grafana/pkg/api/http_server.go

package api

import (
	"context"
	"crypto/tls"
	"errors"
	"fmt"
	"net"
	"net/http"
	"os"
	"path"
	"path/filepath"
	"strings"
	"sync"

	"github.com/grafana/grafana/pkg/services/searchusers"

	"github.com/grafana/grafana/pkg/api/routing"
	httpstatic "github.com/grafana/grafana/pkg/api/static"
	"github.com/grafana/grafana/pkg/bus"
	"github.com/grafana/grafana/pkg/components/simplejson"
	"github.com/grafana/grafana/pkg/infra/localcache"
	"github.com/grafana/grafana/pkg/infra/log"
	"github.com/grafana/grafana/pkg/infra/metrics"
	"github.com/grafana/grafana/pkg/infra/remotecache"
	"github.com/grafana/grafana/pkg/infra/tracing"
	"github.com/grafana/grafana/pkg/login/social"
	"github.com/grafana/grafana/pkg/middleware"
	"github.com/grafana/grafana/pkg/models"
	"github.com/grafana/grafana/pkg/plugins"
	"github.com/grafana/grafana/pkg/plugins/backendplugin"
	_ "github.com/grafana/grafana/pkg/plugins/backendplugin/manager"
	"github.com/grafana/grafana/pkg/plugins/plugincontext"
	"github.com/grafana/grafana/pkg/services/accesscontrol"
	"github.com/grafana/grafana/pkg/services/alerting"
	"github.com/grafana/grafana/pkg/services/cleanup"
	"github.com/grafana/grafana/pkg/services/contexthandler"
	"github.com/grafana/grafana/pkg/services/datasourceproxy"
	"github.com/grafana/grafana/pkg/services/datasources"
	"github.com/grafana/grafana/pkg/services/encryption"
	"github.com/grafana/grafana/pkg/services/hooks"
	"github.com/grafana/grafana/pkg/services/libraryelements"
	"github.com/grafana/grafana/pkg/services/librarypanels"
	"github.com/grafana/grafana/pkg/services/live"
	"github.com/grafana/grafana/pkg/services/live/pushhttp"
	"github.com/grafana/grafana/pkg/services/login"
	"github.com/grafana/grafana/pkg/services/ngalert"
	"github.com/grafana/grafana/pkg/services/notifications"
	"github.com/grafana/grafana/pkg/services/oauthtoken"
	"github.com/grafana/grafana/pkg/services/provisioning"
	"github.com/grafana/grafana/pkg/services/quota"
	"github.com/grafana/grafana/pkg/services/rendering"
	"github.com/grafana/grafana/pkg/services/schemaloader"
	"github.com/grafana/grafana/pkg/services/search"
	"github.com/grafana/grafana/pkg/services/shorturls"
	"github.com/grafana/grafana/pkg/services/sqlstore"
	"github.com/grafana/grafana/pkg/setting"
	"github.com/grafana/grafana/pkg/tsdb"
	"github.com/grafana/grafana/pkg/util/errutil"
	"github.com/grafana/grafana/pkg/web"
	"github.com/prometheus/client_golang/prometheus"
	"github.com/prometheus/client_golang/prometheus/promhttp"
)

type HTTPServer struct {
	log         log.Logger
	web         *web.Mux
	context     context.Context
	httpSrv     *http.Server
	middlewares []web.Handler

	PluginContextProvider  *plugincontext.Provider
	RouteRegister          routing.RouteRegister
	Bus                    bus.Bus
	RenderService          rendering.Service
	Cfg                    *setting.Cfg
	SettingsProvider       setting.Provider
	HooksService           *hooks.HooksService
	CacheService           *localcache.CacheService
	DataSourceCache        datasources.CacheService
	AuthTokenService       models.UserTokenService
	QuotaService           *quota.QuotaService
	RemoteCacheService     *remotecache.RemoteCache
	ProvisioningService    provisioning.ProvisioningService
	Login                  login.Service
	License                models.Licensing
	AccessControl          accesscontrol.AccessControl
	BackendPluginManager   backendplugin.Manager
	DataProxy              *datasourceproxy.DataSourceProxyService
	PluginRequestValidator models.PluginRequestValidator
	PluginManager          plugins.Manager
	SearchService          *search.SearchService
	ShortURLService        shorturls.Service
	Live                   *live.GrafanaLive
	LivePushGateway        *pushhttp.Gateway
	ContextHandler         *contexthandler.ContextHandler
	SQLStore               *sqlstore.SQLStore
	DataService            *tsdb.Service
	AlertEngine            *alerting.AlertEngine
	LoadSchemaService      *schemaloader.SchemaLoaderService
	AlertNG                *ngalert.AlertNG
	LibraryPanelService    librarypanels.Service
	LibraryElementService  libraryelements.Service
	notificationService    *notifications.NotificationService
	SocialService          social.Service
	OAuthTokenService      oauthtoken.OAuthTokenService
	Listener               net.Listener
	EncryptionService      encryption.Service
	DataSourcesService     *datasources.Service
	cleanUpService         *cleanup.CleanUpService
	tracingService         *tracing.TracingService
	internalMetricsSvc     *metrics.InternalMetricsService
	searchUsersService     searchusers.Service
}

