log

package
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 Go to latest Published: May 16, 2024 License: Apache-2.0, BSD-2-Clause, BSD-3-Clause, + 2 more Imports: 17 Imported by: 144

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log

Overview

Here is the simplest program that uses the log package:

 // The code below is located in example/main.go
package main

import "trpc.group/trpc-go/trpc-go/log"

func main() {
    log.Info("hello, world")
}

As of this writing, it prints:

2023-09-07 11:46:40.905 INFO example/main.go:6 hello, world

The Info function prints out a message with a log level of Info using the default Logger in the log package. Depending on the importance and urgency of the output message, the log package supports five other logging levels (Trace, Debug, Warn, Error, and Fatal) in addition to the Info level mentioned above. The log contains the message "hello, world" and the log level "INFO", but also the print time "2023-09-07 11:46:40.905" and the call stack "example/main.go:6".

You can also use Infof to output the same log level, Infof is more flexible and allows you to print messages in the format you want.

Infof is more flexible, allowing you to print messages in the format you want.

log.Infof("hello, %s", "world")

In addition, you can pass a series of key-value pairs to the With function to create a new Logger from the default Logger. The new Logger will output the key-value pairs to the end of the message when it prints the log.

logger := log.With(log.Field{Key: "user", Value: os.Getenv("USER")})
logger.Info("hello, world")

The output now looks like this:

2023-09-07 15:05:21.168 INFO example/main.go:12 hello, world {"user": "goodliu"}

As mentioned before, the Info function uses the default Logger. You can explicitly get this Logger and call its methods:

dl := log.GetDefaultLogger()
l := dl.With(log.Field{Key: "user", Value: os.Getenv("USER")})
l.Info("hello, world")

Main Types

The log package contains two main types:

  • Logger is the front end, providing output methods similar to Info and Infof, which you can use to generate logs.
  • Writer is the back end, processing the logs generated by Logger and writing them to various logging service systems, such as the console, local files, and remote servers.

The log package supports setting up multiple independent Loggers, each of which can be configured with multiple independent Writers. As shown in the diagram, this example contains three Loggers: "Default Logger", "Other Logger-1", and "Other Logger-2", with "Default Logger" being the default Logger built into the log package. "Default Logger" contains three different Writers: "Console Writer", "File Writer", and "Remote Writer", with "Console Writer" being the default Writer of "Default Logger". Logger and Writer are both designed as customizable plug-ins, and you can refer to here for information on how to develop them.

                                             +------------------+
                                             | +--------------+ |
                                             | |Console Writer| |
                                             | +--------------+ |
                                             | +-----------+    |
                   +----------------+        | | File Witer|    |
     +-------------> Default Logger +--------> +-----------+    |
     |             +----------------+        | +-------------+  |
     |                                       | |Remote Writer|  |
     |                                       | +-------------+  |
     |                                       +------------------+
     |                                        +-------------+
     |                                        | +--------+  |
     |                                        | |Writer-A|  |
+----+----+        +----------------+         | +--------+  |
| Loggers +--------> Other Logger-1 +-------->| +--------+  |
+----+----+        +----------------+         | |Writer-B|  |
     |                                        | +--------+  |
     |                                        +-------------+
     |             +----------------+          +---------+
     +-------------> Other Logger-2 +----------> Writer-C|
                   +----------------+          +---------+

First, we will introduce how to configure Logger and Writer in the configuration file. And then we will introduce Writer and Logger separately in a bottom-up manner.

Configure Logger and Writer

Since both Logger and Writer are implemented as plugins, their related configurations need to be placed under the plugins field.

plugins:
  log:
    default:
      - writer: console
        ...
      - writer: file
        ...
    logger1:
      - writer: console
        ...
      - writer: atta
        ...
    logger2:
      - writer: file
        ...
      - writer: file
        ...

The above configuration includes three Loggers named "default", "logger1", and "logger2". The "default" Logger is the system default Logger, which is configured with Writers named "console", "file", and "remote". When no logging configuration is done, the logs are written to the console by default, with a log level of Debug and a text format printing method. The corresponding configuration file is:

plugins:
  log:
    default:
      - writer: console
        level: debug
        formatter: console

For the configuration parameters of Writer, the design is as follows:

configuration item configuration item type default value configuration explanation
writer writer string Mandatory Log Writer plug-in name, the framework supports "file, console" by default
writer writer_config object nil only need to be set when the log Writer is "file"
writer formatter string "" Log printing format, supports "console" and "json", and defaults to "console" when it is empty
writer formatter_config object nil zapcore Encoder configuration when log output, when it is empty, refer to the default value of formatter_config
writer remote_config Object nil Remote log format The configuration format can be set at will by the third-party component.
writer level string Mandatory When the log level is greater than or equal to the set level, output to the writer backend Value range: trace, debug, info, warn, error, fatal
writer caller_skip int 2 Used to control the nesting depth of the log function, if not filled or 0 is entered, the default is 2
writer.formatter_config time_fmt string "" Log output time format, empty default is "2006-01-02 15:04:05.000"
writer.formatter_config time_key string "" The name of the key when the log output time is output in Json, the default is "T", use "none" to disable this field
writer.formatter_config level_key string "" The name of the key when the log level is output in Json, the default is "L", use "none" to disable this field
writer.formatter_config name_key string "" The name of the key when the log name is output in Json, the default is "N", use "none" to disable this field
writer.formatter_config caller_key string "" The name of the log output caller's key when outputting in Json, default is "C", use "none" to disable this field
writer.formatter_config message_key string "" The name of the key when the log output message body is output in Json, the default is "M", use "none" to disable this field
writer.formatter_config stacktrace_key string "" The name of the key when the log output stack is output in Json, default is "S", use "none" to disable this field
writer.writer_config log_path string Mandatory Log path name, for example: /usr/local/trpc/log/
writer.writer_config filename string Mandatory Log file name, for example: trpc.log
writer.writer_config write_mode int 0 Log writing mode, 1-synchronous, 2-asynchronous, 3-extreme speed (asynchronous discard), do not configure the default extreme speed mode, that is, asynchronous discard
writer.writer_config roll_type string "" File roll type, "size" splits files by size, "time" splits files by time, and defaults to split by size when it is empty
writer.writer_config max_age int 0 The maximum log retention time, 0 means do not clean up old files
writer.writer_config time_unit string "" Only valid when split by time, the time unit of split files by time, support year/month/day/hour/minute, the default value is day
writer.writer_config max_backups int 0 The maximum number of files in the log, 0 means not to delete redundant files
writer.writer_config compress bool false Whether to compress the log file, default is not compressed
writer.writer_config max_size string "" Only valid when splitting by size, the maximum size of the log file (in MB), 0 means not rolling by size

