feat: add capability to convert from 2.x to 3.x format

cmd/convert.go

@@ -54,8 +54,8 @@ can be converted into a 'konnect' configuration file.`,
 		},
 	}
 
-	sourceFormats := []convert.Format{convert.FormatKongGateway}
-	destinationFormats := []convert.Format{convert.FormatKonnect}
+	sourceFormats := []convert.Format{convert.FormatKongGateway, convert.FormatKongGateway2x}
+	destinationFormats := []convert.Format{convert.FormatKonnect, convert.FormatKongGateway3x}
 	convertCmd.Flags().StringVar(&convertCmdSourceFormat, "from", "",
 		fmt.Sprintf("format of the source file, allowed formats: %v", sourceFormats))
 	convertCmd.Flags().StringVar(&convertCmdDestinationFormat, "to", "",

convert/convert.go

@@ -4,6 +4,7 @@ import (
 	"fmt"
 	"strings"
 
+	"github.com/kong/deck/cprint"
 	"github.com/kong/deck/file"
 	"github.com/kong/deck/utils"
 	"github.com/kong/go-kong/kong"
@@ -16,6 +17,10 @@ const (
 	FormatKongGateway Format = "kong-gateway"
 	// FormatKonnect represents the Konnect format.
 	FormatKonnect Format = "konnect"
+	// FormatKongGateway2x represents the Kong gateway 2.x format.
+	FormatKongGateway2x Format = "kong-gateway-2.x"
+	// FormatKongGateway3x represents the Kong gateway 3.x format.
+	FormatKongGateway3x Format = "kong-gateway-3.x"
 )
 
 // AllFormats contains all available formats.
@@ -28,6 +33,10 @@ func ParseFormat(key string) (Format, error) {
 		return FormatKongGateway, nil
 	case FormatKonnect:
 		return FormatKonnect, nil
+	case FormatKongGateway2x:
+		return FormatKongGateway2x, nil
+	case FormatKongGateway3x:
+		return FormatKongGateway3x, nil
 	default:
 		return "", fmt.Errorf("invalid format: '%v'", key)
 	}
@@ -50,6 +59,11 @@ func Convert(inputFilename, outputFilename string, from, to Format) error {
 		if err != nil {
 			return err
 		}
+	case from == FormatKongGateway2x && to == FormatKongGateway3x:
+		outputContent, err = convertKongGateway2xTo3x(inputContent)
+		if err != nil {
+			return err
+		}
 	default:
 		return fmt.Errorf("cannot convert from '%s' to '%s' format", from, to)
 	}
@@ -61,6 +75,50 @@ func Convert(inputFilename, outputFilename string, from, to Format) error {
 	return nil
 }
 
+func convertKongGateway2xTo3x(input *file.Content) (*file.Content, error) {
+	if input == nil {
+		return nil, fmt.Errorf("input content is nil")
+	}
+	outputContent := input.DeepCopy()
+
+	convertedRoutes := []*file.FRoute{}
+	for _, service := range outputContent.Services {
+		for _, route := range service.Routes {
+			convertedRoutes = append(convertedRoutes, migrateRoutesPathFieldPre300(route))
+		}
+		service.Routes = convertedRoutes
+	}
+
+	cprint.UpdatePrintf(
+		"From the config file, the _format_version field has been migrated from '%s' to '%s'.\n"+
+			"These automatic changes may not be fully correct or exhaustive, so please\n"+
+			"take the time to perform a manual audit of the config file.\n\n"+
+			"For related information, please visit: https://docs.konghq.com/gateway/latest/\n",
+		outputContent.FormatVersion, "3.0")
+	outputContent.FormatVersion = "3.0"
+	return outputContent, nil
+}
+
+func migrateRoutesPathFieldPre300(route *file.FRoute) *file.FRoute {
+	changedPaths := []string{}
+	for _, path := range route.Paths {
+		if !strings.HasPrefix(*path, "~/") && utils.IsPathRegexLike(*path) {
+			changedPaths = append(changedPaths, *path)
+			*path = "~" + *path
+		}
+	}
+	if len(changedPaths) > 0 {
+		cprint.UpdatePrintf(
+			"From the config file, for the route '%s', a regex pattern usage was detected\n"+
+				"for the '%s' paths in the 'paths' field.\n"+
+				"Kong gateway versions 3.0 and above require that regular expressions\n"+
+				"start with a '~' character to distinguish from simple prefix match.\n"+
+				"In order to make these paths compatible with 3.x, a '~' prefix has been added.\n\n",
+			*route.Name, strings.Join(changedPaths, ", "))
+	}
+	return route
+}
+
 func convertKongGatewayToKonnect(input *file.Content) (*file.Content, error) {
 	if input == nil {
 		return nil, fmt.Errorf("input content is nil")

