使用 http.Request.Context() 而不是 context.Background() 时，文件不会提交到谷歌云存储

Question

我是新手，我编写了一个简单的宠物项目来将加密文件上传到谷歌云存储。 问题： 在我调用

AddEntry

函数的 http 处理程序中，当我传递

r.Context()

而不是

context.Background()

时，文件不会上传到谷歌存储。在谷歌的控制台中，我可以看到收到的字节，而且我根本没有收到任何错误，但文件本身不存在。

处理程序代码：

//imports, structs skipped

func ProcessAddEntryRequest(w http.ResponseWriter, r *http.Request) {
    //validation, getting params from jwt skipped

    reader, err := r.MultipartReader()
    if err != nil {
        http.Error(w, "multipart/form-data expected, not found", http.StatusBadRequest)
        log.Println("could not init MultipartReader from request: %w", err)
        return
    }

    gsService, err := googleStorageService.New()
    if err != nil {
        http.Error(w, "internal server error", http.StatusInternalServerError)
        log.Println(err)
        return
    }

    bservice, err := backupService.New(
        backupService.WithCipher(aes.New()),
        backupService.WithStorageService(gsService))

    if err != nil {
        http.Error(w, "internal server error", http.StatusInternalServerError)
        log.Println(err)
        return
    }
    var entry *entryRepo.BackupEntry
    for {
        part, err := reader.NextPart()
        if err == io.EOF {
            break
        }
        if err != nil {
            err = fmt.Errorf("error reading: %w", err)
            log.Println(err)
            http.Error(w, "internal server error", http.StatusInternalServerError)
            return
        }

        formName := part.FormName()
        if formName == "file" {
            entry, err = bservice.AddEntry(r.Context(), backupId, part.FileName(), part.Header.Get("Content-Type"), part)
            if err != nil {
                errClose := part.Close()
                err = fmt.Errorf("failed to add entry for backup %s: %w; error while closing multipart.Part: %w", backupId, err, errClose)
                log.Println(err)
                http.Error(w, "internal server error", http.StatusInternalServerError)
                return

            }
        }
        err = part.Close()
        if err != nil {
            err = fmt.Errorf("failed to close part for backup %s: %w", backupId, err)
            log.Println(err)
            http.Error(w, "internal server error", http.StatusInternalServerError)
            return
        }

    }
    response.Entry = *entry
    jsonData, err := json.Marshal(response)
    if err != nil {
        http.Error(w, "internal server error", http.StatusInternalServerError)
        log.Println("failed to marshal JSON: %w\n", err)
        return
    }
    w.WriteHeader(http.StatusOK)
    w.Header().Set("Content-Type", "application/json")
    w.Write(jsonData)
}

AddEntry函数代码：

func (backupService *BackupService) AddEntry(ctx context.Context, backupId string, entryFullName string,
    entryMimeType string, in io.Reader) (*ber.BackupEntry, error) {
    // validation skipped for readability
    entryId := uuid.New()
    outPath := backupId + "/" + entryId.String()

    entryChan := make(chan *ber.BackupEntry)
    errChan := make(chan error)
    go func() {
        gstorageClient, err := backupService.storageService.GetClient(ctx)
        if err != nil {
            errChan <- fmt.Errorf("could not add entry: %w", err)
        }
        defer gstorageClient.Close()

        out := gstorageClient.Bucket(config.GCBucketName()).Object(outPath).NewWriter(ctx)
        defer out.Close()

        mac, size, err := backupService.cipher.Encrypt(ctx, in, out,
            []byte(config.EncryptionKey()), []byte(config.HmacKey()))
        if err != nil {
            errChan <- fmt.Errorf("could not upload encrypted backupEntry with id=%s: %w", entryId.String(), err)
        }

