Web API Trigger capability and handler

core/capabilities/webapi/trigger/trigger.go

@@ -0,0 +1,299 @@
+package webapi
+
+import (
+	"context"
+	"encoding/json"
+	"errors"
+	"fmt"
+	"sync"
+
+	ethCommon "github.com/ethereum/go-ethereum/common"
+
+	"github.com/smartcontractkit/chainlink-common/pkg/capabilities"
+	"github.com/smartcontractkit/chainlink-common/pkg/services"
+	"github.com/smartcontractkit/chainlink-common/pkg/types/core"
+	"github.com/smartcontractkit/chainlink-common/pkg/values"
+	"github.com/smartcontractkit/chainlink/v2/core/logger"
+	"github.com/smartcontractkit/chainlink/v2/core/services/gateway/api"
+	"github.com/smartcontractkit/chainlink/v2/core/services/gateway/connector"
+	"github.com/smartcontractkit/chainlink/v2/core/services/gateway/handlers/common"
+	"github.com/smartcontractkit/chainlink/v2/core/services/gateway/handlers/webapicapabilities"
+)
+
+const defaultSendChannelBufferSize = 1000
+
+var webapiTriggerInfo = capabilities.MustNewCapabilityInfo(
+	webapicapabilities.TriggerType,
+	capabilities.CapabilityTypeTrigger,
+	"A trigger to start workflow execution from a web api call",
+)
+
+type Input struct {
+}
+type TriggerConfig struct {
+	AllowedSenders []string `toml:"allowedSenders"`
+	AllowedTopics  []string `toml:"allowedTopics"`
+	// RateLimiter    common.RateLimiterConfig `toml:"rateLimiter"`
+	RateLimiter    *values.Map `toml:"rateLimiter"`
+	RequiredParams []string    `toml:"requiredParams"`
+}
+
+type webapiTrigger struct {
+	allowedSendersMap map[string]bool
+	allowedTopicsMap  map[string]bool
+	ch                chan<- capabilities.TriggerResponse
+	config            TriggerConfig
+	rateLimiter       *common.RateLimiter
+}
+
+type triggerConnectorHandler struct {
+	services.StateMachine
+
+	capabilities.CapabilityInfo
+	capabilities.Validator[TriggerConfig, Input, capabilities.TriggerResponse]
+	connector           connector.GatewayConnector
+	lggr                logger.Logger
+	mu                  sync.Mutex
+	registeredWorkflows map[string]webapiTrigger
+}
+
+var _ capabilities.TriggerCapability = (*triggerConnectorHandler)(nil)
+var _ services.Service = &triggerConnectorHandler{}
+
+func NewTrigger(config string, registry core.CapabilitiesRegistry, connector connector.GatewayConnector, lggr logger.Logger) (*triggerConnectorHandler, error) {
+	if connector == nil {
+		return nil, errors.New("missing connector")
+	}
+	handler := &triggerConnectorHandler{
+		Validator:           capabilities.NewValidator[TriggerConfig, Input, capabilities.TriggerResponse](capabilities.ValidatorArgs{Info: webapiTriggerInfo}),
+		connector:           connector,
+		registeredWorkflows: map[string]webapiTrigger{},
+		lggr:                lggr.Named("WorkflowConnectorHandler"),
+	}
+
+	return handler, nil
+}
+
+// Iterate over each topic, checking against senders and rateLimits, then starting event processing and responding
+func (h *triggerConnectorHandler) processTrigger(ctx context.Context, gatewayID string, body *api.MessageBody, sender ethCommon.Address, payload webapicapabilities.TriggerRequestPayload) {
+	// Pass on the payload with the expectation that that is acceptable format for the executor
+	wrappedPayload, _ := values.WrapMap(payload)
+	hasMatchedAWorkflow := false
+	var response webapicapabilities.TriggerResponsePayload
+
+	for _, trigger := range h.registeredWorkflows {
+		topics := payload.Topics
+		// empty topics means all topics
+		if len(topics) == 0 {
+			topics = []string{}
+			for k := range trigger.allowedTopicsMap {
+				topics = append(topics, k)
+			}
+		}
+
+		for _, topic := range topics {
+
+			if trigger.allowedTopicsMap[topic] {
+				hasMatchedAWorkflow = true
+
+				if !trigger.allowedSendersMap[sender.String()] {
+					h.lggr.Errorw("Unauthorized Sender")
+					h.sendResponse(ctx, gatewayID, body, webapicapabilities.TriggerResponsePayload{Status: "ERROR", ErrorMessage: "Unauthorized Sender"})
+					return
+				}
+				if !trigger.rateLimiter.Allow(body.Sender) {
+					h.lggr.Errorw("request rate-limited")
+					h.sendResponse(ctx, gatewayID, body, webapicapabilities.TriggerResponsePayload{Status: "ERROR", ErrorMessage: "request rate-limited"})
+					return
+				}
+
+				TriggerEventID := body.Sender + payload.TriggerEventID
+				tr := capabilities.TriggerResponse{
+					Event: capabilities.TriggerEvent{
+						TriggerType: webapicapabilities.TriggerType,
+						ID:          TriggerEventID,
+						Outputs:     wrappedPayload,
+					},
+				}
+
+				trigger.ch <- tr
+				response = webapicapabilities.TriggerResponsePayload{Status: "ACCEPTED"}
+				// Sending n topics that match a workflow with n allowedTopics, can only be triggered once.