convert/convert_test.go

@@ -28,6 +28,22 @@ func TestParseFormat(t *testing.T) {
 			want:    FormatKongGateway,
 			wantErr: false,
 		},
+		{
+			name: "parses valid values",
+			args: args{
+				key: "kong-gateway-2.x",
+			},
+			want:    FormatKongGateway2x,
+			wantErr: false,
+		},
+		{
+			name: "parses valid values",
+			args: args{
+				key: "kong-gateway-3.x",
+			},
+			want:    FormatKongGateway3x,
+			wantErr: false,
+		},
 		{
 			name: "parses values in a case-insensitive manner",
 			args: args{
@@ -161,6 +177,15 @@ func Test_Convert(t *testing.T) {
 			},
 			wantErr: true,
 		},
+		{
+			name: "errors out due to invalid conversion",
+			args: args{
+				inputFilename: "testdata/3/input.yaml",
+				fromFormat:    FormatKongGateway3x,
+				toFormat:      FormatKongGateway2x,
+			},
+			wantErr: true,
+		},
 		{
 			name: "errors out when a nameless service is present in the input",
 			args: args{
@@ -190,6 +215,28 @@ func Test_Convert(t *testing.T) {
 			},
 			wantErr: false,
 		},
+		{
+			name: "converts from Kong Gateway 2.x to Kong Gateway 3.x format",
+			args: args{
+				inputFilename:          "testdata/3/input.yaml",
+				outputFilename:         "testdata/3/output.yaml",
+				expectedOutputFilename: "testdata/3/output-expected.yaml",
+				fromFormat:             FormatKongGateway2x,
+				toFormat:               FormatKongGateway3x,
+			},
+			wantErr: false,
+		},
+		{
+			name: "converts from Kong Gateway 2.x to Kong Gateway 3.x format (no _format_version input)",
+			args: args{
+				inputFilename:          "testdata/4/input.yaml",
+				outputFilename:         "testdata/4/output.yaml",
+				expectedOutputFilename: "testdata/4/output-expected.yaml",
+				fromFormat:             FormatKongGateway2x,
+				toFormat:               FormatKongGateway3x,
+			},
+			wantErr: false,
+		},
 	}
 	for _, tt := range tests {
 		t.Run(tt.name, func(t *testing.T) {

convert/testdata/3/input.yaml

@@ -0,0 +1,9 @@
+services:
+- name: svc1
+  host: mockbin.org
+  path: /status/200
+  routes:
+  - name: r1
+    paths:
+    - /status/\d+
+    - /code/\d+

convert/testdata/3/output-expected.yaml

@@ -0,0 +1,10 @@
+_format_version: "3.0"
+services:
+- name: svc1
+  host: mockbin.org
+  path: /status/200
+  routes:
+  - name: r1
+    paths:
+    - ~/status/\d+
+    - ~/code/\d+

convert/testdata/3/output.yaml

@@ -0,0 +1,10 @@
+_format_version: "3.0"
+services:
+- host: mockbin.org
+  name: svc1
+  path: /status/200
+  routes:
+  - name: r1
+    paths:
+    - ~/status/\d+
+    - ~/code/\d+

convert/testdata/4/input.yaml

@@ -0,0 +1,10 @@
+_format_version: "1.1"
+services:
+- name: svc1
+  host: mockbin.org
+  path: /status/200
+  routes:
+  - name: r1
+    paths:
+    - /status/\d+
+    - /code/\d+

convert/testdata/4/output-expected.yaml

@@ -0,0 +1,10 @@
+_format_version: "3.0"
+services:
+- name: svc1
+  host: mockbin.org
+  path: /status/200
+  routes:
+  - name: r1
+    paths:
+    - ~/status/\d+
+    - ~/code/\d+

convert/testdata/4/output.yaml

@@ -0,0 +1,10 @@
+_format_version: "3.0"
+services:
+- host: mockbin.org
+  name: svc1
+  path: /status/200
+  routes:
+  - name: r1
+    paths:
+    - ~/status/\d+
+    - ~/code/\d+