        //db operation skipped
        entryChan <- entry
    }()
    select {
    case <-ctx.Done():
        dbCleanupErr, storageCleanupErr := backupService.cleanupEntry(entryId.String(), outPath)
        return nil,
            fmt.Errorf("could not add entry %s to backup %s: context was cancelled; db cleanup err: %w; gstorage cleanup err: %w",
                entryId.String(), backupId, dbCleanupErr, storageCleanupErr)
    case err := <-errChan:
        dbCleanupErr, storageCleanupErr := backupService.cleanupEntry(entryId.String(), outPath)
        return nil,
            fmt.Errorf("could not add entry %s to backup %s: %w; db cleanup err: %w; gstorage cleanup err: %w",
                entryId.String(), backupId, err, dbCleanupErr, storageCleanupErr)
    case entry := <-entryChan:
        return entry, nil
    }
}

我尝试过的：

1. 启用

   GODEBUG: http2debug=1

   检查调试 http 日志。日志不同，我将它们留在下面。
2. 检查上下文是否在所有级别上关闭：在 http 处理程序本身中，在

   AddEntry

   函数中添加

   Encrypt

   函数。上下文没有关闭，一切似乎都工作正常。
3. 从

   r.Context()

   创建派生上下文，结果与

   r.Context()

相同
4. 显然，将

   context.Background()

   而不是

   r.Context()

   传递给

   AddEntry

   函数，就可以解决问题

当

r.Context()

作为参数传递时的调试日志：

ft-api  | 2023/08/02 19:23:46 stdout: 2023/08/02 19:23:46 [2606f10843ab/yuHa6i98Ak-000004] "POST http://0.0.0.0:8080/backup HTTP/1.1" from 172.18.0.1:36052 - 200 570B in 193.850041ms
ft-api  | 2023/08/02 19:23:47 stdout: 2023/08/02 19:23:47 [2606f10843ab/yuHa6i98Ak-000005] "POST http://0.0.0.0:8080/entry HTTP/1.1" from 172.18.0.1:36052 - 200 127B in 171.975584ms
ft-api  | 2023/08/02 19:23:47 stderr: 2023/08/02 19:23:47 h2_bundle.go:9019: http2: Transport encoding header ":authority" = "oauth2.googleapis.com"
ft-api  | 2023/08/02 19:23:47 stderr: 2023/08/02 19:23:47 h2_bundle.go:9019: http2: Transport encoding header ":method" = "POST"
ft-api  | 2023/08/02 19:23:47 stderr: 2023/08/02 19:23:47 h2_bundle.go:9019: http2: Transport encoding header ":path" = "/token"
ft-api  | 2023/08/02 19:23:47 stderr: 2023/08/02 19:23:47 h2_bundle.go:9019: http2: Transport encoding header ":scheme" = "https"
ft-api  | 2023/08/02 19:23:47 stderr: 2023/08/02 19:23:47 h2_bundle.go:9019: http2: Transport encoding header "content-type" = "application/x-www-form-urlencoded"
ft-api  | 2023/08/02 19:23:47 stderr: 2023/08/02 19:23:47 h2_bundle.go:9019: http2: Transport encoding header "content-length" = "861"
ft-api  | 2023/08/02 19:23:47 stderr: 2023/08/02 19:23:47 h2_bundle.go:9019: http2: Transport encoding header "accept-encoding" = "gzip"
ft-api  | 2023/08/02 19:23:47 stderr: 2023/08/02 19:23:47 h2_bundle.go:9019: http2: Transport encoding header "user-agent" = "Go-http-client/2.0"
ft-api  | 2023/08/02 19:23:47 stderr: 2023/08/02 19:23:47 h2_bundle.go:9968: http2: Transport received HEADERS flags=END_HEADERS stream=3 len=42
ft-api  | 2023/08/02 19:23:47 stderr: 2023/08/02 19:23:47 h2_bundle.go:9968: http2: Transport received DATA flags=PADDED stream=3 len=974 data="\x1f\x8b\b\x00\x00\x00\x00\x00\x02\xff\x1d\xd4Ɏ\xa3H\x00\x04\xd0\x7f\xf1\xb9iA&\xeb܌]\xb4\xc9*L\x01\x05\x06.\x88%\xd9\xf7d\xcd\xd6\xfc\xfbXs\f).q\x88\xf7\xf7\x12\xa7)&$Z\x86\x06\xf7\x97\x7f.g\f\x94\xdf\xe9\uf13dƸ\xe98=\x9a\r\xe33\xe6FѶ\xa3\xcf\xd7ϪN-\x04\x9b]\x7f\xaf\xfc|\x95\xec!Ha\x97^[\xa4\xad\x0f\xe8\xeb\x03:\x051U\xb1\x12~2\x1e\xf5\xbe\xbfTν9\x8f\xe7\xedз\xaa\xac\x87\a\xa3\xfd!\x82ȡӝyb\xe3N\xb8\x91\xf8\x91*\xa1\xc5\xe7\x80\xc1|ڗ}P\x99\xd0D\xf7\xf8\xc7\xc7\"\xda\x1d\xabl\x96\xa4\x98\xf1'\xb2g\xef\xb1=\x10o\x7f\x8dC\x96\x8d\xc6\xfe\xfc\xae\xdc?\xb7f\x0f\xc0\xa2K\xb9^\xd5!\xc38\xe2\a\x84\xca1\x83\xfeG6\xbaNjPzW\xcf\xfb\xd3jͯn\x8d\xac\xf2[\xbe۰\xfcX\xbfBp\xbd\xdd\x14\xa1--\xbe" (613 bytes omitted)
ft-api  | 2023/08/02 19:23:47 stderr: 2023/08/02 19:23:47 h2_bundle.go:9968: http2: Transport received DATA flags=END_STREAM|PADDED stream=3 len=136 data=""
ft-api  | 2023/08/02 19:23:47 stderr: 2023/08/02 19:23:47 h2_bundle.go:9968: http2: Transport received PING len=8 ping="\x00\x00\x00\x00\x00\x00\x00\x02"
ft-api  | 2023/08/02 19:23:47 stderr: 2023/08/02 19:23:47 transport.go:3015: http2: Transport failed to get client conn for storage.googleapis.com:443: http2: no cached connection was available

