logger

README

Logger configuration

snet-daemon uses zap log library. Logger configuration is a set of properties started from log. prefix. If configuration file is formatted using JSON then all logger configuration is one JSON object located in log field.

• log - log configuration section

  • level (default: info) - log level. Possible values are:

    • debug
    • info
    • warn
    • error
    • fatal
    • panic

  • timezone (default: UTC) - timezone to format timestamps and log file names. It should be name of the time.Location, see time.LoadLocation.

  • formatter - set of properties with log.formatter. prefix describes logger formatter configuration.

    • type (default: text) - type of the log formatter. Two types are supported, which correspond to zap formatter types:

      • json
      • text

    • timestamp_format (default: "2006-01-02T15:04:05.999Z07:00") - timestamp format to use in log lines, standard time.Time formats are supported, see time.Time.Format

  • output - set of properties with log.output. prefix describes logger output configuration.

    • type (default: file & stdout) - type of the logger output. You can specify one or several values at the same time by using an array (examples are provided below). Types are supported:

      • file - lumberjack output which supports log rotation
      • stdout - os.Stdout
      • stderr - os.Stderr

    • file_pattern (default: ./snet-daemon.%Y%m%d.log) - log file name which may include date/time patterns in strftime (3) format. Time and date in file name are necessary to support log rotation.

    • current_link (default: ./snet-daemon.log) - link to the latest log file.

    • max_size_in_mb (default: 10 Mb) - max size of current log file in megabytes.

    • max_age_in_days (default: 7 days) - number of days since last modification time before log file is removed.

    • rotation_count (default: 0 (disabled)) - max number of rotation files. When number of log files becomes greater then oldest log file is removed.

  • hooks (optional, default empty) - list of names of the hooks which will be executed when message with specified log level appears in log. List contains names of the hooks and hook configuration can be found by name prefix. Thus for hook named <hook-name> properties will start from log.<hook-name>. prefix.

  • <hook-name> - configuration of log hook with <hook-name> name

    • type (required always) - Type of the hook. This type is used to find actual hook implementation. Hook types supported:

      1. email
      2. telegram_bot

    • levels (required always) - list of log levels to trigger the hook.

    Next are the parameters depending on the type of hook:

    Email hook configuration

    For hook type email. Its configuration should contain all the properties which are required to send email:

    • host (required) - host of mail server.
    • port (required) - port of mail server.
    • from (required) - the mail from which the logs will be sent.
    • to (required) - the mail to which the logs will be sent.
    • username (required) - username is often equal to from.
    • password (required) - password (to send from a Google account, you will need to create the special "app password").
    • application_name (optional, default empty) - for smtp auth.

    Telegram bot hook configuration

    For hook type telegram_bot:

    • telegram_api_key (required) - api key of your telegram bot.
    • telegram_chat_id (required) - the chat id to which the logs will be sent.
    • disable_notification (optional, default false) - if true, the bot will send the message silently.

Examples

Simple configuration with logs output both to the console and to a file in JSON format

"log": {
   "formatter": {
      "type": "json"
   },
   "output": {
      "type": ["file", "stdout"]
   },
}

Logger configuration with text format in file

"log": {
   "formatter": {
   "timestamp_format": "2006-01-02T15:04:05.999Z07:00",
   "type": "text"
},
"level": "info",
"output": {
   "current_link": "./snet-daemon.log",
   "file_pattern": "./snet-daemon.%Y%m%d.log",
   "max_age_in_days": 1,
   "rotation_count": 0,
   "max_size_in_mb": 300,
   "type": "file"
},
"timezone": "UTC"
}

Email hook configuration

  "log": {
   "hooks": ["send-mail"],
   "send-mail": {
      "type": "email",
      "levels": ["error", "warn", "fatal", "panic"],
      "application_name": "test-application-name",
      "host": "smtp.gmail.com",
      "port": 587,
      "from": "from-user@gmail.com",
      "to": "to-user@gmail.com",
      "username": "from-user@gmail.com",
      "password": "secret"
   },
}

Telegram bot hook configuration

"log": {
   "hooks":["tg"],
   "tg": {
      "telegram_api_key": "7258436601:AAFlAm8gIGIyOTEv7lb9ipHcuB7YTR9-TuR",
      "telegram_chat_id": -4103253970,
      "disable_notification": false,
      "type": "telegram_bot",
      "levels": [ "fatal", "panic"]
    },
}

Adding new hooks implementations

Adding a new hook implementation is trivial. You should implement interface hook with method call which inputs entry zapcore.Entry. Also you need impelement init method which inputs configuration as Viper config and returns new instance of the Hook structure. Then register the new hook type by calling RegisterHookType() function from init() method. Please see "email" hook implementation as example in hook.go file.

Documentation

Index

• Constants
• Variables
• func Initialize()
• func RegisterHookType(hookType string, f func(config *viper.Viper) (hook, error))

Constants

const (
	LogHookTypeKey   = "type"
	LogHookLevelsKey = "levels"
	LogHooksKey      = "log.hooks"

	LogHookMailApplicationNameKey   = "application_name"
	LogHookMailHostKey              = "host"
	LogHookMailPortKey              = "port"
	LogHookMailFromKey              = "from"
	LogHookMailToKey                = "to"
	LogHookMailUsernameKey          = "username"
	LogHookMailPasswordKey          = "password"
	LogHookTelegramAPIKey           = "telegram_api_key"
	LogHookTelegramChatID           = "telegram_chat_id"
	LogHookTelegramDisNotifications = "telegram_disable_notifications"
)

const (
	LogLevelKey    = "log.level"
	LogTimezoneKey = "log.timezone"

	LogFormatterTypeKey   = "log.formatter.type"
	LogTimestampFormatKey = "log.formatter.timestamp_format"

	LogOutputTypeKey        = "log.output.type"
	LogOutputFilePatternKey = "log.output.file_pattern"
	LogOutputCurrentLinkKey = "log.output.current_link"
	LogMaxSizeKey           = "log.output.max_size_in_mb"
	LogMaxAgeKey            = "log.output.max_age_in_days"
	LogRotationCountKey     = "log.output.rotation_count"
)

Variables

var InvalidMailHookConf = errors.New("unable to create instance of mail auth hook: invalid configuration")

var InvalidTelegramBotHookConf = errors.New("unable to create instance of telegram bot hook: invalid configuration")

var NoLevelsSpecifiedError = errors.New("no levels in hook config")

Functions

func Initialize

func Initialize()

func RegisterHookType

func RegisterHookType(hookType string, f func(config *viper.Viper) (hook, error))

RegisterHookType registers new hook type in the system.