ext: namespace detector -> featurens

cmd/clair/main.go

@@ -26,6 +26,11 @@ import (
 	"github.com/coreos/clair/config"
 
 	// Register extensions.
+	_ "github.com/coreos/clair/ext/featurens/alpinerelease"
+	_ "github.com/coreos/clair/ext/featurens/aptsources"
+	_ "github.com/coreos/clair/ext/featurens/lsbrelease"
+	_ "github.com/coreos/clair/ext/featurens/osrelease"
+	_ "github.com/coreos/clair/ext/featurens/redhatrelease"
 	_ "github.com/coreos/clair/ext/imagefmt/aci"
 	_ "github.com/coreos/clair/ext/imagefmt/docker"
 	_ "github.com/coreos/clair/ext/notification/webhook"
@@ -40,12 +45,6 @@ import (
 	_ "github.com/coreos/clair/worker/detectors/feature/dpkg"
 	_ "github.com/coreos/clair/worker/detectors/feature/rpm"
 
-	_ "github.com/coreos/clair/worker/detectors/namespace/alpinerelease"
-	_ "github.com/coreos/clair/worker/detectors/namespace/aptsources"
-	_ "github.com/coreos/clair/worker/detectors/namespace/lsbrelease"
-	_ "github.com/coreos/clair/worker/detectors/namespace/osrelease"
-	_ "github.com/coreos/clair/worker/detectors/namespace/redhatrelease"
-
 	_ "github.com/coreos/clair/database/pgsql"
 )
 

ext/featurens/alpinerelease/alpinerelease.go

@@ -1,4 +1,4 @@
-// Copyright 2016 clair authors
+// Copyright 2017 clair authors
 //
 // Licensed under the Apache License, Version 2.0 (the "License");
 // you may not use this file except in compliance with the License.
@@ -12,6 +12,8 @@
 // See the License for the specific language governing permissions and
 // limitations under the License.
 
+// Package alpinerelease implements a featurens.Detector for Alpine Linux based
+// container image layers.
 package alpinerelease
 
 import (
@@ -21,8 +23,9 @@ import (
 	"strings"
 
 	"github.com/coreos/clair/database"
+	"github.com/coreos/clair/ext/featurens"
 	"github.com/coreos/clair/ext/versionfmt/dpkg"
-	"github.com/coreos/clair/worker/detectors"
+	"github.com/coreos/clair/pkg/tarutil"
 )
 
 const (
@@ -33,15 +36,13 @@ const (
 var versionRegexp = regexp.MustCompile(`^(\d)+\.(\d)+\.(\d)+$`)
 
 func init() {
-	detectors.RegisterNamespaceDetector("alpine-release", &detector{})
+	featurens.RegisterDetector("alpine-release", &detector{})
 }
 
-// detector implements NamespaceDetector by reading the current version of
-// Alpine Linux from /etc/alpine-release.
 type detector struct{}
 
-func (d *detector) Detect(data map[string][]byte) *database.Namespace {
+func (d detector) Detect(files tarutil.FilesMap) (*database.Namespace, error) {
-	file, exists := data[alpineReleasePath]
+	file, exists := files[alpineReleasePath]
 	if exists {
 		scanner := bufio.NewScanner(bytes.NewBuffer(file))
 		for scanner.Scan() {
@@ -52,14 +53,14 @@ func (d *detector) Detect(data map[string][]byte) *database.Namespace {
 				return &database.Namespace{
 					Name:          osName + ":" + "v" + versionNumbers[0] + "." + versionNumbers[1],
 					VersionFormat: dpkg.ParserName,
-				}
+				}, nil
 			}
 		}
 	}
 
-	return nil
+	return nil, nil
 }
 
-func (d *detector) GetRequiredFiles() []string {
+func (d detector) RequiredFilenames() []string {
 	return []string{alpineReleasePath}
 }

ext/featurens/alpinerelease/alpinerelease_test.go

@@ -1,4 +1,4 @@
-// Copyright 2016 clair authors
+// Copyright 2017 clair authors
 //
 // Licensed under the Apache License, Version 2.0 (the "License");
 // you may not use this file except in compliance with the License.
@@ -18,34 +18,35 @@ import (
 	"testing"
 
 	"github.com/coreos/clair/database"
-	"github.com/coreos/clair/worker/detectors/namespace"
+	"github.com/coreos/clair/ext/featurens"
+	"github.com/coreos/clair/pkg/tarutil"
 )
 
