The highest tagged major version is v2.

log

package module

v1.0.5 Latest Latest Go to latest Published: Mar 18, 2021 License: MIT Imports: 15 Imported by: 2,072

Details

Valid go.mod file
Redistributable license
Tagged version
Stable version
Learn more about best practices

Repository

github.com/ipfs/go-log

Links

Open Source Insights

README ¶

go-log

The logging library used by go-ipfs

It currently uses a modified version of go-logging to implement the standard printf-style log output.

Install

go get github.com/ipfs/go-log

Usage

Once the package is imported under the name logging, an instance of EventLogger can be created like so:

var log = logging.Logger("subsystem name")

It can then be used to emit log messages, either plain printf-style messages at six standard levels or structured messages using Start, StartFromParentState, Finish and FinishWithErr methods.

Example

func (s *Session) GetBlock(ctx context.Context, c *cid.Cid) (blk blocks.Block, err error) {

    // Starts Span called "Session.GetBlock", associates with `ctx`
    ctx = log.Start(ctx, "Session.GetBlock")

    // defer so `blk` and `err` can be evaluated after call
    defer func() {
        // tag span associated with `ctx`
        log.SetTags(ctx, map[string]interface{}{
            "cid": c,
            "block", blk,
        })
        // if err is non-nil tag the span with an error
        log.FinishWithErr(ctx, err)
    }()

    if shouldStartSomething() {
        // log message on span associated with `ctx`
        log.LogKV(ctx, "startSomething", true)
    }
  ...
}

Tracing

go-log wraps the opentracing-go methods - StartSpan, Finish, LogKV, and SetTag.

go-log implements its own tracer - loggabletracer - based on the basictracer-go implementation. If there is an active WriterGroup the loggabletracer will record span data to the WriterGroup. An example of this can be seen in the log tail command of go-ipfs.

Third party tracers may be used by calling opentracing.SetGlobalTracer() with your desired tracing implementation. An example of this can be seen using the go-jaeger-plugin and the go-ipfs tracer plugin

Contribute

Feel free to join in. All welcome. Open an issue!

This repository falls under the IPFS Code of Conduct.

Want to hack on IPFS?

License

MIT

Documentation ¶

Constants ¶

This section is empty.

Variables ¶

View Source

var (
	LevelDebug  = log2.LevelDebug
	LevelInfo   = log2.LevelInfo
	LevelWarn   = log2.LevelWarn
	LevelError  = log2.LevelError
	LevelDPanic = log2.LevelDPanic
	LevelPanic  = log2.LevelPanic
	LevelFatal  = log2.LevelFatal
)

Functions ¶

func ContextWithLoggable ¶

func ContextWithLoggable(ctx context.Context, l Loggable) context.Context

ContextWithLoggable returns a derived context which contains the provided Loggable. Any Events logged with the derived context will include the provided Loggable.

func FormatRFC3339 ¶

func FormatRFC3339(t time.Time) string

FormatRFC3339 returns the given time in UTC with RFC3999Nano format.

func GetSubsystems ¶

func GetSubsystems() []string

GetSubsystems returns a slice containing the names of the current loggers

func SetAllLoggers ¶

func SetAllLoggers(lvl LogLevel)

SetAllLoggers changes the logging level of all loggers to lvl

func SetDebugLogging ¶

func SetDebugLogging()

SetDebugLogging calls SetAllLoggers with logging.DEBUG

func SetLogLevel ¶

func SetLogLevel(name, level string) error

SetLogLevel changes the log level of a specific subsystem name=="*" changes all subsystems

func SetLogLevelRegex ¶ added in v1.0.0

func SetLogLevelRegex(e, l string) error

SetLogLevelRegex sets all loggers to level `l` that match expression `e`. An error is returned if `e` fails to compile.

func SetupLogging ¶

func SetupLogging()

Types ¶

type EventInProgress ¶

type EventInProgress struct {
	// contains filtered or unexported fields
}

DEPRECATED EventInProgress represent and event which is happening Deprecated: Stop using go-log for event logging

func (*EventInProgress) Append ¶

func (eip *EventInProgress) Append(l Loggable)

