web

Documentation

Overview

Package web contains a small web framework extension.

Index

• func Decode(r *http.Request, val interface{}) error
• func GetTraceID(ctx context.Context) string
• func IsShutdown(err error) bool
• func NewShutdownError(message string) error
• func Param(r *http.Request, key string) string
• func Respond(ctx context.Context, w http.ResponseWriter, data interface{}, statusCode int) error
• func SetStatusCode(ctx context.Context, statusCode int) error
• type App
  • func NewApp(shutdown chan os.Signal, mw ...Middleware) *App
  • func (a *App) Handle(method string, group string, path string, handler Handler, mw ...Middleware)
  • func (a *App) ServeHTTP(w http.ResponseWriter, r *http.Request)
  • func (a *App) SignalShutdown()
• type Handler
• type Middleware
• type Values
  • func GetValues(ctx context.Context) (*Values, error)

Functions

func Decode

func Decode(r *http.Request, val interface{}) error

Decode reads the body of an HTTP request looking for a JSON document. The body is decoded into the provided value.

If the provided value is a struct then it is checked for validation tags.

func GetTraceID

func GetTraceID(ctx context.Context) string

GetTraceID returns the trace id from the context.

func IsShutdown

func IsShutdown(err error) bool

IsShutdown checks to see if the shutdown error is contained in the specified error value.

func NewShutdownError

func NewShutdownError(message string) error

NewShutdownError returns an error that causes the framework to signal a graceful shutdown.

func Param

func Param(r *http.Request, key string) string

Param returns the web call parameters from the request.

func Respond

func Respond(ctx context.Context, w http.ResponseWriter, data interface{}, statusCode int) error

Respond converts a Go value to JSON and sends it to the client.

func SetStatusCode

func SetStatusCode(ctx context.Context, statusCode int) error

SetStatusCode sets the status code back into the context.

Types

type App

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

App is the entrypoint into our application and what configures our context object for each of our http handlers. Feel free to add any configuration data/logic on this App struct.

func NewApp

func NewApp(shutdown chan os.Signal, mw ...Middleware) *App

NewApp creates an App value that handle a set of routes for the application.

func (*App) Handle

func (a *App) Handle(method string, group string, path string, handler Handler, mw ...Middleware)

Handle sets a handler function for a given HTTP method and path pair to the application server mux.

func (*App) ServeHTTP

func (a *App) ServeHTTP(w http.ResponseWriter, r *http.Request)

ServeHTTP implements the http.Handler interface. It's the entry point for all http traffic and allows the opentelemetry mux to run first to handle tracing. The opentelemetry mux then calls the application mux to handle application traffic. This was set up on line 44 in the NewApp function.

func (*App) SignalShutdown

func (a *App) SignalShutdown()

SignalShutdown is used to gracefully shut down the app when an integrity issue is identified.

type Handler

type Handler func(ctx context.Context, w http.ResponseWriter, r *http.Request) error

A Handler is a type that handles a http request within our own little mini framework.

type Middleware

type Middleware func(Handler) Handler

Middleware is a function designed to run some code before and/or after another Handler. It is designed to remove boilerplate or other concerns not direct to any given Handler.

type Values

type Values struct {
	TraceID    string
	Now        time.Time
	StatusCode int
}

Values represent state for each request.

func GetValues

func GetValues(ctx context.Context) (*Values, error)

GetValues returns the values from the context.