Serve locally stored fbc content via an http server

Closes #113

Signed-off-by: Anik <anikbhattacharya93@gmail.com>

cmd/manager/main.go

@@ -19,7 +19,9 @@ package main
 import (
 	"flag"
 	"fmt"
+	"net/http"
 	"os"
+	"time"
 
 	// Import all Kubernetes client auth plugins (e.g. Azure, GCP, OIDC, etc.)
 	// to ensure that exec-entrypoint and run can make use of them.
@@ -35,6 +37,7 @@ import (
 	"github.com/spf13/pflag"
 
 	"github.com/operator-framework/catalogd/internal/source"
+	"github.com/operator-framework/catalogd/internal/third_party/server"
 	"github.com/operator-framework/catalogd/internal/version"
 	corecontrollers "github.com/operator-framework/catalogd/pkg/controllers/core"
 	"github.com/operator-framework/catalogd/pkg/features"
@@ -67,6 +70,7 @@ func main() {
 		catalogdVersion      bool
 		systemNamespace      string
 		storageDir           string
+		catalogServerAddr    string
 	)
 	flag.StringVar(&metricsAddr, "metrics-bind-address", ":8080", "The address the metric endpoint binds to.")
 	flag.StringVar(&probeAddr, "health-probe-bind-address", ":8081", "The address the probe endpoint binds to.")
@@ -77,6 +81,7 @@ func main() {
 	flag.StringVar(&unpackImage, "unpack-image", "quay.io/operator-framework/rukpak:v0.12.0", "The unpack image to use when unpacking catalog images")
 	flag.StringVar(&systemNamespace, "system-namespace", "", "The namespace catalogd uses for internal state, configuration, and workloads")
 	flag.StringVar(&storageDir, "catalogs-storage-dir", "/var/cache/catalogs", "The directory in the filesystem where unpacked catalog content will be stored and served from")
+	flag.StringVar(&catalogServerAddr, "catalogs-server-addr", ":8083", "The address where the unpacked catalogs' content will be accessible")
 	flag.BoolVar(&profiling, "profiling", false, "enable profiling endpoints to allow for using pprof")
 	flag.BoolVar(&catalogdVersion, "version", false, "print the catalogd version and exit")
 	opts := zap.Options{
@@ -122,10 +127,27 @@ func main() {
 	if err := os.MkdirAll(storageDir, 0700); err != nil {
 		setupLog.Error(err, "unable to create storage directory for catalogs")
 	}
+	localStorage := storage.LocalDir{RootDir: storageDir}
+	shutdownTimeout := 30 * time.Second
+	catalogServer := server.Server{
+		Kind: "catalogs",
+		Server: &http.Server{
+			Addr:         catalogServerAddr,
+			Handler:      localStorage.StorageServerHandler(),
+			ReadTimeout:  5 * time.Second,
+			WriteTimeout: 10 * time.Second,
+		},
+		ShutdownTimeout: &shutdownTimeout,
+	}
+	if err := mgr.Add(&catalogServer); err != nil {
+		setupLog.Error(err, "unable to start catalog server")
+		os.Exit(1)
+	}
+
 	if err = (&corecontrollers.CatalogReconciler{
 		Client:   mgr.GetClient(),
 		Unpacker: unpacker,
-		Storage:  storage.LocalDir{RootDir: storageDir},
+		Storage:  localStorage,
 	}).SetupWithManager(mgr); err != nil {
 		setupLog.Error(err, "unable to create controller", "controller", "Catalog")
 		os.Exit(1)

config/default/manager_auth_proxy_patch.yaml

@@ -51,4 +51,5 @@ spec:
         - "--metrics-bind-address=127.0.0.1:8080"
         - "--leader-elect"
         - "--catalogs-storage-dir=/var/cache/catalogs"
-        - "--feature-gates=CatalogMetadataAPI=true,HTTPServer=false"
+        - "--feature-gates=CatalogMetadataAPI=true,HTTPServer=true"
+