-func TestAlpineReleaseNamespaceDetection(t *testing.T) {
+func TestDetector(t *testing.T) {
-	testData := []namespace.TestData{
+	testData := []featurens.TestData{
 		{
 			ExpectedNamespace: &database.Namespace{Name: "alpine:v3.3"},
-			Data:              map[string][]byte{"etc/alpine-release": []byte(`3.3.4`)},
+			Files:             tarutil.FilesMap{"etc/alpine-release": []byte(`3.3.4`)},
 		},
 		{
 			ExpectedNamespace: &database.Namespace{Name: "alpine:v3.4"},
-			Data:              map[string][]byte{"etc/alpine-release": []byte(`3.4.0`)},
+			Files:             tarutil.FilesMap{"etc/alpine-release": []byte(`3.4.0`)},
 		},
 		{
 			ExpectedNamespace: &database.Namespace{Name: "alpine:v0.3"},
-			Data:              map[string][]byte{"etc/alpine-release": []byte(`0.3.4`)},
+			Files:             tarutil.FilesMap{"etc/alpine-release": []byte(`0.3.4`)},
 		},
 		{
 			ExpectedNamespace: &database.Namespace{Name: "alpine:v0.3"},
-			Data: map[string][]byte{"etc/alpine-release": []byte(`
+			Files: tarutil.FilesMap{"etc/alpine-release": []byte(`
 0.3.4
 `)},
 		},
 		{
 			ExpectedNamespace: nil,
-			Data:              map[string][]byte{},
+			Files:             tarutil.FilesMap{},
 		},
 	}
 
-	namespace.TestDetector(t, &detector{}, testData)
+	featurens.TestDetector(t, &detector{}, testData)
 }

ext/featurens/aptsources/aptsources.go

@@ -1,4 +1,4 @@
-// Copyright 2015 clair authors
+// Copyright 2017 clair authors
 //
 // Licensed under the Apache License, Version 2.0 (the "License");
 // you may not use this file except in compliance with the License.
@@ -12,6 +12,11 @@
 // See the License for the specific language governing permissions and
 // limitations under the License.
 
+// Package aptsources implements a featurens.Detector for apt based container
+// image layers.
+//
+// This detector is necessary to determine the precise Debian version when it
+// is an unstable version for instance.
 package aptsources
 
 import (
@@ -19,25 +24,21 @@ import (
 	"strings"
 
 	"github.com/coreos/clair/database"
+	"github.com/coreos/clair/ext/featurens"
 	"github.com/coreos/clair/ext/versionfmt/dpkg"
-	"github.com/coreos/clair/worker/detectors"
+	"github.com/coreos/clair/pkg/tarutil"
 )
 
-// AptSourcesNamespaceDetector implements NamespaceDetector and detects the Namespace from the
+type detector struct{}
-// /etc/apt/sources.list file.
-//
-// This detector is necessary to determine precise Debian version when it is
-// an unstable version for instance.
-type AptSourcesNamespaceDetector struct{}
 
 func init() {
-	detectors.RegisterNamespaceDetector("apt-sources", &AptSourcesNamespaceDetector{})
+	featurens.RegisterDetector("apt-sources", &detector{})
 }
 
-func (detector *AptSourcesNamespaceDetector) Detect(data map[string][]byte) *database.Namespace {
+func (d detector) Detect(files tarutil.FilesMap) (*database.Namespace, error) {
-	f, hasFile := data["etc/apt/sources.list"]
+	f, hasFile := files["etc/apt/sources.list"]
 	if !hasFile {
-		return nil
+		return nil, nil
 	}
 
 	var OS, version string
@@ -79,11 +80,11 @@ func (detector *AptSourcesNamespaceDetector) Detect(data map[string][]byte) *dat
 		return &database.Namespace{
 			Name:          OS + ":" + version,
 			VersionFormat: dpkg.ParserName,
+		}, nil
 	}
-	}
+	return nil, nil
-	return nil
 }
 
-func (detector *AptSourcesNamespaceDetector) GetRequiredFiles() []string {
+func (d detector) RequiredFilenames() []string {
 	return []string{"etc/apt/sources.list"}
 }

ext/featurens/aptsources/aptsources_test.go

@@ -1,4 +1,4 @@
-// Copyright 2016 clair authors
+// Copyright 2017 clair authors
 //
 // Licensed under the Apache License, Version 2.0 (the "License");
 // you may not use this file except in compliance with the License.
@@ -18,14 +18,15 @@ import (
 	"testing"
 
 	"github.com/coreos/clair/database"
-	"github.com/coreos/clair/worker/detectors/namespace"
+	"github.com/coreos/clair/ext/featurens"
+	"github.com/coreos/clair/pkg/tarutil"
 )
 
-func TestAptSourcesNamespaceDetector(t *testing.T) {
+func TestDetector(t *testing.T) {
-	testData := []namespace.TestData{
+	testData := []featurens.TestData{
 		{
 			ExpectedNamespace: &database.Namespace{Name: "debian:unstable"},
-			Data: map[string][]byte{
+			Files: tarutil.FilesMap{
 				"etc/os-release": []byte(
 					`PRETTY_NAME="Debian GNU/Linux stretch/sid"
 NAME="Debian GNU/Linux"
@@ -38,5 +39,5 @@ BUG_REPORT_URL="https://bugs.debian.org/"`),
 		},
 	}
 
