package check

import "github.com/influxdata/influxdb/kit/check"

Package check standardizes /health and /ready endpoints. This allows you to easily know when your server is ready and healthy.

Index

Examples

Types

type Check 

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

Check wraps a map of service names to status checkers.

func NewCheck 

func NewCheck() *Check

NewCheck returns a Health with a default checker.

Example

Code: 

{
	// Run the default healthcheck. it always return 200. It is good if you
	// have a service without any dependency
	h := NewCheck()
	h.CheckHealth(context.Background())
}

func (*Check) AddHealthCheck 

func (c *Check) AddHealthCheck(check Checker)

AddHealthCheck adds the check to the list of ready checks. If c is a NamedChecker, the name will be added.

func (*Check) AddReadyCheck 

func (c *Check) AddReadyCheck(check Checker)

AddReadyCheck adds the check to the list of ready checks. If c is a NamedChecker, the name will be added.

func (*Check) CheckHealth 

func (c *Check) CheckHealth(ctx context.Context) Response

CheckHealth evaluates c's set of health checks and returns a populated Response.

Example

Code: 

{
	h := NewCheck()
	h.AddHealthCheck(Named("google", CheckerFunc(func(ctx context.Context) Response {
		var r net.Resolver
		_, err := r.LookupHost(ctx, "google.com")
		if err != nil {
			return Error(err)
		}
		return Pass()
	})))
	ctx, cancel := context.WithTimeout(context.Background(), 5*time.Second)
	defer cancel()
	h.CheckHealth(ctx)
}

func (*Check) CheckReady 

func (c *Check) CheckReady(ctx context.Context) Response

CheckReady evaluates c's set of ready checks and returns a populated Response.

func (*Check) ServeHTTP 

func (c *Check) ServeHTTP(w http.ResponseWriter, r *http.Request)

ServeHTTP serves /ready and /health requests with the respective checks.

Example

Code: 

{
	c := NewCheck()
	http.ListenAndServe(":6060", c)
}

func (*Check) SetPassthrough 

func (c *Check) SetPassthrough(h http.Handler)

SetPassthrough allows you to set a handler to use if the request is not a ready or health check. This can be useful if you intend to use this as a middleware.

Example

Code: 

{
	c := NewCheck()

	http.HandleFunc("/", func(w http.ResponseWriter, r *http.Request) {
		w.Write([]byte("Hello friends!"))
	})

	c.SetPassthrough(http.DefaultServeMux)
	http.ListenAndServe(":6060", c)
}

type Checker 

type Checker interface {
	Check(ctx context.Context) Response
}

Checker indicates a service whose health can be checked.

func ErrCheck 

func ErrCheck(fn func() error) Checker

ErrCheck will create a health checker that executes a function. If the function returns an error, it will return an unhealthy response. Otherwise, it will be as if the Ok function was called. Note: it is better to use CheckFunc, because with Check, the context is ignored.

func Named 

func Named(name string, checker Checker) Checker

Named returns a Checker that will attach a name to the Response from the check. This way, it is possible to augment a Response with a human-readable name, but not have to encode that logic in the actual check itself.

func NamedFunc 

func NamedFunc(name string, fn CheckerFunc) Checker

NamedFunc is the same as Named except it takes a CheckerFunc.

type CheckerFunc 

type CheckerFunc func(ctx context.Context) Response

CheckerFunc is an adapter of a plain func() error to the Checker interface.

func (CheckerFunc) Check 

func (f CheckerFunc) Check(ctx context.Context) Response

Check implements Checker.

type NamedChecker 

type NamedChecker interface {
	Checker
	CheckName() string
}

NamedChecker is a superset of Checker that also indicates the name of the service. Prefer to implement NamedChecker if your service has a fixed name, as opposed to calling *Health.AddNamed.

type Response 

type Response struct {
	Name    string    `json:"name"`
	Status  Status    `json:"status"`
	Message string    `json:"message,omitempty"`
	Checks  Responses `json:"checks,omitempty"`
}

Response is a result of a collection of health checks.

func Error 

func Error(err error) Response

Error is a utility function for creating a response from an error message.

func Info 

func Info(msg string, args ...interface{}) Response

Info is a utility function to generate a healthy status with a printf message.

func Pass 

func Pass() Response

Pass is a utility function to generate a passing status response with the default parameters.

func (*Response) HasCheck 

func (r *Response) HasCheck(name string) bool

HasCheck verifies whether the receiving Response has a check with the given name or not.

type Responses 

type Responses []Response

Responses is a sortable collection of Response objects.

func (Responses) Len 

func (r Responses) Len() int

func (Responses) Less 

func (r Responses) Less(i, j int) bool

Less defines the order in which responses are sorted.

Failing responses are always sorted before passing responses. Responses with the same status are then sorted according to the name of the check.

func (Responses) Swap 

func (r Responses) Swap(i, j int)

type Status 

type Status string

Status string to indicate the overall status of the check. 

const (
	// StatusFail indicates a specific check has failed.
	StatusFail Status = "fail"
	// StatusPass indicates a specific check has passed.
	StatusPass Status = "pass"

	// DefaultCheckName is the name of the default checker.
	DefaultCheckName = "internal"
)

Source Files

check.go helpers.go response.go

Version
v1.12.0 (latest)
Published
Apr 8, 2025
Platform
linux/amd64
Imports
6 packages
Last checked
2 days ago –

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