feat(oci): oci helm support [r8s-361] (#787)

api/http/proxy/factory/github/client.go

@@ -0,0 +1,108 @@
+package github
+
+import (
+	"context"
+	"fmt"
+	"io"
+	"net/http"
+	"strings"
+	"time"
+
+	"github.com/segmentio/encoding/json"
+	"oras.land/oras-go/v2/registry/remote/retry"
+)
+
+const GitHubAPIHost = "https://api.github.com"
+
+// Package represents a GitHub container package
+type Package struct {
+	Name  string `json:"name"`
+	Owner struct {
+		Login string `json:"login"`
+	} `json:"owner"`
+}
+
+// Client represents a GitHub API client
+type Client struct {
+	httpClient *http.Client
+	baseURL    string
+}
+
+// NewClient creates a new GitHub API client
+func NewClient(token string) *Client {
+	return &Client{
+		httpClient: NewHTTPClient(token),
+		baseURL:    GitHubAPIHost,
+	}
+}
+
+// GetContainerPackages fetches container packages for the configured namespace
+// It's a small http client wrapper instead of using the github client because listing repositories is the only known operation that isn't directly supported by oras
+func (c *Client) GetContainerPackages(ctx context.Context, useOrganisation bool, organisationName string) ([]string, error) {
+	// Determine the namespace (user or organisation) for the request
+	namespace := "user"
+	if useOrganisation {
+		namespace = "orgs/" + organisationName
+	}
+
+	// Build the full URL for listing container packages
+	url := fmt.Sprintf("%s/%s/packages?package_type=container", c.baseURL, namespace)
+
+	req, err := http.NewRequestWithContext(ctx, http.MethodGet, url, nil)
+	if err != nil {
+		return nil, fmt.Errorf("failed to create request: %w", err)
+	}
+
+	resp, err := c.httpClient.Do(req)
+	if err != nil {
+		return nil, fmt.Errorf("failed to execute request: %w", err)
+	}
+	defer resp.Body.Close()
+
+	if resp.StatusCode != http.StatusOK {
+		return nil, fmt.Errorf("GitHub API returned status %d: %s", resp.StatusCode, resp.Status)
+	}
+
+	body, err := io.ReadAll(resp.Body)
+	if err != nil {
+		return nil, fmt.Errorf("failed to read response body: %w", err)
+	}
+
+	var packages []Package
+	if err := json.Unmarshal(body, &packages); err != nil {
+		return nil, fmt.Errorf("failed to parse response: %w", err)
+	}
+
+	// Extract repository names in the form "owner/name"
+	repositories := make([]string, len(packages))
+	for i, pkg := range packages {
+		repositories[i] = fmt.Sprintf("%s/%s", strings.ToLower(pkg.Owner.Login), strings.ToLower(pkg.Name))
+	}
+
+	return repositories, nil
+}
+
+// NewHTTPClient creates a new HTTP client configured for GitHub API requests
+func NewHTTPClient(token string) *http.Client {
+	return &http.Client{
+		Transport: &tokenTransport{
+			token:     token,
+			transport: retry.NewTransport(&http.Transport{}), // Use ORAS retry transport for consistent rate limiting and error handling
+		},
+		Timeout: 1 * time.Minute,
+	}
+}
+
+// tokenTransport automatically adds the Bearer token header to requests
+type tokenTransport struct {
+	token     string
+	transport http.RoundTripper
+}
+
+func (t *tokenTransport) RoundTrip(req *http.Request) (*http.Response, error) {
+	if t.token != "" {
+		req.Header.Set("Authorization", "Bearer "+t.token)
+		req.Header.Set("Accept", "application/vnd.github+json")
+	}
+	return t.transport.RoundTrip(req)
+}