-	namespace.TestDetector(t, &AptSourcesNamespaceDetector{}, testData)
+	featurens.TestDetector(t, &detector{}, testData)
 }

ext/featurens/driver.go

@@ -0,0 +1,124 @@
+// Copyright 2017 clair 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.
+
+// Package featurens exposes functions to dynamically register methods for
+// determining a namespace for features present in an image layer.
+package featurens
+
+import (
+	"sync"
+	"testing"
+
+	"github.com/coreos/pkg/capnslog"
+	"github.com/stretchr/testify/assert"
+
+	"github.com/coreos/clair/database"
+	"github.com/coreos/clair/pkg/tarutil"
+)
+
+var (
+	log = capnslog.NewPackageLogger("github.com/coreos/clair", "ext/featurens")
+
+	detectorsM sync.RWMutex
+	detectors  = make(map[string]Detector)
+)
+
+// Detector represents an ability to detect a namespace used for organizing
+// features present in an image layer.
+type Detector interface {
+	// Detect attempts to determine a Namespace from a FilesMap of an image
+	// layer.
+	Detect(tarutil.FilesMap) (*database.Namespace, error)
+
+	// RequireFilenames returns the list of files required to be in the FilesMap
+	// provided to the Detect method.
+	// TODO(jzelinskie): strip "/" prefix
+	RequiredFilenames() []string
+}
+
+// RegisterDetector makes a detector available by the provided name.
+//
+// If called twice with the same name, the name is blank, or if the provided
+// Detector is nil, this function panics.
+func RegisterDetector(name string, d Detector) {
+	if name == "" {
+		panic("namespace: could not register a Detector with an empty name")
+	}
+	if d == nil {
+		panic("namespace: could not register a nil Detector")
+	}
+
+	detectorsM.Lock()
+	defer detectorsM.Unlock()
+
+	if _, dup := detectors[name]; dup {
+		panic("namespace: RegisterDetector called twice for " + name)
+	}
+
+	detectors[name] = d
+}
+
+// Detect iterators through all registered Detectors and returns the first
+// non-nil detected namespace.
+func Detect(files tarutil.FilesMap) (*database.Namespace, error) {
+	detectorsM.RLock()
+	defer detectorsM.RUnlock()
+
+	for name, detector := range detectors {
+		namespace, err := detector.Detect(files)
+		if err != nil {
+			log.Warningf("failed while attempting to detect namespace %s: %s", name, err)
+			return nil, err
+		}
+
+		if namespace != nil {
+			log.Debugf("detected namespace %s: %#v", name, namespace)
+			return namespace, nil
+		}
+	}
+
+	return nil, nil
+}
+
+// RequiredFilenames returns the total list of files required for all
+// registered Detectors.
+func RequiredFilenames() (files []string) {
+	for _, detector := range detectors {
+		files = append(files, detector.RequiredFilenames()...)
+	}
+
+	return
+}
+
+// TestData represents the data used to test an implementation of
+// NameSpaceDetector.
+type TestData struct {
+	Files             tarutil.FilesMap
+	ExpectedNamespace *database.Namespace
+}
+
+// TestDetector runs a Detector on each provided instance of TestData and
+// asserts the output to be equal to the expected output.
+func TestDetector(t *testing.T, d Detector, testData []TestData) {
+	for _, td := range testData {
+		namespace, err := d.Detect(td.Files)
+		assert.Nil(t, err)
+
+		if namespace == nil {
+			assert.Equal(t, td.ExpectedNamespace, namespace)
+		} else {
+			assert.Equal(t, td.ExpectedNamespace.Name, namespace.Name)
+		}
+	}
+}

ext/featurens/lsbrelease/lsbrelease.go

@@ -1,4 +1,4 @@
-// Copyright 2015 clair authors
+// Copyright 2017 clair authors
 //
 // Licensed under the Apache License, Version 2.0 (the "License");
 // you may not use this file except in compliance with the License.
@@ -12,6 +12,10 @@
 // See the License for the specific language governing permissions and
 // limitations under the License.
 