Multiple Writers

Multiple Writers can provide the following features:

  • Support for logging to multiple output backends simultaneously, such as printing to the console and saving to a local log file at the same time.
  • Support for setting log levels individually for each output backend, for example, printing debug-level logs to the console and saving warning-level logs to a log file.
  • Support for setting log formats (console, JSON, etc.) and log field names individually for each output backend.
  • Support for log file rolling, including splitting log files by size or time, for file type backends.

It should be emphasized here that settings of log are configured at the Writer level. You need to configure each output separately. For example, if you want to print debug-level logs to the console and save warning-level logs to a log file, you must configure both the console and file Writers separately.

The system defaults to supporting two Writers: "console" and "file".

Write logs to the console

When the writer is set to "console", it means that the log will be written to the console. Here's an example configuration:

plugins:
  log:  # All log configuration
    default:  # default log configuration, log.Debug("xxx")
      - writer: console  # Console standard output default
        level: debug  # Standard output log level
        formatter: json  # Standard output log format
        formatter_config:
          time_fmt: 2006-01-02 15:04:05  # Log time format. "2006-01-02 15:04:05" is the regular time format, "seconds" is the second-level timestamp, "milliseconds" is the millisecond timestamp, "nanoseconds" is the nanosecond timestamp
          time_key: Time  # Log time field name, default "T" if not filled, use "none" to disable this field
          level_key: Level  # Log level field name, default "L" if not filled, use "none" to disable this field
          name_key: Name  # log name field name, default "N" if not filled, use "none" to disable this field
          caller_key: Caller  # log caller field name, default "C" if not filled, use "none" to disable this field
          message_key: Message  # Log message body field name, default "M" if not filled, use "none" to disable this field
          stacktrace_key: StackTrace  # Log stack field name, default "S" if not filled, use "none" to disable this field
Write logs to a local file.

When the writer is set to "file", it means that the log is written to a local log file. The configuration example of log file rolling storage according to time is as follows:

plugins:
  log:  # All log configuration
    default:  # default log configuration, log.Debug("xxx")
      - writer: file  # Local file log
        level: info  # Local file rolling log level
        formatter: json  # Standard output log format
        formatter_config:
          time_fmt: 2006-01-02 15:04:05  # Log time format. "2006-01-02 15:04:05" is the regular time format, "seconds" is the second-level timestamp, "milliseconds" is the millisecond timestamp, "nanoseconds" is the nanosecond timestamp
          time_key: Time  # Log time field name, default "T" if not filled, use "none" to disable this field
          level_key: Level  # Log level field name, default "L" if not filled, use "none" to disable this field
          name_key: Name  # log name field name, default "N" if not filled, use "none" to disable this field
          caller_key: Caller  # log caller field name, default "C" if not filled, use "none" to disable this field
          message_key: Message  # Log message body field name, default "M" if not filled, use "none" to disable this field
          stacktrace_key: StackTrace  # Log stack field name, default "S" if not filled, use "none" to disable this field
        writer_config:
          log_path: /tmp/log/
          filename: trpc_size.log  # Local file rolling log storage path
          write_mode: 2  # log write mode, 1-synchronous, 2-asynchronous, 3-extreme speed (asynchronous discard), do not configure the default asynchronous mode
          roll_type: time  # File roll type, time is roll by time
          max_age: 7  # Maximum log retention days
          max_backups: 10  # Maximum number of log files
          time_unit: day  # Rolling time interval, support: minute/hour/day/month/year

An example configuration of rolling logs based on file size is as follows:

plugins:
  log:  # All log configuration
    default:  # default log configuration, log.Debug("xxx")
      - writer: file  # Local file log
        level: info  # Local file rolling log level
        formatter: json  # Standard output log format
        formatter_config:
          time_fmt: 2006-01-02 15:04:05  # Log time format. "2006-01-02 15:04:05" is the regular time format, "seconds" is the second-level timestamp, "milliseconds" is the millisecond timestamp, "nanoseconds" is the nanosecond timestamp
          time_key: Time  # Log time field name, default "T" if not filled, use "none" to disable this field
          level_key: Level  # Log level field name, default "L" if not filled, use "none" to disable this field
          name_key: Name  # log name field name, default "N" if not filled, use "none" to disable this field
          caller_key: Caller  # log caller field name, default "C" if not filled, use "none" to disable this field
          message_key: Message  # Log message body field name, default "M" if not filled, use "none" to disable this field
          stacktrace_key: StackTrace  # Log stack field name, default "S" if not filled, use "none" to disable this field
        writer_config:
          log_path: /tmp/log/
          filename: trpc_size.log  # Local file rolling log storage path
          write_mode: 2  # log write mode, 1-synchronous, 2-asynchronous, 3-extreme speed (asynchronous discard), do not configure the default asynchronous mode
          roll_type: size  # File roll type, size is roll by size
          max_age: 7  # Maximum log retention days
          max_backups: 10  # Maximum number of log files
          compress: false  # Whether the log file is compressed
          max_size: 10  # The size of the local file rolling log, in MB
Write logs to a remote location