DEPRECATED use `LogKV` or `SetTag` Append adds loggables to be included in the call to Done

func (*EventInProgress) Close ¶

func (eip *EventInProgress) Close() error

Close is an alias for done Deprecated: Stop using go-log for event logging

func (*EventInProgress) Done ¶

func (eip *EventInProgress) Done()

Done creates a new Event entry that includes the duration and appended loggables. Deprecated: Stop using go-log for event logging

func (*EventInProgress) DoneWithErr ¶

func (eip *EventInProgress) DoneWithErr(err error)

DEPRECATED use `FinishWithErr` DoneWithErr creates a new Event entry that includes the duration and appended loggables. DoneWithErr accepts an error, if err is non-nil, it is set on the EventInProgress. Otherwise the logic is the same as the `Done()` method

func (*EventInProgress) SetError ¶

func (eip *EventInProgress) SetError(err error)

DEPRECATED use `SetError(ctx, error)` SetError includes the provided error

type EventLogger ¶

type EventLogger interface {
	StandardLogger

	// Event merges structured data from the provided inputs into a single
	// machine-readable log event.
	//
	// If the context contains metadata, a copy of this is used as the base
	// metadata accumulator.
	//
	// If one or more loggable objects are provided, these are deep-merged into base blob.
	//
	// Next, the event name is added to the blob under the key "event". If
	// the key "event" already exists, it will be over-written.
	//
	// Finally the timestamp and package name are added to the accumulator and
	// the metadata is logged.
	// DEPRECATED
	// Deprecated: Stop using go-log for event logging
	Event(ctx context.Context, event string, m ...Loggable)

	// DEPRECATED
	// Deprecated: Stop using go-log for event logging
	EventBegin(ctx context.Context, event string, m ...Loggable) *EventInProgress

	// Start starts an opentracing span with `name`, using
	// any Span found within `ctx` as a ChildOfRef. If no such parent could be
	// found, Start creates a root (parentless) Span.
	//
	// The return value is a context.Context object built around the
	// returned Span.
	//
	// Example usage:
	//
	//    SomeFunction(ctx context.Context, ...) {
	//        ctx := log.Start(ctx, "SomeFunction")
	//        defer log.Finish(ctx)
	//        ...
	//    }
	// Deprecated: Stop using go-log for event logging
	Start(ctx context.Context, name string) context.Context

	// StartFromParentState starts an opentracing span with `name`, using
	// any Span found within `ctx` as a ChildOfRef. If no such parent could be
	// found, StartSpanFromParentState creates a root (parentless) Span.
	//
	// StartFromParentState will attempt to deserialize a SpanContext from `parent`,
	// using any Span found within to continue the trace
	//
	// The return value is a context.Context object built around the
	// returned Span.
	//
	// An error is returned when `parent` cannot be deserialized to a SpanContext
	//
	// Example usage:
	//
	//    SomeFunction(ctx context.Context, bParent []byte) {
	//        ctx := log.StartFromParentState(ctx, "SomeFunction", bParent)
	//        defer log.Finish(ctx)
	//        ...
	//    }
	// Deprecated: Stop using go-log for event logging
	StartFromParentState(ctx context.Context, name string, parent []byte) (context.Context, error)

	// Finish completes the span associated with `ctx`.
	//
	// Finish() must be the last call made to any span instance, and to do
	// otherwise leads to undefined behavior.
	// Finish will do its best to notify (log) when used in correctly
	//		.e.g called twice, or called on a spanless `ctx`
	// Deprecated: Stop using go-log for event logging
	Finish(ctx context.Context)

	// FinishWithErr completes the span associated with `ctx` and also calls
	// SetErr if `err` is non-nil
	//
	// FinishWithErr() must be the last call made to any span instance, and to do
	// otherwise leads to undefined behavior.
	// FinishWithErr will do its best to notify (log) when used in correctly
	//		.e.g called twice, or called on a spanless `ctx`
	// Deprecated: Stop using go-log for event logging
	FinishWithErr(ctx context.Context, err error)

	// SetErr tags the span associated with `ctx` to reflect an error occured, and
	// logs the value `err` under key `error`.
	// Deprecated: Stop using go-log for event logging
	SetErr(ctx context.Context, err error)

	// LogKV records key:value logging data about an event stored in `ctx`
	// Eexample:
	//    log.LogKV(
	//        "error", "resolve failure",
	//        "type", "cache timeout",
	//        "waited.millis", 1500)
	// Deprecated: Stop using go-log for event logging
	LogKV(ctx context.Context, alternatingKeyValues ...interface{})

