/
handler.go
174 lines (154 loc) · 4.39 KB
/
handler.go
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package main
import (
"context"
"encoding/json"
"fmt"
"io"
"net/http"
"time"
"github.com/aws/aws-sdk-go-v2/aws"
s3manager "github.com/aws/aws-sdk-go-v2/feature/s3/manager"
"github.com/aws/aws-sdk-go-v2/service/s3"
)
type credentialsProvider struct{}
func (credentialsProvider) Retrieve(ctx context.Context) (aws.Credentials, error) {
return awsCredentials, nil
}
var client *s3.Client
const bucketPathPrefix = len("/bucket/")
const partSize = 128 << 20 // 128MiB
// getHeaderOrNil gets header value or return nil if the key does not exist
func getHeaderOrNil(header http.Header, key string) *string {
value := header.Get(key)
if value == "" {
return nil
} else {
return &value
}
}
// setHeaderOrNil sets header value or delete key if the value is nil
func setHeaderOrNil(header http.Header, key string, value *string) {
if value == nil {
header.Del(key)
} else {
header.Set(key, *value)
}
}
type Object struct {
Key string `json:"key"`
Size int64 `json:"size"`
LastModified time.Time `json:"last-modified"`
ETag string `json:"etag"`
}
type listResult struct {
Objects []Object `json:"objects"`
}
func newListResult() *listResult {
result := listResult{
Objects: []Object{},
}
return &result
}
func listHandlerFunc(res http.ResponseWriter, req *http.Request) {
if req.Method != "GET" {
res.WriteHeader(http.StatusMethodNotAllowed)
return
}
input := &s3.ListObjectsV2Input{
Bucket: &bucketName,
}
output, err := client.ListObjectsV2(req.Context(), input)
if err != nil {
res.WriteHeader(http.StatusBadRequest) // XXX we cannot determine appropriate status code
res.Write([]byte(err.Error()))
return
}
result := newListResult()
for _, c := range output.Contents {
result.Objects = append(result.Objects, Object{
Key: *c.Key,
Size: *c.Size,
LastModified: c.LastModified.UTC(),
ETag: *c.ETag,
})
}
marshalled, err := json.Marshal(result)
if err != nil {
res.WriteHeader(http.StatusInternalServerError)
res.Write([]byte(err.Error()))
return
}
res.Header().Set("Content-Length", fmt.Sprint(len(marshalled)))
res.Write(marshalled)
}
func objectHandlerFunc(res http.ResponseWriter, req *http.Request) {
switch req.Method {
case "GET":
objectGetHandlerFunc(res, req)
case "PUT":
objectPutHandlerFunc(res, req)
case "DELETE":
objectDeleteHandlerFunc(res, req)
default:
res.WriteHeader(http.StatusMethodNotAllowed)
}
}
func objectGetHandlerFunc(res http.ResponseWriter, req *http.Request) {
objectKey := req.URL.Path[bucketPathPrefix:]
input := &s3.GetObjectInput{
Bucket: &bucketName,
Key: &objectKey,
}
output, err := client.GetObject(req.Context(), input)
if err != nil {
res.WriteHeader(http.StatusBadRequest) // XXX we cannot determine appropriate status code
res.Write([]byte(err.Error()))
return
}
setHeaderOrNil(res.Header(), "Content-Type", output.ContentType)
setHeaderOrNil(res.Header(), "ETag", output.ETag)
res.Header().Set("Content-Length", fmt.Sprint(output.ContentLength))
if output.LastModified != nil {
res.Header().Set("Last-Modified", output.LastModified.UTC().Format(http.TimeFormat))
}
io.Copy(res, output.Body)
}
func objectPutHandlerFunc(res http.ResponseWriter, req *http.Request) {
objectKey := req.URL.Path[bucketPathPrefix:]
input := &s3.PutObjectInput{
Bucket: &bucketName,
Key: &objectKey,
Body: req.Body,
ContentLength: &req.ContentLength,
ContentType: getHeaderOrNil(req.Header, "Content-Type"),
}
uploader := s3manager.NewUploader(client, func(u *s3manager.Uploader) {
u.Concurrency = 1
u.PartSize = partSize
u.LeavePartsOnError = false
})
_, err := uploader.Upload(req.Context(), input)
if err != nil {
res.WriteHeader(http.StatusBadRequest) // XXX we cannot determine appropriate status code
res.Write([]byte(err.Error()))
return
}
res.WriteHeader(http.StatusOK)
}
func objectDeleteHandlerFunc(res http.ResponseWriter, req *http.Request) {
objectKey := req.URL.Path[bucketPathPrefix:]
input := &s3.DeleteObjectInput{
Bucket: &bucketName,
Key: &objectKey,
}
_, err := client.DeleteObject(req.Context(), input)
if err != nil {
res.WriteHeader(http.StatusBadRequest) // XXX we cannot determine appropriate status code
res.Write([]byte(err.Error()))
return
}
res.WriteHeader(http.StatusOK) // ?
}
func healthHandler(res http.ResponseWriter, req *http.Request) {
res.WriteHeader(http.StatusOK)
}