Extensions: Adds extensions package (#4718)

Adds the core components for the azd management plane of azd extensions.

cli/azd/pkg/extensions/extension.go

@@ -0,0 +1,16 @@
+// Copyright (c) Microsoft Corporation. All rights reserved.
+// Licensed under the MIT License.
+
+package extensions
+
+// Extension represents an installed extension.
+type Extension struct {
+	Id          string `json:"id"`
+	Namespace   string `json:"namespace"`
+	DisplayName string `json:"displayName"`
+	Description string `json:"description"`
+	Version     string `json:"version"`
+	Usage       string `json:"usage"`
+	Path        string `json:"path"`
+	Source      string `json:"source"`
+}

cli/azd/pkg/extensions/file_source.go

@@ -0,0 +1,68 @@
+// Copyright (c) Microsoft Corporation. All rights reserved.
+// Licensed under the MIT License.
+
+package extensions
+
+import (
+	"fmt"
+	"os"
+	"path/filepath"
+
+	"github.com/azure/azure-dev/cli/azd/pkg/config"
+)
+
+// newFileSource creates a new file base registry source.
+func newFileSource(name string, path string) (Source, error) {
+	absolutePath, err := getAbsolutePath(path)
+	if err != nil {
+		return nil, fmt.Errorf("failed converting path '%s' to absolute path, %w", path, err)
+	}
+
+	registryBytes, err := os.ReadFile(absolutePath)
+	if err != nil {
+		return nil, fmt.Errorf("failed reading file '%s', %w", path, err)
+	}
+
+	return newJsonSource(name, string(registryBytes))
+}
+
+// getAbsolutePath converts a relative path to an absolute path.
+func getAbsolutePath(filePath string) (string, error) {
+	// Check if the path is absolute
+	if filepath.IsAbs(filePath) {
+		return filePath, nil
+	}
+
+	roots := []string{}
+
+	// Get the current working directory
+	cwd, err := os.Getwd()
+	if err != nil {
+		return "", err
+	}
+
+	azdConfigPath, err := config.GetUserConfigDir()
+	if err != nil {
+		return "", err
+	}
+
+	roots = append(roots, cwd)
+	roots = append(roots, azdConfigPath)
+
+	for _, root := range roots {
+		// Join the root directory with the relative path
+		absolutePath := filepath.Join(root, filePath)
+
+		// Normalize the path to handle any ".." or "." segments
+		absolutePath, err = filepath.Abs(absolutePath)
+		if err != nil {
+			return "", err
+		}
+
+		if _, err := os.Stat(absolutePath); err == nil {
+			return absolutePath, nil
+		}
+	}
+
+	return "", fmt.Errorf("file '%s' was not found, %w", filePath, os.ErrNotExist)
+}

cli/azd/pkg/extensions/json_source.go

@@ -0,0 +1,20 @@
+// Copyright (c) Microsoft Corporation. All rights reserved.
+// Licensed under the MIT License.
+
+package extensions
+
+import (
+	"encoding/json"
+	"fmt"
+)
+
+// newJsonSource creates a new JSON base registry source.
+func newJsonSource(name string, jsonRegistry string) (Source, error) {
+	var registry *Registry
+	err := json.Unmarshal([]byte(jsonRegistry), &registry)
+	if err != nil {
+		return nil, fmt.Errorf("unable to unmarshal extensions JSON %w", err)
+	}
+
+	return newRegistrySource(name, registry)
+}