+// Package lsbrelease implements a featurens.Detector for container image
+// layers containing an lsb-release file.
+//
+// This detector is necessary for detecting Ubuntu Precise.
 package lsbrelease
 
 import (
@@ -20,9 +24,10 @@ import (
 	"strings"
 
 	"github.com/coreos/clair/database"
+	"github.com/coreos/clair/ext/featurens"
 	"github.com/coreos/clair/ext/versionfmt/dpkg"
 	"github.com/coreos/clair/ext/versionfmt/rpm"
-	"github.com/coreos/clair/worker/detectors"
+	"github.com/coreos/clair/pkg/tarutil"
 )
 
 var (
@@ -30,20 +35,16 @@ var (
 	lsbReleaseVersionRegexp = regexp.MustCompile(`^DISTRIB_RELEASE=(.*)`)
 )
 
-// LsbReleaseNamespaceDetector implements NamespaceDetector and detects the
+type detector struct{}
-// Namespace from the /etc/lsb-release file.
-//
-// This detector is necessary for Ubuntu Precise.
-type LsbReleaseNamespaceDetector struct{}
 
 func init() {
-	detectors.RegisterNamespaceDetector("lsb-release", &LsbReleaseNamespaceDetector{})
+	featurens.RegisterDetector("lsb-release", &detector{})
 }
 
-func (detector *LsbReleaseNamespaceDetector) Detect(data map[string][]byte) *database.Namespace {
+func (d detector) Detect(files tarutil.FilesMap) (*database.Namespace, error) {
-	f, hasFile := data["etc/lsb-release"]
+	f, hasFile := files["etc/lsb-release"]
 	if !hasFile {
-		return nil
+		return nil, nil
 	}
 
 	var OS, version string
@@ -79,19 +80,19 @@ func (detector *LsbReleaseNamespaceDetector) Detect(data map[string][]byte) *dat
 	case "centos", "rhel", "fedora", "amzn", "ol", "oracle":
 		versionFormat = rpm.ParserName
 	default:
-		return nil
+		return nil, nil
 	}
 
 	if OS != "" && version != "" {
 		return &database.Namespace{
 			Name:          OS + ":" + version,
 			VersionFormat: versionFormat,
+		}, nil
 	}
-	}
+
-	return nil
+	return nil, nil
 }
 
-// GetRequiredFiles returns the list of files that are required for Detect()
+func (d *detector) RequiredFilenames() []string {
-func (detector *LsbReleaseNamespaceDetector) GetRequiredFiles() []string {
 	return []string{"etc/lsb-release"}
 }

ext/featurens/lsbrelease/lsbrelease_test.go

@@ -1,4 +1,4 @@
-// Copyright 2016 clair authors
+// Copyright 2017 clair authors
 //
 // Licensed under the Apache License, Version 2.0 (the "License");
 // you may not use this file except in compliance with the License.
@@ -18,14 +18,15 @@ import (
 	"testing"
 
 	"github.com/coreos/clair/database"
-	"github.com/coreos/clair/worker/detectors/namespace"
+	"github.com/coreos/clair/ext/featurens"
+	"github.com/coreos/clair/pkg/tarutil"
 )
 
-func TestLsbReleaseNamespaceDetector(t *testing.T) {
+func TestDetector(t *testing.T) {
-	testData := []namespace.TestData{
+	testData := []featurens.TestData{
 		{
 			ExpectedNamespace: &database.Namespace{Name: "ubuntu:12.04"},
-			Data: map[string][]byte{
+			Files: tarutil.FilesMap{
 				"etc/lsb-release": []byte(
 					`DISTRIB_ID=Ubuntu
 DISTRIB_RELEASE=12.04
@@ -35,7 +36,7 @@ DISTRIB_DESCRIPTION="Ubuntu 12.04 LTS"`),
 		},
 		{ // We don't care about the minor version of Debian
 			ExpectedNamespace: &database.Namespace{Name: "debian:7"},
-			Data: map[string][]byte{
+			Files: tarutil.FilesMap{
 				"etc/lsb-release": []byte(
 					`DISTRIB_ID=Debian
 DISTRIB_RELEASE=7.1
@@ -45,5 +46,5 @@ DISTRIB_DESCRIPTION="Debian 7.1"`),
 		},
 	}
 
-	namespace.TestDetector(t, &LsbReleaseNamespaceDetector{}, testData)
+	featurens.TestDetector(t, &detector{}, testData)
 }

ext/featurens/osrelease/osrelease.go

@@ -1,4 +1,4 @@
-// Copyright 2015 clair authors
+// Copyright 2017 clair authors
 //
 // Licensed under the Apache License, Version 2.0 (the "License");
 // you may not use this file except in compliance with the License.
@@ -12,6 +12,10 @@
 // See the License for the specific language governing permissions and
 // limitations under the License.
 
