cleanup: move init funcs to the top of the source

We make sure they're not hiding at the bottom or in the middle
which makes debugging an utter nightmare!

Signed-off-by: Milos Gajdos <milosthegajdos@gmail.com>

health/api/api.go

@@ -9,6 +9,13 @@ import (
 
 var updater = health.NewStatusUpdater()
 
+// init sets up the two endpoints to bring the service up and down
+func init() {
+	health.Register("manual_http_status", updater)
+	http.HandleFunc("/debug/health/down", DownHandler)
+	http.HandleFunc("/debug/health/up", UpHandler)
+}
+
 // DownHandler registers a manual_http_status that always returns an Error
 func DownHandler(w http.ResponseWriter, r *http.Request) {
 	if r.Method == http.MethodPost {
@@ -26,10 +33,3 @@ func UpHandler(w http.ResponseWriter, r *http.Request) {
 		w.WriteHeader(http.StatusNotFound)
 	}
 }
-
-// init sets up the two endpoints to bring the service up and down
-func init() {
-	health.Register("manual_http_status", updater)
-	http.HandleFunc("/debug/health/down", DownHandler)
-	http.HandleFunc("/debug/health/up", UpHandler)
-}

health/health.go

@@ -13,6 +13,12 @@ import (
 	"github.com/distribution/distribution/v3/registry/api/errcode"
 )
 
+// Registers global /debug/health api endpoint, creates default registry
+func init() {
+	DefaultRegistry = NewRegistry()
+	http.HandleFunc("/debug/health", StatusHandler)
+}
+
 // A Registry is a collection of checks. Most applications will use the global
 // registry defined in DefaultRegistry. However, unit tests may need to create
 // separate registries to isolate themselves from other tests.
@@ -278,9 +284,3 @@ func statusResponse(w http.ResponseWriter, r *http.Request, status int, checks m
 		dcontext.GetLogger(r.Context()).Errorf("error writing health status response body: %v", err)
 	}
 }
-
-// Registers global /debug/health api endpoint, creates default registry
-func init() {
-	DefaultRegistry = NewRegistry()
-	http.HandleFunc("/debug/health", StatusHandler)
-}

internal/client/auth/challenge/authchallenge.go

@@ -8,6 +8,48 @@ import (
 	"sync"
 )
 
+// Octet types from RFC 2616.
+type octetType byte
+
+var octetTypes [256]octetType
+
+const (
+	isToken octetType = 1 << iota
+	isSpace
+)
+
+func init() {
+	// OCTET      = <any 8-bit sequence of data>
+	// CHAR       = <any US-ASCII character (octets 0 - 127)>
+	// CTL        = <any US-ASCII control character (octets 0 - 31) and DEL (127)>
+	// CR         = <US-ASCII CR, carriage return (13)>
+	// LF         = <US-ASCII LF, linefeed (10)>
+	// SP         = <US-ASCII SP, space (32)>
+	// HT         = <US-ASCII HT, horizontal-tab (9)>
+	// <">        = <US-ASCII double-quote mark (34)>
+	// CRLF       = CR LF
+	// LWS        = [CRLF] 1*( SP | HT )
+	// TEXT       = <any OCTET except CTLs, but including LWS>
+	// separators = "(" | ")" | "<" | ">" | "@" | "," | ";" | ":" | "\" | <">
+	//              | "/" | "[" | "]" | "?" | "=" | "{" | "}" | SP | HT
+	// token      = 1*<any CHAR except CTLs or separators>
+	// qdtext     = <any TEXT except <">>
+
+	for c := 0; c < 256; c++ {
+		var t octetType
+		isCtl := c <= 31 || c == 127
+		isChar := 0 <= c && c <= 127
+		isSeparator := strings.ContainsRune(" \t\"(),/:;<=>?@[]\\{}", rune(c))
+		if strings.ContainsRune(" \t\r\n", rune(c)) {
+			t |= isSpace
+		}
+		if isChar && !isCtl && !isSeparator {
+			t |= isToken
+		}
+		octetTypes[c] = t
+	}
+}
+
 // Challenge carries information from a WWW-Authenticate response header.
 // See RFC 2617.
 type Challenge struct {
@@ -86,48 +128,6 @@ func (m *simpleManager) AddResponse(resp *http.Response) error {
 	return nil
 }
 
