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blog.vidsey.io/_examples/awsandgo/aws_v2.go
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package main | |
import ( | |
"bytes" | |
"context" | |
"io" | |
"io/ioutil" | |
"log" | |
"math/rand" | |
"net/http" | |
"os" | |
"os/signal" | |
"path/filepath" | |
"sync" | |
"time" | |
"github.com/gin-gonic/gin" | |
"github.com/oklog/ulid" | |
"github.com/aws/aws-sdk-go/aws" | |
"github.com/aws/aws-sdk-go/aws/endpoints" | |
"github.com/aws/aws-sdk-go/aws/session" | |
"github.com/aws/aws-sdk-go/service/s3" | |
) | |
const ( | |
Region = endpoints.UsWest1RegionID | |
Bucket = "video.player" | |
) | |
var client *s3.S3 | |
func init() { | |
if err := cacheInit(); err != nil { | |
log.Fatal(err) | |
} | |
client = s3.New(session.New(&aws.Config{Region: aws.String(Region)})) | |
// ensure that the bucket exists | |
buckets, err := client.ListBuckets(&s3.ListBucketsInput{}) | |
if err != nil { | |
log.Fatal(err) | |
} | |
for _, b := range buckets.Buckets { | |
if *b.Name == Bucket { | |
return | |
} | |
} | |
// create the bucket | |
_, err = client.CreateBucket(&s3.CreateBucketInput{ | |
Bucket: aws.String(Bucket), | |
ACL: aws.String("bucket-owner-full-control"), | |
CreateBucketConfiguration: &s3.CreateBucketConfiguration{ | |
LocationConstraint: aws.String(Region), | |
}, | |
}) | |
if err != nil { | |
log.Fatal(err) | |
} | |
log.Println("Created", Bucket) | |
} | |
func main() { | |
var ( | |
engine = gin.Default() | |
server = http.Server{Addr: ":8080", Handler: engine} | |
) | |
engine.POST("/upload", uploadHandler) | |
engine.POST("/upload/:key", uploadHandler) | |
engine.GET("/download/:key", downloadHandler) | |
go func() { | |
if err := server.ListenAndServe(); err != nil { | |
log.Fatalln("Startup:", err) | |
} | |
}() | |
quit := make(chan os.Signal) | |
signal.Notify(quit, os.Interrupt) | |
<-quit | |
ctx, exit := context.WithTimeout(context.Background(), 60*time.Second) | |
defer exit() | |
if err := cacheClean(); err != nil { | |
log.Println("Clean:", err) | |
} | |
if err := server.Shutdown(ctx); err != nil { | |
log.Fatalln("Shutdown:", err) | |
} | |
} | |
var entropy = rand.New(rand.NewSource(time.Now().UnixNano())) | |
func uploadHandler(c *gin.Context) { | |
var key = c.Param("key") | |
if key == "" { | |
key = ulid.MustNew(ulid.Timestamp(time.Now()), entropy).String() | |
} | |
b, err := ioutil.ReadAll(c.Request.Body) | |
if err != nil { | |
log.Printf("%s: upload error (%s)", key, err) | |
c.JSON(http.StatusInternalServerError, gin.H{"error": "internal error"}) | |
return | |
} | |
reader := bytes.NewReader(b) | |
_, err = client.PutObject(&s3.PutObjectInput{ | |
Bucket: aws.String(Bucket), | |
Key: aws.String(key), | |
Body: reader, | |
ContentLength: aws.Int64(reader.Size()), | |
}) | |
if err != nil { | |
log.Printf("%s: put error (%s)", key, err) | |
c.JSON(http.StatusInternalServerError, gin.H{"error": "internal error"}) | |
return | |
} | |
c.JSON(http.StatusCreated, gin.H{"key": key}) | |
} | |
func downloadHandler(c *gin.Context) { | |
var key = c.Param("key") | |
path, err := cacheEnsure(key) | |
if err != nil { | |
log.Printf("%s: get error (%s)", key, err) | |
c.JSON(http.StatusInternalServerError, gin.H{"error": "internal error"}) | |
return | |
} | |
http.ServeFile(c.Writer, c.Request, path) | |
} | |
const keep = time.Hour | |
var cache struct { | |
sync.Mutex | |
timers map[string]*time.Timer | |
root string | |
client *s3.S3 | |
} | |
func cacheInit() error { | |
cache.Lock() | |
cache.timers = make(map[string]*time.Timer) | |
cache.root = os.TempDir() | |
cache.Unlock() | |
return os.MkdirAll(cache.root, 0644) | |
} | |
func cacheClean() error { return os.RemoveAll(cache.root) } | |
func cacheEnsure(key string) (string, error) { | |
cache.Lock() | |
t := cache.timers[key] | |
cache.Unlock() | |
if t == nil { | |
if err := cacheDownload(key); err != nil { | |
return "", err | |
} | |
} | |
cache.Lock() | |
cache.timers[key].Reset(keep) | |
cache.Unlock() | |
return cachePath(key), nil | |
} | |
func cachePath(key string) string { return filepath.Join(cache.root, key) } | |
func cacheDownload(key string) error { | |
src, err := client.GetObject(&s3.GetObjectInput{ | |
Bucket: aws.String(Bucket), | |
Key: aws.String(key), | |
}) | |
defer src.Body.Close() | |
dst, err := os.OpenFile(cachePath(key), os.O_CREATE|os.O_WRONLY, 0644) | |
if err != nil { | |
return err | |
} | |
defer dst.Close() | |
if _, err = io.Copy(dst, src.Body); err != nil { | |
return err | |
} | |
cache.Lock() | |
cache.timers[key] = cacheDeleteTimer(key) | |
cache.Unlock() | |
return nil | |
} | |
func cacheDeleteTimer(key string) *time.Timer { | |
return time.AfterFunc(keep, func() { | |
cache.Lock() | |
delete(cache.timers, key) | |
os.Remove(cachePath(key)) | |
cache.Unlock() | |
}) | |
} |