add function handling (basic)

internal/worker/handle.go

@@ -0,0 +1,82 @@
+package worker
+
+import (
+	"encoding/json"
+	"fmt"
+	"os"
+	"path/filepath"
+
+	"gorm.io/driver/sqlite"
+	"gorm.io/gorm"
+)
+
+type RootConfig struct {
+	Data struct {
+		Driver string `json:"driver"`
+		Path   string `json:"path"`
+	} `json:"data"`
+}
+
+type Function struct {
+	ID           uint `gorm:"primaryKey"`
+	FunctionName string
+	Version      string
+	Path         string
+	DeletedAt    gorm.DeletedAt `gorm:"index"`
+}
+
+type FuncConfig struct {
+	Name    string `json:"name"`
+	Version string `json:"version"`
+	Entry   string `json:"entry"`
+	Runtime string `json:"runtime"`
+}
+
+func LoadTreeConfig(root string) (*RootConfig, error) {
+	cfgPath := filepath.Join(root, "config.json")
+	b, err := os.ReadFile(cfgPath)
+	if err != nil {
+		return nil, err
+	}
+	var cfg RootConfig
+	if err := json.Unmarshal(b, &cfg); err != nil {
+		return nil, err
+	}
+	return &cfg, nil
+}
+
+func OpenDB(cfg *RootConfig, root string) (*gorm.DB, error) {
+	switch cfg.Data.Driver {
+	case "sqlite":
+		dbPath := filepath.Join(root, cfg.Data.Path)
+		db, err := gorm.Open(sqlite.Open(dbPath), &gorm.Config{})
+		if err != nil {
+			return nil, err
+		}
+		return db, nil
+	default:
+		return nil, fmt.Errorf("unsupported db driver: %s", cfg.Data.Driver)
+	}
+}
+
+func FindFunction(db *gorm.DB, name, version string) (*Function, error) {
+	var f Function
+	if err := db.Where("function_name = ? AND version = ? AND deleted_at IS NULL", name, version).
+		First(&f).Error; err != nil {
+		return nil, err
+	}
+	return &f, nil
+}
+
+func LoadFunctionConfig(root, funcName, funcPath string) (*FuncConfig, error) {
+	cfgFile := filepath.Join(root, funcName, funcPath, "config.json")
+	b, err := os.ReadFile(cfgFile)
+	if err != nil {
+		return nil, err
+	}
+	var cfg FuncConfig
+	if err := json.Unmarshal(b, &cfg); err != nil {
+		return nil, err
+	}
+	return &cfg, nil
+}

internal/worker/run.go

@@ -0,0 +1,25 @@
+package worker
+
+import (
+	"bytes"
+	"fmt"
+	"os/exec"
+)
+
+func RunFunction(path string, fc *FuncConfig, input []byte) ([]byte, error) {
+	if fc.Runtime != "exec" {
+		return nil, fmt.Errorf("unsupported runtime: %s", fc.Runtime)
+	}
+
+	cmd := exec.Command(path)
+	cmd.Stdin = bytes.NewReader(input)
+
+	var out bytes.Buffer
+	cmd.Stdout = &out
+	cmd.Stderr = &out
+
+	if err := cmd.Run(); err != nil {
+		return nil, fmt.Errorf("failed: %w\noutput: %s", err, out.String())
+	}
+	return out.Bytes(), nil
+}