README
¶
Log Package
The log package provides structured logging capabilities for Moov applications.
Usage
Basic Logging
import "github.com/anguishedcha/base/log"
// Create a new logger
logger := log.NewDefaultLogger()
// Log a message with different levels
logger.Info().Log("Application started")
logger.Debug().Log("Debug information")
logger.Warn().Log("Warning message")
logger.Error().Log("Error occurred")
// Log with key-value pairs
logger.Info().Set("request_id", log.String("12345")).Log("Processing request")
// Log formatted messages
logger.Infof("Processing request %s", "12345")
// Log errors
err := someFunction()
if err != nil {
logger.LogError(err)
}
Using Fields
import "github.com/anguishedcha/base/log"
// Create a map of fields
fields := log.Fields{
"request_id": log.String("12345"),
"user_id": log.Int(42),
"timestamp": log.Time(time.Now()),
}
// Log with fields
logger.With(fields).Info().Log("Request processed")
Using StructContext
The StructContext function allows you to log struct fields automatically by using tags.
import "github.com/anguishedcha/base/log"
// Define a struct with log tags
type User struct {
ID int `log:"id"`
Username string `log:"username"`
Email string `log:"email,omitempty"` // won't be logged if empty
Address Address `log:"address"` // nested struct must have log tag
Hidden string // no log tag, won't be logged
}
type Address struct {
Street string `log:"street"`
City string `log:"city"`
Country string `log:"country"`
}
// Create a user
user := User{
ID: 1,
Username: "johndoe",
Email: "john@example.com",
Address: Address{
Street: "123 Main St",
City: "New York",
Country: "USA",
},
Hidden: "secret",
}
// Log with struct context
logger.With(log.StructContext(user)).Info().Log("User logged in")
// Log with struct context and prefix
logger.With(log.StructContext(user, log.WithPrefix("user"))).Info().Log("User details")
// Using custom tag other than "log"
type Product struct {
ID int `otel:"product_id"`
Name string `otel:"product_name"`
Price float64 `otel:"price,omitempty"`
}
product := Product{
ID: 42,
Name: "Widget",
Price: 19.99,
}
// Use otel tags instead of log tags
logger.With(log.StructContext(product, log.WithTag("otel"))).Info().Log("Product details")
The above will produce log entries with the following fields:
id=1username=johndoeemail=john@example.comaddress.street=123 Main Staddress.city=New Yorkaddress.country=USA
With the prefix option, the fields will be:
user.id=1user.username=johndoeuser.email=john@example.comuser.address.street=123 Main Stuser.address.city=New Yorkuser.address.country=USA
With the custom tag option, the fields will be extracted from the tag you specify (such as otel):
product_id=42product_name=Widgetprice=19.99
Note that nested structs or pointers to structs must have the specified tag to be included in the context.
Features
- Structured logging with key-value pairs
- Multiple log levels (Debug, Info, Warn, Error, Fatal)
- JSON and LogFmt output formats
- Context-based logging
- Automatic struct field logging with StructContext
- Support for various value types (string, int, float, bool, time, etc.)
Configuration
The default logger format is determined by the MOOV_LOG_FORMAT environment variable:
json: JSON formatlogfmt: LogFmt format (default)nopornoop: No-op logger that discards all logs
Documentation
¶
Index ¶
- Constants
- func NewBufferLogger() (*BufferedLogger, Logger)
- type BufferedLogger
- type Context
- type Fields
- type Level
- type LoggedError
- type Logger
- type StructContextOption
- type Valuer
- func Bool(b bool) Valuer
- func ByteBase64(b []byte) Valuer
- func ByteString(b []byte) Valuer
- func Float32(f float32) Valuer
- func Float64(f float64) Valuer
- func Int(i int) Valuer
- func Int64(i int64) Valuer
- func Int64OrNil(i *int64) Valuer
- func String(s string) Valuer
- func StringOrNil(s *string) Valuer
- func Stringer(s fmt.Stringer) Valuer
- func Strings(vals []string) Valuer
- func Time(t time.Time) Valuer
- func TimeDuration(d time.Duration) Valuer
- func TimeFormatted(t time.Time, format string) Valuer
- func TimeOrNil(t *time.Time) Valuer
- func Uint32(i uint32) Valuer
- func Uint64(i uint64) Valuer
Constants ¶
const Debug = Level("debug")
Info is sets level=info in the log output
const Error = Level("error")
Error sets level=error in the log output
const Fatal = Level("fatal")
Fatal sets level=fatal in the log output
const Info = Level("info")
Info is sets level=info in the log output
const StackTrace = st("stacktrace")
const Warn = Level("warn")
Info is sets level=warn in the log output
Variables ¶
This section is empty.
Functions ¶
func NewBufferLogger ¶
func NewBufferLogger() (*BufferedLogger, Logger)
Types ¶
type BufferedLogger ¶
type BufferedLogger struct {
// contains filtered or unexported fields
}
func (*BufferedLogger) Reset ¶
func (bl *BufferedLogger) Reset()
func (*BufferedLogger) String ¶
func (bl *BufferedLogger) String() string
type Context ¶
func StructContext ¶
func StructContext(v interface{}, opts ...StructContextOption) Context
StructContext creates a Context from a struct, extracting fields tagged with `log` It supports nested structs and respects omitempty directive
type Level ¶
type Level string
Level just wraps a string to be able to add Context specific to log levels
type LoggedError ¶
type LoggedError struct {
// contains filtered or unexported fields
}
func (LoggedError) Err ¶
func (l LoggedError) Err() error
func (LoggedError) Nil ¶
func (l LoggedError) Nil() error
type Logger ¶
type Logger interface {
Set(key string, value Valuer) Logger
With(ctxs ...Context) Logger
Details() map[string]interface{}
Debug() Logger
Info() Logger
Warn() Logger
Error() Logger
Fatal() Logger
Log(message string)
Logf(format string, args ...interface{})
Send()
LogError(error error) LoggedError
LogErrorf(format string, args ...interface{}) LoggedError
}
func NewDefaultLogger ¶
func NewDefaultLogger() Logger
func NewJSONLogger ¶
func NewJSONLogger() Logger
func NewLogFmtLogger ¶
func NewLogFmtLogger() Logger
func NewNopLogger ¶
func NewNopLogger() Logger
func NewTestLogger ¶
func NewTestLogger() Logger
type StructContextOption ¶
type StructContextOption func(*structContext)
StructContextOption defines options for StructContext
func WithPrefix ¶
func WithPrefix(prefix string) StructContextOption
WithPrefix adds a prefix to all struct field names
func WithTag ¶
func WithTag(tag string) StructContextOption
WithTag adds a custom tag to look for in struct fields
type Valuer ¶
type Valuer interface {
// contains filtered or unexported methods
}
Valuer is an interface to deal with typing problems of just having an interface{} as the acceptable parameters Go-kit logging has a failure case if you attempt to throw any values into it. This is a way to guard our developers from having to worry about error cases of the lower logging framework.
Source Files