Retry request logic

Author: ihippik

go.mod

@@ -3,8 +3,10 @@ module github.com/ihippik/lambda-go
 go 1.21.1
 
 require (
+	github.com/avast/retry-go v3.0.0+incompatible
 	github.com/docker/docker v23.0.3+incompatible
 	github.com/docker/go-connections v0.4.0
+	github.com/gorilla/mux v1.8.0
 	github.com/ihippik/config v0.1.1
 	github.com/sethvargo/go-envconfig v0.9.0
 )
@@ -20,7 +22,6 @@ require (
 	github.com/getsentry/sentry-go v0.23.0 // indirect
 	github.com/gogo/protobuf v1.3.2 // indirect
 	github.com/golang/protobuf v1.5.3 // indirect
-	github.com/gorilla/mux v1.8.0 // indirect
 	github.com/ihippik/slog-sentry v0.1.0 // indirect
 	github.com/klauspost/compress v1.16.7 // indirect
 	github.com/matttproud/golang_protobuf_extensions v1.0.4 // indirect

go.sum

@@ -4,6 +4,8 @@ github.com/Microsoft/go-winio v0.6.1 h1:9/kr64B9VUZrLm5YYwbGtUJnMgqWVOdUAXu6Migc
 github.com/Microsoft/go-winio v0.6.1/go.mod h1:LRdKpFKfdobln8UmuiYcKPot9D2v6svN5+sAH+4kjUM=
 github.com/Microsoft/hcsshim v0.11.0 h1:7EFNIY4igHEXUdj1zXgAyU3fLc7QfOKHbkldRVTBdiM=
 github.com/Microsoft/hcsshim v0.11.0/go.mod h1:OEthFdQv/AD2RAdzR6Mm1N1KPCztGKDurW1Z8b8VGMM=
+github.com/avast/retry-go v3.0.0+incompatible h1:4SOWQ7Qs+oroOTQOYnAHqelpCO0biHSxpiH9JdtuBj0=
+github.com/avast/retry-go v3.0.0+incompatible/go.mod h1:XtSnn+n/sHqQIpZ10K1qAevBhOOCWBLXXy3hyiqqBrY=
 github.com/beorn7/perks v1.0.1 h1:VlbKKnNfV8bJzeqoa4cOKqO6bYr3WgKZxO8Z16+hsOM=
 github.com/beorn7/perks v1.0.1/go.mod h1:G2ZrVWU2WbWT9wwq4/hrbKbnv/1ERSJQ0ibhJ6rlkpw=
 github.com/cespare/xxhash/v2 v2.2.0 h1:DC2CZ1Ep5Y4k3ZQ899DldepgrayRUGE6BBZ/cd9Cj44=

lambda/meta.go

@@ -14,3 +14,7 @@ func newMetaData(containerID string, port int) *metaData {
 func (m metaData) address() string {
 	return "http://localhost:" + strconv.Itoa(m.port)
 }
+
+func (m metaData) short() string {
+	return m.containerID[:5]
+}

lambda/service.go

@@ -16,6 +16,8 @@ import (
 	"strings"
 	"sync"
 
+	"github.com/avast/retry-go"
+
 	"github.com/ihippik/lambda-go/config"
 )
 
@@ -84,37 +86,59 @@ func (s *Service) Invoke(ctx context.Context, name string, data []byte) ([]byte,
 		return nil, fmt.Errorf("start container: %w", err)
 	}
 
-	// FIXME: need to wait for container start
+	respData, err := s.makeRequest(ctx, data, containerMeta)
+	if err != nil {
+		return nil, fmt.Errorf("make request: %w", err)
+	}
+
+	if err := s.builder.ContainerStop(ctx, containerMeta.containerID); err != nil {
+		return nil, fmt.Errorf("stop container: %w", err)
+	}
+
+	return respData, nil
+}
+
+// makeRequest makes http request to container with Lambda.
+// Using retry pattern for waiting container ready for requests.
+func (s *Service) makeRequest(ctx context.Context, data []byte, meta *metaData) ([]byte, error) {
+	const numAttempts = 3
 
 	req, err := http.NewRequestWithContext(
 		ctx,
 		http.MethodPost,
-		containerMeta.address(),
+		meta.address(),
 		bytes.NewReader(data),
 	)
 	if err != nil {
 		return nil, fmt.Errorf("post request: %w", err)
 	}
 
-	resp, err := s.client.Do(req)
-	if err != nil {
-		return nil, fmt.Errorf("do request: %w", err)
-	}
+	var respData []byte
 
-	defer resp.Body.Close()
+	if err = retry.Do(
+		func() error {
+			resp, err := s.client.Do(req)
+			if err != nil {
+				return fmt.Errorf("do request: %w", err)
+			}
+			defer resp.Body.Close()
 
-	respData, err := io.ReadAll(resp.Body)
-	if err != nil {
-		return nil, fmt.Errorf("read response body: %w", err)
-	}
+			respData, err = io.ReadAll(resp.Body)
+			if err != nil {
+				return fmt.Errorf("read response body: %w", err)
+			}
 
-	if err := s.builder.ContainerStop(ctx, containerMeta.containerID); err != nil {
-		return nil, fmt.Errorf("stop container: %w", err)
+			return nil
+		},
+		retry.Attempts(numAttempts),
+	); err != nil {
+		return nil, err
 	}
 
 	return respData, nil
 }
 
+// decompress decompresses tar.gz archive.
 func (s *Service) decompress(dst string, file io.ReadCloser) error {
 	uncompressedStream, err := gzip.NewReader(file)
 	if err != nil {