feat: add an option to trigger a webhook at any block (#79)

pkg/app/flags.go

@@ -77,6 +77,10 @@ var Flags = []cli.Flag{
 		Name:  "webhook-url",
 		Usage: "endpoint where to send upgrade webhooks (experimental)",
 	},
+	&cli.StringSliceFlag{
+		Name:  "webhook-custom-block",
+		Usage: "trigger a custom webhook at a given block number (experimental)",
+	},
 	&cli.StringFlag{
 		Name:  "x-gov",
 		Usage: "version of the gov module to use (v1|v1beta1)",

pkg/app/run.go

@@ -6,6 +6,7 @@ import (
 	"net/url"
 	"os"
 	"os/signal"
+	"strconv"
 	"syscall"
 
 	"github.com/cometbft/cometbft/rpc/client/http"
@@ -31,23 +32,24 @@ func RunFunc(cCtx *cli.Context) error {
 		ctx = cCtx.Context
 
 		// Config flags
-		chainID      = cCtx.String("chain-id")
-		httpAddr     = cCtx.String("http-addr")
-		logLevel     = cCtx.String("log-level")
-		namespace    = cCtx.String("namespace")
-		noColor      = cCtx.Bool("no-color")
-		nodes        = cCtx.StringSlice("node")
-		noGov        = cCtx.Bool("no-gov")
-		noStaking    = cCtx.Bool("no-staking")
-		noUpgrade    = cCtx.Bool("no-upgrade")
-		noCommission = cCtx.Bool("no-commission")
-		denom        = cCtx.String("denom")
-		denomExpon   = cCtx.Uint("denom-exponent")
-		startTimeout = cCtx.Duration("start-timeout")
-		stopTimeout  = cCtx.Duration("stop-timeout")
-		validators   = cCtx.StringSlice("validator")
-		webhookURL   = cCtx.String("webhook-url")
-		xGov         = cCtx.String("x-gov")
+		chainID             = cCtx.String("chain-id")
+		httpAddr            = cCtx.String("http-addr")
+		logLevel            = cCtx.String("log-level")
+		namespace           = cCtx.String("namespace")
+		noColor             = cCtx.Bool("no-color")
+		nodes               = cCtx.StringSlice("node")
+		noGov               = cCtx.Bool("no-gov")
+		noStaking           = cCtx.Bool("no-staking")
+		noUpgrade           = cCtx.Bool("no-upgrade")
+		noCommission        = cCtx.Bool("no-commission")
+		denom               = cCtx.String("denom")
+		denomExpon          = cCtx.Uint("denom-exponent")
+		startTimeout        = cCtx.Duration("start-timeout")
+		stopTimeout         = cCtx.Duration("stop-timeout")
+		validators          = cCtx.StringSlice("validator")
+		webhookURL          = cCtx.String("webhook-url")
+		webhookCustomBlocks = cCtx.StringSlice("webhook-custom-block")
+		xGov                = cCtx.String("x-gov")
 	)
 
 	//
@@ -84,12 +86,34 @@ func RunFunc(cCtx *cli.Context) error {
 		return err
 	}
 
+	var wh *webhook.Webhook
+	if webhookURL != "" {
+		whURL, err := url.Parse(webhookURL)
+		if err != nil {
+			return fmt.Errorf("failed to parse webhook endpoint: %w", err)
+		}
+		wh = webhook.New(*whURL)
+	}
+
+	// Custom block webhooks
+	blockWebhooks := []watcher.BlockWebhook{}
+	for _, block := range webhookCustomBlocks {
+		blockHeight, err := strconv.ParseInt(block, 10, 64)
+		if err != nil {
+			return fmt.Errorf("failed to parse block height for custom webhook (%s): %w", block, err)
+		}
+		blockWebhooks = append(blockWebhooks, watcher.BlockWebhook{
+			Height:   blockHeight,
+			Metadata: map[string]string{},
+		})
+	}
+
 	//
 	// Node Watchers
 	//
 	metrics := metrics.New(namespace)
 	metrics.Register()
-	blockWatcher := watcher.NewBlockWatcher(trackedValidators, metrics, os.Stdout)
+	blockWatcher := watcher.NewBlockWatcher(trackedValidators, metrics, os.Stdout, wh, blockWebhooks)
 	errg.Go(func() error {
 		return blockWatcher.Start(ctx)
 	})
@@ -128,14 +152,6 @@ func RunFunc(cCtx *cli.Context) error {
 			return votesWatcher.Start(ctx)
 		})
 	}
-	var wh *webhook.Webhook
-	if webhookURL != "" {
-		whURL, err := url.Parse(webhookURL)
-		if err != nil {
-			return fmt.Errorf("failed to parse webhook endpoint: %w", err)
-		}
-		wh = webhook.New(*whURL)
-	}
 
 	var upgradeWatcher *watcher.UpgradeWatcher
 	if !noUpgrade {

pkg/watcher/block.go

@@ -13,10 +13,16 @@ import (
 	"github.com/fatih/color"
 	"github.com/kilnfi/cosmos-validator-watcher/pkg/metrics"
 	"github.com/kilnfi/cosmos-validator-watcher/pkg/rpc"
+	"github.com/kilnfi/cosmos-validator-watcher/pkg/webhook"
 	"github.com/rs/zerolog/log"
 	"github.com/shopspring/decimal"
 )
 
