increase test coverage and fix some minor bugs

pkg/registry/manifest/manifest.go

@@ -11,12 +11,9 @@ import (
 
 // BuildManifestURL from raw image data
 func BuildManifestURL(image apiTypes.ImageInspect) (string, error) {
-	parts := strings.Split(image.RepoTags[0], ":")
-	img := parts[0]
-	tag := parts[1]
+	img, tag := extractImageAndTag(image)
 
 	hostName, err := ref.ParseNormalizedNamed(img)
-	fmt.Println(hostName)
 	if err != nil {
 		return "", err
 	}
@@ -25,7 +22,7 @@ func BuildManifestURL(image apiTypes.ImageInspect) (string, error) {
 	if err != nil {
 		return "", err
 	}
-	img = strings.TrimPrefix(img, host)
+	img = strings.TrimPrefix(img, fmt.Sprintf("%s/", host))
 	url := url2.URL{
 		Scheme: "https",
 		Host:   host,
@@ -33,3 +30,17 @@ func BuildManifestURL(image apiTypes.ImageInspect) (string, error) {
 	}
 	return url.String(), nil
 }
+
+func extractImageAndTag(image apiTypes.ImageInspect) (string, string) {
+	var img string
+	var tag string
+	if strings.Contains(image.RepoTags[0], ":") {
+		parts := strings.Split(image.RepoTags[0], ":")
+		img = parts[0]
+		tag = parts[1]
+	} else {
+		img = image.RepoTags[0]
+		tag = "latest"
+	}
+	return img, tag
+}

pkg/registry/manifest/manifest_test.go

@@ -0,0 +1,57 @@
+package manifest_test
+
+import (
+	"github.com/containrrr/watchtower/pkg/registry/manifest"
+	apiTypes "github.com/docker/docker/api/types"
+	. "github.com/onsi/ginkgo"
+	. "github.com/onsi/gomega"
+	"testing"
+)
+
+func TestManifest(t *testing.T) {
+	RegisterFailHandler(Fail)
+	RunSpecs(t, "Manifest Suite")
+}
+
+var _ = Describe("the manifest module", func() {
+
+	When("building a manifest url", func() {
+		It("should return a valid url given a fully qualified image", func() {
+			expected := "https://ghcr.io/v2/containrrr/watchtower/manifests/latest"
+			imageInfo := apiTypes.ImageInspect{
+				RepoTags: []string {
+					"ghcr.io/containrrr/watchtower:latest",
+				},
+			}
+
+			res, err := manifest.BuildManifestURL(imageInfo)
+			Expect(err).NotTo(HaveOccurred())
+			Expect(res).To(Equal(expected))
+		})
+		It("should assume dockerhub for non-qualified images", func() {
+			expected := "https://index.docker.io/v2/containrrr/watchtower/manifests/latest"
+			imageInfo := apiTypes.ImageInspect{
+				RepoTags: []string {
+					"containrrr/watchtower:latest",
+				},
+			}
+
+			res, err := manifest.BuildManifestURL(imageInfo)
+			Expect(err).NotTo(HaveOccurred())
+			Expect(res).To(Equal(expected))
+		})
+		It("should assume latest for images that lack an explicit tag", func() {
+			expected := "https://index.docker.io/v2/containrrr/watchtower/manifests/latest"
+			imageInfo := apiTypes.ImageInspect{
+				RepoTags: []string {
+					"containrrr/watchtower",
+				},
+			}
+
+			res, err := manifest.BuildManifestURL(imageInfo)
+			Expect(err).NotTo(HaveOccurred())
+			Expect(res).To(Equal(expected))
+		})
+	})
+
+})