Create Repositories method

This change removes the Catalog Service and replaces it with a more
simplistic Repositories() method for obtaining a catalog of all
repositories.  The Repositories method takes a pre-allocated slice
and fills it up to the size of the slice and returns the amount
filled.  The catalog is returned lexicographically and will start
being filled from the last entry passed to Repositories().  If there
are no more entries to fill, io.EOF will be returned.

Signed-off-by: Patrick Devine <patrick.devine@docker.com>

Conflicts:
	registry/client/repository.go
	registry/handlers/api_test.go

docs/handlers/api_test.go

@@ -13,6 +13,8 @@ import (
 	"os"
 	"path"
 	"reflect"
+	"regexp"
+	"strconv"
 	"strings"
 	"testing"
 
@@ -60,10 +62,14 @@ func TestCheckAPI(t *testing.T) {
 	}
 }
 
+// TestCatalogAPI tests the /v2/_catalog endpoint
 func TestCatalogAPI(t *testing.T) {
+	chunkLen := 2
 	env := newTestEnv(t)
 
-	values := url.Values{"last": []string{""}, "n": []string{"100"}}
+	values := url.Values{
+		"last": []string{""},
+		"n":    []string{strconv.Itoa(chunkLen)}}
 
 	catalogURL, err := env.builder.BuildCatalogURL(values)
 	if err != nil {
@@ -90,7 +96,7 @@ func TestCatalogAPI(t *testing.T) {
 	}
 
 	// we haven't pushed anything to the registry yet
-	if ctlg.Repositories != nil {
+	if len(ctlg.Repositories) != 0 {
 		t.Fatalf("repositories has unexpected values")
 	}
 
@@ -100,8 +106,49 @@ func TestCatalogAPI(t *testing.T) {
 
 	// -----------------------------------
 	// push something to the registry and try again
-	imageName := "foo/bar"
-	createRepository(env, t, imageName, "sometag")
+	images := []string{"foo/aaaa", "foo/bbbb", "foo/cccc"}
+
+	for _, image := range images {
+		createRepository(env, t, image, "sometag")
+	}
+
+	resp, err = http.Get(catalogURL)
+	if err != nil {
+		t.Fatalf("unexpected error issuing request: %v", err)
+	}
+	defer resp.Body.Close()
+
+	checkResponse(t, "issuing catalog api check", resp, http.StatusOK)
+
+	dec = json.NewDecoder(resp.Body)
+	if err = dec.Decode(&ctlg); err != nil {
+		t.Fatalf("error decoding fetched manifest: %v", err)
+	}
+
+	if len(ctlg.Repositories) != chunkLen {
+		t.Fatalf("repositories has unexpected values")
+	}
+
+	for _, image := range images[:chunkLen] {
+		if !contains(ctlg.Repositories, image) {
+			t.Fatalf("didn't find our repository '%s' in the catalog", image)
+		}
+	}
+
+	link := resp.Header.Get("Link")
+	if link == "" {
+		t.Fatalf("repositories has less data than expected")
+	}
+
+	newValues := checkLink(t, link, chunkLen, ctlg.Repositories[len(ctlg.Repositories)-1])
+
+	// -----------------------------------
+	// get the last chunk of data
+
+	catalogURL, err = env.builder.BuildCatalogURL(newValues)
+	if err != nil {
+		t.Fatalf("unexpected error building catalog url: %v", err)
+	}
 
 	resp, err = http.Get(catalogURL)
 	if err != nil {
@@ -120,14 +167,36 @@ func TestCatalogAPI(t *testing.T) {
 		t.Fatalf("repositories has unexpected values")
 	}
 
-	if !contains(ctlg.Repositories, imageName) {
-		t.Fatalf("didn't find our repository '%s' in the catalog", imageName)
+	lastImage := images[len(images)-1]
+	if !contains(ctlg.Repositories, lastImage) {
+		t.Fatalf("didn't find our repository '%s' in the catalog", lastImage)
 	}
 
-	if resp.Header.Get("Link") != "" {
-		t.Fatalf("repositories has more data when none expected")
+	link = resp.Header.Get("Link")
+	if link != "" {
+		t.Fatalf("catalog has unexpected data")
+	}
+}
+
+func checkLink(t *testing.T, urlStr string, numEntries int, last string) url.Values {
+	re := regexp.MustCompile("<(/v2/_catalog.*)>; rel=\"next\"")
+	matches := re.FindStringSubmatch(urlStr)
+
+	if len(matches) != 2 {
+		t.Fatalf("Catalog link address response was incorrect")
+	}
+	linkURL, _ := url.Parse(matches[1])
+	urlValues := linkURL.Query()
+
+	if urlValues.Get("n") != strconv.Itoa(numEntries) {
+		t.Fatalf("Catalog link entry size is incorrect")
 	}
 
+	if urlValues.Get("last") != last {
+		t.Fatal("Catalog link last entry is incorrect")
+	}
+
+	return urlValues
 }
 
 func contains(elems []string, e string) bool {