-// Octet types from RFC 2616.
-type octetType byte
-
-var octetTypes [256]octetType
-
-const (
-	isToken octetType = 1 << iota
-	isSpace
-)
-
-func init() {
-	// OCTET      = <any 8-bit sequence of data>
-	// CHAR       = <any US-ASCII character (octets 0 - 127)>
-	// CTL        = <any US-ASCII control character (octets 0 - 31) and DEL (127)>
-	// CR         = <US-ASCII CR, carriage return (13)>
-	// LF         = <US-ASCII LF, linefeed (10)>
-	// SP         = <US-ASCII SP, space (32)>
-	// HT         = <US-ASCII HT, horizontal-tab (9)>
-	// <">        = <US-ASCII double-quote mark (34)>
-	// CRLF       = CR LF
-	// LWS        = [CRLF] 1*( SP | HT )
-	// TEXT       = <any OCTET except CTLs, but including LWS>
-	// separators = "(" | ")" | "<" | ">" | "@" | "," | ";" | ":" | "\" | <">
-	//              | "/" | "[" | "]" | "?" | "=" | "{" | "}" | SP | HT
-	// token      = 1*<any CHAR except CTLs or separators>
-	// qdtext     = <any TEXT except <">>
-
-	for c := 0; c < 256; c++ {
-		var t octetType
-		isCtl := c <= 31 || c == 127
-		isChar := 0 <= c && c <= 127
-		isSeparator := strings.ContainsRune(" \t\"(),/:;<=>?@[]\\{}", rune(c))
-		if strings.ContainsRune(" \t\r\n", rune(c)) {
-			t |= isSpace
-		}
-		if isChar && !isCtl && !isSeparator {
-			t |= isToken
-		}
-		octetTypes[c] = t
-	}
-}
-
 // ResponseChallenges returns a list of authorization challenges
 // for the given http Response. Challenges are only checked if
 // the response status code was a 401.

notifications/metrics.go

@@ -20,6 +20,57 @@ var (
 	statusCounter = prometheus.NotificationsNamespace.NewLabeledCounter("status", "The number of status code", "code", "endpoint")
 )
 
+// endpoints is global registry of endpoints used to report metrics to expvar
+var endpoints struct {
+	registered []*Endpoint
+	mu         sync.Mutex
+}
+
+func init() {
+	// NOTE(stevvooe): Setup registry metrics structure to report to expvar.
+	// Ideally, we do more metrics through logging but we need some nice
+	// realtime metrics for queue state for now.
+
+	registry := expvar.Get("registry")
+
+	if registry == nil {
+		registry = expvar.NewMap("registry")
+	}
+
+	var notifications expvar.Map
+	notifications.Init()
+	notifications.Set("endpoints", expvar.Func(func() interface{} {
+		endpoints.mu.Lock()
+		defer endpoints.mu.Unlock()
+
+		var names []interface{}
+		for _, v := range endpoints.registered {
+			var epjson struct {
+				Name string `json:"name"`
+				URL  string `json:"url"`
+				EndpointConfig
+
+				Metrics EndpointMetrics
+			}
+
+			epjson.Name = v.Name()
+			epjson.URL = v.URL()
+			epjson.EndpointConfig = v.EndpointConfig
+
+			v.ReadMetrics(&epjson.Metrics)
+
+			names = append(names, epjson)
+		}
+
+		return names
+	}))
+
+	registry.(*expvar.Map).Set("notifications", &notifications)
+
+	// register prometheus metrics
+	metrics.Register(prometheus.NotificationsNamespace)
+}
+
 // EndpointMetrics track various actions taken by the endpoint, typically by
 // number of events. The goal of this to export it via expvar but we may find
 // some other future solution to be better.
@@ -123,12 +174,6 @@ func (eqc *endpointMetricsEventQueueListener) egress(event events.Event) {
 	pendingGauge.WithValues(eqc.EndpointName).Dec(1)
 }
 