type ServerOptions struct {
	Listener net.Listener
}

func ProvideHTTPServer(opts ServerOptions, cfg *setting.Cfg, routeRegister routing.RouteRegister, bus bus.Bus,
	renderService rendering.Service, licensing models.Licensing, hooksService *hooks.HooksService,
	cacheService *localcache.CacheService, sqlStore *sqlstore.SQLStore,
	dataService *tsdb.Service, alertEngine *alerting.AlertEngine, pluginRequestValidator models.PluginRequestValidator,
	pluginManager plugins.Manager, backendPM backendplugin.Manager, settingsProvider setting.Provider,
	dataSourceCache datasources.CacheService, userTokenService models.UserTokenService,
	cleanUpService *cleanup.CleanUpService, shortURLService shorturls.Service,
	remoteCache *remotecache.RemoteCache, provisioningService provisioning.ProvisioningService,
	loginService login.Service, accessControl accesscontrol.AccessControl,
	dataSourceProxy *datasourceproxy.DataSourceProxyService, searchService *search.SearchService,
	live *live.GrafanaLive, livePushGateway *pushhttp.Gateway, plugCtxProvider *plugincontext.Provider,
	contextHandler *contexthandler.ContextHandler,
	schemaService *schemaloader.SchemaLoaderService, alertNG *ngalert.AlertNG,
	libraryPanelService librarypanels.Service, libraryElementService libraryelements.Service,
	notificationService *notifications.NotificationService, tracingService *tracing.TracingService,
	internalMetricsSvc *metrics.InternalMetricsService, quotaService *quota.QuotaService,
	socialService social.Service, oauthTokenService oauthtoken.OAuthTokenService,
	encryptionService encryption.Service, searchUsersService searchusers.Service,
	dataSourcesService *datasources.Service) (*HTTPServer, error) {
	web.Env = cfg.Env
	m := web.New()

	hs := &HTTPServer{
		Cfg:                    cfg,
		RouteRegister:          routeRegister,
		Bus:                    bus,
		RenderService:          renderService,
		License:                licensing,
		HooksService:           hooksService,
		CacheService:           cacheService,
		SQLStore:               sqlStore,
		DataService:            dataService,
		AlertEngine:            alertEngine,
		PluginRequestValidator: pluginRequestValidator,
		PluginManager:          pluginManager,
		BackendPluginManager:   backendPM,
		SettingsProvider:       settingsProvider,
		DataSourceCache:        dataSourceCache,
		AuthTokenService:       userTokenService,
		cleanUpService:         cleanUpService,
		ShortURLService:        shortURLService,
		RemoteCacheService:     remoteCache,
		ProvisioningService:    provisioningService,
		Login:                  loginService,
		AccessControl:          accessControl,
		DataProxy:              dataSourceProxy,
		SearchService:          searchService,
		Live:                   live,
		LivePushGateway:        livePushGateway,
		PluginContextProvider:  plugCtxProvider,
		ContextHandler:         contextHandler,
		LoadSchemaService:      schemaService,
		AlertNG:                alertNG,
		LibraryPanelService:    libraryPanelService,
		LibraryElementService:  libraryElementService,
		QuotaService:           quotaService,
		notificationService:    notificationService,
		tracingService:         tracingService,
		internalMetricsSvc:     internalMetricsSvc,
		log:                    log.New("http.server"),
		web:                    m,
		Listener:               opts.Listener,
		SocialService:          socialService,
		OAuthTokenService:      oauthTokenService,
		EncryptionService:      encryptionService,
		DataSourcesService:     dataSourcesService,
		searchUsersService:     searchUsersService,
	}
	if hs.Listener != nil {
		hs.log.Debug("Using provided listener")
	}
	hs.registerRoutes()

	if err := hs.declareFixedRoles(); err != nil {
		return nil, err
	}
	return hs, nil
}

func (hs *HTTPServer) AddMiddleware(middleware web.Handler) {
	hs.middlewares = append(hs.middlewares, middleware)
}

func (hs *HTTPServer) Run(ctx context.Context) error {
	hs.context = ctx

	hs.applyRoutes()