当

context.Background()

作为参数传递时调试日志（我从日志中删除了 jwt 令牌值，但它在那里）

ft-api  | 2023/08/02 19:24:51 stdout: 2023/08/02 19:24:51 [2606f10843ab/ukd5p0sXox-000001] "POST http://0.0.0.0:8080/backup HTTP/1.1" from 172.18.0.1:38934 - 200 570B in 465.2635ms
ft-api  | 2023/08/02 19:24:52 stdout: 2023/08/02 19:24:52 [2606f10843ab/ukd5p0sXox-000002] "POST http://0.0.0.0:8080/entry HTTP/1.1" from 172.18.0.1:38934 - 200 127B in 172.084834ms
ft-api  | 2023/08/02 19:24:52 stderr: 2023/08/02 19:24:52 h2_bundle.go:9968: http2: Transport failed to get client conn for oauth2.googleapis.com:443: http2: no cached connection was available
ft-api  | 2023/08/02 19:24:52 stderr: 2023/08/02 19:24:52 h2_bundle.go:9968: http2: Transport creating client conn 0x40003cc780 to 142.250.186.74:443
ft-api  | 2023/08/02 19:24:52 stderr: 2023/08/02 19:24:52 h2_bundle.go:9019: http2: Transport encoding header ":authority" = "oauth2.googleapis.com"
ft-api  | 2023/08/02 19:24:52 stderr: 2023/08/02 19:24:52 h2_bundle.go:9019: http2: Transport encoding header ":method" = "POST"
ft-api  | 2023/08/02 19:24:52 stderr: 2023/08/02 19:24:52 h2_bundle.go:9019: http2: Transport encoding header ":path" = "/token"
ft-api  | 2023/08/02 19:24:52 stderr: 2023/08/02 19:24:52 h2_bundle.go:9019: http2: Transport encoding header ":scheme" = "https"
ft-api  | 2023/08/02 19:24:52 stderr: 2023/08/02 19:24:52 h2_bundle.go:9019: http2: Transport encoding header "content-type" = "application/x-www-form-urlencoded"
ft-api  | 2023/08/02 19:24:52 stderr: 2023/08/02 19:24:52 h2_bundle.go:9019: http2: Transport encoding header "content-length" = "861"
ft-api  | 2023/08/02 19:24:52 stderr: 2023/08/02 19:24:52 h2_bundle.go:9019: http2: Transport encoding header "accept-encoding" = "gzip"
ft-api  | 2023/08/02 19:24:52 stderr: 2023/08/02 19:24:52 h2_bundle.go:9019: http2: Transport encoding header "user-agent" = "Go-http-client/2.0"
ft-api  | 2023/08/02 19:24:52 stderr: 2023/08/02 19:24:52 h2_bundle.go:9968: http2: Transport received SETTINGS len=18, settings: MAX_CONCURRENT_STREAMS=100, INITIAL_WINDOW_SIZE=1048576, MAX_HEADER_LIST_SIZE=65536
ft-api  | 2023/08/02 19:24:52 stderr: 2023/08/02 19:24:52 h2_bundle.go:9968: http2: Transport received WINDOW_UPDATE len=4 (conn) incr=983041
ft-api  | 2023/08/02 19:24:52 stderr: 2023/08/02 19:24:52 h2_bundle.go:9968: http2: Transport received SETTINGS flags=ACK len=0
