42Atomys/webhooked

package server

import (
    "fmt"
    "net/http"

    "github.com/gorilla/mux"
    "github.com/prometheus/client_golang/prometheus/promhttp"
    "github.com/rs/zerolog/log"

    "atomys.codes/webhooked/internal/config"
    v1alpha1 "atomys.codes/webhooked/internal/server/v1alpha1"
)

// APIVersion is the interface for all supported API versions
// that can be served by the webhooked server
type APIVersion interface {
    Version() string
    WebhookHandler() http.HandlerFunc
}

type Server struct {
    *http.Server
}

var (
    // apiVersions is a list of supported API versions by the server
    apiVersions = []APIVersion{
        v1alpha1.NewServer(),
    }
)

// NewServer create a new server instance with the given port
func NewServer(port int) (*Server, error) {
    if !validPort(port) {
        return nil, fmt.Errorf("invalid port")
    }

    return &Server{
        Server: &http.Server{
            Addr:    fmt.Sprintf(":%d", port),
            Handler: nil,
        },
    }, nil
}

// Serve the proxy server on the given port for all supported API versions
func (s *Server) Serve() error {
    router := newRouter()
    router.Use(loggingMiddleware)

    if config.Current().Observability.MetricsEnabled {
        router.Use(prometheusMiddleware)
        router.Handle("/metrics", promhttp.Handler()).Name("metrics")
    }

    s.Handler = router
    log.Info().Msgf("Listening on %s", s.Addr)
    return s.ListenAndServe()
}

// newRouter returns a new router with all the routes
// for all supported API versions
func newRouter() *mux.Router {
    var api = mux.NewRouter()
    for _, version := range apiVersions {
        api.Methods("POST").PathPrefix("/" + version.Version()).Handler(version.WebhookHandler()).Name(version.Version())
    }

    api.NotFoundHandler = http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
        w.WriteHeader(http.StatusNotFound)
    })

    return api
}

// validPort returns true if the port is valid
// following the RFC https://datatracker.ietf.org/doc/html/rfc6056#section-2.1
func validPort(port int) bool {
    return port > 0 && port < 65535
}