feat: add wasm tranformer sample for adding a K8s annotation

custom-wasm-transformers/samples/wasm-add-annotation/add-annotation/Makefile

@@ -0,0 +1,4 @@
+.PHONY: build
+build:
+	tinygo build -o maintiny.wasm -target=wasi main.go
+	wasm2wat maintiny.wasm > maintiny.wat

custom-wasm-transformers/samples/wasm-add-annotation/add-annotation/go.mod

@@ -0,0 +1,5 @@
+module mydomain.com/mypackage
+
+go 1.21.6
+
+require gopkg.in/yaml.v3 v3.0.1 // indirect

custom-wasm-transformers/samples/wasm-add-annotation/add-annotation/go.sum

@@ -0,0 +1,3 @@
+gopkg.in/check.v1 v0.0.0-20161208181325-20d25e280405/go.mod h1:Co6ibVJAznAaIkqp8huTwlJQCZ016jof/cbN4VW5Yz0=
+gopkg.in/yaml.v3 v3.0.1 h1:fxVm/GzAzEWqLHuvctI91KS9hhNmmWOoWu0XTYJS7CA=
+gopkg.in/yaml.v3 v3.0.1/go.mod h1:K4uyk7z7BCEPqu6E+C64Yfv1cQ7kz7rIZviUmN+EgEM=