config/rbac/catalogserver_service.yaml

@@ -0,0 +1,13 @@
+apiVersion: v1
+kind: Service
+metadata:
+  name: catalogserver
+  namespace: system
+spec:
+  selector:
+    control-plane: controller-manager
+  ports:
+  - name: http
+    protocol: TCP
+    port: 80
+    targetPort: 8083

config/rbac/kustomization.yaml

@@ -9,6 +9,7 @@ resources:
 - role_binding.yaml
 - leader_election_role.yaml
 - leader_election_role_binding.yaml
+- catalogserver_service.yaml
 # Comment the following 4 lines if you want to disable
 # the auth proxy (https://github.com/brancz/kube-rbac-proxy)
 # which protects your /metrics endpoint.

go.mod

@@ -4,6 +4,7 @@ go 1.20
 
 require (
 	github.com/blang/semver/v4 v4.0.0
+	github.com/go-logr/logr v1.2.4
 	github.com/google/go-cmp v0.5.9
 	github.com/nlepage/go-tarfs v1.1.0
 	github.com/onsi/ginkgo/v2 v2.9.7
@@ -31,7 +32,6 @@ require (
 	github.com/go-git/gcfg v1.5.0 // indirect
 	github.com/go-git/go-billy/v5 v5.4.1 // indirect
 	github.com/go-git/go-git/v5 v5.4.2 // indirect
-	github.com/go-logr/logr v1.2.4 // indirect
 	github.com/go-logr/zapr v1.2.3 // indirect
 	github.com/go-openapi/jsonpointer v0.19.5 // indirect
 	github.com/go-openapi/jsonreference v0.20.0 // indirect

internal/third_party/server/server.go

@@ -0,0 +1,122 @@
+/*
+Copyright 2022 The Kubernetes Authors.
+
+Licensed under the Apache License, Version 2.0 (the "License");
+you may not use this file except in compliance with the License.
+You may obtain a copy of the License at
+
+   http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+See the License for the specific language governing permissions and
+limitations under the License.
+*/
+
+// this is copied from https://raw.githubusercontent.com/kubernetes-sigs/controller-runtime/77b08a845e451b695cfa25b79ebe277d85064345/pkg/manager/server.go
+// we will remove this once we update to a version of controller-runitme that has this included
+// https://github.com/kubernetes-sigs/controller-runtime/pull/2473
+
+package server
+
+import (
+	"context"
+	"errors"
+	"net"
+	"net/http"
+	"time"
+
+	"github.com/go-logr/logr"
+
+	crlog "sigs.k8s.io/controller-runtime/pkg/log"
+	"sigs.k8s.io/controller-runtime/pkg/manager"
+)
+
+var (
+	_ manager.Runnable               = (*Server)(nil)
+	_ manager.LeaderElectionRunnable = (*Server)(nil)
+)
+
+// Server is a general purpose HTTP server Runnable for a manager.
+// It is used to serve some internal handlers for health probes and profiling,
+// but it can also be used to run custom servers.
+type Server struct {
+	// Kind is an optional string that describes the purpose of the server. It is used in logs to distinguish
+	// among multiple servers.
+	Kind string
+
+	// Log is the logger used by the server. If not set, a logger will be derived from the context passed to Start.
+	Log logr.Logger
+
+	// Server is the HTTP server to run. It is required.
+	Server *http.Server
+
+	// Listener is an optional listener to use. If not set, the server start a listener using the server.Addr.
+	// Using a listener is useful when the port reservation needs to happen in advance of this runnable starting.
+	Listener net.Listener
+
+	// OnlyServeWhenLeader is an optional bool that indicates that the server should only be started when the manager is the leader.
+	OnlyServeWhenLeader bool
+
+	// ShutdownTimeout is an optional duration that indicates how long to wait for the server to shutdown gracefully. If not set,
+	// the server will wait indefinitely for all connections to close.
+	ShutdownTimeout *time.Duration
+}
+
+// Start starts the server. It will block until the server is stopped or an error occurs.
+func (s *Server) Start(ctx context.Context) error {
+	log := s.Log
+	if log.GetSink() == nil {
+		log = crlog.FromContext(ctx)
+	}
+	if s.Kind != "" {
+		log = log.WithValues("kind", s.Kind)
+	}
+	log = log.WithValues("addr", s.addr())
+
+	serverShutdown := make(chan struct{})
+	go func() {
+		<-ctx.Done()
+		log.Info("shutting down server")
+
+		shutdownCtx := context.Background()
+		if s.ShutdownTimeout != nil {
+			var shutdownCancel context.CancelFunc
+			shutdownCtx, shutdownCancel = context.WithTimeout(context.Background(), *s.ShutdownTimeout)
+			defer shutdownCancel()
+		}
+
+		if err := s.Server.Shutdown(shutdownCtx); err != nil {
+			log.Error(err, "error shutting down server")
+		}
+		close(serverShutdown)
+	}()
+
+	log.Info("starting server")
+	if err := s.serve(); err != nil && !errors.Is(err, http.ErrServerClosed) {
+		return err
+	}
+
+	<-serverShutdown
+	return nil
+}
+
+// NeedLeaderElection returns true if the server should only be started when the manager is the leader.
+func (s *Server) NeedLeaderElection() bool {
+	return s.OnlyServeWhenLeader
+}
+
+func (s *Server) addr() string {
+	if s.Listener != nil {
+		return s.Listener.Addr().String()
+	}
+	return s.Server.Addr
+}
+
+func (s *Server) serve() error {
+	if s.Listener != nil {
+		return s.Server.Serve(s.Listener)
+	}
+	return s.Server.ListenAndServe()
+}