To write logs to a remote location, you need to set the remote_config field. The default Logger configuration for two remote Writers is shown below:

plugins:
  log: # log configuration supports multiple logs, you can log through log.Get("xxx").Debug
    default: # Default log configuration, each log can support multiple writers
      - writer: remote-writer1  # remote writer named remote-writer1
        level: debug # log level of remote log
        remote_config: # remote log configuration, a custom structure for each independent remote log
          # relevant configuration
      - writer: remote-writer2 # remote writer named remote-writer2
        level: info # log level of remote log
        remote_config:  # remote log configuration, a custom structure for each independent remote log
         # relevant configuration

Multiple Loggers

log package supports multiple loggers at the same time. Each logger can set different log levels, print formats, and writers. You can set different loggers for different application scenarios, for example:

  • Different application modules use different log files for storage.
  • Different events, based on the degree of attention of the event, collect logs using different log levels.

The multi-loggers function greatly increases the flexibility of log usage.

Configure logger

Configure your logger in a configuration file, for example, configuring a logger named "custom":

plugins:
  log:  # All log configuration
    default:  # Default log configuration ,log.Debug("xxx")
      - writer: console  # console stdout default
        level: debug  # The level of standard output logging
    custom:  # Your custom logger configuration, the name can be set at will, each service can have multiple loggers, you can use log.Get("custom").Debug("xxx") to log
      - writer: file                       # Your custom core configuration, the name can be set at will
        caller_skip: 1  # The call site used to locate the log
        level: debug  # Your custom core output level
        writer_config:  # Local file output specific configuration
          filename: ../log/trpc1.log  # The path where the local file rolling log is stored

For questions about caller_skip in the configuration file, see Chapter Explanation about caller_skip.

Register the logger plugin

Register the logging plugin at the main function entry point:

import (
    "trpc.group/trpc-go/trpc-go/log"
    "trpc.group/trpc-go/trpc-go/plugin"
)
func main() {
    // Note: plugin.Register should be executed before trpc.NewServer.
    plugin.Register("custom", log.DefaultLogFactory)
    s := trpc.NewServer()
}
Get logger

The log package provides the following two ways for you to get a Logger:

Method 1: Specify logger directly
// use a logger named "custom"
// Note: log.Get should be executed after trpc.NewServer, as plugin loading happens within trpc.NewServer.
log.Get("custom").Debug("message")
Method 2: Specify a logger for the context and use the context type log interface
// Set the logger of the ctx context to custom
trpc.Message(ctx).WithLogger(log.Get("custom"))
// Use the logging interface of type "Context"
log.DebugContext(ctx, "custom log msg")
Log Levels

According to the importance and urgency of the output messages, the log package provides six levels of logging, which are divided as follows from lowest to highest:

  1. Trace: This is the lowest level, usually used to record all running information of the program, including some details and debugging information. This level of logging is usually only used in the development and debugging phase because it may generate a large amount of log data.

  2. Debug: This level is mainly used in the debugging process to provide detailed information about program execution, helping you find the cause of problems.

  3. Info: This level is used to record the general operation of the program, such as user login, system status updates, etc. These pieces of information are helpful in understanding the system's running status and performance.

  4. Warn: The warning level indicates possible problems that will not immediately affect the program's functionality, but may cause errors in the future. This level of logging can help you discover and prevent problems in advance.

  5. Error: The error level indicates serious problems that may prevent the program from executing certain functions. This level of logging requires immediate attention and handling.

  6. Fatal: The fatal error level indicates very serious errors that may cause the program to crash. This is the highest log level, indicating a serious problem that needs to be addressed immediately.

  7. Using log levels correctly can help you better understand and debug your application program.

Log printing interface

The log package provides 3 sets of log printing interfaces:

  • Log function of Default Logger: the most frequently used method. Directly use the default Logger for log printing, which is convenient and simple.
  • Log function based on Context Logger: Provide a specified logger for a specific scenario and save it in the context, and then use the current context logger for log printing. This method is especially suitable for the RPC call mode: when the service receives the RPC request, set the logger for ctx and attach the field information related to this request, and the subsequent log report of this RPC call will bring the previously set field information
  • Log function of the specified Logger: it can be used for users to select logger by themselves, and call the interface function of logger to realize log printing.
Log function of Default Logger

The name of the default logger is fixed as "default", the default print level is debug, print console, and the print format is text format. Configuration can be modified in the framework file plugins.log. The function to print logs using the default Logger is as follows, and the function style is consistent with "fmt.Print()" and "fmt.Printf()".

// Provide "fmt.Print()" style function interface for the default Logger
func Trace(args ... interface{})
func Debug(args...interface{})
func Info(args...interface{})
func Warn(args...interface{})
func Error(args...interface{})
func Fatal(args ... interface{})

// Provide "fmt.Printf()" style function interface for the default Logger
// Formatted printing follows the fmt.Printf() standard
func Tracef(format string, args ... interface{})
func Debugf(format string, args ... interface{})
func Infof(format string, args...interface{})
func Warnf(format string, args...interface{})
func Errorf(format string, args...interface{})
func Fatalf(format string, args ... interface{})

At the same time, the system also provides management functions of the default Logger, including obtaining, setting the default logger, and setting the printing level of the logger.

