Merge pull request #80 from blinklabs-io/feat/webhook

feat: webhook

output/output.go

@@ -18,4 +18,5 @@ package output
 import (
 	_ "github.com/blinklabs-io/snek/output/log"
 	_ "github.com/blinklabs-io/snek/output/notify"
+	_ "github.com/blinklabs-io/snek/output/webhook"
 )

output/webhook/options.go

@@ -0,0 +1,26 @@
+// Copyright 2023 Blink Labs, LLC.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package webhook
+
+// import "github.com/blinklabs-io/snek/event"
+
+type WebhookOptionFunc func(*WebhookOutput)
+
+// WithUrl specifies the webhook URL
+func WithUrl(url string) WebhookOptionFunc {
+	return func(o *WebhookOutput) {
+		o.url = url
+	}
+}

output/webhook/plugin.go

@@ -0,0 +1,50 @@
+// Copyright 2023 Blink Labs, LLC.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package webhook
+
+import (
+	"github.com/blinklabs-io/snek/plugin"
+)
+
+var cmdlineOptions struct {
+	url string
+}
+
+func init() {
+	plugin.Register(
+		plugin.PluginEntry{
+			Type:               plugin.PluginTypeOutput,
+			Name:               "webhook",
+			Description:        "send events via HTTP POST to a webhook server",
+			NewFromOptionsFunc: NewFromCmdlineOptions,
+			Options: []plugin.PluginOption{
+				{
+					Name:         "url",
+					Type:         plugin.PluginOptionTypeString,
+					Description:  "specifies the url to use",
+					DefaultValue: "http://localhost:3000",
+					Dest:         &(cmdlineOptions.url),
+				},
+			},
+		},
+	)
+}
+
+func NewFromCmdlineOptions() plugin.Plugin {
+	p := New(
+		WithUrl(cmdlineOptions.url),
+	)
+	return p
+}

output/webhook/webhook.go

@@ -0,0 +1,143 @@
+// Copyright 2023 Blink Labs, LLC.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package webhook
+
+import (
+	"bytes"
+	"encoding/json"
+	"fmt"
+	"io"
+	"net/http"
+
+	"github.com/blinklabs-io/snek/event"
+	"github.com/blinklabs-io/snek/input/chainsync"
+	"github.com/blinklabs-io/snek/internal/logging"
+	"github.com/blinklabs-io/snek/internal/version"
+)
+
+type WebhookOutput struct {
+	errorChan chan error
+	eventChan chan event.Event
+	url       string
+}
+
+func New(options ...WebhookOptionFunc) *WebhookOutput {
+	w := &WebhookOutput{
+		errorChan: make(chan error),
+		eventChan: make(chan event.Event, 10),
+		url:       "http://localhost:3000",
+	}
+	for _, option := range options {
+		option(w)
+	}
+	return w
+}
+
+// Start the webhook output
+func (w *WebhookOutput) Start() error {
+	logger := logging.GetLogger()
+	logger.Infof("starting webhook server")
+	go func() {
+		for {
+			evt, ok := <-w.eventChan
+			// Channel has been closed, which means we're shutting down
+			if !ok {
+				return
+			}
+			payload := evt.Payload
+			if payload == nil {
+				panic(fmt.Errorf("ERROR: %v", payload))
+			}
+			logger.Infof("debug: type: %s", evt.Type)
+			switch evt.Type {
+			case "chainsync.block":
+				be := payload.(chainsync.BlockEvent)
+				evt.Payload = be
+			case "chainsync.rollback":
+				re := payload.(chainsync.RollbackEvent)
+				evt.Payload = re
+			case "chainsync.transaction":
+				te := payload.(chainsync.TransactionEvent)
+				evt.Payload = te
+			default:
+				logger.Errorf("unknown event type: %s", evt.Type)
+				return
+			}
+			// TODO: error handle
+			err := SendWebhook(&evt, w.url)
+			if err != nil {
+				logger.Errorf("ERROR: %s", err)
+			}
+		}
+	}()
+	return nil
+}
+
+func SendWebhook(e *event.Event, url string) error {
+	logger := logging.GetLogger()
+	logger.Infof("sending event %s to %s", e.Type, url)
+	data, err := json.Marshal(e)
+	if err != nil {
+		return fmt.Errorf("%s", err)
+	}
+	// Setup request
+	req, err := http.NewRequest(http.MethodPost, url, bytes.NewReader(data))
+	if err != nil {
+		return fmt.Errorf("%s", err)
+	}
+	req.Header.Add("Content-Type", "application/json")
+	req.Header.Add("User-Agent", fmt.Sprintf("Snek/%s", version.GetVersionString()))
+	// Send payload
+	resp, err := http.DefaultClient.Do(req)
+	if err != nil {
+		return fmt.Errorf("%s", err)
+	}
+	respBody, err := io.ReadAll(resp.Body)
+	if err != nil {
+		return fmt.Errorf("%s", err)
+	}
+	defer resp.Body.Close()
+
+	logger.Infof("sent: %s, payload: %s, body: %s, response: %s, status: %d",
+		url,
+		string(data),
+		string(respBody),
+		resp.Status,
+		resp.StatusCode,
+	)
+	return nil
+}
+
+// Stop the embedded output
+func (w *WebhookOutput) Stop() error {
+	close(w.eventChan)
+	close(w.errorChan)
+	return nil
+}
+
+// ErrorChan returns the input error channel
+func (w *WebhookOutput) ErrorChan() chan error {
+	return w.errorChan
+}
+
+// InputChan returns the input event channel
+func (w *WebhookOutput) InputChan() chan<- event.Event {
+	return w.eventChan
+}
+
+// OutputChan always returns nil
+func (w *WebhookOutput) OutputChan() <-chan event.Event {
+	return nil
+}