Add kong2tf command (#1391)

* feat: Add new command for Kong to Terraform conversion

* Granular testing

* fix plugin route reference

* feat(kong2tf): PROTOTYPE kong2tf with import blocks and lifecycle-ignore blocks, plus appropriate switches; patches "route ID is read only field" bug

* Replace templated kong2tf with recursive implementation

* fix: linting issues

---------

Co-authored-by: battlebyte <[email protected]>
Co-authored-by: Jack Tysoe <[email protected]>
Co-authored-by: Prashansa Kulshrestha <[email protected]>

.gitignore

@@ -38,3 +38,5 @@ docs/cli-docs/
 
 # generated test 'actuals'
 kong2kic/testdata/**/*-actual.*
+kong2tf/testdata/**/*-actual.*
+kong2tf/terraform

cmd/file_kong2tf.go

@@ -0,0 +1,95 @@
+package cmd
+
+import (
+	"fmt"
+	"log"
+
+	"github.com/kong/deck/kong2tf"
+	"github.com/kong/go-apiops/filebasics"
+	"github.com/kong/go-apiops/logbasics"
+	"github.com/kong/go-database-reconciler/pkg/file"
+	"github.com/spf13/cobra"
+)
+
+var (
+	cmdKong2TfInputFilename                    string
+	cmdKong2TfOutputFilename                   string
+	cmdKong2TfGenerateImportsForControlPlaneID string
+	cmdKong2TfIgnoreCredentialChanges          bool
+)
+
+// Executes the CLI command "kong2Tf"
+func executeKong2Tf(cmd *cobra.Command, _ []string) error {
+	_ = sendAnalytics("file-kong2Tf", "", modeLocal)
+	var (
+		result string
+		err    error
+	)
+
+	verbosity, _ := cmd.Flags().GetInt("verbose")
+	logbasics.Initialize(log.LstdFlags, verbosity)
+
+	logbasics.Info("Starting execution of executeKong2Tf")
+
+	inputContent, err := file.GetContentFromFiles([]string{cmdKong2TfInputFilename}, false)
+	if err != nil {
+		log.Printf("Error reading input file '%s'; %v", cmdKong2TfInputFilename, err)
+		return fmt.Errorf("failed reading input file '%s'; %w", cmdKong2TfInputFilename, err)
+	}
+	logbasics.Info("Successfully read input file '%s'", cmdKong2TfInputFilename)
+
+	logbasics.Info("Converting Kong configuration to Terraform")
+
+	var generateImportsForControlPlaneID *string
+	if cmdKong2TfGenerateImportsForControlPlaneID != "" {
+		generateImportsForControlPlaneID = &cmdKong2TfGenerateImportsForControlPlaneID
+	}
+	result, err = kong2tf.Convert(inputContent, generateImportsForControlPlaneID, cmdKong2TfIgnoreCredentialChanges)
+	if err != nil {
+		log.Printf("Error converting Kong configuration to Terraform; %v", err)
+		return fmt.Errorf("failed converting Kong configuration to Terraform; %w", err)
+	}
+	logbasics.Info("Successfully converted Kong configuration to Terraform")
+
+	logbasics.Info("Writing output to file '%s'", cmdKong2TfOutputFilename)
+	err = filebasics.WriteFile(cmdKong2TfOutputFilename, []byte(result))
+	if err != nil {
+		log.Printf("Error writing output to file '%s'; %v", cmdKong2TfOutputFilename, err)
+		return err
+	}
+	logbasics.Info("Successfully wrote output to file '%s'", cmdKong2TfOutputFilename)
+
+	logbasics.Info("Finished execution of executeKong2Tf")
+	return nil
+}
+
+//
+//
+// Define the CLI data for the kong2Tf command
+//
+//
+
+func newKong2TfCmd() *cobra.Command {
+	kong2TfCmd := &cobra.Command{
+		Use:   "kong2tf",
+		Short: "Convert Kong configuration files to Terraform resources",
+		Long: `Convert Kong configuration files to Terraform resources.
+		
+The kong2tf subcommand transforms Kong Gateway entities in deck format, 
+into Terraform resources.`,
+		RunE: executeKong2Tf,
+		Args: cobra.NoArgs,
+	}
+
+	kong2TfCmd.Flags().StringVarP(&cmdKong2TfInputFilename, "state", "s", "-",
+		"decK file to process. Use - to read from stdin.")
+	kong2TfCmd.Flags().StringVarP(&cmdKong2TfOutputFilename, "output-file", "o", "-",
+		"Output file to write. Use - to write to stdout.")
+	kong2TfCmd.Flags().StringVarP(&cmdKong2TfGenerateImportsForControlPlaneID,
+		"generate-imports-for-control-plane-id", "g", "", "Generate terraform import statements for the control plane ID.")
+	kong2TfCmd.Flags().BoolVar(&cmdKong2TfIgnoreCredentialChanges, "ignore-credential-changes", false,
+		"Enable flag to add a 'lifecycle' block to each consumer credential, "+
+			"that ignores any changes from local to remote state.")
+
+	return kong2TfCmd
+}