// Get Logger by name
func Get(name string) Logger
// Set the specified Logger as the default Logger
func SetLogger(logger Logger)
// Set the log level of the specified writer under the default Logger, and the output is the subscript of the writer array "0" "1" "2"
func SetLevel(output string, level Level)
// Get the log level of the specified writer under the default Logger, and the output is the subscript of the writer array "0" "1" "2"
func GetLevel(output string) Level
Log function based on Context Logger

For the use of context type logs, each context logger must exclusively have one logger to ensure that the configuration of the context logger will not be tampered with. The framework provides WithFields() and WithFieldsContext() to inherit the parent logger configuration and generate a new logger.

// Based on the default Logger, create a new Logger and add fields to the log printing of the new Logger.
// fields fields must appear in pairs, for example: logger := log.WithFields("key1","value1")
func WithFields(fields ... string) Logger
// Based on the Logger under the current context, create a new Logger and add fields to the log printing of the new Logger.
// fields fields must appear in pairs, for example: logger := log.WithFields("key1","value1")
func WithFieldsContext(ctx context.Context, fields...string) Logger {

Then set the Logger for the context by the following function:

logger := ...
trpc.Message(ctx).WithLogger(logger)

The log printing function at the context level is similar to the default logger printing function:

// Provide "fmt.Print()" style function to Context Logger
func TraceContext(args...interface{})
func DebugContext(args...interface{})
func InfoContext(args...interface{})
func WarnContext(args ... interface{})
func ErrorContext(args ... interface{})
func FatalContext(args ... interface{})

// Provide "fmt.Printf()" style function to Context Logger
// Formatted printing follows the fmt.Printf() standard
func TraceContextf(format string, args ... interface{})
func DebugContextf(format string, args ... interface{})
func InfoContextf(format string, args...interface{})
func WarnContextf(format string, args...interface{})
func ErrorContextf(format string, args ... interface{})
func FatalContextf(format string, args ... interface{})
Log function of the specified Logger

At the same time, the framework also provides functions for users to choose loggers by themselves. For each Logger implements the Logger Interface. The interface is defined as:

type Logger interface {
     // The interface provides "fmt.Print()" style functions
     Trace(args...interface{})
     Debug(args...interface{})
     Info(args...interface{})
     Warn(args ... interface{})
     Error(args...interface{})
     Fatal(args...interface{})

     // The interface provides "fmt.Printf()" style functions
     Tracef(format string, args...interface{})
     Debugf(format string, args...interface{})
     Infof(format string, args...interface{})
     Warnf(format string, args ... interface{})
     Errorf(format string, args...interface{})
     Fatalf(format string, args ... interface{})

     // SetLevel sets the output log level
     SetLevel(output string, level Level)
     // GetLevel to get the output log level
     GetLevel(output string) Level

     // WithFields set some your custom data into each log: such as uid, imei and other fields must appear in pairs of kv
     WithFields(fields...string) Logger
}

Users can directly use the above interface functions to print logs, for example

log.Get("custom").Debug("message")
log.Get("custom").Debugf("hello %s", "world")

Framework Logs

  1. The framework should log as little as possible and throw error up to user for handling.
  2. Some underlying severe errors may print trace logs. To enable trace log, you need to set TRPC_LOG_TRACE environment variable:
   export TRPC_LOG_TRACE=1
Enabling trace level logging

To enable trace level logging, you must first ensure that the log level is set to debug or trace in the configuration. Then, you can enable trace through either environment variables:

  • Setting through environment variables

Add the following to the script that executes the server binary:

export TRPC_LOG_TRACE=1
./server -conf path/to/trpc_go.yaml
  • Setting through code

Add the following code:

import "trpc.group/trpc-go/trpc-go/log"

func init() {
    log.EnableTrace()
}

It is recommended to use the environment variable method as it is more flexible.

Notes about caller_skip

Depending on how the logger is used, the caller_skip setting is also different:

Usage 1: Use Default Logger
log.Debug("default logger") // use the default logger

At this time, the configuration used by the log is default:

default:  # default log configuration, log.Debug("xxx")
  - writer: console  # Console standard output default
    level: debug  # Standard output log level
  - writer: file  # Local file log
    level: debug  # Local file rolling log level
    formatter: json  # Standard output log format
    writer_config:  # Local file output specific configuration
      filename: ../log/trpc_time.log  # Local file rolling log storage path
      write_mode: 2  # log write mode, 1-synchronous, 2-asynchronous, 3-extreme speed (asynchronous discard), do not configure the default asynchronous mode
      roll_type: time  # File roll type, time is roll by time
      max_age: 7  # Maximum log retention days
      max_backups: 10  # Maximum number of log files
      compress: false  # Whether the log file is compressed
      max_size: 10  # The size of the local file rolling log, in MB
      time_unit: day  # Rolling time interval, support: minute/hour/day/month/year

At this time, there is no need to pay attention to or set the value of caller_skip, the default value is 2, which means that there are two layers on zap.Logger.Debug (trpc.log.Debug -> trpc.log.zapLog. Debug -> zap.Logger.Debug)

Usage 2: Put the custom logger into the context
trpc.Message(ctx).WithLogger(log.Get("custom"))
log.DebugContext(ctx, "custom log msg")

At this time, there is no need to pay attention to or set the value of caller_skip, the value is 2 by default, which means that there are two layers on zap.Logger.Debug (trpc.log.DebugContext -> trpc.log.zapLog .Debug -> zap.Logger.Debug).

The configuration example is as follows:

custom:  # Your custom logger configuration, the name can be set at will, each service can have multiple loggers, you can use log.Get("custom").Debug("xxx") to log
  - writer: file  # Your core configuration, the name can be set at will
    level: debug  # Your custom core output level
    writer_config:  # Local file output specific configuration
      filename: ../log/trpc1.log  # Local file rolling log storage path
Do not use custom logger in context:
log.Get("custom").Debug("message")

At this time, you need to set the caller_skip value of custom logger to 1, because log.Get("custom") directly returns trpc.log.zapLog, call trpc.log.zapLog.Debug Only one layer on top of zap.Logger.Debug (trpc.log.zapLog.Debug -> zap.Logger.Debug).