+type BlockWebhook struct {
+	Height   int64             `json:"height"`
+	Metadata map[string]string `json:"metadata"`
+}
+
 type BlockWatcher struct {
 	trackedValidators   []TrackedValidator
 	metrics             *metrics.Metrics
@@ -25,14 +31,18 @@ type BlockWatcher struct {
 	validatorSet        atomic.Value // []*types.Validator
 	latestBlockHeight   int64
 	latestBlockProposer string
+	webhook             *webhook.Webhook
+	customWebhooks      []BlockWebhook
 }
 
-func NewBlockWatcher(validators []TrackedValidator, metrics *metrics.Metrics, writer io.Writer) *BlockWatcher {
+func NewBlockWatcher(validators []TrackedValidator, metrics *metrics.Metrics, writer io.Writer, webhook *webhook.Webhook, customWebhooks []BlockWebhook) *BlockWatcher {
 	return &BlockWatcher{
 		trackedValidators: validators,
 		metrics:           metrics,
 		writer:            writer,
 		blockChan:         make(chan *BlockInfo),
+		webhook:           webhook,
+		customWebhooks:    customWebhooks,
 	}
 }
 
@@ -42,7 +52,7 @@ func (w *BlockWatcher) Start(ctx context.Context) error {
 		case <-ctx.Done():
 			return nil
 		case block := <-w.blockChan:
-			w.handleBlockInfo(block)
+			w.handleBlockInfo(ctx, block)
 		}
 	}
 }
@@ -159,7 +169,7 @@ func (w *BlockWatcher) syncValidatorSet(ctx context.Context, n *rpc.Node) error
 	return nil
 }
 
-func (w *BlockWatcher) handleBlockInfo(block *BlockInfo) {
+func (w *BlockWatcher) handleBlockInfo(ctx context.Context, block *BlockInfo) {
 	chainId := block.ChainID
 
 	if w.latestBlockHeight >= block.Height {
@@ -220,6 +230,9 @@ func (w *BlockWatcher) handleBlockInfo(block *BlockInfo) {
 		strings.Join(validatorStatus, " "),
 	)
 
+	// Handle webhooks
+	w.handleWebhooks(ctx, block)
+
 	w.latestBlockHeight = block.Height
 	w.latestBlockProposer = block.ProposerAddress
 }
@@ -261,3 +274,38 @@ func (w *BlockWatcher) isValidatorActive(address string) bool {
 	}
 	return false
 }
+
+func (w *BlockWatcher) handleWebhooks(ctx context.Context, block *BlockInfo) {
+	if len(w.customWebhooks) == 0 {
+		return
+	}
+
+	newWebhooks := []BlockWebhook{}
+
+	for _, webhook := range w.customWebhooks {
+		// If webhook block height is passed
+		if webhook.Height <= block.Height {
+			w.triggerWebhook(ctx, block.ChainID, webhook)
+		} else {
+			newWebhooks = append(newWebhooks, webhook)
+		}
+	}
+
+	w.customWebhooks = newWebhooks
+}
+
+func (w *BlockWatcher) triggerWebhook(ctx context.Context, chainID string, wh BlockWebhook) {
+	msg := make(map[string]string)
+	msg["type"] = "custom"
+	msg["block"] = fmt.Sprintf("%d", wh.Height)
+	msg["chain_id"] = chainID
+	for k, v := range wh.Metadata {
+		msg[k] = v
+	}
+
+	go func() {
+		if err := w.webhook.Send(context.Background(), msg); err != nil {
+			log.Error().Err(err).Msg("failed to send upgrade webhook")
+		}
+	}()
+}

pkg/watcher/block_test.go

@@ -2,10 +2,13 @@ package watcher
 
 import (
 	"bytes"
+	"context"
+	"net/url"
 	"strings"
 	"testing"
 
 	"github.com/kilnfi/cosmos-validator-watcher/pkg/metrics"
+	"github.com/kilnfi/cosmos-validator-watcher/pkg/webhook"
 	"github.com/prometheus/client_golang/prometheus/testutil"
 	"gotest.tools/assert"
 )
@@ -26,6 +29,8 @@ func TestBlockWatcher(t *testing.T) {
 		},
 		metrics.New("cosmos_validator_watcher"),
 		&bytes.Buffer{},
+		webhook.New(url.URL{}),
+		[]BlockWebhook{},
 	)
 
 	t.Run("Handle BlockInfo", func(t *testing.T) {
@@ -114,7 +119,7 @@ func TestBlockWatcher(t *testing.T) {
 		}
 
 		for _, block := range blocks {
-			blockWatcher.handleBlockInfo(&block)
+			blockWatcher.handleBlockInfo(context.Background(), &block)
 		}
 
 		assert.Equal(t,

pkg/webhook/webhook.go

@@ -54,7 +54,7 @@ func (w *Webhook) Send(ctx context.Context, message interface{}) error {
 	}, retryOpts...)
 }
 
-func (w *Webhook) postRequest(ctx context.Context, req *http.Request) error {
+func (w *Webhook) postRequest(_ context.Context, req *http.Request) error {
 	resp, err := w.client.Do(req)
 	if err != nil {
 		return fmt.Errorf("failed to send request: %w", err)