feat: allow kcl import to load http/https urls

cmd/kcl/commands/import.go

@@ -20,6 +20,8 @@ Supported conversion modes:
 - openapi:         convert OpenAPI spec to KCL schema
 - crd:             convert Kubernetes CRD to KCL schema
 - auto:            automatically detect the input format
+
+Input can be a local file path or an HTTP/HTTPS URL.
 `
 	importExample = `  # Generate KCL models from OpenAPI spec
   kcl import -m openapi swagger.json
@@ -43,7 +45,13 @@ Supported conversion modes:
   kcl import -m terraformschema schema.json
 
   # Generate KCL models from Go structs
-  kcl import -m gostruct schema.go`
+  kcl import -m gostruct schema.go
+
+  # Generate KCL models from a remote JSON URL
+  kcl import -m json https://api.github.com/meta
+
+  # Generate KCL models from a raw GitHub YAML file
+  kcl import https://raw.githubusercontent.com/kcl-lang/cli/main/examples/settings/settings.yaml`
 )
 
 // NewImportCmd returns the import command.

pkg/fs/util.go

@@ -3,10 +3,65 @@ package fs
 import (
 	"fmt"
 	"io"
+	"net/http"
+	"net/url"
 	"os"
 	"path/filepath"
+	"strings"
 )
 
+// IsURL checks if the given path is an HTTP or HTTPS URL.
+func IsURL(path string) bool {
+	return strings.HasPrefix(path, "http://") || strings.HasPrefix(path, "https://")
+}
+
+// GenTempFileFromURL fetches content from a URL and saves it to a temp file.
+// It returns the path to the temp file or an error if the fetch fails.
+// The caller is responsible for removing the temp file after use.
+func GenTempFileFromURL(urlStr string) (string, error) {
+	// Parse the URL to extract the file extension
+	parsedURL, err := url.Parse(urlStr)
+	if err != nil {
+		return "", fmt.Errorf("invalid URL %q: %w", urlStr, err)
+	}
+
+	// Extract file extension from URL path for temp file naming
+	ext := filepath.Ext(parsedURL.Path)
+	if ext == "" {
+		ext = ".tmp"
+	}
+
+	// Create temp file with appropriate extension
+	tempFile, err := os.CreateTemp("", "kcl-import-*"+ext)
+	if err != nil {
+		return "", fmt.Errorf("failed to create temp file: %w", err)
+	}
+	defer tempFile.Close()
+
+	// Fetch content from URL
+	resp, err := http.Get(urlStr)
+	if err != nil {
+		os.Remove(tempFile.Name())
+		return "", fmt.Errorf("failed to fetch URL %q: %w", urlStr, err)
+	}
+	defer resp.Body.Close()
+
+	// Check for successful response
+	if resp.StatusCode != http.StatusOK {
+		os.Remove(tempFile.Name())
+		return "", fmt.Errorf("failed to fetch URL %q: HTTP %d %s", urlStr, resp.StatusCode, resp.Status)
+	}
+
+	// Copy response body to temp file
+	_, err = io.Copy(tempFile, resp.Body)
+	if err != nil {
+		os.Remove(tempFile.Name())
+		return "", fmt.Errorf("failed to save content from URL %q: %w", urlStr, err)
+	}
+
+	return tempFile.Name(), nil
+}
+
 func GenTempFileFromStdin() (string, error) {
 	tempFile, err := os.CreateTemp("", "stdin-*.k")
 	if err != nil {

pkg/options/import.go

@@ -37,7 +37,36 @@ func NewImportOptions() *ImportOptions {
 func (o *ImportOptions) Run() error {
 	opts := &gen.GenKclOptions{}
 	mode := strings.ToLower(o.Mode)
-	files, err := fs.ExpandInputFiles(o.Files, o.Recursive)
+
+	// Process input files, fetching URLs to temp files if needed
+	processedFiles := make([]string, 0, len(o.Files))
+	tempFiles := []string{}
+
+	for _, f := range o.Files {
+		if fs.IsURL(f) {
+			// Fetch URL content to temp file
+			tempPath, err := fs.GenTempFileFromURL(f)
+			if err != nil {
+				for _, tf := range tempFiles {
+					os.Remove(tf)
+				}
+				return err
+			}
+			tempFiles = append(tempFiles, tempPath)
+			processedFiles = append(processedFiles, tempPath)
+		} else {
+			processedFiles = append(processedFiles, f)
+		}
+	}
+
+	// Ensure temp files are cleaned up when function returns
+	defer func() {
+		for _, tf := range tempFiles {
+			os.Remove(tf)
+		}
+	}()
+
+	files, err := fs.ExpandInputFiles(processedFiles, o.Recursive)
 	if err != nil {
 		return err
 	}