The configuration example is as follows:

custom:  # Your custom logger configuration, the name can be set at will, each service can have multiple loggers, you can use log.Get("custom").Debug("xxx") to log
  - writer: file  # Your core configuration, the name can be set at will
    caller_skip: 1  # Caller for locating the log
    level: debug  # Your custom core output level
    writer_config:  # Local file output specific configuration
      filename: ../log/trpc1.log  # Local file rolling log storage path

Pay attention to the location of caller_skip (not in writer_config), and when there are caller_skip for multiple writers, the value of caller_skip of the logger is subject to the last one, for example:

custom:  # Your custom logger configuration, the name can be set at will, each service can have multiple loggers, you can use log.Get("custom").Debug("xxx") to log
  - writer: file  # Your core configuration, the name can be set at will
    caller_skip: 1  # Caller for locating the log
    level: debug  # Your custom core output level
    writer_config:  # Local file output specific configuration
      filename: ../log/trpc1.log  # Local file rolling log storage path
  - writer: file  # Local file log
    caller_skip: 2  # The calling place used to locate the log
    level: debug  # Local file rolling log level
    writer_config:  # Local file output specific configuration
      filename: ../log/trpc2.log  # Local file rolling log storage path

Finally, the caller_skip value of the custom logger will be set to 2.

Note: The above usage 2 and usage 3 are in conflict, only one of them can be used at the same time.

Documentation

Overview

Package log provides a log for the framework and applications.

Example 
package main

import (
	"trpc.group/trpc-go/trpc-go/log"
)

func main() {
	l := log.NewZapLog([]log.OutputConfig{
		{
			Writer:       "console",
			Level:        "debug",
			Formatter:    "console",
			FormatConfig: log.FormatConfig{TimeFmt: "xxx"},
		},
	})
	const defaultLoggerName = "default"
	oldDefaultLogger := log.GetDefaultLogger()
	log.Register(defaultLoggerName, l)
	defer func() {
		log.Register(defaultLoggerName, oldDefaultLogger)
	}()

	l = log.With(log.Field{Key: "tRPC-Go", Value: "log"})
	l.Trace("hello world")
	l.Debug("hello world")
	l.Info("hello world")
	l.Warn("hello world")
	l.Error("hello world")
	l.Tracef("hello world")
	l.Debugf("hello world")
	l.Infof("hello world")
	l.Warnf("hello world")
	l.Errorf("hello world")

}

Output:

xxx	DEBUG	log/example_test.go:35	hello world	{"tRPC-Go": "log"}
xxx	DEBUG	log/example_test.go:36	hello world	{"tRPC-Go": "log"}
xxx	INFO	log/example_test.go:37	hello world	{"tRPC-Go": "log"}
xxx	WARN	log/example_test.go:38	hello world	{"tRPC-Go": "log"}
xxx	ERROR	log/example_test.go:39	hello world	{"tRPC-Go": "log"}
xxx	DEBUG	log/example_test.go:40	hello world	{"tRPC-Go": "log"}
xxx	DEBUG	log/example_test.go:41	hello world	{"tRPC-Go": "log"}
xxx	INFO	log/example_test.go:42	hello world	{"tRPC-Go": "log"}
xxx	WARN	log/example_test.go:43	hello world	{"tRPC-Go": "log"}
xxx	ERROR	log/example_test.go:44	hello world	{"tRPC-Go": "log"}

Index

Examples

Constants

View Source 
const (
	OutputConsole = "console"
	OutputFile    = "file"
)

output name, default support console and file.

View Source 
const (
	// WriteSync writes synchronously.
	WriteSync = 1
	// WriteAsync writes asynchronously.
	WriteAsync = 2
	// WriteFast writes fast(may drop logs asynchronously).
	WriteFast = 3
)
View Source 
const (
	// RollBySize rolls logs by file size.
	RollBySize = "size"
	// RollByTime rolls logs by time.
	RollByTime = "time"
)

By which log rolls.

View Source 
const (
	// TimeFormatMinute is accurate to the minute.
	TimeFormatMinute = "%Y%m%d%H%M"
	// TimeFormatHour is accurate to the hour.
	TimeFormatHour = "%Y%m%d%H"
	// TimeFormatDay is accurate to the day.
	TimeFormatDay = "%Y%m%d"
	// TimeFormatMonth is accurate to the month.
	TimeFormatMonth = "%Y%m"
	// TimeFormatYear is accurate to the year.
	TimeFormatYear = "%Y"
)

Some common used time formats.

View Source 
const (
	// Minute splits by the minute.
	Minute = "minute"
	// Hour splits by the hour.
	Hour = "hour"
	// Day splits by the day.
	Day = "day"
	// Month splits by the month.
	Month = "month"
	// Year splits by the year.
	Year = "year"
)
View Source 
const (
	ConsoleZapCore = "console"
	FileZapCore    = "file"
)

Some ZapCore constants.

Variables

View Source 
var (
	// DefaultConsoleWriterFactory is the default console output implementation.
	DefaultConsoleWriterFactory = &ConsoleWriterFactory{}
	// DefaultFileWriterFactory is the default file output implementation.
	DefaultFileWriterFactory = &FileWriterFactory{}
)
View Source 
var LevelNames = map[string]Level{
	"trace": LevelTrace,
	"debug": LevelDebug,
	"info":  LevelInfo,
	"warn":  LevelWarn,
	"error": LevelError,
	"fatal": LevelFatal,
}

LevelNames is the map from string to log level.

