feat: add handler for wasm transformer

transformer/external/wasmtransformer.go

@@ -0,0 +1,157 @@
+/*
+ *  Copyright IBM Corporation 2021
+ *
+ *  Licensed under the Apache License, Version 2.0 (the "License");
+ *  you may not use this file except in compliance with the License.
+ *  You may obtain a copy of the License at
+ *
+ *        http://www.apache.org/licenses/LICENSE-2.0
+ *
+ *  Unless required by applicable law or agreed to in writing, software
+ *  distributed under the License is distributed on an "AS IS" BASIS,
+ *  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ *  See the License for the specific language governing permissions and
+ *  limitations under the License.
+ */
+
+package external
+
+import (
+	"encoding/binary"
+	"encoding/json"
+	"fmt"
+	"os"
+	"path/filepath"
+
+	"github.com/dchest/uniuri"
+	"github.com/konveyor/move2kube/common"
+	"github.com/konveyor/move2kube/environment"
+	transformertypes "github.com/konveyor/move2kube/types/transformer"
+	"github.com/second-state/WasmEdge-go/wasmedge"
+	"github.com/sirupsen/logrus"
+	core "k8s.io/kubernetes/pkg/apis/core"
+)
+
+const (
+	wasmEnvDelimiter              = "="
+	detectInputPathWASMEnvKey     = "M2K_DETECT_INPUT_PATH"
+	detectOutputPathWASMEnvKey    = "M2K_DETECT_OUTPUT_PATH"
+	transformInputPathWASMEnvKey  = "M2K_TRANSFORM_INPUT_PATH"
+	transformOutputPathWASMEnvKey = "M2K_TRANSFORM_OUTPUT_PATH"
+)
+
+// WASM implements wasm transformer interface and is used for wasm based transformers
+type WASM struct {
+	Config     transformertypes.Transformer
+	Env        *environment.Environment
+	WASMConfig *WASMYamlConfig
+	VM         *wasmedge.VM
+}
+
+// WASMYamlConfig is the format of wasm transformer yaml config
+type WASMYamlConfig struct {
+	WASMModule string        `yaml:"wasm_module"`
+	EnvList    []core.EnvVar `yaml:"env,omitempty"`
+}
+
+var (
+	// WASMSharedDir is the directory where wasm transformer detect and transform output is stored
+	WASMSharedDir = "/var/tmp/m2k_detect_wasm_output"
+)
+
+// Init Initializes the transformer
+func (t *WASM) Init(tc transformertypes.Transformer, env *environment.Environment) (err error) {
+	t.Config = tc
+	t.WASMConfig = &WASMYamlConfig{}
+	if err := common.GetObjFromInterface(t.Config.Spec.Config, t.WASMConfig); err != nil {
+		return fmt.Errorf("unable to load config for Transformer %+v into %T . Error: %q", t.Config.Spec.Config, t.WASMConfig, err)
+	}
+	WASMSharedDir = filepath.Join(WASMSharedDir, uniuri.NewLen(5))
+	os.MkdirAll(WASMSharedDir, common.DefaultDirectoryPermission)
+	// load wasm module
+	wasmedge.SetLogErrorLevel()
+	conf := wasmedge.NewConfigure(wasmedge.WASI)
+	vm := wasmedge.NewVMWithConfig(conf)
+
+	wasi := vm.GetImportModule(wasmedge.HostRegistration(wasmedge.WASI))
+	wasi.InitWasi(
+		[]string{},
+		t.prepareEnv(),
+		[]string{".:" + WASMSharedDir},
+	)
+
+	err = vm.LoadWasmFile(t.WASMConfig.WASMModule)
+	vm.Validate()
+	vm.Instantiate()
+	t.VM = vm
+	return err
+}
+
+func (t *WASM) prepareEnv() []string {
+	envList := []string{}
+	for _, env := range t.WASMConfig.EnvList {
+		envList = append(envList, env.Name+wasmEnvDelimiter+env.Value)
+	}
+	return envList
+}
+
+// GetConfig returns the transformer config
+func (t *WASM) GetConfig() (transformertypes.Transformer, *environment.Environment) {
+	return t.Config, t.Env
+}
+
+// DirectoryDetect runs detect in each sub directory
+func (t *WASM) DirectoryDetect(dir string) (map[string][]transformertypes.Artifact, error) {
+	allocateResult, _ := t.VM.Execute("malloc", int32(len(dir)+1))
+	dirPointer := allocateResult[0].(int32)
+	mod := t.VM.GetActiveModule()
+	mem := mod.FindMemory("memory")
+	memData, _ := mem.GetData(uint(dirPointer), uint(len(dir)+1))
+	copy(memData, dir)
+	memData[len(dir)] = 0
+	directoryDetectOutput, dderr := t.VM.Execute("directoryDetect", dirPointer)
+	var err error
+	if dderr != nil {
+		err = fmt.Errorf("failed to execute directoryDetect in the wasm module. Error : %s", dderr.Error())
+	}
+	directoryDetectOutputPointer := directoryDetectOutput[0].(int32)
+	memData, _ = mem.GetData(uint(directoryDetectOutputPointer), 8)
+	resultPointer := binary.LittleEndian.Uint32(memData[:4])
+	resultLength := binary.LittleEndian.Uint32(memData[4:])
+	memData, _ = mem.GetData(uint(resultPointer), uint(resultLength))
+	logrus.Debug(string(memData))
+	services := map[string][]transformertypes.Artifact{}
+	// will handles errors
+	_ = json.Unmarshal(memData, &services)
+	return services, err
+}
+
+// Transform transforms the artifacts
+func (t *WASM) Transform(newArtifacts []transformertypes.Artifact, alreadySeenArtifacts []transformertypes.Artifact) ([]transformertypes.PathMapping, []transformertypes.Artifact, error) {
+	pathMappings := []transformertypes.PathMapping{}
+	createdArtifacts := []transformertypes.Artifact{}
+	data := make(map[string]interface{})
+	data["newArtifacts"] = newArtifacts
+	data["oldArtifacts"] = alreadySeenArtifacts
+	dataByt, _ := json.Marshal(data)
+	dataStr := string(dataByt)
+	allocateResult, _ := t.VM.Execute("malloc", int32(len(dataStr)+1))
+	dataPointer := allocateResult[0].(int32)
+	mod := t.VM.GetActiveModule()
+	mem := mod.FindMemory("memory")
+	memData, _ := mem.GetData(uint(dataPointer), uint(len(dataStr)+1))
+	copy(memData, dataStr)
+	memData[len(dataStr)] = 0
+	transformOutput, err := t.VM.Execute("transform", dataPointer)
+	transformOutputPointer := transformOutput[0].(int32)
+	memData, _ = mem.GetData(uint(transformOutputPointer), 8)
+	resultPointer := binary.LittleEndian.Uint32(memData[:4])
+	resultLength := binary.LittleEndian.Uint32(memData[4:])
+	memData, _ = mem.GetData(uint(resultPointer), uint(resultLength))
+	logrus.Debug(string(memData))
+	var output transformertypes.TransformOutput
+	json.Unmarshal(memData, &output)
+	pathMappings = append(pathMappings, output.PathMappings...)
+	createdArtifacts = append(createdArtifacts, output.CreatedArtifacts...)
+	return pathMappings, createdArtifacts, err
+}