github.com/wmuizelaar/kpt@v0.0.0-20221018115725-bd564717b2ed/internal/fnruntime/nodejs.go (about)

     1  // Copyright 2022 Google LLC
     2  //
     3  // Licensed under the Apache License, Version 2.0 (the "License");
     4  // you may not use this file except in compliance with the License.
     5  // You may obtain a copy of the License at
     6  //
     7  //      http://www.apache.org/licenses/LICENSE-2.0
     8  //
     9  // Unless required by applicable law or agreed to in writing, software
    10  // distributed under the License is distributed on an "AS IS" BASIS,
    11  // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
    12  // See the License for the specific language governing permissions and
    13  // limitations under the License.
    14  
    15  package fnruntime
    16  
    17  import (
    18  	"fmt"
    19  	"io"
    20  	"os"
    21  	"path/filepath"
    22  
    23  	fnresult "github.com/GoogleContainerTools/kpt/pkg/api/fnresult/v1"
    24  )
    25  
    26  const (
    27  	WasmPathEnv = "KPT_FN_WASM_PATH"
    28  )
    29  
    30  type WasmNodejsFn struct {
    31  	NodeJsRunner *ExecFn
    32  	loader       WasmLoader
    33  }
    34  
    35  func NewNodejsFn(loader WasmLoader) (*WasmNodejsFn, error) {
    36  	cacheDir := filepath.Join(os.TempDir(), "kpt-wasm-fn")
    37  	err := os.MkdirAll(cacheDir, 0755)
    38  	if err != nil {
    39  		return nil, fmt.Errorf("unable to create cache dir: %w", err)
    40  	}
    41  	tempDir, err := os.MkdirTemp(cacheDir, "nodejs-")
    42  	if err != nil {
    43  		return nil, fmt.Errorf("unable to create temp dir: %w", err)
    44  	}
    45  	jsPath := filepath.Join(tempDir, "kpt-fn-wasm-glue-runner.js")
    46  	if err = os.WriteFile(jsPath, []byte(golangWasmJSCode+glueCode), 0644); err != nil {
    47  		return nil, fmt.Errorf("unable to write the js glue code file: %w", err)
    48  	}
    49  
    50  	wasmFile, err := loader.getFilePath()
    51  	if err != nil {
    52  		return nil, err
    53  	}
    54  
    55  	f := &WasmNodejsFn{
    56  		NodeJsRunner: &ExecFn{
    57  			Path: "node",
    58  			Args: []string{jsPath},
    59  			Env: map[string]string{
    60  				WasmPathEnv: wasmFile,
    61  			},
    62  			FnResult: &fnresult.Result{},
    63  		},
    64  		loader: loader,
    65  	}
    66  	return f, nil
    67  }
    68  
    69  func (f *WasmNodejsFn) Run(r io.Reader, w io.Writer) error {
    70  	if err := f.NodeJsRunner.Run(r, w); err != nil {
    71  		return fmt.Errorf("failed to run wasm with node.js: %w", err)
    72  	}
    73  	return f.loader.cleanup()
    74  }