cmd/root.go

@@ -253,6 +253,7 @@ It can be used to export, import, or sync entities to Kong.`,
 		fileCmd.AddCommand(newConvertCmd(false))
 		fileCmd.AddCommand(newValidateCmd(false, false)) // file-based validation
 		fileCmd.AddCommand(newKong2KicCmd())
+		fileCmd.AddCommand(newKong2TfCmd())
 	}
 	return rootCmd
 }

go.mod

@@ -102,6 +102,7 @@ require (
 	github.com/mattn/go-colorable v0.1.13 // indirect
 	github.com/mattn/go-isatty v0.0.20 // indirect
 	github.com/mattn/go-runewidth v0.0.15 // indirect
+	github.com/mitchellh/hashstructure v1.1.0
 	github.com/mitchellh/mapstructure v1.5.0 // indirect
 	github.com/modern-go/concurrent v0.0.0-20180306012644-bacd9c7ef1dd // indirect
 	github.com/modern-go/reflect2 v1.0.2 // indirect

go.sum

@@ -218,6 +218,8 @@ github.com/mattn/go-runewidth v0.0.15 h1:UNAjwbU9l54TA3KzvqLGxwWjHmMgBUVhBiTjelZ
 github.com/mattn/go-runewidth v0.0.15/go.mod h1:Jdepj2loyihRzMpdS35Xk/zdY8IAYHsh153qUoGf23w=
 github.com/mitchellh/go-homedir v1.1.0 h1:lukF9ziXFxDFPkA1vsr5zpc1XuPDn/wFntq5mG+4E0Y=
 github.com/mitchellh/go-homedir v1.1.0/go.mod h1:SfyaCUpYCn1Vlf4IUYiD9fPX4A5wJrkLzIz1N1q0pr0=
+github.com/mitchellh/hashstructure v1.1.0 h1:P6P1hdjqAAknpY/M1CGipelZgp+4y9ja9kmUZPXP+H0=
+github.com/mitchellh/hashstructure v1.1.0/go.mod h1:xUDAozZz0Wmdiufv0uyhnHkUTN6/6d8ulp4AwfLKrmA=
 github.com/mitchellh/mapstructure v1.5.0 h1:jeMsZIYE/09sWLaz43PL7Gy6RuMjD2eJVyuac5Z2hdY=
 github.com/mitchellh/mapstructure v1.5.0/go.mod h1:bFUtVrKA4DC2yAKiSyO/QUcy7e+RRV2QTWOzhPopBRo=
 github.com/modern-go/concurrent v0.0.0-20180228061459-e0a39a4cb421/go.mod h1:6dJC0mAP4ikYIbvyc7fijjWJddQyLn8Ig3JB5CqoB9Q=

kong2tf/builder.go

@@ -0,0 +1,51 @@
+package kong2tf
+
+import (
+	"github.com/kong/go-database-reconciler/pkg/file"
+)
+
+type ITerraformBuilder interface {
+	buildControlPlaneVar(*string)
+	buildServices(*file.Content, *string)
+	buildRoutes(*file.Content, *string)
+	buildGlobalPlugins(*file.Content, *string)
+	buildConsumers(*file.Content, *string, bool)
+	buildConsumerGroups(*file.Content, *string)
+	buildUpstreams(*file.Content, *string)
+	buildCACertificates(*file.Content, *string)
+	buildCertificates(*file.Content, *string)
+	buildVaults(*file.Content, *string)
+	getContent() string
+}
+
+func getTerraformBuilder() ITerraformBuilder {
+	return newDefaultTerraformBuilder()
+}
+
+type Director struct {
+	builder ITerraformBuilder
+}
+
+func newDirector(builder ITerraformBuilder) *Director {
+	return &Director{
+		builder: builder,
+	}
+}
+
+func (d *Director) builTerraformResources(
+	content *file.Content,
+	generateImportsForControlPlaneID *string,
+	ignoreCredentialChanges bool,
+) string {
+	d.builder.buildControlPlaneVar(generateImportsForControlPlaneID)
+	d.builder.buildGlobalPlugins(content, generateImportsForControlPlaneID)
+	d.builder.buildServices(content, generateImportsForControlPlaneID)
+	d.builder.buildUpstreams(content, generateImportsForControlPlaneID)
+	d.builder.buildRoutes(content, generateImportsForControlPlaneID)
+	d.builder.buildConsumers(content, generateImportsForControlPlaneID, ignoreCredentialChanges)
+	d.builder.buildConsumerGroups(content, generateImportsForControlPlaneID)
+	d.builder.buildCACertificates(content, generateImportsForControlPlaneID)
+	d.builder.buildCertificates(content, generateImportsForControlPlaneID)
+	d.builder.buildVaults(content, generateImportsForControlPlaneID)
+	return d.builder.getContent()
+}