"
)

var log *noodlog.Logger

func init() {
   log = noodlog.NewLogger()
}

To enable pretty printing of the JSON logs you can use:

log.EnableJSONPrettyPrint()

or

log.SetConfigs(
    noodlog.Configs{
       JSONPrettyPrint: noodlog.Enable,
    },
)

noodlog.Enable is a pre-built pointer to the bool true.

to disable pretty printing you can use:

log.DisableJSONPrettyPrint()

or

log.SetConfigs(
    noodlog.Configs{
       JSONPrettyPrint: noodlog.Disable,
    },
)

noodlog.Disable is a pre-built pointer to the bool false.

The default value is false.

Colors

After importing the library with:

import (
    "github.com/gyozatech/noodlog"
)

var log *noodlog.Logger

func init() {
   log = noodlog.NewLogger()
}

to enable colors in JSON logs you can use:

log.EnableColors()

or

log.SetConfigs(
    noodlog.Configs{
        Colors: noodlog.Enable,
    },
)

noodlog.Enable is a pre-built pointer to the bool true.

To disable colors you can use:

log.DisableColors()

or

log.SetConfigs(
    noodlog.Configs{
        Colors: noodlog.Disable,
    },
)

noodlog.Disable is a pre-built pointer to the bool false.

The default value is false.

Color

The basic way to use a custom color is declaring using a pointer of a string representing the color. log.Cyan, log.Green, log.Default, log.Yellow, log.Purple, log.Red, log.Blue are pre-build pointers to the strings "cyan", "green", "default", "yellow", "purple", "red", "blue".

For instance, you can customize trace color by:

log.SetTraceColor(noodlog.Cyan)

A more detailed explanation of each log level is available later into this section.

Composition of a color

Color can be composed with text color and background color. For each level it can be composed using a string or a true color notation.

Trivial usage is creating a new color like:

log.NewColor(noodlog.Red)

It results a red text on default background

Adding a background color can be done through:

log.NewColor(noodlog.Red).Background(noodlog.Cyan)

In this scenario it prints red text on cyan background

A third option is to edit just background color using default text color:

log.Background(noodlog.Cyan)

A list of pre-built pointer of a string is [here](#Composition of a color).

Library provides also more customization through the usage of true color notation (RGB value). Before the usage of this notation, please consider if your terminal supports truecolor. For instance if you execute (printf required):

printf '\033[38;2;255;0;0mHello World\033[0m'

a red text "Hello World" should be displayed on the screen

In this way a wider set of color is available for logging, besides of the previous way it can be created a color as:

log.NewColorRGB(255,0,0).BackgroundRGB(0,0,255)

Where a red text (255 for red, 0 the others) is showed on blue background (255 for blue, 0 for others).

As in the previous scenario, NewColorRGB and BackgroundRGB hasn't to be executed combined.

Color can be used to set color of Trace log, by typing:

log.SetTraceColor(noodlog.NewColorRGB(255,0,0).BackgroundRGB(0,0,255))

You can customize the single colors (for log level) by using:

log.SetTraceColor(noodlog.Cyan)
log.SetDebugColor(noodlog.NewColorRGB(255,255,0))
log.SetInfoColor(noodlog.NewColor(noodlog.Red).Background(noodlog.Cyan))
log.SetWarnColor(noodlog.NewColor(noodlog.Green).BackgroundRGB(0,255,255))
log.SetErrorColor(noodlog.NewColorRGB(128,255,0).Background(noodlog.Purple))

or

log.SetConfigs(
    noodlog.Configs{
        Colors: noodlog.Enable,
        CustomColors: &noodlog.CustomColors{ 
            Trace: noodlog.Cyan, 
            Debug: noodlog.NewColorRGB(255,255,0),
            Info:  noodlog.NewColor(noodlog.Red).Background(noodlog.Cyan),
            Warn:  noodlog.NewColor(noodlog.Green).BackgroundRGB(0,255,255),
            Error: noodlog.NewColorRGB(128,255,0).Background(noodlog.Purple),    
        },
    },
)

Here we highlight all the different combination available to customize colors.

When enabled, the default colors are:

• trace: "default"
• info: "default"
• debug: "green"
• warn: "yellow"
• error: "red"

Trace the caller

Noodles allows you to print the file and the function which are calling the log functions.

After importing the library with:

import (
    "github.com/gyozatech/noodlog"
)

var log *noodlog.Logger

func init() {
   log = noodlog.NewLogger()
}

to enable the trace caller you can use:

log.EnableTraceCaller()

or

log.SetConfigs(
    noodlog.Configs{
        TraceCaller: noodlog.Enable,
    },
)

noodlog.Enable is a pre-built pointer to the bool true.

To disable it:

log.DisableTraceCaller()

or

log.SetConfigs(
    noodlog.Configs{
        TraceCaller: noodlog.Disable,
    },
)

noodlog.Disable is a pre-built pointer to the bool false.

The default value is false.

Important: if you want to import noodlog only in one package of your project (in order to configure it once) and wraps the logging functions you can use the EnableSinglePointTracing to trace file and function the real caller and not of your logging package.

For example:

main.go

package main

import (
   log "example/logging"
)

func main() {
   // main.main real caller we want to track 
   log.Info("Hello folks!")
}

logging/logger.go

package logging

import (
    "github.com/gyozatech/noodlog"
)

var l *noodlog.Logger

func init() {
    l = noodlog.NewLogger()
    // configure logger once
    l.SetConfig(
        noodlog.Configs{
         TraceCaller: noodlog.Enable,
         SinglePointTracing: noodlog.Enable,
      },
    )
}

// wrapper function
func Info(message ...interface{}) {
    // if we wouldn't enable SinglePointTracing
    // logger.Info would have been considered the caller to be tracked
    l.Info(message...)
}

Sensitive params

Noodlog gives you the possibility to enable the obscuration of sensitive params when recognized in the JSON structures (not in the simple strings that you compose).

After importing the library with:

import (
    "github.com/gyozatech/noodlog"
)

var log *noodlog.Logger

func init() {
   log = noodlog.NewLogger()
}

You can enable the sensitive params obscuration with the facility methods:

log.EnableObscureSensitiveData([]string{"param1", "param2", "param3"})

or with the SetConfig function:

log.SetConfigs(
    noodlog.Configs{
        ObscureSensitiveData: noodlog.Enable,
        SensitiveParams: []string{"param1", "param2", "param3"},
    },
)

Where noodlog.Enable is a pre-built pointer to the bool true.

To disable the sensitive params obscuration you can set:

log.DisableObscureSensitiveData()

or

log.SetConfigs(
    noodlog.Configs{
        ObscureSensitiveData: noodlog.Disable,
    },
)

Where noodlog.Disable is a pre-built pointer to the bool false.

The default value for the obscuration is false.

Contribute to the project

If you want to contribute to the project follow the following guidelines. Any form of contribution is encouraged!