-// endpoints is global registry of endpoints used to report metrics to expvar
-var endpoints struct {
-	registered []*Endpoint
-	mu         sync.Mutex
-}
-
 // register places the endpoint into expvar so that stats are tracked.
 func register(e *Endpoint) {
 	endpoints.mu.Lock()
@@ -136,48 +181,3 @@ func register(e *Endpoint) {
 
 	endpoints.registered = append(endpoints.registered, e)
 }
-
-func init() {
-	// NOTE(stevvooe): Setup registry metrics structure to report to expvar.
-	// Ideally, we do more metrics through logging but we need some nice
-	// realtime metrics for queue state for now.
-
-	registry := expvar.Get("registry")
-
-	if registry == nil {
-		registry = expvar.NewMap("registry")
-	}
-
-	var notifications expvar.Map
-	notifications.Init()
-	notifications.Set("endpoints", expvar.Func(func() interface{} {
-		endpoints.mu.Lock()
-		defer endpoints.mu.Unlock()
-
-		var names []interface{}
-		for _, v := range endpoints.registered {
-			var epjson struct {
-				Name string `json:"name"`
-				URL  string `json:"url"`
-				EndpointConfig
-
-				Metrics EndpointMetrics
-			}
-
-			epjson.Name = v.Name()
-			epjson.URL = v.URL()
-			epjson.EndpointConfig = v.EndpointConfig
-
-			v.ReadMetrics(&epjson.Metrics)
-
-			names = append(names, epjson)
-		}
-
-		return names
-	}))
-
-	registry.(*expvar.Map).Set("notifications", &notifications)
-
-	// register prometheus metrics
-	metrics.Register(prometheus.NotificationsNamespace)
-}

registry/api/v2/descriptors.go

@@ -9,6 +9,16 @@ import (
 	"github.com/opencontainers/go-digest"
 )
 
+var routeDescriptorsMap map[string]RouteDescriptor
+
+func init() {
+	routeDescriptorsMap = make(map[string]RouteDescriptor, len(routeDescriptors))
+
+	for _, descriptor := range routeDescriptors {
+		routeDescriptorsMap[descriptor.Name] = descriptor
+	}
+}
+
 var (
 	nameParameterDescriptor = ParameterDescriptor{
 		Name:        "name",
@@ -1600,13 +1610,3 @@ var routeDescriptors = []RouteDescriptor{
 		},
 	},
 }
-
-var routeDescriptorsMap map[string]RouteDescriptor
-
-func init() {
-	routeDescriptorsMap = make(map[string]RouteDescriptor, len(routeDescriptors))
-
-	for _, descriptor := range routeDescriptors {
-		routeDescriptorsMap[descriptor.Name] = descriptor
-	}
-}

registry/auth/auth.go

@@ -45,6 +45,16 @@ var (
 	ErrAuthenticationFailure = errors.New("authentication failure")
 )
 
+// InitFunc is the type of an AccessController factory function and is used
+// to register the constructor for different AccesController backends.
+type InitFunc func(options map[string]interface{}) (AccessController, error)
+
+var accessControllers map[string]InitFunc
+
+func init() {
+	accessControllers = make(map[string]InitFunc)
+}
+
 // UserInfo carries information about
 // an autenticated/authorized client.
 type UserInfo struct {
@@ -104,16 +114,6 @@ type CredentialAuthenticator interface {
 	AuthenticateUser(username, password string) error
 }
 
-// InitFunc is the type of an AccessController factory function and is used
-// to register the constructor for different AccesController backends.
-type InitFunc func(options map[string]interface{}) (AccessController, error)
-
-var accessControllers map[string]InitFunc
-
-func init() {
-	accessControllers = make(map[string]InitFunc)
-}
-
 // Register is used to register an InitFunc for
 // an AccessController backend with the given name.
 func Register(name string, initFunc InitFunc) error {

registry/auth/htpasswd/access.go

@@ -23,6 +23,12 @@ import (
 	"github.com/sirupsen/logrus"
 )
 
+func init() {
+	if err := auth.Register("htpasswd", auth.InitFunc(newAccessController)); err != nil {
+		logrus.Errorf("failed to register htpasswd auth: %v", err)
+	}
+}
+
 type accessController struct {
 	realm    string
 	path     string
@@ -150,9 +156,3 @@ func createHtpasswdFile(path string) error {
 	}).Warnf("htpasswd is missing, provisioning with default user")
 	return nil
 }
-
-func init() {
-	if err := auth.Register("htpasswd", auth.InitFunc(newAccessController)); err != nil {
-		logrus.Errorf("failed to register htpasswd auth: %v", err)
-	}
-}

registry/auth/silly/access.go

@@ -16,6 +16,13 @@ import (
 	"github.com/sirupsen/logrus"
 )
 
