refactor thumbnails

Signed-off-by: Christian Richter <crichter@owncloud.com>

extensions/thumbnails/pkg/service/http/v0/instrument.go

@@ -0,0 +1,30 @@
+package svc
+
+import (
+	"net/http"
+
+	"github.com/owncloud/ocis/extensions/thumbnails/pkg/metrics"
+)
+
+// NewInstrument returns a service that instruments metrics.
+func NewInstrument(next Service, metrics *metrics.Metrics) Service {
+	return instrument{
+		next:    next,
+		metrics: metrics,
+	}
+}
+
+type instrument struct {
+	next    Service
+	metrics *metrics.Metrics
+}
+
+// ServeHTTP implements the Service interface.
+func (i instrument) ServeHTTP(w http.ResponseWriter, r *http.Request) {
+	i.next.ServeHTTP(w, r)
+}
+
+// GetThumbnail implements the Service interface.
+func (i instrument) GetThumbnail(w http.ResponseWriter, r *http.Request) {
+	i.next.GetThumbnail(w, r)
+}

extensions/thumbnails/pkg/service/http/v0/logging.go

@@ -0,0 +1,30 @@
+package svc
+
+import (
+	"net/http"
+
+	"github.com/owncloud/ocis/ocis-pkg/log"
+)
+
+// NewLogging returns a service that logs messages.
+func NewLogging(next Service, logger log.Logger) Service {
+	return logging{
+		next:   next,
+		logger: logger,
+	}
+}
+
+type logging struct {
+	next   Service
+	logger log.Logger
+}
+
+// ServeHTTP implements the Service interface.
+func (l logging) ServeHTTP(w http.ResponseWriter, r *http.Request) {
+	l.next.ServeHTTP(w, r)
+}
+
+// GetThumbnail implements the Service interface.
+func (l logging) GetThumbnail(w http.ResponseWriter, r *http.Request) {
+	l.next.GetThumbnail(w, r)
+}

extensions/thumbnails/pkg/service/http/v0/option.go

@@ -0,0 +1,59 @@
+package svc
+
+import (
+	"net/http"
+
+	"github.com/owncloud/ocis/extensions/thumbnails/pkg/config"
+	"github.com/owncloud/ocis/extensions/thumbnails/pkg/thumbnail/storage"
+	"github.com/owncloud/ocis/ocis-pkg/log"
+)
+
+// Option defines a single option function.
+type Option func(o *Options)
+
+// Options defines the available options for this package.
+type Options struct {
+	Logger           log.Logger
+	Config           *config.Config
+	Middleware       []func(http.Handler) http.Handler
+	ThumbnailStorage storage.Storage
+}
+
+// newOptions initializes the available default options.
+func newOptions(opts ...Option) Options {
+	opt := Options{}
+
+	for _, o := range opts {
+		o(&opt)
+	}
+
+	return opt
+}
+
+// Logger provides a function to set the logger option.
+func Logger(val log.Logger) Option {
+	return func(o *Options) {
+		o.Logger = val
+	}
+}
+
+// Config provides a function to set the config option.
+func Config(val *config.Config) Option {
+	return func(o *Options) {
+		o.Config = val
+	}
+}
+
+// Middleware provides a function to set the middleware option.
+func Middleware(val ...func(http.Handler) http.Handler) Option {
+	return func(o *Options) {
+		o.Middleware = val
+	}
+}
+
+// ThumbnailStorage provides a function to set the ThumbnailStorage option.
+func ThumbnailStorage(storage storage.Storage) Option {
+	return func(o *Options) {
+		o.ThumbnailStorage = storage
+	}
+}

