feat: shorten generated container name (#1220)

Co-authored-by: taskbot <taskbot@users.noreply.github.com>
Co-authored-by: Copilot <175728472+Copilot@users.noreply.github.com>

Author: 3 people

pkg/container/name.go

@@ -27,21 +27,44 @@ func GetOrGenerateContainerName(containerName, image string) (string, string) {
 
 // generateContainerBaseName generates a base name for a container from the image name
 func generateContainerBaseName(image string) string {
-	// Extract the base name from the image, preserving registry namespaces
-	// Examples:
-	// - "nginx:latest" -> "nginx"
-	// - "docker.io/library/nginx:latest" -> "docker.io-library-nginx"
-	// - "quay.io/stacklok/mcp-server:v1" -> "quay.io-stacklok-mcp-server"
+	// Find last '/' and last ':' to distinguish port from tag
+	lastSlash := strings.LastIndex(image, "/")
+	lastColon := strings.LastIndex(image, ":")
 
-	// First, remove the tag part (everything after the colon)
-	imageWithoutTag := strings.Split(image, ":")[0]
+	imageWithoutTag := image
+	if lastColon > lastSlash {
+		imageWithoutTag = image[:lastColon]
+	}
+
+	// Split by '/'
+	parts := strings.Split(imageWithoutTag, "/")
+	var registryOrNamespace, name string
+	switch len(parts) {
+	case 1:
+		name = parts[0]
+	case 2:
+		registryOrNamespace = parts[0]
+		name = parts[1]
+	default:
+		registryOrNamespace = parts[len(parts)-2]
+		name = parts[len(parts)-1]
+	}
+	// Strip the port from registryOrNamespace if it looks like host:port
+	if registryOrNamespace != "" && strings.Contains(registryOrNamespace, ":") {
+		registryOrNamespace = strings.SplitN(registryOrNamespace, ":", 2)[0]
+	}
 
-	// Replace slashes with dashes to preserve namespace structure
-	namespaceName := strings.ReplaceAll(imageWithoutTag, "/", "-")
+	// Construct the base name using the sanitized registryOrNamespace and name
+	var base string
+	if registryOrNamespace != "" {
+		base = registryOrNamespace + "-" + name
+	} else {
+		base = name
+	}
 
-	// Sanitize the name (allow alphanumeric, dashes)
+	// Sanitize: allow alphanumeric and dashes
 	var sanitizedName strings.Builder
-	for _, c := range namespaceName {
+	for _, c := range base {
 		if (c >= 'a' && c <= 'z') || (c >= 'A' && c <= 'Z') || (c >= '0' && c <= '9') || c == '-' {
 			sanitizedName.WriteRune(c)
 		} else {

pkg/container/name_test.go

@@ -0,0 +1,90 @@
+package container
+
+import (
+	"testing"
+
+	"github.com/stretchr/testify/assert"
+)
+
+func TestGenerateContainerBaseName(t *testing.T) {
+	t.Parallel()
+	tests := []struct {
+		name     string
+		image    string
+		expected string
+	}{
+		{
+			name:     "no namespace, with tag",
+			image:    "nginx:latest",
+			expected: "nginx",
+		},
+		{
+			name:     "namespace and image, with tag",
+			image:    "library/nginx:latest",
+			expected: "library-nginx",
+		},
+		{
+			name:     "registry, namespace, image, with tag",
+			image:    "docker.io/library/nginx:latest",
+			expected: "library-nginx",
+		},
+		{
+			name:     "deep registry, multiple namespaces, image, with tag",
+			image:    "quay.io/stacklok/mcp-server:v1",
+			expected: "stacklok-mcp-server",
+		},
+		{
+			name:     "simple image, no tag",
+			image:    "server",
+			expected: "server",
+		},
+		{
+			name:     "namespace, image, no tag",
+			image:    "stacklok/server",
+			expected: "stacklok-server",
+		},
+		{
+			name:     "multiple slashes, should pick last two",
+			image:    "a/b/c/d:foo",
+			expected: "c-d",
+		},
+		{
+			name:     "image with special characters",
+			image:    "foo/bar@sha256:abcdef",
+			expected: "foo-bar-sha256",
+		},
+		{
+			name:     "localhost registry with port",
+			image:    "localhost:5000/image:latest",
+			expected: "localhost-image",
+		},
+		{
+			name:     "very deep path",
+			image:    "x/y/z/w/foo:bar",
+			expected: "w-foo",
+		},
+		{
+			name:     "empty image name",
+			image:    "",
+			expected: "",
+		},
+		{
+			name:     "single slash (should treat as namespace-image)",
+			image:    "foo/bar",
+			expected: "foo-bar",
+		},
+		{
+			name:     "single image with special chars",
+			image:    "my$image:latest",
+			expected: "my-image",
+		},
+	}
+
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			t.Parallel()
+			got := generateContainerBaseName(tt.image)
+			assert.Equal(t, tt.expected, got, "generateContainerBaseName(%q)", tt.image)
+		})
+	}
+}