	// Remove any square brackets enclosing IPv6 addresses, a format we support for backwards compatibility
	host := strings.TrimSuffix(strings.TrimPrefix(hs.Cfg.HTTPAddr, "["), "]")
	hs.httpSrv = &http.Server{
		Addr:        net.JoinHostPort(host, hs.Cfg.HTTPPort),
		Handler:     hs.web,
		ReadTimeout: hs.Cfg.ReadTimeout,
	}
	switch hs.Cfg.Protocol {
	case setting.HTTP2Scheme:
		if err := hs.configureHttp2(); err != nil {
			return err
		}
	case setting.HTTPSScheme:
		if err := hs.configureHttps(); err != nil {
			return err
		}
	default:
	}

	listener, err := hs.getListener()
	if err != nil {
		return err
	}

	hs.log.Info("HTTP Server Listen", "address", listener.Addr().String(), "protocol",
		hs.Cfg.Protocol, "subUrl", hs.Cfg.AppSubURL, "socket", hs.Cfg.SocketPath)

	var wg sync.WaitGroup
	wg.Add(1)

	// handle http shutdown on server context done
	go func() {
		defer wg.Done()

		<-ctx.Done()
		if err := hs.httpSrv.Shutdown(context.Background()); err != nil {
			hs.log.Error("Failed to shutdown server", "error", err)
		}
	}()

	switch hs.Cfg.Protocol {
	case setting.HTTPScheme, setting.SocketScheme:
		if err := hs.httpSrv.Serve(listener); err != nil {
			if errors.Is(err, http.ErrServerClosed) {
				hs.log.Debug("server was shutdown gracefully")
				return nil
			}
			return err
		}
	case setting.HTTP2Scheme, setting.HTTPSScheme:
		if err := hs.httpSrv.ServeTLS(listener, hs.Cfg.CertFile, hs.Cfg.KeyFile); err != nil {
			if errors.Is(err, http.ErrServerClosed) {
				hs.log.Debug("server was shutdown gracefully")
				return nil
			}
			return err
		}
	default:
		panic(fmt.Sprintf("Unhandled protocol %q", hs.Cfg.Protocol))
	}

	wg.Wait()

	return nil
}

func (hs *HTTPServer) getListener() (net.Listener, error) {
	if hs.Listener != nil {
		return hs.Listener, nil
	}

	switch hs.Cfg.Protocol {
	case setting.HTTPScheme, setting.HTTPSScheme, setting.HTTP2Scheme:
		listener, err := net.Listen("tcp", hs.httpSrv.Addr)
		if err != nil {
			return nil, errutil.Wrapf(err, "failed to open listener on address %s", hs.httpSrv.Addr)
		}
		return listener, nil
	case setting.SocketScheme:
		listener, err := net.ListenUnix("unix", &net.UnixAddr{Name: hs.Cfg.SocketPath, Net: "unix"})
		if err != nil {
			return nil, errutil.Wrapf(err, "failed to open listener for socket %s", hs.Cfg.SocketPath)
		}

		// Make socket writable by group
		// nolint:gosec
		if err := os.Chmod(hs.Cfg.SocketPath, 0660); err != nil {
			return nil, errutil.Wrapf(err, "failed to change socket permissions")
		}

		return listener, nil
	default:
		hs.log.Error("Invalid protocol", "protocol", hs.Cfg.Protocol)
		return nil, fmt.Errorf("invalid protocol %q", hs.Cfg.Protocol)
	}
}

func (hs *HTTPServer) configureHttps() error {
	if hs.Cfg.CertFile == "" {
		return fmt.Errorf("cert_file cannot be empty when using HTTPS")
	}

	if hs.Cfg.KeyFile == "" {
		return fmt.Errorf("cert_key cannot be empty when using HTTPS")
	}

	if _, err := os.Stat(hs.Cfg.CertFile); os.IsNotExist(err) {
		return fmt.Errorf(`cannot find SSL cert_file at %q`, hs.Cfg.CertFile)
	}

	if _, err := os.Stat(hs.Cfg.KeyFile); os.IsNotExist(err) {
		return fmt.Errorf(`cannot find SSL key_file at %q`, hs.Cfg.KeyFile)
	}