custom-wasm-transformers/samples/wasm-add-annotation/add-annotation/main.go

@@ -0,0 +1,235 @@
+package main
+
+import (
+	"encoding/json"
+	"fmt"
+	"os"
+	"path/filepath"
+	"strings"
+	"unsafe"
+
+	"gopkg.in/yaml.v3"
+)
+
+// PathMappingType refers to the Path Mapping type
+type PathMappingType string
+
+const (
+	// DefaultPathMappingType allows normal copy with overwrite
+	DefaultPathMappingType PathMappingType = "Default" // Normal Copy with overwrite
+	// TemplatePathMappingType allows copy of source to destination and applying of template
+	TemplatePathMappingType PathMappingType = "Template" // Source path when relative, is relative to yaml file location
+	// SourcePathMappingType allows for copying of source directory to another directory
+	SourcePathMappingType PathMappingType = "Source" // Source path becomes relative to source directory
+	// DeletePathMappingType allows for deleting of files or folder directory
+	DeletePathMappingType PathMappingType = "Delete" // Delete path becomes relative to source directory
+	// ModifiedSourcePathMappingType allows for copying of deltas wrt source
+	ModifiedSourcePathMappingType PathMappingType = "SourceDiff" // Source path becomes relative to source directory
+	// PathTemplatePathMappingType allows for path template registration
+	PathTemplatePathMappingType PathMappingType = "PathTemplate" // Path Template type
+	// SpecialTemplatePathMappingType allows copy of source to destination and applying of template with custom delimiter
+	SpecialTemplatePathMappingType PathMappingType = "SpecialTemplate" // Source path when relative, is relative to yaml file location
+)
+
+// Artifact represents the artifact that can be passed between transformers
+type Artifact struct {
+	Name string `yaml:"name,omitempty" json:"name,omitempty"`
+	Type string `yaml:"type,omitempty" json:"type,omitempty"`
+	// ProcessWith metav1.LabelSelector `yaml:"processWith,omitempty" json:"processWith,omitempty"` // Selector for choosing transformers that should process this artifact, empty is everything
+
+	Paths   map[string][]string    `yaml:"paths,omitempty" json:"paths,omitempty" m2kpath:"normal"`
+	Configs map[string]interface{} `yaml:"configs,omitempty" json:"configs,omitempty"` // Could be IR or template config or any custom configuration
+}
+
+// PathMapping is the mapping between source and intermediate files and output files
+type PathMapping struct {
+	Type           PathMappingType `yaml:"type,omitempty" json:"type,omitempty"` // Default - Normal copy
+	SrcPath        string          `yaml:"sourcePath" json:"sourcePath" m2kpath:"normal"`
+	DestPath       string          `yaml:"destinationPath" json:"destinationPath" m2kpath:"normal"` // Relative to output directory
+	TemplateConfig interface{}     `yaml:"templateConfig" json:"templateConfig"`
+}
+
+type TransformInput struct {
+	NewArtifacts         []Artifact `yaml:"newArtifacts,omitempty" json:"newArtifacts,omitempty"`
+	AlreadySeenArtifacts []Artifact `yaml:"alreadySeenArtifacts,omitempty" json:"alreadySeenArtifacts,omitempty"`
+}
+
+type TransformOutput struct {
+	NewPathMappings []PathMapping `yaml:"newPathMappings,omitempty" json:"newPathMappings,omitempty"`
+	NewArtifacts    []Artifact    `yaml:"newArtifacts,omitempty" json:"newArtifacts,omitempty"`
+}
+
+// https://github.com/tinygo-org/tinygo/issues/411#issuecomment-503066868
+var keyToAllocatedBytes = map[uint32][]byte{}
+var nextKey uint32 = 41
+
+// https://github.com/ejcx/wazero/blob/40f59a877bcdb4949eba51f9e1dee3deaba1ff83/examples/allocation/tinygo/testdata/greet.go#L64C1-L68C2
+// ptrToString returns a string from WebAssembly compatible numeric types
+// representing its pointer and length.
+func ptrToString(ptr uint32, size uint32) string {
+	return unsafe.String((*byte)(unsafe.Pointer(uintptr(ptr))), size)
+}
+
+//go:export myAllocate
+func myAllocate(size uint32) *byte {
+	nextKey += 1
+	newArr := make([]byte, size)
+	keyToAllocatedBytes[nextKey] = newArr
+	return &newArr[0]
+}
+
+func saveBytes(ptrBytes []byte) uint32 {
+	nextKey += 1
+	keyToAllocatedBytes[nextKey] = ptrBytes
+	ptr := &ptrBytes[0]
+	return uint32(uintptr(unsafe.Pointer(ptr)))
+}
+
+func Transform(
+	newArtifacts []Artifact,
+	alreadySeenArtifacts []Artifact,
+) ([]PathMapping, []Artifact, error) {
+	pathMappings := []PathMapping{}
+	artifacts := []Artifact{}
+
+	for _, newArtifact := range newArtifacts {
+		if len(newArtifact.Paths) == 0 {
+			fmt.Println("[DEBUG] newArtifact.Paths is nil/empty")
+			continue
+		}
+		if len(newArtifact.Paths["KubernetesYamls"]) == 0 {