+// init registers the silly auth backend.
+func init() {
+	if err := auth.Register("silly", auth.InitFunc(newAccessController)); err != nil {
+		logrus.Errorf("failed to register silly auth: %v", err)
+	}
+}
+
 // accessController provides a simple implementation of auth.AccessController
 // that simply checks for a non-empty Authorization header. It is useful for
 // demonstration and testing.
@@ -85,10 +92,3 @@ func (ch challenge) SetHeaders(r *http.Request, w http.ResponseWriter) {
 func (ch challenge) Error() string {
 	return fmt.Sprintf("silly authentication challenge: %#v", ch)
 }
-
-// init registers the silly auth backend.
-func init() {
-	if err := auth.Register("silly", auth.InitFunc(newAccessController)); err != nil {
-		logrus.Errorf("failed to register silly auth: %v", err)
-	}
-}

registry/auth/token/accesscontroller.go

@@ -17,6 +17,13 @@ import (
 	"github.com/sirupsen/logrus"
 )
 
+// init handles registering the token auth backend.
+func init() {
+	if err := auth.Register("token", auth.InitFunc(newAccessController)); err != nil {
+		logrus.Errorf("tailed to register token auth: %v", err)
+	}
+}
+
 // accessSet maps a typed, named resource to
 // a set of actions requested or authorized.
 type accessSet map[auth.Resource]actionSet
@@ -337,10 +344,3 @@ func (ac *accessController) Authorized(req *http.Request, accessItems ...auth.Ac
 		Resources: claims.resources(),
 	}, nil
 }
-
-// init handles registering the token auth backend.
-func init() {
-	if err := auth.Register("token", auth.InitFunc(newAccessController)); err != nil {
-		logrus.Errorf("tailed to register token auth: %v", err)
-	}
-}

registry/proxy/proxyblobstore_test.go

@@ -20,14 +20,20 @@ import (
 	"github.com/opencontainers/go-digest"
 )
 
-var sbsMu sync.Mutex
-var randSource rand.Rand
+var (
+	sbsMu      sync.Mutex
+	randSource rand.Rand
+)
 
 type statsBlobStore struct {
 	stats map[string]int
 	blobs distribution.BlobStore
 }
 
+func init() {
+	randSource = *rand.New(rand.NewSource(42))
+}
+
 func (sbs statsBlobStore) Put(ctx context.Context, mediaType string, p []byte) (distribution.Descriptor, error) {
 	sbsMu.Lock()
 	sbs.stats["put"]++
@@ -195,10 +201,6 @@ func makeBlob(size int) []byte {
 	return blob
 }
 
-func init() {
-	randSource = *rand.New(rand.NewSource(42))
-}
-
 func populate(t *testing.T, te *testEnv, blobCount, size, numUnique int) {
 	var inRemote []distribution.Descriptor
 

registry/proxy/proxymetrics.go

@@ -36,6 +36,34 @@ type proxyMetricsCollector struct {
 	manifestMetrics Metrics
 }
 
+// proxyMetrics tracks metrics about the proxy cache.  This is
+// kept globally and made available via expvar.
+var proxyMetrics = &proxyMetricsCollector{}
+
+func init() {
+	registry := expvar.Get("registry")
+	if registry == nil {
+		registry = expvar.NewMap("registry")
+	}
+
+	pm := registry.(*expvar.Map).Get("proxy")
+	if pm == nil {
+		pm = &expvar.Map{}
+		pm.(*expvar.Map).Init()
+		registry.(*expvar.Map).Set("proxy", pm)
+	}
+
+	pm.(*expvar.Map).Set("blobs", expvar.Func(func() interface{} {
+		return proxyMetrics.blobMetrics
+	}))
+
+	pm.(*expvar.Map).Set("manifests", expvar.Func(func() interface{} {
+		return proxyMetrics.manifestMetrics
+	}))
+
+	metrics.Register(prometheus.ProxyNamespace)
+}
+
 // BlobPull tracks metrics about blobs pulled into the cache
 func (pmc *proxyMetricsCollector) BlobPull(bytesPulled uint64) {
 	atomic.AddUint64(&pmc.blobMetrics.Misses, 1)
@@ -83,31 +111,3 @@ func (pmc *proxyMetricsCollector) ManifestPush(bytesPushed uint64, isHit bool) {
 		hits.WithValues("manifest").Inc(1)
 	}
 }
-
-// proxyMetrics tracks metrics about the proxy cache.  This is
-// kept globally and made available via expvar.
-var proxyMetrics = &proxyMetricsCollector{}
-
-func init() {
-	registry := expvar.Get("registry")
-	if registry == nil {
-		registry = expvar.NewMap("registry")
-	}
-
-	pm := registry.(*expvar.Map).Get("proxy")
-	if pm == nil {
-		pm = &expvar.Map{}
-		pm.(*expvar.Map).Init()
-		registry.(*expvar.Map).Set("proxy", pm)
-	}
-
-	pm.(*expvar.Map).Set("blobs", expvar.Func(func() interface{} {
-		return proxyMetrics.blobMetrics
-	}))
-
-	pm.(*expvar.Map).Set("manifests", expvar.Func(func() interface{} {
-		return proxyMetrics.manifestMetrics
-	}))
-
-	metrics.Register(prometheus.ProxyNamespace)
-}