	tlsCfg := &tls.Config{
		MinVersion:               tls.VersionTLS12,
		PreferServerCipherSuites: true,
		CipherSuites: []uint16{
			tls.TLS_ECDHE_ECDSA_WITH_AES_128_GCM_SHA256,
			tls.TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256,
			tls.TLS_ECDHE_ECDSA_WITH_AES_256_GCM_SHA384,
			tls.TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384,
			tls.TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA,
			tls.TLS_ECDHE_ECDSA_WITH_AES_256_CBC_SHA,
			tls.TLS_ECDHE_RSA_WITH_AES_256_CBC_SHA,
			tls.TLS_RSA_WITH_AES_128_GCM_SHA256,
			tls.TLS_RSA_WITH_AES_256_GCM_SHA384,
			tls.TLS_RSA_WITH_AES_128_CBC_SHA,
			tls.TLS_RSA_WITH_AES_256_CBC_SHA,
		},
	}

	hs.httpSrv.TLSConfig = tlsCfg
	hs.httpSrv.TLSNextProto = make(map[string]func(*http.Server, *tls.Conn, http.Handler))

	return nil
}

func (hs *HTTPServer) configureHttp2() error {
	if hs.Cfg.CertFile == "" {
		return fmt.Errorf("cert_file cannot be empty when using HTTP2")
	}

	if hs.Cfg.KeyFile == "" {
		return fmt.Errorf("cert_key cannot be empty when using HTTP2")
	}

	if _, err := os.Stat(hs.Cfg.CertFile); os.IsNotExist(err) {
		return fmt.Errorf(`cannot find SSL cert_file at %q`, hs.Cfg.CertFile)
	}

	if _, err := os.Stat(hs.Cfg.KeyFile); os.IsNotExist(err) {
		return fmt.Errorf(`cannot find SSL key_file at %q`, hs.Cfg.KeyFile)
	}

	tlsCfg := &tls.Config{
		MinVersion:               tls.VersionTLS12,
		PreferServerCipherSuites: true,
		CipherSuites: []uint16{
			tls.TLS_CHACHA20_POLY1305_SHA256,
			tls.TLS_AES_128_GCM_SHA256,
			tls.TLS_AES_256_GCM_SHA384,
			tls.TLS_ECDHE_ECDSA_WITH_AES_128_GCM_SHA256,
			tls.TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256,
			tls.TLS_ECDHE_ECDSA_WITH_AES_256_GCM_SHA384,
			tls.TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384,
			tls.TLS_ECDHE_ECDSA_WITH_CHACHA20_POLY1305,
			tls.TLS_ECDHE_RSA_WITH_CHACHA20_POLY1305,
		},
		NextProtos: []string{"h2", "http/1.1"},
	}

	hs.httpSrv.TLSConfig = tlsCfg

	return nil
}

func (hs *HTTPServer) applyRoutes() {
	// start with middlewares & static routes
	hs.addMiddlewaresAndStaticRoutes()
	// then add view routes & api routes
	hs.RouteRegister.Register(hs.web)
	// then custom app proxy routes
	hs.initAppPluginRoutes(hs.web)
	// lastly not found route
	hs.web.NotFound(middleware.ReqSignedIn, hs.NotFoundHandler)
}

func (hs *HTTPServer) addMiddlewaresAndStaticRoutes() {
	m := hs.web

	m.Use(middleware.RequestTracing())

	m.Use(middleware.Logger(hs.Cfg))

	if hs.Cfg.EnableGzip {
		m.UseMiddleware(middleware.Gziper())
	}

	m.Use(middleware.Recovery(hs.Cfg))

	hs.mapStatic(m, hs.Cfg.StaticRootPath, "build", "public/build")
	hs.mapStatic(m, hs.Cfg.StaticRootPath, "", "public")
	hs.mapStatic(m, hs.Cfg.StaticRootPath, "robots.txt", "robots.txt")

	if hs.Cfg.ImageUploadProvider == "local" {
		hs.mapStatic(m, hs.Cfg.ImagesDir, "", "/public/img/attachments")
	}

	m.Use(middleware.AddDefaultResponseHeaders(hs.Cfg))

	if hs.Cfg.ServeFromSubPath && hs.Cfg.AppSubURL != "" {
		m.SetURLPrefix(hs.Cfg.AppSubURL)
	}

	m.UseMiddleware(web.Renderer(filepath.Join(hs.Cfg.StaticRootPath, "views"), "[[", "]]"))

