web.go

/*
 * Copyright (C) 2020 Canonical Ltd
 *
 * This program is free software: you can redistribute it and/or modify
 * it under the terms of the GNU General Public License version 3 as
 * published by the Free Software Foundation.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program.  If not, see <http://www.gnu.org/licenses/>.
 *
 */

package web

import (
	"fmt"
	"github.com/CanonicalLtd/device-config/config"
	"github.com/CanonicalLtd/device-config/service"
	"github.com/CanonicalLtd/device-config/service/network"
	"github.com/CanonicalLtd/device-config/service/snapd"
	"github.com/CanonicalLtd/device-config/service/system"
	"github.com/CanonicalLtd/device-config/service/transfer"
	"github.com/gorilla/mux"
	"log"
	"net"
	"net/http"
	"strconv"
	"syscall"
)

// Web implements the web service
type Web struct {
	Settings    *config.Settings
	Auth        service.AuthService
	NetSrv      network.Service
	Snapd       snapd.Client
	TimeSrv     service.TimeService
	SystemSrv   system.Service
	TransferSrv transfer.Service
}

// NewWebService starts a new web service
func NewWebService(settings *config.Settings, auth service.AuthService, network network.Service, snapd snapd.Client, t service.TimeService, sys system.Service, xfer transfer.Service) *Web {
	return &Web{
		Settings:    settings,
		Auth:        auth,
		NetSrv:      network,
		Snapd:       snapd,
		TimeSrv:     t,
		SystemSrv:   sys,
		TransferSrv: xfer,
	}
}

const (
	soBINDTODEVICE = 0x19
)

// Start the web service
func (srv Web) Start() error {
	if len(srv.Settings.NetworkInterfaceDevice) > 0 {
		return srv.StartOnInterface(srv.Settings.NetworkInterfaceDevice)
	}

	listenOn := fmt.Sprintf("%s:%s", srv.Settings.NetworkInterfaceIP, srv.Settings.Port)
	fmt.Printf("Starting service on port %s\n", listenOn)
	return http.ListenAndServe(listenOn, srv.Router())
}

// StartOnInterface starts the web service on a specific network interface
func (srv Web) StartOnInterface(iface string) error {
	fmt.Printf("Starting service on port %s:%s (%s)\n", srv.Settings.NetworkInterfaceIP, srv.Settings.Port, iface)

	// Create a TCP listener
	port, _ := strconv.Atoi(srv.Settings.Port)
	listenOn := net.TCPAddr{
		IP:   net.ParseIP(srv.Settings.NetworkInterfaceIP),
		Port: port,
	}
	tcpListener, err := net.ListenTCP("tcp", &listenOn)
	if err != nil {
		log.Fatal("net.ListenTCP()", err)
	}

	// Bind to a specific interface (SO_BINDTODEVICE is linux only)
	f, _ := tcpListener.File()
	syscall.SetsockoptString(int(f.Fd()), syscall.SOL_SOCKET, soBINDTODEVICE, iface)

	// Service the routes
	return http.Serve(tcpListener, srv.Router())
}

// Router returns the application router
func (srv Web) Router() *mux.Router {
	// Start the web service router
	router := mux.NewRouter()

	router.Handle("/v1/config", Middleware(http.HandlerFunc(srv.AppConfig))).Methods("GET")
	router.Handle("/v1/login", Middleware(http.HandlerFunc(srv.Login))).Methods("POST")
	router.Handle("/v1/factory-reset", Middleware(http.HandlerFunc(srv.FactoryReset))).Methods("POST")
	router.Handle("/v1/network", srv.MiddlewareWithAuth(http.HandlerFunc(srv.Network))).Methods("GET")
	router.Handle("/v1/network", srv.MiddlewareWithAuth(http.HandlerFunc(srv.NetworkInterface))).Methods("POST")
	router.Handle("/v1/network/apply", srv.MiddlewareWithAuth(http.HandlerFunc(srv.NetworkApply))).Methods("POST")
	router.Handle("/v1/proxy", srv.MiddlewareWithAuth(http.HandlerFunc(srv.Proxy))).Methods("GET")
	router.Handle("/v1/proxy", srv.MiddlewareWithAuth(http.HandlerFunc(srv.ProxyUpdate))).Methods("POST")
	router.Handle("/v1/time", srv.MiddlewareWithAuth(http.HandlerFunc(srv.Time))).Methods("GET")
	router.Handle("/v1/time", srv.MiddlewareWithAuth(http.HandlerFunc(srv.TimeConfig))).Methods("POST")
	router.Handle("/v1/services", srv.MiddlewareWithAuth(http.HandlerFunc(srv.AppServices))).Methods("GET")
	router.Handle("/v1/system", srv.MiddlewareWithAuth(http.HandlerFunc(srv.SystemResources))).Methods("GET")
	router.Handle("/v1/snaps", srv.MiddlewareWithAuth(http.HandlerFunc(srv.SnapList))).Methods("GET")
	router.Handle("/v1/snaps/{snap}", srv.MiddlewareWithAuth(http.HandlerFunc(srv.SnapSet))).Methods("PUT")
	router.Handle("/v1/transfer/export", srv.MiddlewareWithAuth(http.HandlerFunc(srv.TransferExport))).Methods("GET")
	router.Handle("/v1/transfer/import", srv.MiddlewareWithAuth(http.HandlerFunc(srv.TransferImport))).Methods("POST")
	router.Handle("/logout", Middleware(http.HandlerFunc(srv.Logout))).Methods("GET")

	// Serve the static path
	//p := path.Join(srv.Settings.DocRoot, "/static/")
	fs := http.StripPrefix("/static/", http.FileServer(http.Dir(srv.Settings.DocRoot)))
	router.PathPrefix("/static/").Handler(fs)

	// Default path is the index page
	router.Handle("/", Middleware(http.HandlerFunc(srv.Index))).Methods("GET")
	router.Handle("/login", Middleware(http.HandlerFunc(srv.Index))).Methods("GET")
	router.Handle("/network", srv.MiddlewareWithAuth(http.HandlerFunc(srv.Index))).Methods("GET")
	router.Handle("/proxy", srv.MiddlewareWithAuth(http.HandlerFunc(srv.Index))).Methods("GET")
	router.Handle("/time", srv.MiddlewareWithAuth(http.HandlerFunc(srv.Index))).Methods("GET")
	router.Handle("/services", srv.MiddlewareWithAuth(http.HandlerFunc(srv.Index))).Methods("GET")
	router.Handle("/snaps", srv.MiddlewareWithAuth(http.HandlerFunc(srv.Index))).Methods("GET")
	router.Handle("/settings", srv.MiddlewareWithAuth(http.HandlerFunc(srv.Index))).Methods("GET")
	router.NotFoundHandler = Middleware(http.HandlerFunc(srv.Index))

	return router
}