View Source 
var LevelStrings = map[Level]string{
	LevelTrace: "trace",
	LevelDebug: "debug",
	LevelInfo:  "info",
	LevelWarn:  "warn",
	LevelError: "error",
	LevelFatal: "fatal",
}

LevelStrings is the map from log level to its string representation.

View Source 
var Levels = map[string]zapcore.Level{
	"":      zapcore.DebugLevel,
	"trace": zapcore.DebugLevel,
	"debug": zapcore.DebugLevel,
	"info":  zapcore.InfoLevel,
	"warn":  zapcore.WarnLevel,
	"error": zapcore.ErrorLevel,
	"fatal": zapcore.FatalLevel,
}

Levels is the map from string to zapcore.Level.

Functions

func CustomTimeFormat 

func CustomTimeFormat(t time.Time, format string) string

CustomTimeFormat customize time format. Deprecated: Use https://pkg.go.dev/time#Time.Format instead.

func Debug 

func Debug(args ...interface{})

Debug logs to DEBUG log. Arguments are handled in the manner of fmt.Println.

func DebugContext 

func DebugContext(ctx context.Context, args ...interface{})

DebugContext logs to DEBUG log. Arguments are handled in the manner of fmt.Println.

func DebugContextf 

func DebugContextf(ctx context.Context, format string, args ...interface{})

DebugContextf logs to DEBUG log. Arguments are handled in the manner of fmt.Printf.

func Debugf 

func Debugf(format string, args ...interface{})

Debugf logs to DEBUG log. Arguments are handled in the manner of fmt.Printf.

func DefaultTimeFormat 

func DefaultTimeFormat(t time.Time) []byte

DefaultTimeFormat returns the default time format "2006-01-02 15:04:05.000". Deprecated: Use https://pkg.go.dev/time#Time.AppendFormat instead.

func EnableTrace 

func EnableTrace()

EnableTrace enables trace.

func Error 

func Error(args ...interface{})

Error logs to ERROR log. Arguments are handled in the manner of fmt.Println.

func ErrorContext 

func ErrorContext(ctx context.Context, args ...interface{})

ErrorContext logs to ERROR log. Arguments are handled in the manner of fmt.Println.

func ErrorContextf 

func ErrorContextf(ctx context.Context, format string, args ...interface{})

ErrorContextf logs to ERROR log. Arguments are handled in the manner of fmt.Printf.

func Errorf 

func Errorf(format string, args ...interface{})

Errorf logs to ERROR log. Arguments are handled in the manner of fmt.Printf.

func Fatal 

func Fatal(args ...interface{})

Fatal logs to ERROR log. Arguments are handled in the manner of fmt.Println. All Fatal logs will exit by calling os.Exit(1). Implementations may also call os.Exit() with a non-zero exit code.

func FatalContext 

func FatalContext(ctx context.Context, args ...interface{})

FatalContext logs to ERROR log. Arguments are handled in the manner of fmt.Println. All Fatal logs will exit by calling os.Exit(1). Implementations may also call os.Exit() with a non-zero exit code.

func FatalContextf 

func FatalContextf(ctx context.Context, format string, args ...interface{})

FatalContextf logs to ERROR log. Arguments are handled in the manner of fmt.Printf.

func Fatalf 

func Fatalf(format string, args ...interface{})

Fatalf logs to ERROR log. Arguments are handled in the manner of fmt.Printf.

func GetLogEncoderKey 

func GetLogEncoderKey(defKey, key string) string

GetLogEncoderKey gets user defined log output name, uses defKey if empty.

func GetWriter 

func GetWriter(name string) plugin.Factory

GetWriter gets log output writer, returns nil if not exist.

func Info 

func Info(args ...interface{})

Info logs to INFO log. Arguments are handled in the manner of fmt.Println.

func InfoContext 

func InfoContext(ctx context.Context, args ...interface{})

InfoContext logs to INFO log. Arguments are handled in the manner of fmt.Println.

func InfoContextf 

func InfoContextf(ctx context.Context, format string, args ...interface{})

InfoContextf logs to INFO log. Arguments are handled in the manner of fmt.Printf.

func Infof 

func Infof(format string, args ...interface{})

Infof logs to INFO log. Arguments are handled in the manner of fmt.Printf.

func NewTimeEncoder 

func NewTimeEncoder(format string) zapcore.TimeEncoder

NewTimeEncoder creates a time format encoder.

func RedirectStdLog 

func RedirectStdLog(logger Logger) (func(), error)

RedirectStdLog redirects std log to trpc logger as log level INFO. After redirection, log flag is zero, the prefix is empty. The returned function may be used to recover log flag and prefix, and redirect output to os.Stderr.

func RedirectStdLogAt 

func RedirectStdLogAt(logger Logger, level zapcore.Level) (func(), error)

RedirectStdLogAt redirects std log to trpc logger with a specific level. After redirection, log flag is zero, the prefix is empty. The returned function may be used to recover log flag and prefix, and redirect output to os.Stderr.

func Register 

func Register(name string, logger Logger)

Register registers Logger. It supports multiple Logger implementation.

func RegisterFormatEncoder added in v1.0.3 

func RegisterFormatEncoder(formatName string, newFormatEncoder NewFormatEncoder)

RegisterFormatEncoder registers a NewFormatEncoder with the specified formatName key. The existing formats include "console" and "json", but you can override these format encoders or provide a new custom one.

func RegisterWriter 

func RegisterWriter(name string, writer plugin.Factory)

RegisterWriter registers log output writer. Writer may have multiple implementations.

func SetLevel 

func SetLevel(output string, level Level)

SetLevel sets log level for different output which may be "0", "1" or "2".

func SetLogger 

func SetLogger(logger Logger)

SetLogger sets the default Logger.