ft-api  | 2023/08/02 19:24:52 stderr: 2023/08/02 19:24:52 h2_bundle.go:9968: http2: Transport received HEADERS flags=END_HEADERS stream=1 len=220
ft-api  | 2023/08/02 19:24:52 stderr: 2023/08/02 19:24:52 h2_bundle.go:9968: http2: Transport received DATA flags=PADDED stream=1 len=1030 data="\x1f\x8b\b\x00\x00\x00\x00\x00\x02\xff\x1d\xd4Ir\xa3:\x00\x00лx\xddt1\x83z\x179&\x86\x84`#3n(!F3\v̠\xae\x7f\xf7\x9f\xea;\xbcz\x7fO\x98\x90|\x9e\x93eh\xf2\xfe\xf4\xe7t`\x11\xfc&\xbfS\xfe\r\xe7M'|\x9d\x83\x1b'\x06\xdf\x1f\xa2\xfa\xcd]78\xf5\xc4,\xedf\x8f\x18r\xb9+\xf8\x1aņl\xaf\x0f<\\#\x14\xa3\xeb\xce8O\xfb\xec\xa8p\xef#|}&\xeeM\x1e\xc5E\x94\x91-<Е\xbd\xea\x88X\xc8y\xbf<\x94\xfeHL5\xb8\x19&\x1e{?\xe3\x1a\xa3\xb2y\xf3\xd2T:ȿ\x1dX9K[4ԟ\x98a\x0e9\xfe \xea\xe1h\x910\xac\x9a\xf7h\xaf\xba\xa2\xd1\xeak\x1b\xc2\xcb\xea\xe4\x03\x9c\xaf\xfa\xed\xbd\x05\x89\x1f\xbf)\x1d5\xfc\xfevT\xf8\x9d\x9c\x81*4\xe9\xad|P̍(\xdb\xe8l=d\xe3\xc3c\xf5\xf2q\xdd\x05\xf4\xf6\x95\xc7\x10Ŗ\xbe\xa6\xf6\xf9Q|w" (611 bytes omitted)
ft-api  | 2023/08/02 19:24:52 stderr: 2023/08/02 19:24:52 h2_bundle.go:9968: http2: Transport received DATA flags=END_STREAM|PADDED stream=1 len=208 data=""
ft-api  | 2023/08/02 19:24:52 stderr: 2023/08/02 19:24:52 h2_bundle.go:9968: http2: Transport received PING len=8 ping="\x00\x00\x00\x00\x00\x00\x00\x00"
ft-api  | 2023/08/02 19:24:52 stderr: 2023/08/02 19:24:52 transport.go:3015: http2: Transport failed to get client conn for storage.googleapis.com:443: http2: no cached connection was available
ft-api  | 2023/08/02 19:24:52 stderr: 2023/08/02 19:24:52 transport.go:3015: http2: Transport creating client conn 0x400029e000 to 216.58.212.144:443
ft-api  | 2023/08/02 19:24:52 stderr: 2023/08/02 19:24:52 transport.go:2076: http2: Transport encoding header ":authority" = "storage.googleapis.com"
ft-api  | 2023/08/02 19:24:52 stderr: 2023/08/02 19:24:52 transport.go:2076: http2: Transport encoding header ":method" = "POST"
ft-api  | 2023/08/02 19:24:52 stderr: 2023/08/02 19:24:52 transport.go:2076: http2: Transport encoding header ":path" = "/upload/storage/v1/b/bucketname/o?alt=json&name=a934c415-07bd-4686-8ad0-90ff5ef68c7e%2F6e6b9563-c9d9-484e-a24f-cd2f8bd1fcd8&prettyPrint=false&projection=full&uploadType=multipart"
ft-api  | 2023/08/02 19:24:52 stderr: 2023/08/02 19:24:52 transport.go:2076: http2: Transport encoding header ":scheme" = "https"