+			fmt.Println("[DEBUG] newArtifact.Paths[KubernetesYamls] is nil/empty")
+			continue
+		}
+		yamlsPath := newArtifact.Paths["KubernetesYamls"][0]
+		fmt.Printf("[DEBUG] newArtifact yamlsPath: '%s'\n", yamlsPath)
+		serviceName := newArtifact.Name
+		artifacts = append(artifacts, newArtifact)
+
+		yamlsBasePath := filepath.Base(yamlsPath)
+		// Create a custom path template for the service, whose values gets filled and can be used in other pathmappings
+		pathTemplateName := serviceName + yamlsBasePath
+		pathTemplateName = strings.ReplaceAll(pathTemplateName, "-", "")
+		tplPathData := map[string]string{"PathTemplateName": pathTemplateName}
+		pathMappings = append(pathMappings, PathMapping{
+			Type:           "PathTemplate",
+			SrcPath:        "{{ OutputRel \"" + yamlsPath + "\" }}",
+			TemplateConfig: tplPathData,
+		})
+		fileList, err := os.ReadDir(yamlsPath)
+		if err != nil {
+			return nil, nil, fmt.Errorf("failed to read the directory '%s' . Error: %w", yamlsPath, err)
+		}
+		fmt.Printf("[DEBUG] newArtifact fileList: '%d'\n", len(fileList))
+		for _, f := range fileList {
+			filePath := filepath.Join(yamlsPath, f.Name())
+			fmt.Printf("[DEBUG] filePath: '%s'\n", filePath)
+			inputBytes, err := os.ReadFile(filePath)
+			if err != nil {
+				fmt.Printf("[ERROR] read file filePath: '%s' . Error: %q\n", filePath, err)
+				continue
+			}
+			// inputYaml := string(inputBytes)
+			yamlData := map[string]interface{}{}
+			if err := yaml.Unmarshal(inputBytes, &yamlData); err != nil {
+				fmt.Printf("[ERROR] yaml unmarshal filePath: '%s' . Error: %q\n", filePath, err)
+				continue
+			}
+			if yamlData["kind"] != "Deployment" {
+				fmt.Println("kind does not exist/kind is not Deployment")
+				continue
+			}
+			__svc_name, ok := yamlData["metadata"].(map[string]interface{})
+			if !ok {
+				fmt.Println("metadata is missing")
+				continue
+			}
+			svc_name, ok := __svc_name["name"].(string)
+			if !ok {
+				fmt.Println("name is missing")
+				continue
+			}
+			fmt.Printf("[DEBUG] svc_name %s\n", svc_name)
+			annotations, ok := __svc_name["annotations"].(map[string]string)
+			if !ok {
+				annotations = map[string]string{}
+				__svc_name["annotations"] = annotations
+			}
+			annotations["my.domain.com/custom-annotation"] = "foo"
+			fmt.Printf("[DEBUG] annotations %+v\n", annotations)
+			sBytes, err := yaml.Marshal(yamlData)
+			if err != nil {
+				fmt.Printf("[ERROR] yaml marshal error: %q\n", err)
+				continue
+			}
+			if err := os.WriteFile(filePath, sBytes, 0644); err != nil {
+				fmt.Printf("[ERROR] write file %s error: %q\n", filePath, err)
+				continue
+			}
+			pathMappings = append(pathMappings,
+				PathMapping{
+					Type:     "Default",
+					SrcPath:  yamlsPath,
+					DestPath: "{{ ." + pathTemplateName + " }}",
+				},
+			)
+		}
+	}
+	return pathMappings, artifacts, nil
+}
+
+//go:export RunDirectoryDetect
+func RunDirectoryDetect(
+	inputJsonPtr uint32,
+	inputJsonLen uint32,
+	outputJsonPtrPtr uint32,
+	outputJsonLenPtr uint32,
+) (successOrError int32) {
+	fmt.Println("mycustomtransformer: RunDirectoryDetect start")
+	defer fmt.Println("mycustomtransformer: RunDirectoryDetect end")
+	return 0
+}
+
+//go:export RunTransform
+func RunTransform(
+	inputJsonPtr uint32,
+	inputJsonLen uint32,
+	outputJsonPtrPtr uint32,
+	outputJsonLenPtr uint32,
+) (successOrError int32) {
+	fmt.Println("mycustomtransformer: RunTransform start")
+	defer fmt.Println("mycustomtransformer: RunTransform end")
+	transformInputJson := ptrToString(inputJsonPtr, inputJsonLen)
+	input := TransformInput{}
+	if err := json.Unmarshal([]byte(transformInputJson), &input); err != nil {
+		fmt.Println("mycustomtransformer: failed to unmarshal")
+		return -1
+	}
+	ps, as, err := Transform(input.NewArtifacts, input.AlreadySeenArtifacts)
+	if err != nil {
+		fmt.Printf("mycustomtransformer: failed to transform. Error: %q\n", err)
+		return -1
+	}
+	output := TransformOutput{
+		NewPathMappings: ps,
+		NewArtifacts:    as,
+	}
+	outputJson, err := json.Marshal(output)
+	if err != nil {
+		fmt.Println("mycustomtransformer: failed to marshal")
+		return -1
+	}
+	ptr := saveBytes(outputJson)
+	ptrr := (*uint32)(unsafe.Pointer(uintptr(outputJsonPtrPtr)))
+	*ptrr = ptr
+	ptrl := (*uint32)(unsafe.Pointer(uintptr(outputJsonLenPtr)))
+	*ptrl = uint32(len(outputJson))
+	return 0
+}
+
+func main() {
+	// wasmexport hasn't been implemented yet
+	// https://github.com/golang/go/issues/42372a
+	args := os.Args
+	fmt.Printf("args: %+v\n", args)
+}