kinesis-consumer/examples/consumer-dynamo/main.go
2021-12-04 10:42:17 -08:00

149 lines
3.6 KiB
Go

package main
import (
"context"
"expvar"
"flag"
"fmt"
"log"
"net"
"net/http"
"os"
"os/signal"
alog "github.com/apex/log"
"github.com/apex/log/handlers/text"
"github.com/aws/aws-sdk-go-v2/aws"
"github.com/aws/aws-sdk-go-v2/config"
"github.com/aws/aws-sdk-go-v2/credentials"
"github.com/aws/aws-sdk-go-v2/service/dynamodb"
"github.com/aws/aws-sdk-go-v2/service/kinesis"
"github.com/aws/aws-sdk-go-v2/service/kinesis/types"
consumer "github.com/harlow/kinesis-consumer"
storage "github.com/harlow/kinesis-consumer/store/ddb"
)
// kick off a server for exposing scan metrics
func init() {
sock, err := net.Listen("tcp", "localhost:8080")
if err != nil {
log.Printf("net listen error: %v", err)
}
go func() {
fmt.Println("Metrics available at http://localhost:8080/debug/vars")
http.Serve(sock, nil)
}()
}
// A myLogger provides a minimalistic logger satisfying the Logger interface.
type myLogger struct {
logger alog.Logger
}
// Log logs the parameters to the stdlib logger. See log.Println.
func (l *myLogger) Log(args ...interface{}) {
l.logger.Infof("producer: %v", args...)
}
func main() {
// Wrap myLogger around apex logger
mylog := &myLogger{
logger: alog.Logger{
Handler: text.New(os.Stdout),
Level: alog.DebugLevel,
},
}
var (
app = flag.String("app", "", "Consumer app name")
stream = flag.String("stream", "", "Stream name")
table = flag.String("table", "", "Checkpoint table name")
kinesisEndpoint = flag.String("endpoint", "http://localhost:4567", "Kinesis endpoint")
awsRegion = flag.String("region", "us-west-2", "AWS Region")
)
flag.Parse()
resolver := aws.EndpointResolverFunc(func(service, region string) (aws.Endpoint, error) {
return aws.Endpoint{
PartitionID: "aws",
URL: *kinesisEndpoint,
SigningRegion: *awsRegion,
}, nil
})
// client
cfg, err := config.LoadDefaultConfig(
context.TODO(),
config.WithRegion(*awsRegion),
config.WithEndpointResolver(resolver),
config.WithCredentialsProvider(credentials.NewStaticCredentialsProvider("user", "pass", "token")),
)
if err != nil {
log.Fatalf("unable to load SDK config, %v", err)
}
var (
myDdbClient = dynamodb.NewFromConfig(cfg)
myKsis = kinesis.NewFromConfig(cfg)
)
// ddb persitance
ddb, err := storage.New(*app, *table, storage.WithDynamoClient(myDdbClient), storage.WithRetryer(&MyRetryer{}))
if err != nil {
log.Fatalf("checkpoint error: %v", err)
}
// expvar counter
var counter = expvar.NewMap("counters")
// consumer
c, err := consumer.New(
*stream,
consumer.WithStore(ddb),
consumer.WithLogger(mylog),
consumer.WithCounter(counter),
consumer.WithClient(myKsis),
)
if err != nil {
log.Fatalf("consumer error: %v", err)
}
// use cancel func to signal shutdown
ctx, cancel := context.WithCancel(context.Background())
// trap SIGINT, wait to trigger shutdown
signals := make(chan os.Signal, 1)
signal.Notify(signals, os.Interrupt)
go func() {
<-signals
cancel()
}()
// scan stream
err = c.Scan(ctx, func(r *consumer.Record) error {
fmt.Println(string(r.Data))
return nil // continue scanning
})
if err != nil {
log.Fatalf("scan error: %v", err)
}
if err := ddb.Shutdown(); err != nil {
log.Fatalf("storage shutdown error: %v", err)
}
}
// MyRetryer used for storage
type MyRetryer struct {
storage.Retryer
}
// ShouldRetry implements custom logic for when errors should retry
func (r *MyRetryer) ShouldRetry(err error) bool {
switch err.(type) {
case *types.ProvisionedThroughputExceededException, *types.LimitExceededException:
return true
}
return false
}