	// SetTag tags key `k` and value `v` on the span associated with `ctx`
	// Deprecated: Stop using go-log for event logging
	SetTag(ctx context.Context, key string, value interface{})

	// SetTags tags keys from the `tags` maps on the span associated with `ctx`
	// Example:
	//    log.SetTags(ctx, map[string]{
	//		"type": bizStruct,
	//      "request": req,
	//		})
	// Deprecated: Stop using go-log for event logging
	SetTags(ctx context.Context, tags map[string]interface{})

	// SerializeContext takes the SpanContext instance stored in `ctx` and Seralizes
	// it to bytes. An error is returned if the `ctx` cannot be serialized to
	// a bytes array
	// Deprecated: Stop using go-log for event logging
	SerializeContext(ctx context.Context) ([]byte, error)
}

EventLogger extends the StandardLogger interface to allow for log items containing structured metadata

Example ¶

{
	log := EventLogger(nil)
	e := log.EventBegin(context.Background(), "dial")
	e.Done()
}
{
	log := EventLogger(nil)
	e := log.EventBegin(context.Background(), "dial")
	_ = e.Close() // implements io.Closer for convenience
}

Output:

type LogLevel ¶ added in v1.0.0

type LogLevel = log2.LogLevel

LogLevel represents a log severity level. Use the package variables as an enum.

func LevelFromString ¶ added in v1.0.0

func LevelFromString(level string) (LogLevel, error)

LevelFromString parses a string-based level and returns the corresponding LogLevel.

Supported strings are: DEBUG, INFO, WARN, ERROR, DPANIC, PANIC, FATAL, and their lower-case forms.

The returned LogLevel must be discarded if error is not nil.

type Loggable ¶

type Loggable interface {
	Loggable() map[string]interface{}
}

Loggable describes objects that can be marshalled into Metadata for logging

func Deferred ¶

func Deferred(key string, f func() string) Loggable

Deferred returns a LoggableF where the execution of the provided function is deferred.

func Pair ¶

func Pair(key string, l Loggable) Loggable

Pair returns a Loggable where key is paired to Loggable.

type LoggableF ¶

type LoggableF func() map[string]interface{}

LoggableF converts a func into a Loggable

func (LoggableF) Loggable ¶

func (l LoggableF) Loggable() map[string]interface{}

Loggable implements the Loggable interface by running the LoggableF function.

type LoggableMap ¶

type LoggableMap map[string]interface{}

LoggableMap is just a generic map keyed by string. It implements the Loggable interface.

func (LoggableMap) Loggable ¶

func (l LoggableMap) Loggable() map[string]interface{}

Loggable implements the Loggable interface for LoggableMap

type Metadata ¶

type Metadata map[string]interface{}

Metadata is a convenience type for generic maps

func DeepMerge ¶

func DeepMerge(b, a Metadata) Metadata

DeepMerge merges the second Metadata parameter into the first. Nested Metadata are merged recursively. Primitives are over-written.

func MetadataFromContext ¶

func MetadataFromContext(ctx context.Context) (Metadata, error)

MetadataFromContext extracts Matadata from a given context's value.

func Metadatify ¶

func Metadatify(i interface{}) (Metadata, error)

Metadatify converts maps into Metadata.

func (Metadata) JsonString ¶

func (m Metadata) JsonString() (string, error)

JsonString returns the marshaled JSON string for the metadata.

func (Metadata) Loggable ¶

func (m Metadata) Loggable() map[string]interface{}

Loggable implements the Loggable interface.

type StandardLogger ¶

type StandardLogger interface {
	log2.StandardLogger
	// Deprecated use Warn
	Warning(args ...interface{})
	// Deprecated use Warnf
	Warningf(format string, args ...interface{})
}

StandardLogger provides API compatibility with standard printf loggers eg. go-logging

type ZapEventLogger ¶ added in v1.0.0

type ZapEventLogger struct {
	zap.SugaredLogger
	// contains filtered or unexported fields
}

ZapEventLogger implements the EventLogger and wraps a go-logging Logger

func Logger ¶

func Logger(system string) *ZapEventLogger

Logger retrieves an event logger by name