go aws sdk -> s3rver docker; just morphed the README.md example a lil' bit

main.go

package main

import (
	"context"
	"encoding/json"
	"flag"
	"fmt"
	"log"
	"os"
	"time"

	"github.com/aws/aws-sdk-go/aws"
	"github.com/aws/aws-sdk-go/aws/credentials"
	"github.com/aws/aws-sdk-go/aws/session"
	"github.com/aws/aws-sdk-go/service/s3"
)

// Usage:
//   # Upload myfile.txt to myBucket/myKey. Must complete within 10 minutes or will fail
//   go run main.go -b mybucket -k myKey -d 10m < myFile.txt
func main() {
	var bucket, key string
	var timeout time.Duration

	flag.StringVar(&bucket, "b", "", "Bucket name.")
	flag.StringVar(&key, "k", "", "Object key name.")
	flag.DurationVar(&timeout, "d", 0, "Upload timeout.")
	flag.Parse()

	// docker run -d --name s3server -p 8000:8000 scality/s3server:mem-latest
	// The default access key is accessKey1 with a secret key of verySecretKey1.
	sess := session.New(&aws.Config{
		Credentials:      credentials.NewStaticCredentials("accessKey1", "verySecretKey1", ""),
		Endpoint:         aws.String("http://0.0.0.0:8000"),
		Region:           aws.String("us-east-1"),
		S3ForcePathStyle: aws.Bool(true),
	})
	svc := s3.New(sess)

	_, err := svc.CreateBucket(&s3.CreateBucketInput{
		Bucket: aws.String(bucket),
	})
	if err != nil {
		panic(err)
	}

	// wedge context in so there's impatience
	ctx := context.Background()
	cancelFn := func() {
		log.Print("¡context timed out!")
	}
	if timeout > 0 {
		ctx, cancelFn = context.WithTimeout(ctx, timeout)
	}
	defer cancelFn()

	_, err = svc.PutObjectWithContext(ctx, &s3.PutObjectInput{
		Bucket: aws.String(bucket),
		Key:    aws.String(key),
		Body:   os.Stdin,
	})
	if err != nil {
		panic(err)
	}

	getObjectOutput, err := svc.GetObject(&s3.GetObjectInput{
		Bucket: aws.String(bucket),
		Key:    aws.String(key),
	})
	if err != nil {
		panic(err)
	}

	out := map[string]interface{}{}
	err = json.NewDecoder(getObjectOutput.Body).Decode(&out)
	if err != nil {
		panic(err)
	}

	fmt.Printf("successfully uploaded file to %s/%s\n", bucket, key)
	fmt.Printf("got it back too: %v\n", out)
}

myFile.txt

{"hi":"mom"}