	// These endpoints are used for monitoring the Grafana instance
	// and should not be redirected or rejected.
	m.Use(hs.healthzHandler)
	m.Use(hs.apiHealthHandler)
	m.Use(hs.metricsEndpoint)

	m.Use(hs.ContextHandler.Middleware)
	m.Use(middleware.OrgRedirect(hs.Cfg))

	// needs to be after context handler
	if hs.Cfg.EnforceDomain {
		m.Use(middleware.ValidateHostHeader(hs.Cfg))
	}

	m.Use(middleware.HandleNoCacheHeader)
	m.UseMiddleware(middleware.AddCSPHeader(hs.Cfg, hs.log))

	for _, mw := range hs.middlewares {
		m.Use(mw)
	}
}

func (hs *HTTPServer) metricsEndpoint(ctx *web.Context) {
	if !hs.Cfg.MetricsEndpointEnabled {
		return
	}

	if ctx.Req.Method != http.MethodGet || ctx.Req.URL.Path != "/metrics" {
		return
	}

	if hs.metricsEndpointBasicAuthEnabled() && !BasicAuthenticatedRequest(ctx.Req, hs.Cfg.MetricsEndpointBasicAuthUsername, hs.Cfg.MetricsEndpointBasicAuthPassword) {
		ctx.Resp.WriteHeader(http.StatusUnauthorized)
		return
	}

	promhttp.
		HandlerFor(prometheus.DefaultGatherer, promhttp.HandlerOpts{EnableOpenMetrics: true}).
		ServeHTTP(ctx.Resp, ctx.Req)
}

// healthzHandler always return 200 - Ok if Grafana's web server is running
func (hs *HTTPServer) healthzHandler(ctx *web.Context) {
	notHeadOrGet := ctx.Req.Method != http.MethodGet && ctx.Req.Method != http.MethodHead
	if notHeadOrGet || ctx.Req.URL.Path != "/healthz" {
		return
	}

	ctx.Resp.WriteHeader(200)
	_, err := ctx.Resp.Write([]byte("Ok"))
	if err != nil {
		hs.log.Error("could not write to response", "err", err)
	}
}

// apiHealthHandler will return ok if Grafana's web server is running and it
// can access the database. If the database cannot be accessed it will return
// http status code 503.
func (hs *HTTPServer) apiHealthHandler(ctx *web.Context) {
	notHeadOrGet := ctx.Req.Method != http.MethodGet && ctx.Req.Method != http.MethodHead
	if notHeadOrGet || ctx.Req.URL.Path != "/api/health" {
		return
	}

	data := simplejson.New()
	data.Set("database", "ok")
	if !hs.Cfg.AnonymousHideVersion {
		data.Set("version", hs.Cfg.BuildVersion)
		data.Set("commit", hs.Cfg.BuildCommit)
	}

	if !hs.databaseHealthy(ctx.Req.Context()) {
		data.Set("database", "failing")
		ctx.Resp.Header().Set("Content-Type", "application/json; charset=UTF-8")
		ctx.Resp.WriteHeader(503)
	} else {
		ctx.Resp.Header().Set("Content-Type", "application/json; charset=UTF-8")
		ctx.Resp.WriteHeader(200)
	}

	dataBytes, err := data.EncodePretty()
	if err != nil {
		hs.log.Error("Failed to encode data", "err", err)
		return
	}

	if _, err := ctx.Resp.Write(dataBytes); err != nil {
		hs.log.Error("Failed to write to response", "err", err)
	}
}

func (hs *HTTPServer) mapStatic(m *web.Mux, rootDir string, dir string, prefix string) {
	headers := func(c *web.Context) {
		c.Resp.Header().Set("Cache-Control", "public, max-age=3600")
	}

	if prefix == "public/build" {
		headers = func(c *web.Context) {
			c.Resp.Header().Set("Cache-Control", "public, max-age=31536000")
		}
	}

	if hs.Cfg.Env == setting.Dev {
		headers = func(c *web.Context) {
			c.Resp.Header().Set("Cache-Control", "max-age=0, must-revalidate, no-cache")
		}
	}

	m.Use(httpstatic.Static(
		path.Join(rootDir, dir),
		httpstatic.StaticOptions{
			SkipLogging: true,
			Prefix:      prefix,
			AddHeaders:  headers,
		},
	))
}

func (hs *HTTPServer) metricsEndpointBasicAuthEnabled() bool {
	return hs.Cfg.MetricsEndpointBasicAuthUsername != "" && hs.Cfg.MetricsEndpointBasicAuthPassword != ""
}