god

README

god

A small tool for simplifying debugging of go applications.

Import the library in your app:

import "github.com/256dpi/god"

Then add the following line as early as possible:

god.Debug()

This will open a pprof and prometheus endpoint on port 6060.

Use the god utility to interact with the endpoint:

god -duration 10

The tool will fetch all available profiles, run the pprof servers and open a custom frontend from which all profiles can be accessed.

Documentation

Index

• func Init(opts Options)
• func Register(name string, m Metric)
• func Track(name string, fn func() string)
• func TrackFloat(name string, fn func() float64)
• func TrackInt(name string, fn func() int64)
• type Counter
  • func NewCounter(name string, formatter func(total int) string) *Counter
  • func (c *Counter) Add(n int)
  • func (c *Counter) Collect() string
• type Metric
• type Options
• type Timer
  • func NewTimer(name string) *Timer
  • func (t *Timer) Add(d time.Duration)
  • func (t *Timer) Collect() string
  • func (t *Timer) Measure() func()

Examples

• Init

Functions

func Init

func Init(opts Options)

Init will run a god compatible debug endpoint.

Example

// init
Init(Options{})

// block events
go func() {
	for {
		<-time.After(time.Millisecond)
	}
}()

// mutex events
var m sync.Mutex
for i := 0; i < 2; i++ {
	go func() {
		for {
			m.Lock()
			time.Sleep(time.Millisecond)
			m.Unlock()
		}
	}()
}

fmt.Println("Hello")

select {}

Output:

Hello

func Register

func Register(name string, m Metric)

Register will register the provided metric.

func Track

func Track(name string, fn func() string)

Track will track a string over time.

func TrackFloat

func TrackFloat(name string, fn func() float64)

TrackFloat will track a float over time.

func TrackInt

func TrackInt(name string, fn func() int64)

TrackInt will track an integer over time.

Types

type Counter

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

Counter is a simple operations counter.

func NewCounter

func NewCounter(name string, formatter func(total int) string) *Counter

NewCounter will create and return a counter.

func (*Counter) Add

func (c *Counter) Add(n int)

Add will increment the counter.

func (*Counter) Collect

func (c *Counter) Collect() string

Collect implements the Metric interface.

type Metric

type Metric interface {
	// Collect is called every second to retrieve the current value.
	Collect() string
}

Metric represents a periodically collected metric.

type Options

type Options struct {
	// The port to run the debug interface on.
	//
	// Default: 6060.
	Port int

	// The memory profile rate.
	//
	// Default: 1024.
	MemoryProfileRate int

	// The mutex profile fraction.
	//
	// Default: 1.
	MutexProfileFraction int

	// The block profile rate.
	//
	// Default: 1.
	BlockProfileRate int

	// Custom handler for the status endpoint.
	//
	// Default: "OK" writer.
	StatusHandler http.HandlerFunc

	// Custom handler for the metrics endpoint.
	MetricsHandler http.HandlerFunc
}

Options define the available debugging options.

type Timer

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

Timer is a simple operations timer.

func NewTimer

func NewTimer(name string) *Timer

NewTimer will create and return a timer.

func (*Timer) Add

func (t *Timer) Add(d time.Duration)

Add will add the duration to the timer.

func (*Timer) Collect

func (t *Timer) Collect() string

Collect implements the Metric interface.

func (*Timer) Measure

func (t *Timer) Measure() func()

Measure can be used to track a function using defer.