package plugins import ( "context" "encoding/json" "fmt" "path" "reflect" "strings" "github.com/mitchellh/mapstructure" "github.com/traefik/traefik/v2/pkg/config/dynamic" "github.com/traefik/traefik/v2/pkg/log" "github.com/traefik/traefik/v2/pkg/provider" "github.com/traefik/traefik/v2/pkg/safe" ) // PP the interface of a plugin's provider. type PP interface { Init() error Provide(cfgChan chan<- json.Marshaler) error Stop() error } type _PP struct { WInit func() error WProvide func(cfgChan chan<- json.Marshaler) error WStop func() error } func (p _PP) Init() error { return p.WInit() } func (p _PP) Provide(cfgChan chan<- json.Marshaler) error { return p.WProvide(cfgChan) } func (p _PP) Stop() error { return p.WStop() } func ppSymbols() map[string]map[string]reflect.Value { return map[string]map[string]reflect.Value{ "github.com/traefik/traefik/v2/pkg/plugins": { "PP": reflect.ValueOf((*PP)(nil)), "_PP": reflect.ValueOf((*_PP)(nil)), }, } } // BuildProvider builds a plugin's provider. func (b Builder) BuildProvider(pName string, config map[string]interface{}) (provider.Provider, error) { if b.providerDescriptors == nil { return nil, fmt.Errorf("no plugin definition in the static configuration: %s", pName) } descriptor, ok := b.providerDescriptors[pName] if !ok { return nil, fmt.Errorf("unknown plugin type: %s", pName) } return newProvider(descriptor, config, "plugin-"+pName) } // Provider is a plugin's provider wrapper. type Provider struct { name string pp PP } func newProvider(descriptor pluginContext, config map[string]interface{}, providerName string) (*Provider, error) { basePkg := descriptor.BasePkg if basePkg == "" { basePkg = strings.ReplaceAll(path.Base(descriptor.Import), "-", "_") } vConfig, err := descriptor.interpreter.Eval(basePkg + `.CreateConfig()`) if err != nil { return nil, fmt.Errorf("failed to eval CreateConfig: %w", err) } cfg := &mapstructure.DecoderConfig{ DecodeHook: mapstructure.StringToSliceHookFunc(","), WeaklyTypedInput: true, Result: vConfig.Interface(), } decoder, err := mapstructure.NewDecoder(cfg) if err != nil { return nil, fmt.Errorf("failed to create configuration decoder: %w", err) } err = decoder.Decode(config) if err != nil { return nil, fmt.Errorf("failed to decode configuration: %w", err) } _, err = descriptor.interpreter.Eval(`package wrapper import ( "context" ` + basePkg + ` "` + descriptor.Import + `" "github.com/traefik/traefik/v2/pkg/plugins" ) func NewWrapper(ctx context.Context, config *` + basePkg + `.Config, name string) (plugins.PP, error) { p, err := ` + basePkg + `.New(ctx, config, name) var pv plugins.PP = p return pv, err } `) if err != nil { return nil, fmt.Errorf("failed to eval wrapper: %w", err) } fnNew, err := descriptor.interpreter.Eval("wrapper.NewWrapper") if err != nil { return nil, fmt.Errorf("failed to eval New: %w", err) } ctx := context.Background() args := []reflect.Value{reflect.ValueOf(ctx), vConfig, reflect.ValueOf(providerName)} results := fnNew.Call(args) if len(results) > 1 && results[1].Interface() != nil { return nil, results[1].Interface().(error) } prov, ok := results[0].Interface().(PP) if !ok { return nil, fmt.Errorf("invalid provider type: %T", results[0].Interface()) } return &Provider{name: providerName, pp: prov}, nil } // Init wraps the Init method of a plugin. func (p *Provider) Init() error { return p.pp.Init() } // Provide wraps the Provide method of a plugin. func (p *Provider) Provide(configurationChan chan<- dynamic.Message, pool *safe.Pool) error { defer func() { if err := recover(); err != nil { log.WithoutContext().WithField(log.ProviderName, p.name).Errorf("panic inside the plugin %v", err) } }() cfgChan := make(chan json.Marshaler) err := p.pp.Provide(cfgChan) if err != nil { return fmt.Errorf("error from %s: %w", p.name, err) } pool.GoCtx(func(ctx context.Context) { logger := log.FromContext(log.With(ctx, log.Str(log.ProviderName, p.name))) for { select { case <-ctx.Done(): err := p.pp.Stop() if err != nil { logger.Errorf("failed to stop the provider: %v", err) } return case cfgPg := <-cfgChan: marshalJSON, err := cfgPg.MarshalJSON() if err != nil { logger.Errorf("failed to marshal configuration: %v", err) continue } cfg := &dynamic.Configuration{} err = json.Unmarshal(marshalJSON, cfg) if err != nil { logger.Errorf("failed to unmarshal configuration: %v", err) continue } configurationChan <- dynamic.Message{ ProviderName: p.name, Configuration: cfg, } } } }) return nil }