dump

Documentation

Overview

Package dump provides the endpoint "debug/dump", registered with http.DefaultServeMux, which returns a dump of useful diagnostic information as a tarball. The base configuration includes several useful diagnostics (see init). You may also register your own dump parts to be included, e.g.:

Register("mystuff", func(ctx context.Context, w io.Writer) error {
    w.Write([]byte("mystuff diagnostic data"))
    return nil
})

The endpoint responds with a gzipped tarball. The Content-Disposition of the response suggests a pseudo-unique filename to make it easier to deal with multiple dumps. Use curl flags to accept the suggested filename (recommended).

curl -OJ http://example:1234/debug/dump

Note that it will take at least 30 seconds to respond, as some of the parts of the base configuration are 30-second profiles.

Index

• Variables
• func Name() string
• func Register(name string, f Func)
• func WriteDump(ctx context.Context, pfx string, zw *zip.Writer)
• type Func
• type Registry
  • func NewRegistry(id string) *Registry
  • func (reg *Registry) Name() string
  • func (reg *Registry) Register(name string, f Func)
  • func (reg *Registry) ServeHTTP(w http.ResponseWriter, r *http.Request)
  • func (reg *Registry) WriteDump(ctx context.Context, pfx string, zw *zip.Writer)

Variables

var DefaultRegistry = NewRegistry(readExec())

DefaultRegistry is a default registry that has this process's GUID as its ID.

var ErrSkipPart = errors.New("skip part")

ErrSkipPart signals that we should skip a part. Return this from your Func to silently ignore the part for the current dump. If your Func returns anything else non-nil, it will be logged as an error. This is mostly useful for keeping logs quiet for parts that are sometimes unavailable for non-error reasons.

Functions

func Name

func Name() string

Name returns the name of the default registry. See (*Registry).Name.

func Register

func Register(name string, f Func)

Register registers a new part to be included in the dump of the DefaultRegistry. name will become the filename of the part file in the dump tarball. f will be called to produce the contents of that file.

func WriteDump

func WriteDump(ctx context.Context, pfx string, zw *zip.Writer)

WriteDump writes a dump of the default registry.

Types

type Func

type Func func(ctx context.Context, w io.Writer) error

Func is the function to be called when producing a dump for a part.

type Registry

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

Registry maintains the set of parts that will compose the dump.

func NewRegistry

func NewRegistry(id string) *Registry

NewRegistry returns a new registry for the parts to be included in the dump.

func (*Registry) Name

func (reg *Registry) Name() string

Name returns a name for reg that is convenient for naming dump files, as it is pseudo-unique and includes the registry ID, the time at which the registry was created, and the duration from that creation time.

func (*Registry) Register

func (reg *Registry) Register(name string, f Func)

Register registers a new part to be included in the dump of reg. Name will become the filename of the part file in the dump tarball. Func f will be called to produce the contents of that file.

func (*Registry) ServeHTTP

func (reg *Registry) ServeHTTP(w http.ResponseWriter, r *http.Request)

ServeHTTP serves the dump with a Content-Disposition set with a unique filename.

func (*Registry) WriteDump

func (reg *Registry) WriteDump(ctx context.Context, pfx string, zw *zip.Writer)

WriteDump writes the dump to w. pfx is prepended to the names of the parts of the dump, e.g. if pfx == "dump-123" and part name == "cpu", "dump-123/cpu" will be written into the archive. It returns no error, as it is best-effort.