+				break
+			}
+		}
+	}
+	if !hasMatchedAWorkflow {
+		h.lggr.Errorw("No Matching Workflow Topics")
+		response = webapicapabilities.TriggerResponsePayload{Status: "ERROR", ErrorMessage: "No Matching Workflow Topics"}
+	}
+	_ = h.sendResponse(ctx, gatewayID, body, response)
+
+}
+
+// https://gateway-us-1.chain.link/web-trigger
+//   {
+//     jsonrpc: "2.0",
+//     id: "...",
+//     method: "web-trigger",
+//     params: {
+//       signature: "...",
+//       body: {
+//         don_id: "workflow_123",
+//         payload: {
+//           trigger_id: "[email protected]",
+//           trigger_event_id: "action_1234567890",
+//           timestamp: 1234567890,
+//           topics: ["daily_price_update"],
+//           params: {
+//             bid: "101",
+//             ask: "102"
+//           }
+//         }
+//       }
+//     }
+//   }
+
+// from Web API Trigger Doc
+// trigger_id          - ID of the trigger corresponding to the capability ID
+// trigger_event_id    - uniquely identifies generated event (scoped to trigger_id and sender)
+// timestamp           - timestamp of the event (unix time), needs to be within certain freshness to be processed
+// topics            - [OPTIONAL] list of topics (strings) to be started by this event (affects all topics if empty)
+// workflow_owners   - [OPTIONAL] list of workflow owners allowed to receive this event (affects all workflows if empty)
+// params            - key-value pairs that will be used as trigger output in the workflow Engine (translated to values.Map)
+
+func (h *triggerConnectorHandler) HandleGatewayMessage(ctx context.Context, gatewayID string, msg *api.Message) {
+	// TODO: Validate Signature
+	body := &msg.Body
+	sender := ethCommon.HexToAddress(body.Sender)
+	var payload webapicapabilities.TriggerRequestPayload
+	err := json.Unmarshal(body.Payload, &payload)
+	if err != nil {
+		h.lggr.Errorw("error decoding payload", "err", err)
+		h.sendResponse(ctx, gatewayID, body, webapicapabilities.TriggerResponsePayload{Status: "ERROR", ErrorMessage: fmt.Errorf("error %s decoding payload", err.Error()).Error()})
+		return
+	}
+
+	switch body.Method {
+	case webapicapabilities.MethodWebAPITrigger:
+		h.processTrigger(ctx, gatewayID, body, sender, payload)
+
+	default:
+		h.lggr.Errorw("unsupported method", "id", gatewayID, "method", body.Method)
+		h.sendResponse(ctx, gatewayID, body, webapicapabilities.TriggerResponsePayload{Status: "ERROR", ErrorMessage: fmt.Errorf("unsupported method %s", body.Method).Error()})
+	}
+}
+
+func (h *triggerConnectorHandler) RegisterTrigger(ctx context.Context, req capabilities.TriggerRegistrationRequest) (<-chan capabilities.TriggerResponse, error) {
+	cfg := req.Config
+	if cfg == nil {
+		h.lggr.Errorw("config is required to register a web api trigger")
+		return nil, errors.New("config is required to register a web api trigger")
+	}
+
+	reqConfig, err := h.ValidateConfig(cfg)
+	if err != nil {
+		h.lggr.Errorw("error unwrapping config", "err", err)
+		return nil, err
+	}
+
+	if len(reqConfig.AllowedSenders) == 0 {
