feat: plugins integration.

pkg/plugins/plugins.go

@@ -0,0 +1,146 @@
+package plugins
+
+import (
+	"context"
+	"errors"
+	"fmt"
+	"strings"
+
+	"github.com/containous/traefik/v2/pkg/log"
+)
+
+// Setup setup plugins environment.
+func Setup(client *Client, plugins map[string]Descriptor, devPlugin *DevPlugin) error {
+	err := checkPluginsConfiguration(plugins)
+	if err != nil {
+		return fmt.Errorf("invalid configuration: %w", err)
+	}
+
+	err = client.CleanArchives(plugins)
+	if err != nil {
+		return fmt.Errorf("failed to clean archives: %w", err)
+	}
+
+	ctx := context.Background()
+
+	for pAlias, desc := range plugins {
+		log.FromContext(ctx).Debugf("loading of plugin: %s: %s@%s", pAlias, desc.ModuleName, desc.Version)
+
+		hash, err := client.Download(ctx, desc.ModuleName, desc.Version)
+		if err != nil {
+			_ = client.ResetAll()
+			return fmt.Errorf("failed to download plugin %s: %w", desc.ModuleName, err)
+		}
+
+		err = client.Check(ctx, desc.ModuleName, desc.Version, hash)
+		if err != nil {
+			_ = client.ResetAll()
+			return fmt.Errorf("failed to check archive integrity of the plugin %s: %w", desc.ModuleName, err)
+		}
+	}
+
+	err = client.WriteState(plugins)
+	if err != nil {
+		_ = client.ResetAll()
+		return fmt.Errorf("failed to write plugins state: %w", err)
+	}
+
+	for _, desc := range plugins {
+		err = client.Unzip(desc.ModuleName, desc.Version)
+		if err != nil {
+			_ = client.ResetAll()
+			return fmt.Errorf("failed to unzip archive: %w", err)
+		}
+	}
+
+	if devPlugin != nil {
+		err := checkDevPluginConfiguration(devPlugin)
+		if err != nil {
+			return fmt.Errorf("invalid configuration: %w", err)
+		}
+	}
+
+	return nil
+}
+
+func checkDevPluginConfiguration(plugin *DevPlugin) error {
+	if plugin == nil {
+		return nil
+	}
+
+	if plugin.GoPath == "" {
+		return errors.New("missing Go Path (prefer a dedicated Go Path)")
+	}
+
+	if plugin.ModuleName == "" {
+		return errors.New("missing module name")
+	}
+
+	m, err := ReadManifest(plugin.GoPath, plugin.ModuleName)
+	if err != nil {
+		return err
+	}
+
+	if m.Type != "middleware" {
+		return errors.New("unsupported type")
+	}
+
+	if m.Import == "" {
+		return errors.New("missing import")
+	}
+
+	if !strings.HasPrefix(m.Import, plugin.ModuleName) {
+		return fmt.Errorf("the import %q must be related to the module name %q", m.Import, plugin.ModuleName)
+	}
+
+	if m.DisplayName == "" {
+		return errors.New("missing DisplayName")
+	}
+
+	if m.Summary == "" {
+		return errors.New("missing Summary")
+	}
+
+	if m.TestData == nil {
+		return errors.New("missing TestData")
+	}
+
+	return nil
+}
+
+func checkPluginsConfiguration(plugins map[string]Descriptor) error {
+	if plugins == nil {
+		return nil
+	}
+
+	uniq := make(map[string]struct{})
+
+	var errs []string
+	for pAlias, descriptor := range plugins {
+		if descriptor.ModuleName == "" {
+			errs = append(errs, fmt.Sprintf("%s: plugin name is missing", pAlias))
+		}
+
+		if descriptor.Version == "" {
+			errs = append(errs, fmt.Sprintf("%s: plugin version is missing", pAlias))
+		}
+
+		if strings.HasPrefix(descriptor.ModuleName, "/") || strings.HasSuffix(descriptor.ModuleName, "/") {
+			errs = append(errs, fmt.Sprintf("%s: plugin name should not start or end with a /", pAlias))
+			continue
+		}
+
+		if _, ok := uniq[descriptor.ModuleName]; ok {
+			errs = append(errs, fmt.Sprintf("only one version of a plugin is allowed, there is a duplicate of %s", descriptor.ModuleName))
+			continue
+		}
+
+		uniq[descriptor.ModuleName] = struct{}{}
+	}
+
+	if len(errs) > 0 {
+		return errors.New(strings.Join(errs, ": "))
+	}
+
+	return nil
+}