Merge pull request #272 from netlify/zip_functions_runtime

Allow to read runtime information from zip files.

Author: calavera

go/internal/data/hello-rs-function-test.zip

@@ -8,6 +8,7 @@ import (
 	"crypto/sha256"
 	"debug/elf"
 	"encoding/hex"
+	"encoding/json"
 	"fmt"
 	"io"
 	"io/ioutil"
@@ -103,6 +104,10 @@ type FileBundle struct {
 	Buffer io.ReadSeeker
 }
 
+type toolchainSpec struct {
+	Runtime string `json:"runtime"`
+}
+
 func (f *FileBundle) Read(p []byte) (n int, err error) {
 	return f.Buffer.Read(p)
 }
@@ -582,7 +587,11 @@ func bundle(functionDir string, observer DeployObserver) (*deployFiles, error) {
 
 		switch {
 		case zipFile(i):
-			file, err := newFunctionFile(filePath, i, jsRuntime, observer)
+			runtime, err := readZipRuntime(filePath)
+			if err != nil {
+				return nil, err
+			}
+			file, err := newFunctionFile(filePath, i, runtime, observer)
 			if err != nil {
 				return nil, err
 			}
@@ -609,6 +618,36 @@ func bundle(functionDir string, observer DeployObserver) (*deployFiles, error) {
 	return functions, nil
 }
 
+func readZipRuntime(filePath string) (string, error) {
+	zf, err := zip.OpenReader(filePath)
+	if err != nil {
+		return "", err
+	}
+	defer zf.Close()
+
+	for _, file := range zf.File {
+		if file.Name == "netlify-toolchain" {
+			fc, err := file.Open()
+			if err != nil {
+				// Ignore any errors and choose the default runtime.
+				// This preserves the current behavior in this library.
+				return jsRuntime, nil
+			}
+			defer fc.Close()
+
+			var tc toolchainSpec
+			if err := json.NewDecoder(fc).Decode(&tc); err != nil {
+				// Ignore any errors and choose the default runtime.
+				// This preserves the current behavior in this library.
+				return jsRuntime, nil
+			}
+			return tc.Runtime, nil
+		}
+	}
+
+	return jsRuntime, nil
+}
+
 func newFunctionFile(filePath string, i os.FileInfo, runtime string, observer DeployObserver) (*FileBundle, error) {
 	file := &FileBundle{
 		Name:    strings.TrimSuffix(i.Name(), filepath.Ext(i.Name())),

go/porcelain/deploy.go

@@ -130,3 +130,14 @@ func TestConcurrentFileUpload(t *testing.T) {
 		}()
 	}
 }
+
+func TestReadZipRuntime(t *testing.T) {
+	runtime, err := readZipRuntime("../internal/data/hello-rs-function-test.zip")
+	if err != nil {
+		t.Fatalf("unexpected error reading zip file: %v", err)
+	}
+
+	if runtime != "rs" {
+		t.Fatalf("unexpected runtime value, expected='rs', got='%s'", runtime)
+	}
+}