+		h.lggr.Errorw("allowedSenders must have at least 1 entry")
+		return nil, errors.New("allowedSenders must have at least 1 entry")
+	}
+
+	h.mu.Lock()
+	defer h.mu.Unlock()
+	_, errBool := h.registeredWorkflows[req.TriggerID]
+	if errBool {
+		h.lggr.Errorf("triggerId %s already registered", req.TriggerID)
+		return nil, fmt.Errorf("triggerId %s already registered", req.TriggerID)
+	}
+
+	var rateLimiterCfg common.RateLimiterConfig
+	err = reqConfig.RateLimiter.UnwrapTo(&rateLimiterCfg)
+	if err != nil {
+		h.lggr.Errorw("error creating unwrapping RateLimiter", "err", err, "RateLimiter config", reqConfig.RateLimiter)
+		return nil, err
+	}
+
+	rateLimiter, err := common.NewRateLimiter(rateLimiterCfg)
+	if err != nil {
+		h.lggr.Errorw("error creating RateLimiter", "err", err, "RateLimiter config", reqConfig.RateLimiter)
+		return nil, err
+	}
+
+	allowedSendersMap := map[string]bool{}
+	for _, k := range reqConfig.AllowedSenders {
+		allowedSendersMap[k] = true
+	}
+
+	allowedTopicsMap := map[string]bool{}
+	for _, k := range reqConfig.AllowedTopics {
+		allowedTopicsMap[k] = true
+	}
+
+	ch := make(chan capabilities.TriggerResponse, defaultSendChannelBufferSize)
+
+	h.registeredWorkflows[req.TriggerID] = webapiTrigger{
+		allowedTopicsMap:  allowedTopicsMap,
+		allowedSendersMap: allowedSendersMap,
+		ch:                ch,
+		config:            *reqConfig,
+		rateLimiter:       rateLimiter,
+	}
+
+	return ch, nil
+}
+
+func (h *triggerConnectorHandler) UnregisterTrigger(ctx context.Context, req capabilities.TriggerRegistrationRequest) error {
+	h.mu.Lock()
+	defer h.mu.Unlock()
+	workflow, ok := h.registeredWorkflows[req.TriggerID]
+	if !ok {
+		return fmt.Errorf("triggerId %s not registered", req.TriggerID)
+	}
+
+	close(workflow.ch)
+	delete(h.registeredWorkflows, req.TriggerID)
+	return nil
+}
+
+func (h *triggerConnectorHandler) Start(ctx context.Context) error {
+	return h.StartOnce("GatewayConnectorServiceWrapper", func() error {
+		return h.connector.AddHandler([]string{"web_trigger"}, h)
+	})
+}
+func (h *triggerConnectorHandler) Close() error {
+	return h.StopOnce("GatewayConnectorServiceWrapper", func() error {
+		return nil
+	})
+}
+
+func (h *triggerConnectorHandler) HealthReport() map[string]error {
+	return map[string]error{h.Name(): h.Healthy()}
+}
+
+func (h *triggerConnectorHandler) Name() string {
+	return "WebAPITrigger"
+}
+
+func (h *triggerConnectorHandler) sendResponse(ctx context.Context, gatewayID string, requestBody *api.MessageBody, payload any) error {
+	payloadJSON, err := json.Marshal(payload)
+	if err != nil {
+		h.lggr.Errorw("error marshalling payload", "err", err)
+		payloadJSON, _ = json.Marshal(webapicapabilities.TriggerResponsePayload{Status: "ERROR", ErrorMessage: fmt.Errorf("error %s marshalling payload", err.Error()).Error()})
+	}
+
+	msg := &api.Message{
+		Body: api.MessageBody{
+			MessageId: requestBody.MessageId,
+			DonId:     requestBody.DonId,
+			Method:    requestBody.Method,
+			Receiver:  requestBody.Sender,
+			Payload:   payloadJSON,
+		},
+	}
+
+	return h.connector.SendToGateway(ctx, gatewayID, msg)
+}