metricator/internal/httpserver/httpserver.go

97 lines
2.6 KiB
Go

package httpserver
import (
"context"
"net"
"net/http"
"strings"
"time"
"go.dev.pztrn.name/metricator/internal/common"
"go.dev.pztrn.name/metricator/internal/configuration"
"go.dev.pztrn.name/metricator/internal/logger"
)
// HTTPServer is a controlling structure for HTTP server.
type HTTPServer struct {
config *configuration.Config
ctx context.Context
doneChan chan struct{}
logger *logger.Logger
handler *handler
server *http.Server
}
// NewHTTPServer creates HTTP server and executes preliminary initialization
// (HTTP server structure initialized but it doesn't start).
func NewHTTPServer(ctx context.Context, cfg *configuration.Config, logger *logger.Logger) (*HTTPServer, chan struct{}) {
h := &HTTPServer{
config: cfg,
ctx: ctx,
doneChan: make(chan struct{}),
logger: logger,
}
h.initialize()
return h, h.doneChan
}
// Returns request's context based on main context of application.
// Basically it returns main context and does nothing more.
func (h *HTTPServer) getRequestContext(_ net.Listener) context.Context {
return h.ctx
}
// Initializes handler and HTTP server structure.
func (h *HTTPServer) initialize() {
h.logger.Debugln("Initializing HTTP server...")
h.handler = &handler{
handlers: make(map[string]common.HTTPHandlerFunc),
}
// We do not need to specify all possible parameters for HTTP server, so:
// nolint:exhaustivestruct
h.server = &http.Server{
// ToDo: make it all configurable.
Addr: ":34421",
BaseContext: h.getRequestContext,
Handler: h.handler,
ReadTimeout: time.Second * 10,
WriteTimeout: time.Second * 10,
MaxHeaderBytes: 1 << 20,
}
}
// RegisterHandlerForApplication registers HTTP handler for application.
func (h *HTTPServer) RegisterHandlerForApplication(name string, handler common.HTTPHandlerFunc) {
h.logger.Debugln("Registering handler for application", name)
h.handler.register(name, handler)
}
// Start starts HTTP server in another goroutine and one more goroutine which
// is listening to main context's Cancel() call to stop HTTP server.
func (h *HTTPServer) Start() {
go func() {
err := h.server.ListenAndServe()
if err != nil {
if !strings.Contains(err.Error(), "Server closed") {
h.logger.Infoln("HTTP server failed to listen:", err.Error())
}
}
}()
go func() {
<-h.ctx.Done()
h.logger.Infoln("Shutting down HTTP server")
err := h.server.Shutdown(h.ctx)
if err != nil && !strings.Contains(err.Error(), "context canceled") {
h.logger.Infoln("Failed to stop HTTP server:", err.Error())
}
h.logger.Infoln("HTTP server stopped")
h.doneChan <- struct{}{}
}()
}