diff --git a/client/request.go b/client/request.go index c799095c12..babe462a6d 100644 --- a/client/request.go +++ b/client/request.go @@ -10,6 +10,7 @@ import ( "net/http" "net/url" "os" + "reflect" "strings" "github.com/docker/docker/api/types" @@ -54,11 +55,17 @@ func (cli *Client) put(ctx context.Context, path string, query url.Values, obj i if err != nil { return serverResponse{}, err } - return cli.sendRequest(ctx, http.MethodPut, path, query, body, headers) + return cli.putRaw(ctx, path, query, body, headers) } // putRaw sends an http request to the docker API using the method PUT. func (cli *Client) putRaw(ctx context.Context, path string, query url.Values, body io.Reader, headers map[string][]string) (serverResponse, error) { + // PUT requests are expected to always have a body (apparently) + // so explicitly pass an empty body to sendRequest to signal that + // it should set the Content-Type header if not already present. + if body == nil { + body = http.NoBody + } return cli.sendRequest(ctx, http.MethodPut, path, query, body, headers) } @@ -73,6 +80,12 @@ func encodeBody(obj interface{}, headers headers) (io.Reader, headers, error) { if obj == nil { return nil, headers, nil } + // encoding/json encodes a nil pointer as the JSON document `null`, + // irrespective of whether the type implements json.Marshaler or encoding.TextMarshaler. + // That is almost certainly not what the caller intended as the request body. + if reflect.TypeOf(obj).Kind() == reflect.Ptr && reflect.ValueOf(obj).IsNil() { + return nil, headers, nil + } body, err := encodeData(obj) if err != nil { @@ -86,11 +99,6 @@ func encodeBody(obj interface{}, headers headers) (io.Reader, headers, error) { } func (cli *Client) buildRequest(method, path string, body io.Reader, headers headers) (*http.Request, error) { - expectedPayload := (method == http.MethodPost || method == http.MethodPut) - if expectedPayload && body == nil { - body = bytes.NewReader([]byte{}) - } - req, err := http.NewRequest(method, path, body) if err != nil { return nil, err @@ -106,7 +114,7 @@ func (cli *Client) buildRequest(method, path string, body io.Reader, headers hea req.URL.Host = cli.addr req.URL.Scheme = cli.scheme - if expectedPayload && req.Header.Get("Content-Type") == "" { + if body != nil && req.Header.Get("Content-Type") == "" { req.Header.Set("Content-Type", "text/plain") } return req, nil