Documentation
¶
Overview ¶
Package zlog lets you use golang structured logging (slog) with context. Add and retrieve logger to and from context. Add and retrieve attributes to and from context. Automatically read any custom context values, such as OpenTelemetry TraceID.
This package borrows code from package `github.com/veqryn/slog-context`. The reason of forking is that I want opinionated different API design, the code is simple, it's easy to maintain a new package.
Index ¶
- Constants
- func AppendAttrs(parent context.Context, args ...any) context.Context
- func ArgsToAttrSlice(args ...any) []slog.Attr
- func Debug(ctx context.Context, msg string, args ...any)
- func Debugf(format string, args ...any)
- func Error(ctx context.Context, msg string, args ...any)
- func Errorf(format string, args ...any)
- func ExtractAppended(ctx context.Context, _ *slog.Record) slog.Attr
- func ExtractPrepended(ctx context.Context, _ *slog.Record) slog.Attr
- func Fatal(ctx context.Context, msg string, args ...any)
- func Fatalf(format string, args ...any)
- func Info(ctx context.Context, msg string, args ...any)
- func Infof(format string, args ...any)
- func Log(ctx context.Context, level slog.Level, msg string, args ...any)
- func LogAttrs(ctx context.Context, level slog.Level, msg string, attrs ...slog.Attr)
- func LogAttrsSkip(ctx context.Context, skip int, level slog.Level, msg string, ...)
- func LogSkip(ctx context.Context, skip int, level slog.Level, msg string, args ...any)
- func NewCtx(parent context.Context, logger *Logger) context.Context
- func NewMiddleware(opts *HandlerOptions) func(slog.Handler) slog.Handler
- func PrependAttrs(parent context.Context, args ...any) context.Context
- func Print(args ...any)
- func Printf(format string, args ...any)
- func Println(args ...any)
- func RedirectStdLog(l *Logger, attrs []slog.Attr)
- func SetDefault(l *Logger)
- func SetDevelopment(level slog.Level)
- func Warn(ctx context.Context, msg string, args ...any)
- func Warnf(format string, args ...any)
- type AttrExtractor
- type Handler
- type HandlerOptions
- type Logger
Constants ¶
const ErrorKey = "error"
Variables ¶
This section is empty.
Functions ¶
func AppendAttrs ¶ added in v2.17.0
AppendAttrs adds the attribute arguments to the end of the group that will be appended to the end of the log record when it is handled. The attributes could be in a group or subgroup, if the log has used WithGroup at some point.
func ArgsToAttrSlice ¶ added in v2.17.0
ArgsToAttrSlice turns a slice of arguments, some of which pairs of primitives, some might be attributes already, into a slice of attributes.
func Debugf ¶
Debugf logs a message at level slog.LevelDebug. Arguments are handled in the manner of fmt.Printf.
func Errorf ¶
Errorf logs a message at level slog.LevelError. Arguments are handled in the manner of fmt.Printf.
func ExtractAppended ¶ added in v2.17.0
ExtractAppended is an AttrExtractor that returns the appended attributes stored in the context. The returned attr should not be modified in any way, doing so will cause a race condition.
func ExtractPrepended ¶ added in v2.17.0
ExtractPrepended is an AttrExtractor that returns the prepended attributes stored in the context. The returned attr should not be modified in any way, doing so will cause a race condition.
func Infof ¶
Infof logs a message at level slog.LevelInfo. Arguments are handled in the manner of fmt.Printf.
func LogAttrsSkip ¶ added in v2.17.0
func NewCtx ¶ added in v2.17.0
NewCtx returns a copy of ctx with the logger attached. The parent context will be unaffected.
func NewMiddleware ¶ added in v2.17.0
func NewMiddleware(opts *HandlerOptions) func(slog.Handler) slog.Handler
NewMiddleware creates a slog.Handler middleware that conforms to github.com/samber/slog-multi.Middleware interface. It can be used with slogmulti methods such as Pipe to easily setup a pipeline of slog handlers:
slog.SetDefault(slog.New(slogmulti.
Pipe(zlog.NewMiddleware(&zlog.HandlerOptions{})).
Pipe(zlog.NewOverwriteMiddleware(&slogdedup.OverwriteHandlerOptions{})).
Handler(slog.NewJSONHandler(os.Stdout, &slog.HandlerOptions{})),
))
func PrependAttrs ¶ added in v2.17.0
PrependAttrs adds the attribute arguments to the end of the group that will be prepended to the start of the log record when it is handled. The attributes will be at the root level, and not in any groups.
func Print ¶
func Print(args ...any)
Print logs a message at level slog.LevelInfo, or level detected from args, if it's enabled. It has same signature with log.Print, arguments are handled in the manner of fmt.Print.
func Printf ¶
Printf logs a message at level slog.LevelInfo, or level detected from args, if it's enabled. It has same signature with log.Printf, arguments are handled in the manner of fmt.Printf.
func Println ¶ added in v2.1.0
func Println(args ...any)
Println logs a message at level slog.LevelInfo, or level detected from args, if it's enabled. It has same signature with log.Println, arguments are handled in the manner of fmt.Println.
func RedirectStdLog ¶ added in v2.4.0
func SetDefault ¶ added in v2.17.0
func SetDefault(l *Logger)
SetDefault makes l the default Logger. After this call, output from the log package's default Logger (as with log.Print, etc.) will be logged at LevelInfo using l's Handler.
func SetDevelopment ¶
SetDevelopment sets the default logger to use slogconsolehandler.Default as the underlying handler.
func Warnf ¶
Warnf logs a message at level slog.LevelWarn. Arguments are handled in the manner of fmt.Printf.
Types ¶
type AttrExtractor ¶ added in v2.17.0
AttrExtractor is a function that retrieves or creates slog.Attr based on information/values found in the context.Context and the slog.Record.
type Handler ¶ added in v2.17.0
type Handler struct {
// contains filtered or unexported fields
}
Handler is a slog.Handler middleware that will prepend and append attributes to log lines. The attributes are extracted out of the log record's context by the provided AttrExtractor functions. It passes the final record and attributes off to the next handler when finished.
func NewHandler ¶ added in v2.17.0
func NewHandler(next slog.Handler, opts *HandlerOptions) *Handler
NewHandler creates a slog.Handler middleware that will prepend and append attributes to log lines. The attributes are extracted out of the log record's context by the provided AttrExtractor functions. It passes the final record and attributes off to the next handler when finished. If opts is nil, the default options are used.
type HandlerOptions ¶ added in v2.17.0
type HandlerOptions struct {
// A list of functions to be called, each of which returns attributes
// that should be prepended to the start of every log line with the context.
// If left nil, the default ExtractPrepended function will be used.
Prependers []AttrExtractor
// A list of functions to be called, each of which will return attributes
// that should be appended to the end of every log line with the context.
// If left nil, the default ExtractAppended function will be used.
Appenders []AttrExtractor
}
HandlerOptions are options for a Handler
Source Files
Directories