extensions/thumbnails/pkg/service/http/v0/service.go

@@ -0,0 +1,123 @@
+package svc
+
+import (
+	"context"
+	"fmt"
+	"net/http"
+	"strconv"
+
+	"github.com/go-chi/chi/v5"
+	"github.com/golang-jwt/jwt/v4"
+
+	"github.com/owncloud/ocis/extensions/thumbnails/pkg/config"
+	tjwt "github.com/owncloud/ocis/extensions/thumbnails/pkg/service/jwt"
+	"github.com/owncloud/ocis/extensions/thumbnails/pkg/thumbnail"
+	"github.com/owncloud/ocis/ocis-pkg/log"
+)
+
+type contextKey string
+
+const (
+	keyContextKey contextKey = "key"
+)
+
+// Service defines the extension handlers.
+type Service interface {
+	ServeHTTP(http.ResponseWriter, *http.Request)
+	GetThumbnail(http.ResponseWriter, *http.Request)
+}
+
+// NewService returns a service implementation for Service.
+func NewService(opts ...Option) Service {
+	options := newOptions(opts...)
+
+	m := chi.NewMux()
+	m.Use(options.Middleware...)
+
+	logger := options.Logger
+	resolutions, err := thumbnail.ParseResolutions(options.Config.Thumbnail.Resolutions)
+	if err != nil {
+		logger.Fatal().Err(err).Msg("resolutions not configured correctly")
+	}
+	svc := Thumbnails{
+		config: options.Config,
+		mux:    m,
+		logger: options.Logger,
+		manager: thumbnail.NewSimpleManager(
+			resolutions,
+			options.ThumbnailStorage,
+			logger,
+		),
+	}
+
+	m.Route(options.Config.HTTP.Root, func(r chi.Router) {
+		r.Use(svc.TransferTokenValidator)
+		r.Get("/data", svc.GetThumbnail)
+	})
+
+	return svc
+}
+
+// Thumbnails implements the business logic for Service.
+type Thumbnails struct {
+	config  *config.Config
+	logger  log.Logger
+	mux     *chi.Mux
+	manager thumbnail.Manager
+}
+
+// ServeHTTP implements the Service interface.
+func (s Thumbnails) ServeHTTP(w http.ResponseWriter, r *http.Request) {
+	s.mux.ServeHTTP(w, r)
+}
+
+// GetThumbnail implements the Service interface.
+func (s Thumbnails) GetThumbnail(w http.ResponseWriter, r *http.Request) {
+	key := r.Context().Value(keyContextKey).(string)
+
+	thumbnail, err := s.manager.GetThumbnail(key)
+	if err != nil {
+		s.logger.Error().
+			Err(err).
+			Str("key", key).
+			Msg("could not get the thumbnail")
+		w.WriteHeader(http.StatusInternalServerError)
+		return
+	}
+
+	w.WriteHeader(http.StatusOK)
+	w.Header().Set("Content-Length", strconv.Itoa(len(thumbnail)))
+	if _, err = w.Write(thumbnail); err != nil {
+		s.logger.Error().
+			Err(err).
+			Str("key", key).
+			Msg("could not write the thumbnail response")
+	}
+}
+
+func (s Thumbnails) TransferTokenValidator(next http.Handler) http.Handler {
+	return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+		tokenString := r.Header.Get("Transfer-Token")
+		token, err := jwt.ParseWithClaims(tokenString, &tjwt.ThumbnailClaims{}, func(token *jwt.Token) (interface{}, error) {
+			if _, ok := token.Method.(*jwt.SigningMethodHMAC); !ok {
+				return nil, fmt.Errorf("unexpected signing method: %v", token.Header["alg"])
+			}
+			return []byte(s.config.Thumbnail.TransferTokenSecret), nil
+		})
+		if err != nil {
+			s.logger.Error().
+				Err(err).
+				Str("transfer-token", tokenString).
+				Msg("failed to parse transfer token")
+			w.WriteHeader(http.StatusUnauthorized)
+			return
+		}
+
+		if claims, ok := token.Claims.(*tjwt.ThumbnailClaims); ok && token.Valid {
+			ctx := context.WithValue(r.Context(), keyContextKey, claims.Key)
+			next.ServeHTTP(w, r.WithContext(ctx))
+			return
+		}
+		w.WriteHeader(http.StatusUnauthorized)
+	})
+}

extensions/thumbnails/pkg/service/http/v0/tracing.go

@@ -0,0 +1,28 @@
+package svc
+
+import (
+	"net/http"
+
+	"github.com/owncloud/ocis/ocis-pkg/middleware"
+)
+
+// NewTracing returns a service that instruments traces.
+func NewTracing(next Service) Service {
+	return tracing{
+		next: next,
+	}
+}
+
+type tracing struct {
+	next Service
+}
+
+// ServeHTTP implements the Service interface.
+func (t tracing) ServeHTTP(w http.ResponseWriter, r *http.Request) {
+	middleware.TraceContext(t.next).ServeHTTP(w, r)
+}
+
+// GetThumbnail implements the Service interface.
+func (t tracing) GetThumbnail(w http.ResponseWriter, r *http.Request) {
+	t.next.GetThumbnail(w, r)
+}