registry/storage/driver/middleware/cloudfront/middleware.go

@@ -20,6 +20,13 @@ import (
 	"github.com/sirupsen/logrus"
 )
 
+// init registers the cloudfront layerHandler backend.
+func init() {
+	if err := storagemiddleware.Register("cloudfront", newCloudFrontStorageMiddleware); err != nil {
+		logrus.Errorf("failed to register cloudfront middleware: %v", err)
+	}
+}
+
 // cloudFrontStorageMiddleware provides a simple implementation of layerHandler that
 // constructs temporary signed CloudFront URLs from the storagedriver layer URL,
 // then issues HTTP Temporary Redirects to this CloudFront content URL.
@@ -224,10 +231,3 @@ func (lh *cloudFrontStorageMiddleware) RedirectURL(r *http.Request, path string)
 	}
 	return cfURL, nil
 }
-
-// init registers the cloudfront layerHandler backend.
-func init() {
-	if err := storagemiddleware.Register("cloudfront", newCloudFrontStorageMiddleware); err != nil {
-		logrus.Errorf("failed to register cloudfront middleware: %v", err)
-	}
-}

registry/storage/driver/middleware/redirect/middleware.go

@@ -12,6 +12,12 @@ import (
 	"github.com/sirupsen/logrus"
 )
 
+func init() {
+	if err := storagemiddleware.Register("redirect", newRedirectStorageMiddleware); err != nil {
+		logrus.Errorf("tailed to register redirect storage middleware: %v", err)
+	}
+}
+
 type redirectStorageMiddleware struct {
 	storagedriver.StorageDriver
 	scheme   string
@@ -51,9 +57,3 @@ func (r *redirectStorageMiddleware) RedirectURL(_ *http.Request, urlPath string)
 	u := &url.URL{Scheme: r.scheme, Host: r.host, Path: urlPath}
 	return u.String(), nil
 }
-
-func init() {
-	if err := storagemiddleware.Register("redirect", newRedirectStorageMiddleware); err != nil {
-		logrus.Errorf("tailed to register redirect storage middleware: %v", err)
-	}
-}

registry/storage/driver/testsuites/testsuites.go

@@ -24,6 +24,14 @@ import (
 // Test hooks up gocheck into the "go test" runner.
 func Test(t *testing.T) { check.TestingT(t) }
 
+// randomBytes pre-allocates all of the memory sizes needed for the test. If
+// anything panics while accessing randomBytes, just make this number bigger.
+var randomBytes = make([]byte, 128<<20)
+
+func init() {
+	_, _ = crand.Read(randomBytes) // always returns len(randomBytes) and nil error
+}
+
 // RegisterSuite registers an in-process storage driver test suite with
 // the go test runner.
 func RegisterSuite(driverConstructor DriverConstructor, skipCheck SkipCheck) {
@@ -1343,14 +1351,6 @@ func randomFilename(length int64) string {
 	return string(b)
 }
 
-// randomBytes pre-allocates all of the memory sizes needed for the test. If
-// anything panics while accessing randomBytes, just make this number bigger.
-var randomBytes = make([]byte, 128<<20)
-
-func init() {
-	_, _ = crand.Read(randomBytes) // always returns len(randomBytes) and nil error
-}
-
 func randomContents(length int64) []byte {
 	return randomBytes[:length]
 }