func Sync 

func Sync()

Sync syncs all registered loggers.

func Trace 

func Trace(args ...interface{})

Trace logs to TRACE log. Arguments are handled in the manner of fmt.Println.

func TraceContext 

func TraceContext(ctx context.Context, args ...interface{})

TraceContext logs to TRACE log. Arguments are handled in the manner of fmt.Println.

func TraceContextf 

func TraceContextf(ctx context.Context, format string, args ...interface{})

TraceContextf logs to TRACE log. Arguments are handled in the manner of fmt.Printf.

func Tracef 

func Tracef(format string, args ...interface{})

Tracef logs to TRACE log. Arguments are handled in the manner of fmt.Printf.

func Warn 

func Warn(args ...interface{})

Warn logs to WARNING log. Arguments are handled in the manner of fmt.Println.

func WarnContext 

func WarnContext(ctx context.Context, args ...interface{})

WarnContext logs to WARNING log. Arguments are handled in the manner of fmt.Println.

func WarnContextf 

func WarnContextf(ctx context.Context, format string, args ...interface{})

WarnContextf logs to WARNING log. Arguments are handled in the manner of fmt.Printf.

func Warnf 

func Warnf(format string, args ...interface{})

Warnf logs to WARNING log. Arguments are handled in the manner of fmt.Printf.

func WithContextFields 

func WithContextFields(ctx context.Context, fields ...string) context.Context

WithContextFields sets some user defined data to logs, such as uid, imei, etc. Fields must be paired. If ctx has already set a Msg, this function returns that ctx, otherwise, it returns a new one.

Types

type Config 

type Config []OutputConfig

Config is the log config. Each log may have multiple outputs.

type ConsoleWriterFactory 

type ConsoleWriterFactory struct {
}

ConsoleWriterFactory is the console writer instance.

func (*ConsoleWriterFactory) Setup 

func (f *ConsoleWriterFactory) Setup(name string, dec plugin.Decoder) error

Setup starts, loads and registers console output writer.

func (*ConsoleWriterFactory) Type 

func (f *ConsoleWriterFactory) Type() string

Type returns the log plugin type.

type Decoder 

type Decoder struct {
	OutputConfig *OutputConfig
	Core         zapcore.Core
	ZapLevel     zap.AtomicLevel
}

Decoder decodes the log.

func (*Decoder) Decode 

func (d *Decoder) Decode(cfg interface{}) error

Decode decodes writer configuration, copy one.

type Factory 

type Factory struct{}

Factory is the log plugin factory. When server start, the configuration is feed to Factory to generate a log instance.

func (*Factory) Setup 

func (f *Factory) Setup(name string, dec plugin.Decoder) error

Setup starts, load and register logs.

func (*Factory) Type 

func (f *Factory) Type() string

Type returns the log plugin type.

type Field 

type Field struct {
	Key   string
	Value interface{}
}

Field is the user defined log field.

type FileWriterFactory 

type FileWriterFactory struct {
}

FileWriterFactory is the file writer instance Factory.

func (*FileWriterFactory) Setup 

func (f *FileWriterFactory) Setup(name string, dec plugin.Decoder) error

Setup starts, loads and register file output writer.

func (*FileWriterFactory) Type 

func (f *FileWriterFactory) Type() string

Type returns log file type.

type FormatConfig 

type FormatConfig struct {
	// TimeFmt is the time format of log output, default as "2006-01-02 15:04:05.000" on empty.
	TimeFmt string `yaml:"time_fmt"`

	// TimeKey is the time key of log output, default as "T".
	TimeKey string `yaml:"time_key"`
	// LevelKey is the level key of log output, default as "L".
	LevelKey string `yaml:"level_key"`
	// NameKey is the name key of log output, default as "N".
	NameKey string `yaml:"name_key"`
	// CallerKey is the caller key of log output, default as "C".
	CallerKey string `yaml:"caller_key"`
	// FunctionKey is the function key of log output, default as "", which means not to print
	// function name.
	FunctionKey string `yaml:"function_key"`
	// MessageKey is the message key of log output, default as "M".
	MessageKey string `yaml:"message_key"`
	// StackTraceKey is the stack trace key of log output, default as "S".
	StacktraceKey string `yaml:"stacktrace_key"`
}

FormatConfig is the log format config.

type Level 

type Level int

Level is the log level. 

const (
	LevelNil Level = iota
	LevelTrace
	LevelDebug
	LevelInfo
	LevelWarn
	LevelError
	LevelFatal
)

Enums log level constants.

func GetLevel 

func GetLevel(output string) Level

GetLevel gets log level for different output.

func (*Level) String 

func (lv *Level) String() string

String turns the LogLevel to string.

type Logger 

type Logger interface {
	// Trace logs to TRACE log. Arguments are handled in the manner of fmt.Println.
	Trace(args ...interface{})
	// Tracef logs to TRACE log. Arguments are handled in the manner of fmt.Printf.
	Tracef(format string, args ...interface{})
	// Debug logs to DEBUG log. Arguments are handled in the manner of fmt.Println.
	Debug(args ...interface{})
	// Debugf logs to DEBUG log. Arguments are handled in the manner of fmt.Printf.
	Debugf(format string, args ...interface{})
	// Info logs to INFO log. Arguments are handled in the manner of fmt.Println.
	Info(args ...interface{})
	// Infof logs to INFO log. Arguments are handled in the manner of fmt.Printf.
	Infof(format string, args ...interface{})
	// Warn logs to WARNING log. Arguments are handled in the manner of fmt.Println.
	Warn(args ...interface{})
	// Warnf logs to WARNING log. Arguments are handled in the manner of fmt.Printf.
	Warnf(format string, args ...interface{})
	// Error logs to ERROR log. Arguments are handled in the manner of fmt.Println.
	Error(args ...interface{})
	// Errorf logs to ERROR log. Arguments are handled in the manner of fmt.Printf.
	Errorf(format string, args ...interface{})
	// Fatal logs to ERROR log. Arguments are handled in the manner of fmt.Println.
	// All Fatal logs will exit by calling os.Exit(1).
	// Implementations may also call os.Exit() with a non-zero exit code.
	Fatal(args ...interface{})
	// Fatalf logs to ERROR log. Arguments are handled in the manner of fmt.Printf.
	Fatalf(format string, args ...interface{})