+// Package osrelease implements a featurens.Detector for container image
+// layers containing an os-release file.
+//
+// This detector is typically useful for detecting Debian or Ubuntu.
 package osrelease
 
 import (
@@ -20,40 +24,41 @@ import (
 	"strings"
 
 	"github.com/coreos/clair/database"
+	"github.com/coreos/clair/ext/featurens"
 	"github.com/coreos/clair/ext/versionfmt/dpkg"
 	"github.com/coreos/clair/ext/versionfmt/rpm"
-	"github.com/coreos/clair/worker/detectors"
+	"github.com/coreos/clair/pkg/tarutil"
 )
 
 var (
-	//log = capnslog.NewPackageLogger("github.com/coreos/clair", "worker/detectors/namespace/osrelease")
-
 	osReleaseOSRegexp      = regexp.MustCompile(`^ID=(.*)`)
 	osReleaseVersionRegexp = regexp.MustCompile(`^VERSION_ID=(.*)`)
+
+	// blacklistFilenames are files that should exclude this detector.
+	blacklistFilenames = []string{
+		"etc/oracle-release",
+		"etc/redhat-release",
+		"usr/lib/centos-release",
+	}
 )
 
-// OsReleaseNamespaceDetector implements NamespaceDetector and detects the OS from the
+type detector struct{}
-// /etc/os-release and usr/lib/os-release files.
-type OsReleaseNamespaceDetector struct{}
 
 func init() {
-	detectors.RegisterNamespaceDetector("os-release", &OsReleaseNamespaceDetector{})
+	featurens.RegisterDetector("os-release", &detector{})
 }
 
-// Detect tries to detect OS/Version using "/etc/os-release" and "/usr/lib/os-release"
+func (d detector) Detect(files tarutil.FilesMap) (*database.Namespace, error) {
-// Typically for Debian / Ubuntu
-// /etc/debian_version can't be used, it does not make any difference between testing and unstable, it returns stretch/sid
-func (detector *OsReleaseNamespaceDetector) Detect(data map[string][]byte) *database.Namespace {
 	var OS, version string
 
-	for _, filePath := range detector.getExcludeFiles() {
+	for _, filePath := range blacklistFilenames {
-		if _, hasFile := data[filePath]; hasFile {
+		if _, hasFile := files[filePath]; hasFile {
-			return nil
+			return nil, nil
 		}
 	}
 
-	for _, filePath := range detector.GetRequiredFiles() {
+	for _, filePath := range d.RequiredFilenames() {
-		f, hasFile := data[filePath]
+		f, hasFile := files[filePath]
 		if !hasFile {
 			continue
 		}
@@ -82,24 +87,18 @@ func (detector *OsReleaseNamespaceDetector) Detect(data map[string][]byte) *data
 	case "centos", "rhel", "fedora", "amzn", "ol", "oracle":
 		versionFormat = rpm.ParserName
 	default:
-		return nil
+		return nil, nil
 	}
 
 	if OS != "" && version != "" {
 		return &database.Namespace{
 			Name:          OS + ":" + version,
 			VersionFormat: versionFormat,
+		}, nil
 	}
-	}
+	return nil, nil
-	return nil
 }
 
-// GetRequiredFiles returns the list of files that are required for Detect()
+func (d detector) RequiredFilenames() []string {
-func (detector *OsReleaseNamespaceDetector) GetRequiredFiles() []string {
 	return []string{"etc/os-release", "usr/lib/os-release"}
 }
-
-// getExcludeFiles returns the list of files that are ought to exclude this detector from Detect()
-func (detector *OsReleaseNamespaceDetector) getExcludeFiles() []string {
-	return []string{"etc/oracle-release", "etc/redhat-release", "usr/lib/centos-release"}
-}

ext/featurens/osrelease/osrelease_test.go

@@ -1,4 +1,4 @@
-// Copyright 2016 clair authors
+// Copyright 2017 clair authors
 //
 // Licensed under the Apache License, Version 2.0 (the "License");
 // you may not use this file except in compliance with the License.
@@ -18,14 +18,15 @@ import (
 	"testing"
 
 	"github.com/coreos/clair/database"
-	"github.com/coreos/clair/worker/detectors/namespace"
+	"github.com/coreos/clair/ext/featurens"
+	"github.com/coreos/clair/pkg/tarutil"
 )
 
-func TestOsReleaseNamespaceDetector(t *testing.T) {
+func TestDetector(t *testing.T) {
-	testData := []namespace.TestData{
+	testData := []featurens.TestData{
 		{
 			ExpectedNamespace: &database.Namespace{Name: "debian:8"},
-			Data: map[string][]byte{
+			Files: tarutil.FilesMap{
 				"etc/os-release": []byte(
 					`PRETTY_NAME="Debian GNU/Linux 8 (jessie)"
 NAME="Debian GNU/Linux"
@@ -39,7 +40,7 @@ BUG_REPORT_URL="https://bugs.debian.org/"`),
 		},
 		{
 			ExpectedNamespace: &database.Namespace{Name: "ubuntu:15.10"},
-			Data: map[string][]byte{
+			Files: tarutil.FilesMap{
 				"etc/os-release": []byte(
 					`NAME="Ubuntu"
 VERSION="15.10 (Wily Werewolf)"
@@ -54,7 +55,7 @@ BUG_REPORT_URL="http://bugs.launchpad.net/ubuntu/"`),
 		},
 		{ // Doesn't have quotes around VERSION_ID
 			ExpectedNamespace: &database.Namespace{Name: "fedora:20"},
-			Data: map[string][]byte{
+			Files: tarutil.FilesMap{
 				"etc/os-release": []byte(
 					`NAME=Fedora
 VERSION="20 (Heisenbug)"
@@ -73,5 +74,5 @@ REDHAT_SUPPORT_PRODUCT_VERSION=20`),
 		},
 	}
 
