common: common ping w/ backoff, use in aggregator/verifier/indexer (#507)

* common: common ping w/ backoff, use in aggregator/verifier/indexer

* lint

Author: makramkd

aggregator/pkg/storage/factory.go

@@ -10,6 +10,7 @@ import (
 	"github.com/smartcontractkit/chainlink-ccv/aggregator/pkg/common"
 	"github.com/smartcontractkit/chainlink-ccv/aggregator/pkg/model"
 	"github.com/smartcontractkit/chainlink-ccv/aggregator/pkg/storage/postgres"
+	ccvcommon "github.com/smartcontractkit/chainlink-ccv/common"
 	"github.com/smartcontractkit/chainlink-common/pkg/logger"
 
 	_ "github.com/lib/pq" // PostgreSQL driver
@@ -93,7 +94,7 @@ func (f *Factory) createPostgreSQLStorage(config *model.StorageConfig) (CommitVe
 		"connMaxIdleTime", connMaxIdleTime,
 	)
 
-	if err := db.Ping(); err != nil {
+	if err := ccvcommon.EnsureDBConnection(f.logger, db); err != nil {
 		return nil, fmt.Errorf("failed to ping PostgreSQL database: %w", err)
 	}
 

cmd/verifier/committee/main.go

@@ -17,6 +17,7 @@ import (
 	"go.uber.org/zap/zapcore"
 
 	cmd "github.com/smartcontractkit/chainlink-ccv/cmd/verifier"
+	ccvcommon "github.com/smartcontractkit/chainlink-ccv/common"
 	"github.com/smartcontractkit/chainlink-ccv/integration/storageaccess"
 	"github.com/smartcontractkit/chainlink-ccv/protocol"
 	"github.com/smartcontractkit/chainlink-ccv/protocol/common/hmac"
@@ -333,7 +334,7 @@ func createChainStatusManager(lggr logger.Logger) (protocol.ChainStatusManager,
 	db.SetConnMaxLifetime(time.Duration(connMaxLifetime) * time.Second)
 	db.SetConnMaxIdleTime(time.Duration(connMaxIdleTime) * time.Second)
 
-	if err := db.Ping(); err != nil {
+	if err := ccvcommon.EnsureDBConnection(lggr, db); err != nil {
 		_ = db.Close()
 		return nil, nil, fmt.Errorf("failed to ping postgres database: %w", err)
 	}

common/db_utils.go

@@ -0,0 +1,42 @@
+package common
+
+import (
+	"context"
+	"fmt"
+	"time"
+
+	"github.com/smartcontractkit/chainlink-common/pkg/logger"
+)
+
+const (
+	maxRetries    = 10
+	timeout       = 1 * time.Second
+	retryInterval = 3 * time.Second
+)
+
+// Pingable is implemented by servers that support pings.
+type Pingable interface {
+	// PingContext pings the server and returns an error if the ping is unsuccessful.
+	PingContext(ctx context.Context) error
+}
+
+// EnsureDBConnection ensures that the database is up and running by pinging it.
+func EnsureDBConnection(lggr logger.Logger, db Pingable) error {
+	pingFn := func() error {
+		ctx, cancel := context.WithTimeout(context.Background(), timeout)
+		defer cancel()
+		return db.PingContext(ctx)
+	}
+	for range maxRetries {
+		err := pingFn()
+		if err == nil {
+			return nil
+		}
+		lggr.Warnw("failed to connect to database, retrying after sleeping",
+			"err", err,
+			"retryInterval", retryInterval.String(),
+			"maxRetries", maxRetries)
+		time.Sleep(retryInterval)
+	}
+	return fmt.Errorf("failed to connect to database after %d retries", maxRetries)
+}

indexer/cmd/main.go

@@ -12,6 +12,7 @@ import (
 	"github.com/pressly/goose/v3"
 	"go.uber.org/zap/zapcore"
 
+	ccvcommon "github.com/smartcontractkit/chainlink-ccv/common"
 	"github.com/smartcontractkit/chainlink-ccv/indexer/pkg/api"
 	"github.com/smartcontractkit/chainlink-ccv/indexer/pkg/common"
 	"github.com/smartcontractkit/chainlink-ccv/indexer/pkg/config"
@@ -287,32 +288,6 @@ func createPostgresStorage(ctx context.Context, lggr logger.Logger, cfg *config.
 	return dbStore
 }
 
-// ensureDBConnection ensures that the database is up and running by pinging it.
-func ensureDBConnection(lggr logger.Logger, db *sql.DB) error {
-	const (
-		maxRetries    = 10
-		timeout       = 1 * time.Second
-		retryInterval = 3 * time.Second
-	)
-	pingFn := func() error {
-		ctx, cancel := context.WithTimeout(context.Background(), timeout)
-		defer cancel()
-		return db.PingContext(ctx)
-	}
-	for range maxRetries {
-		err := pingFn()
-		if err == nil {
-			return nil
-		}
-		lggr.Warnw("failed to connect to database, retrying after sleeping",
-			"err", err,
-			"retryInterval", retryInterval.String(),
-			"maxRetries", maxRetries)
-		time.Sleep(retryInterval)
-	}
-	return fmt.Errorf("failed to connect to database after %d retries", maxRetries)
-}
-
 // runMigrations runs all pending database migrations using goose.
 func runMigrations(lggr logger.Logger, dbURI, migrationsDir string) error {
 	// Open a connection to the database for migrations
@@ -321,7 +296,7 @@ func runMigrations(lggr logger.Logger, dbURI, migrationsDir string) error {
 		return err
 	}
 
-	err = ensureDBConnection(lggr, db)
+	err = ccvcommon.EnsureDBConnection(lggr, db)
 	if err != nil {
 		return fmt.Errorf("could not connect to database: %w", err)
 	}