	// Sync calls the underlying Core's Sync method, flushing any buffered log entries.
	// Applications should take care to call Sync before exiting.
	Sync() error

	// SetLevel sets the output log level.
	SetLevel(output string, level Level)
	// GetLevel gets the output log level.
	GetLevel(output string) Level

	// With adds user defined fields to Logger. Fields support multiple values.
	With(fields ...Field) Logger
}

Logger is the underlying logging work for tRPC framework. 

var (
	// DefaultLogger the default Logger. The initial output is console. When frame start, it is
	// over write by configuration.
	DefaultLogger Logger
	// DefaultLogFactory is the default log loader. Users may replace it with their own
	// implementation.
	DefaultLogFactory = &Factory{}
)

func Get 

func Get(name string) Logger

Get returns the Logger implementation by log name. log.Debug use DefaultLogger to print logs. You may also use log.Get("name").Debug.

func GetDefaultLogger 

func GetDefaultLogger() Logger

GetDefaultLogger gets the default Logger. To configure it, set key in configuration file to default. The console output is the default value.

func NewZapLog 

func NewZapLog(c Config) Logger

NewZapLog creates a trpc default Logger from zap whose caller skip is set to 2.

func NewZapLogWithCallerSkip 

func NewZapLogWithCallerSkip(cfg Config, callerSkip int) Logger

NewZapLogWithCallerSkip creates a trpc default Logger from zap.

func With 

func With(fields ...Field) Logger

With adds user defined fields to Logger. Field support multiple values.

func WithContext 

func WithContext(ctx context.Context, fields ...Field) Logger

WithContext add user defined fields to the Logger of context. Fields support multiple values.

type LoggerOption 

type LoggerOption func(*LoggerOptions)

LoggerOption modifies the LoggerOptions.

type LoggerOptions 

type LoggerOptions struct {
	LogLevel Level
	Pattern  string
	Writer   io.Writer
}

LoggerOptions is the log options.

type NewFormatEncoder added in v1.0.3 

type NewFormatEncoder func(zapcore.EncoderConfig) zapcore.Encoder

NewFormatEncoder is the function type for creating a format encoder out of an encoder config.

type Option 

type Option func(*options)

Option modifies the options of optionLogger.

func WithAdditionalCallerSkip 

func WithAdditionalCallerSkip(skip int) Option

WithAdditionalCallerSkip adds additional caller skip.

type OptionLogger 

type OptionLogger interface {
	WithOptions(opts ...Option) Logger
}

OptionLogger defines logger with additional options.

type OutputConfig 

type OutputConfig struct {
	// Writer is the output of log, such as console or file.
	Writer      string      `yaml:"writer"`
	WriteConfig WriteConfig `yaml:"writer_config"`

	// Formatter is the format of log, such as console or json.
	Formatter    string       `yaml:"formatter"`
	FormatConfig FormatConfig `yaml:"formatter_config"`

	// RemoteConfig is the remote config. It's defined by business and should be registered by
	// third-party modules.
	RemoteConfig yaml.Node `yaml:"remote_config"`

	// Level controls the log level, like debug, info or error.
	Level string `yaml:"level"`

	// CallerSkip controls the nesting depth of log function.
	CallerSkip int `yaml:"caller_skip"`

	// EnableColor determines if the output is colored. The default value is false.
	EnableColor bool `yaml:"enable_color"`
}

OutputConfig is the output config, includes console, file and remote.

type TimeUnit 

type TimeUnit string

TimeUnit is the time unit by which files are split, one of minute/hour/day/month/year.

func (TimeUnit) Format 

func (t TimeUnit) Format() string

Format returns a string preceding with `.`. Use TimeFormatDay as default.

func (TimeUnit) RotationGap 

func (t TimeUnit) RotationGap() time.Duration

RotationGap returns the time.Duration for time unit. Use one day as the default.

type WriteConfig 

type WriteConfig struct {
	// LogPath is the log path like /usr/local/trpc/log/.
	LogPath string `yaml:"log_path"`
	// Filename is the file name like trpc.log.
	Filename string `yaml:"filename"`
	// WriteMode is the log write mod. 1: sync, 2: async, 3: fast(maybe dropped), default as 3.
	WriteMode int `yaml:"write_mode"`
	// RollType is the log rolling type. Split files by size/time, default by size.
	RollType string `yaml:"roll_type"`
	// MaxAge is the max expire times(day).
	MaxAge int `yaml:"max_age"`
	// MaxBackups is the max backup files.
	MaxBackups int `yaml:"max_backups"`
	// Compress defines whether log should be compressed.
	Compress bool `yaml:"compress"`
	// MaxSize is the max size of log file(MB).
	MaxSize int `yaml:"max_size"`

	// TimeUnit splits files by time unit, like year/month/hour/minute, default day.
	// It takes effect only when split by time.
	TimeUnit TimeUnit `yaml:"time_unit"`
}

WriteConfig is the local file config.

type WriteMode 

type WriteMode int

WriteMode is the log write mode, one of 1, 2, 3.

Source Files

View all Source files

Directories

Path Synopsis
Package rollwriter provides a high performance rolling file log.
 Package rollwriter provides a high performance rolling file log.

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