-	namespace.TestDetector(t, &OsReleaseNamespaceDetector{}, testData)
+	featurens.TestDetector(t, &detector{}, testData)
 }

ext/featurens/redhatrelease/redhatrelease.go

@@ -1,4 +1,4 @@
-// Copyright 2015 clair authors
+// Copyright 2017 clair authors
 //
 // Licensed under the Apache License, Version 2.0 (the "License");
 // you may not use this file except in compliance with the License.
@@ -12,6 +12,11 @@
 // See the License for the specific language governing permissions and
 // limitations under the License.
 
+// Package redhatrelease implements a featurens.Detector for container image
+// layers containing an redhat-release-like files.
+//
+// This detector is typically useful for detecting CentOS and Red-Hat like
+// systems.
 package redhatrelease
 
 import (
@@ -19,77 +24,64 @@ import (
 	"strings"
 
 	"github.com/coreos/clair/database"
+	"github.com/coreos/clair/ext/featurens"
 	"github.com/coreos/clair/ext/versionfmt/rpm"
-	"github.com/coreos/clair/worker/detectors"
+	"github.com/coreos/clair/pkg/tarutil"
-	"github.com/coreos/pkg/capnslog"
 )
 
 var (
-	log = capnslog.NewPackageLogger("github.com/coreos/clair", "worker/detectors/namespace/redhatrelease")
-
 	oracleReleaseRegexp = regexp.MustCompile(`(?P<os>[^\s]*) (Linux Server release) (?P<version>[\d]+)`)
 	centosReleaseRegexp = regexp.MustCompile(`(?P<os>[^\s]*) (Linux release|release) (?P<version>[\d]+)`)
 	redhatReleaseRegexp = regexp.MustCompile(`(?P<os>Red Hat Enterprise Linux) (Client release|Server release|Workstation release) (?P<version>[\d]+)`)
 )
 
-// RedhatReleaseNamespaceDetector implements NamespaceDetector and detects the OS from the
+type detector struct{}
-// /etc/oracle-release, /etc/centos-release, /etc/redhat-release and /etc/system-release files.
-//
-// Typically for CentOS and Red-Hat like systems
-// eg. CentOS release 5.11 (Final)
-// eg. CentOS release 6.6 (Final)
-// eg. CentOS Linux release 7.1.1503 (Core)
-// eg. Oracle Linux Server release 7.3
-// eg. Red Hat Enterprise Linux Server release 7.2 (Maipo)
-type RedhatReleaseNamespaceDetector struct{}
 
 func init() {
-	detectors.RegisterNamespaceDetector("redhat-release", &RedhatReleaseNamespaceDetector{})
+	featurens.RegisterDetector("redhat-release", &detector{})
 }
 
-func (detector *RedhatReleaseNamespaceDetector) Detect(data map[string][]byte) *database.Namespace {
+func (d detector) Detect(files tarutil.FilesMap) (*database.Namespace, error) {
-	for _, filePath := range detector.GetRequiredFiles() {
+	for _, filePath := range d.RequiredFilenames() {
-		f, hasFile := data[filePath]
+		f, hasFile := files[filePath]
 		if !hasFile {
 			continue
 		}
 
 		var r []string
 
-		// try for Oracle Linux
+		// Attempt to match Oracle Linux.
 		r = oracleReleaseRegexp.FindStringSubmatch(string(f))
 		if len(r) == 4 {
 			return &database.Namespace{
 				Name:          strings.ToLower(r[1]) + ":" + r[3],
 				VersionFormat: rpm.ParserName,
-			}
+			}, nil
 		}
 
-		// try for RHEL
+		// Attempt to match RHEL.
 		r = redhatReleaseRegexp.FindStringSubmatch(string(f))
 		if len(r) == 4 {
-			// TODO(vbatts) this is a hack until https://github.com/coreos/clair/pull/193
+			// TODO(vbatts): this is a hack until https://github.com/coreos/clair/pull/193
 			return &database.Namespace{
 				Name:          "centos" + ":" + r[3],
 				VersionFormat: rpm.ParserName,
-			}
+			}, nil
 		}
 