pkg/controllers/core/catalog_controller_test.go

@@ -5,6 +5,7 @@ import (
 	"errors"
 	"fmt"
 	"io/fs"
+	"net/http"
 	"os"
 	"testing/fstest"
 
@@ -67,6 +68,10 @@ func (m MockStore) Delete(_ string) error {
 	return nil
 }
 
+func (m MockStore) StorageServerHandler() http.Handler {
+	panic("not needed")
+}
+
 var _ = Describe("Catalogd Controller Test", func() {
 	format.MaxLength = 0
 	var (

pkg/storage/localdir.go

@@ -3,6 +3,7 @@ package storage
 import (
 	"fmt"
 	"io/fs"
+	"net/http"
 	"os"
 	"path/filepath"
 
@@ -45,3 +46,36 @@ func (s LocalDir) Store(catalog string, fsys fs.FS) error {
 func (s LocalDir) Delete(catalog string) error {
 	return os.RemoveAll(filepath.Join(s.RootDir, catalog))
 }
+
+func (s LocalDir) StorageServerHandler() http.Handler {
+	mux := http.NewServeMux()
+	mux.Handle("/catalogs/", http.StripPrefix("/catalogs/", http.FileServer(http.FS(&filesOnlyFilesystem{os.DirFS(s.RootDir)}))))
+	return mux
+}
+
+// filesOnlyFilesystem is a file system that can open only regular
+// files from the underlying filesystem. All other file types result
+// in os.ErrNotExists
+type filesOnlyFilesystem struct {
+	FS fs.FS
+}
+
+// Open opens a named file from the underlying filesystem. If the file
+// is not a regular file, it return os.ErrNotExists. Callers are resposible
+// for closing the file returned.
+func (f *filesOnlyFilesystem) Open(name string) (fs.File, error) {
+	file, err := f.FS.Open(name)
+	if err != nil {
+		return nil, err
+	}
+	stat, err := file.Stat()
+	if err != nil {
+		_ = file.Close()
+		return nil, err
+	}
+	if !stat.Mode().IsRegular() {
+		_ = file.Close()
+		return nil, os.ErrNotExist
+	}
+	return file, nil
+}

pkg/storage/localdir_test.go

@@ -2,7 +2,10 @@ package storage
 
 import (
 	"fmt"
+	"io"
 	"io/fs"
+	"net/http"
+	"net/http/httptest"
 	"os"
 	"path/filepath"
 	"testing/fstest"
@@ -34,8 +37,8 @@ var _ = Describe("LocalDir Storage Test", func() {
 	)
 	BeforeEach(func() {
 		d, err := os.MkdirTemp(GinkgoT().TempDir(), "cache")
-		rootDir = d
 		Expect(err).ToNot(HaveOccurred())
+		rootDir = d
 
 		store = LocalDir{RootDir: rootDir}
 		unpackResultFS = &fstest.MapFS{
@@ -76,6 +79,68 @@ var _ = Describe("LocalDir Storage Test", func() {
 	})
 })
 