ft-api  | 2023/08/02 19:24:52 stderr: 2023/08/02 19:24:52 transport.go:2076: http2: Transport encoding header "content-type" = "multipart/related; boundary=976d8006696028fea8c40fc53fe0a817a80f334ae41925d1e08c3bb3c917"
ft-api  | 2023/08/02 19:24:52 stderr: 2023/08/02 19:24:52 transport.go:2076: http2: Transport encoding header "x-cloud-trace-context" = "cb5a9d07f5007be3d8dfe277e1fb6beb/9294889295348469653;o=0"
ft-api  | 2023/08/02 19:24:52 stderr: 2023/08/02 19:24:52 transport.go:2076: http2: Transport encoding header "authorization" = "Bearer <<token value removed>>"
ft-api  | 2023/08/02 19:24:52 stderr: 2023/08/02 19:24:52 transport.go:2076: http2: Transport encoding header "x-goog-api-client" = "gl-go/1.20.6 gccl/1.30.1"
ft-api  | 2023/08/02 19:24:52 stderr: 2023/08/02 19:24:52 transport.go:2076: http2: Transport encoding header "user-agent" = "gcloud-golang-storage/1.30.1"
ft-api  | 2023/08/02 19:24:52 stderr: 2023/08/02 19:24:52 transport.go:2076: http2: Transport encoding header "accept-encoding" = "gzip"
ft-api  | 2023/08/02 19:24:52 stderr: 2023/08/02 19:24:52 transport.go:3015: http2: Transport received SETTINGS len=18, settings: MAX_CONCURRENT_STREAMS=100, INITIAL_WINDOW_SIZE=1048576, MAX_HEADER_LIST_SIZE=65536
ft-api  | 2023/08/02 19:24:52 stderr: 2023/08/02 19:24:52 transport.go:3015: http2: Transport received WINDOW_UPDATE len=4 (conn) incr=983041
ft-api  | 2023/08/02 19:24:52 stderr: 2023/08/02 19:24:52 transport.go:3015: http2: Transport received SETTINGS flags=ACK len=0
ft-api  | 2023/08/02 19:24:52 stderr: 2023/08/02 19:24:52 transport.go:3015: http2: Transport received HEADERS flags=END_HEADERS stream=1 len=314
ft-api  | 2023/08/02 19:24:52 stderr: 2023/08/02 19:24:52 transport.go:3015: http2: Transport received DATA stream=1 len=944 data="{\"kind\":\"storage#object\",\"id\":\"bucketname/a934c415-07bd-4686-8ad0-90ff5ef68c7e/6e6b9563-c9d9-484e-a24f-cd2f8bd1fcd8/1691004292747760\",\"selfLink\":\"https://www.googleapis.com/storage/v1/b/bucketname/o/a934c415-07bd-4686-8ad0-90ff5ef68c7e%2F6e6b9563" (688 bytes omitted)
ft-api  | 2023/08/02 19:24:52 stderr: 2023/08/02 19:24:52 transport.go:3015: http2: Transport received DATA flags=END_STREAM stream=1 len=0 data=""
ft-api  | 2023/08/02 19:24:52 stderr: 2023/08/02 19:24:52 transport.go:3015: http2: Transport received PING len=8 ping="\x00\x00\x00\x00\x00\x00\x00\x00"

Answer 1

通过在 gstorage 对象编写器上显式调用

Close()

方法而不是推迟它来解决该问题。我仍然不完全确定这种行为的原因（我知道除非编写器关闭，否则文件不会提交到 gstorage，但不涉及上下文取消，所以它应该已关闭）。