enhancement: graceful pipeline interrupt

conduit/pipeline/pipeline.go

@@ -6,9 +6,11 @@ import (
 	"fmt"
 	"net/http"
 	"os"
+	"os/signal"
 	"path"
 	"runtime/pprof"
 	"sync"
+	"syscall"
 	"time"
 
 	"github.com/prometheus/client_golang/prometheus"
@@ -329,6 +331,14 @@ func (p *pipelineImpl) Init() error {
 		go p.startMetricsServer()
 	}
 
+	stop := make(chan os.Signal, 1)
+	signal.Notify(stop, os.Interrupt, syscall.SIGTERM, syscall.SIGINT)
+	go func() {
+		sig := <-stop
+		p.logger.Infof("Pipeline received stopping signal <%v>, stopping pipeline. p.pipelineMetadata.NextRound: %d", sig, p.pipelineMetadata.NextRound)
+		p.Stop()
+	}()
+
 	return err
 }
 
@@ -338,31 +348,39 @@ func (p *pipelineImpl) Stop() {
 
 	if p.profFile != nil {
 		if err := p.profFile.Close(); err != nil {
-			p.logger.WithError(err).Errorf("%s: could not close CPUProf file", p.profFile.Name())
+			p.logger.WithError(err).Errorf("Pipeline.Stop(): %s: could not close CPUProf file", p.profFile.Name())
 		}
 		pprof.StopCPUProfile()
 	}
 
 	if p.cfg.PIDFilePath != "" {
 		if err := os.Remove(p.cfg.PIDFilePath); err != nil {
-			p.logger.WithError(err).Errorf("%s: could not remove pid file", p.cfg.PIDFilePath)
+			p.logger.WithError(err).Errorf("Pipeline.Stop(): %s: could not remove pid file", p.cfg.PIDFilePath)
+		} else {
+			p.logger.Infof("Pipeline.Stop(): %s: removed pid file", p.cfg.PIDFilePath)
 		}
 	}
 
 	if err := (*p.importer).Close(); err != nil {
 		// Log and continue on closing the rest of the pipeline
 		p.logger.Errorf("Pipeline.Stop(): Importer (%s) error on close: %v", (*p.importer).Metadata().Name, err)
+	} else {
+		p.logger.Infof("Pipeline.Stop(): Importer (%s) closed without error", (*p.importer).Metadata().Name)
 	}
 
 	for _, processor := range p.processors {
 		if err := (*processor).Close(); err != nil {
 			// Log and continue on closing the rest of the pipeline
 			p.logger.Errorf("Pipeline.Stop(): Processor (%s) error on close: %v", (*processor).Metadata().Name, err)
+		} else {
+			p.logger.Infof("Pipeline.Stop(): Processor (%s) closed without error", (*processor).Metadata().Name)
 		}
 	}
 
 	if err := (*p.exporter).Close(); err != nil {
 		p.logger.Errorf("Pipeline.Stop(): Exporter (%s) error on close: %v", (*p.exporter).Metadata().Name, err)
+	} else {
+		p.logger.Infof("Pipeline.Stop(): Exporter (%s) closed without error", (*p.exporter).Metadata().Name)
 	}
 }
 

conduit/plugins/exporters/postgresql/postgresql_exporter.go

@@ -148,6 +148,7 @@ func (exp *postgresqlExporter) Close() error {
 
 	exp.cf()
 	exp.wg.Wait()
+	exp.logger.Infof("exporter postgresql.Close() at round %d", atomic.LoadUint64(&exp.round))
 	return nil
 }
 

conduit/plugins/importers/algod/algod_importer.go

@@ -11,6 +11,7 @@ import (
 	"reflect"
 	"strconv"
 	"strings"
+	"sync/atomic"
 	"time"
 
 	"github.com/prometheus/client_golang/prometheus"
@@ -55,6 +56,7 @@ type algodImporter struct {
 	cancel  context.CancelFunc
 	mode    int
 	genesis *sdk.Genesis
+	round   uint64
 }
 
 //go:embed sample.yaml
@@ -396,6 +398,7 @@ func (algodImp *algodImporter) Close() error {
 	if algodImp.cancel != nil {
 		algodImp.cancel()
 	}
+	algodImp.logger.Infof("importer algod.Close() at round %d", algodImp.round)
 	return nil
 }
 
@@ -468,8 +471,8 @@ func (algodImp *algodImporter) GetBlock(rnd uint64) (data.BlockData, error) {
 				blk.Delta = &delta
 			}
 		}
-
-		return blk, err
+		atomic.StoreUint64(&algodImp.round, rnd+1)
+		return blk, nil
 	}
 
 	err = fmt.Errorf("failed to get block for round %d after %d attempts, check node configuration: %s", rnd, retries, err)