+var _ = Describe("LocalDir Server Handler tests", func() {
+	var (
+		testServer *httptest.Server
+		store      LocalDir
+	)
+	BeforeEach(func() {
+		d, err := os.MkdirTemp(GinkgoT().TempDir(), "cache")
+		Expect(err).ToNot(HaveOccurred())
+		Expect(os.Mkdir(filepath.Join(d, "test-catalog"), 0700)).To(Succeed())
+		store = LocalDir{RootDir: d}
+		testServer = httptest.NewServer(store.StorageServerHandler())
+
+	})
+	It("gets 404 for the path /", func() {
+		expectNotFound(testServer.URL)
+	})
+	It("gets 404 for the path /catalogs/", func() {
+		expectNotFound(fmt.Sprintf("%s/%s", testServer.URL, "/catalogs/"))
+	})
+	It("gets 404 for the path /catalogs/test-catalog/", func() {
+		expectNotFound(fmt.Sprintf("%s/%s", testServer.URL, "/catalogs/test-catalog/"))
+	})
+	It("gets 404 for the path /test-catalog/foo.txt", func() {
+		// This ensures that even if the file exists, the URL must contain the /catalogs/ prefix
+		Expect(os.WriteFile(filepath.Join(store.RootDir, "test-catalog", "foo.txt"), []byte("bar"), 0600)).To(Succeed())
+		expectNotFound(fmt.Sprintf("%s/%s", testServer.URL, "/test-catalog/foo.txt"))
+	})
+	It("gets 404 for the path /catalogs/test-catalog/non-existent.txt", func() {
+		expectNotFound(fmt.Sprintf("%s/%s", testServer.URL, "/catalogs/test-catalog/non-existent.txt"))
+	})
+	It("gets 200 for the path /catalogs/foo.txt", func() {
+		expectedContent := []byte("bar")
+		Expect(os.WriteFile(filepath.Join(store.RootDir, "foo.txt"), expectedContent, 0600)).To(Succeed())
+		expectFound(fmt.Sprintf("%s/%s", testServer.URL, "/catalogs/foo.txt"), expectedContent)
+	})
+	It("gets 200 for the path /catalogs/test-catalog/foo.txt", func() {
+		expectedContent := []byte("bar")
+		Expect(os.WriteFile(filepath.Join(store.RootDir, "test-catalog", "foo.txt"), expectedContent, 0600)).To(Succeed())
+		expectFound(fmt.Sprintf("%s/%s", testServer.URL, "/catalogs/test-catalog/foo.txt"), expectedContent)
+	})
+	AfterEach(func() {
+		testServer.Close()
+	})
+})
+
+func expectNotFound(url string) {
+	resp, err := http.Get(url) //nolint:gosec
+	Expect(err).To(Not(HaveOccurred()))
+	Expect(resp.StatusCode).To(Equal(http.StatusNotFound))
+	Expect(resp.Body.Close()).To(Succeed())
+}
+
+func expectFound(url string, expectedContent []byte) {
+	resp, err := http.Get(url) //nolint:gosec
+	Expect(err).To(Not(HaveOccurred()))
+	Expect(resp.StatusCode).To(Equal(http.StatusOK))
+	actualContent, err := io.ReadAll(resp.Body)
+	Expect(err).To(Not(HaveOccurred()))
+	Expect(actualContent).To(Equal(expectedContent))
+	Expect(resp.Body.Close()).To(Succeed())
+}
+
 const testBundleTemplate = `---
 image: %s
 name: %s