-		// then try centos first
+		// Atempt to match CentOS.
 		r = centosReleaseRegexp.FindStringSubmatch(string(f))
 		if len(r) == 4 {
 			return &database.Namespace{
 				Name:          strings.ToLower(r[1]) + ":" + r[3],
 				VersionFormat: rpm.ParserName,
+			}, nil
 		}
 	}
 
-	}
+	return nil, nil
-
-	return nil
 }
 
-// GetRequiredFiles returns the list of files that are required for Detect()
+func (d detector) RequiredFilenames() []string {
-func (detector *RedhatReleaseNamespaceDetector) GetRequiredFiles() []string {
 	return []string{"etc/oracle-release", "etc/centos-release", "etc/redhat-release", "etc/system-release"}
 }

ext/featurens/redhatrelease/redhatrelease_test.go

@@ -1,4 +1,4 @@
-// Copyright 2016 clair authors
+// Copyright 2017 clair authors
 //
 // Licensed under the Apache License, Version 2.0 (the "License");
 // you may not use this file except in compliance with the License.
@@ -18,36 +18,37 @@ import (
 	"testing"
 
 	"github.com/coreos/clair/database"
-	"github.com/coreos/clair/worker/detectors/namespace"
+	"github.com/coreos/clair/ext/featurens"
+	"github.com/coreos/clair/pkg/tarutil"
 )
 
-func TestRedhatReleaseNamespaceDetector(t *testing.T) {
+func TestDetector(t *testing.T) {
-	testData := []namespace.TestData{
+	testData := []featurens.TestData{
 		{
 			ExpectedNamespace: &database.Namespace{Name: "oracle:6"},
-			Data: map[string][]byte{
+			Files: tarutil.FilesMap{
 				"etc/oracle-release": []byte(`Oracle Linux Server release 6.8`),
 			},
 		},
 		{
 			ExpectedNamespace: &database.Namespace{Name: "oracle:7"},
-			Data: map[string][]byte{
+			Files: tarutil.FilesMap{
 				"etc/oracle-release": []byte(`Oracle Linux Server release 7.2`),
 			},
 		},
 		{
 			ExpectedNamespace: &database.Namespace{Name: "centos:6"},
-			Data: map[string][]byte{
+			Files: tarutil.FilesMap{
 				"etc/centos-release": []byte(`CentOS release 6.6 (Final)`),
 			},
 		},
 		{
 			ExpectedNamespace: &database.Namespace{Name: "centos:7"},
-			Data: map[string][]byte{
+			Files: tarutil.FilesMap{
 				"etc/system-release": []byte(`CentOS Linux release 7.1.1503 (Core)`),
 			},
 		},
 	}
 
-	namespace.TestDetector(t, &RedhatReleaseNamespaceDetector{}, testData)
+	featurens.TestDetector(t, &detector{}, testData)
 }

worker/detectors/namespace.go

@@ -1,86 +0,0 @@
-// Copyright 2015 clair 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.
-
-// Package detectors exposes functions to register and use container
-// information extractors.
-package detectors
-
-import (
-	"fmt"
-	"sync"
-
-	"github.com/coreos/clair/database"
-	"github.com/coreos/pkg/capnslog"
-)
-
-// The NamespaceDetector interface defines a way to detect a Namespace from input data.
-// A namespace is usually made of an Operating System name and its version.
-type NamespaceDetector interface {
-	// Detect detects a Namespace and its version from input data.
-	Detect(map[string][]byte) *database.Namespace
-	// GetRequiredFiles returns the list of files required for Detect, without
-	// leading /.
-	GetRequiredFiles() []string
-}
-
-var (
-	nlog = capnslog.NewPackageLogger("github.com/coreos/clair", "worker/detectors")
-
-	namespaceDetectorsLock sync.Mutex
-	namespaceDetectors     = make(map[string]NamespaceDetector)
-)
-
-// RegisterNamespaceDetector provides a way to dynamically register an implementation of a
-// NamespaceDetector.
-//
-// If RegisterNamespaceDetector is called twice with the same name if NamespaceDetector is nil,
-// or if the name is blank, it panics.
-func RegisterNamespaceDetector(name string, f NamespaceDetector) {
-	if name == "" {
-		panic("Could not register a NamespaceDetector with an empty name")
-	}
-	if f == nil {
-		panic("Could not register a nil NamespaceDetector")
-	}
-
-	namespaceDetectorsLock.Lock()
-	defer namespaceDetectorsLock.Unlock()
-
-	if _, alreadyExists := namespaceDetectors[name]; alreadyExists {
-		panic(fmt.Sprintf("Detector '%s' is already registered", name))
-	}
-	namespaceDetectors[name] = f
-}
-
-// DetectNamespace finds the OS of the layer by using every registered NamespaceDetector.
-func DetectNamespace(data map[string][]byte) *database.Namespace {
-	for name, detector := range namespaceDetectors {
-		if namespace := detector.Detect(data); namespace != nil {
-			nlog.Debugf("detector: %q; namespace: %q\n", name, namespace.Name)
-			return namespace
-		}
-	}
-
-	return nil
-}
-
-// GetRequiredFilesNamespace returns the list of files required for DetectNamespace for every
-// registered NamespaceDetector, without leading /.
-func GetRequiredFilesNamespace() (files []string) {
-	for _, detector := range namespaceDetectors {
-		files = append(files, detector.GetRequiredFiles()...)
-	}
-
-	return
-}

worker/detectors/namespace/test.go

@@ -1,45 +0,0 @@
-// Copyright 2016 clair 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.
-
-// Package namespace implements utilities common to implementations of
-// NamespaceDetector.
-package namespace
-
-import (
-	"testing"
-
-	"github.com/coreos/clair/database"
-	"github.com/coreos/clair/worker/detectors"
-	"github.com/stretchr/testify/assert"
-)
-
-// TestData represents the data used to test an implementation of
-// NameSpaceDetector.
-type TestData struct {
-	Data              map[string][]byte
-	ExpectedNamespace *database.Namespace
-}
-
-// TestDetector runs a detector on each provided instance of TestData and
-// asserts the output to be equal to the expected output.
-func TestDetector(t *testing.T, detector detectors.NamespaceDetector, testData []TestData) {
-	for _, td := range testData {
-		detectedNamespace := detector.Detect(td.Data)
-		if detectedNamespace == nil {
-			assert.Equal(t, td.ExpectedNamespace, detectedNamespace)
-		} else {
-			assert.Equal(t, td.ExpectedNamespace.Name, detectedNamespace.Name)
-		}
-	}
-}

worker/worker.go

@@ -20,8 +20,10 @@ import (
 	"github.com/coreos/pkg/capnslog"
 
 	"github.com/coreos/clair/database"
+	"github.com/coreos/clair/ext/featurens"
 	"github.com/coreos/clair/ext/imagefmt"
 	"github.com/coreos/clair/pkg/commonerr"
+	"github.com/coreos/clair/pkg/tarutil"
 	"github.com/coreos/clair/utils"
 	"github.com/coreos/clair/worker/detectors"
 )
@@ -110,20 +112,23 @@ func Process(datastore database.Datastore, imageFormat, name, parentName, path s
 	return datastore.InsertLayer(layer)
 }
 
-// detectContent downloads a layer's archive and extracts its Namespace and Features.
+// detectContent downloads a layer's archive and extracts its Namespace and
+// Features.
 func detectContent(imageFormat, name, path string, headers map[string]string, parent *database.Layer) (namespace *database.Namespace, featureVersions []database.FeatureVersion, err error) {
-	files, err := imagefmt.Extract(imageFormat, path, headers, append(detectors.GetRequiredFilesFeatures(), detectors.GetRequiredFilesNamespace()...))
+	totalRequiredFiles := append(detectors.GetRequiredFilesFeatures(), featurens.RequiredFilenames()...)
+	files, err := imagefmt.Extract(imageFormat, path, headers, totalRequiredFiles)
 	if err != nil {
 		log.Errorf("layer %s: failed to extract data from %s: %s", name, utils.CleanURL(path), err)
 		return
 	}
 
-	data := map[string][]byte(files)
+	namespace, err = detectNamespace(name, files, parent)
-
+	if err != nil {
-	// Detect namespace.
+		return
-	namespace = detectNamespace(name, data, parent)
+	}
 
 	// Detect features.
+	data := map[string][]byte(files)
 	featureVersions, err = detectFeatureVersions(name, data, namespace, parent)
 	if err != nil {
 		return
@@ -135,15 +140,17 @@ func detectContent(imageFormat, name, path string, headers map[string]string, pa
 	return
 }
 
-func detectNamespace(name string, data map[string][]byte, parent *database.Layer) (namespace *database.Namespace) {
+func detectNamespace(name string, files tarutil.FilesMap, parent *database.Layer) (namespace *database.Namespace, err error) {
-	// Use registered detectors to get the Namespace.
+	namespace, err = featurens.Detect(files)
-	namespace = detectors.DetectNamespace(data)
+	if err != nil {
+		return
+	}
 	if namespace != nil {
 		log.Debugf("layer %s: detected namespace %q", name, namespace.Name)
 		return
 	}
 
-	// Use the parent's Namespace.
+	// Fallback to the parent's namespace.
 	if parent != nil {
 		namespace = parent.Namespace
 		if namespace != nil {