feat: create write/Error wrapper to better handle http/Error with Headers.

Author: karel-rehor

api/http/error_test.go

@@ -1,4 +1,4 @@
-// Copyright 2020-2021 InfluxData, Inc. All rights reserved.
+// Copyright 2020-2024 InfluxData, Inc. All rights reserved.
 // Use of this source code is governed by MIT
 // license that can be found in the LICENSE file.
 

api/write/error.go

@@ -0,0 +1,64 @@
+// Copyright 2020-2024 InfluxData, Inc. All rights reserved.
+// Use of this source code is governed by MIT
+// license that can be found in the LICENSE file.
+
+package write
+
+import (
+	"errors"
+	"fmt"
+	"github.com/influxdata/influxdb-client-go/v2/api/http"
+	iHttp "net/http"
+	"net/textproto"
+)
+
+// Error wraps an error that may have occurred during a write call.  Most often this will be an http.Error.
+type Error struct {
+	origin  error
+	message string
+}
+
+// NewError returns a new created Error instance wrapping the original error.
+func NewError(origin error, message string) *Error {
+	return &Error{
+		origin:  origin,
+		message: message,
+	}
+}
+
+// Error fulfills the error interface
+func (e *Error) Error() string {
+	return fmt.Sprintf("%s:\n   %s", e.message, e.origin)
+}
+
+func (e *Error) Unwrap() error {
+	return e.origin
+}
+
+// HTTPHeader returns the Header of a wrapped http.Error.  If the original error is not http.Error returns standard error.
+func (e *Error) HTTPHeader() (iHttp.Header, error) {
+	var err *http.Error
+	ok := errors.As(e.origin, &err)
+	if ok {
+		return err.Header, nil
+	}
+	return nil, fmt.Errorf(fmt.Sprintf("Origin error: (%s) is not of type *http.Error.\n", e.origin.Error()))
+}
+
+// GetHeaderValues returns the values from a Header key.  If original error is not http.Error return standard error.
+func (e *Error) GetHeaderValues(key string) ([]string, error) {
+	var err *http.Error
+	if errors.As(e.origin, &err) {
+		return err.Header.Values(textproto.CanonicalMIMEHeaderKey(key)), nil
+	}
+	return nil, fmt.Errorf(fmt.Sprintf("Origin error: (%s) is not of type http.Header.\n", e.origin.Error()))
+}
+
+// GetHeader returns the first value from a header key.  If origin is not http.Error or if no match is found returns "".
+func (e *Error) GetHeader(key string) string {
+	var err *http.Error
+	if errors.As(e.origin, &err) {
+		return err.Header.Get(textproto.CanonicalMIMEHeaderKey(key))
+	}
+	return ""
+}

api/write/error_test.go

@@ -0,0 +1,66 @@
+// Copyright 2020-2024 InfluxData, Inc. All rights reserved.
+// Use of this source code is governed by MIT
+// license that can be found in the LICENSE file.
+
+package write
+
+import (
+	"errors"
+	"fmt"
+	"github.com/influxdata/influxdb-client-go/v2/api/http"
+	"github.com/stretchr/testify/assert"
+	ihttp "net/http"
+	"testing"
+)
+
+func TestNewErrorNotHttpError(t *testing.T) {
+	err := NewError(fmt.Errorf("origin error"), "error message")
+	var errTest *http.Error
+	assert.False(t, errors.As(err, &errTest))
+	header, okh := err.HTTPHeader()
+	assert.Nil(t, header)
+	assert.Error(t, okh)
+	values, okv := err.GetHeaderValues("Date")
+	assert.Nil(t, values)
+	assert.Error(t, okv)
+	assert.Equal(t, "", err.GetHeader("Date"))
+	assert.Equal(t, "error message:\n   origin error", err.Error())
+}
+
+func TestNewErrorHttpError(t *testing.T) {
+	header := ihttp.Header{
+		"Date":           []string{"2024-08-07T12:00:00.009"},
+		"Content-Length": []string{"12"},
+		"Content-Type":   []string{"application/json", "encoding UTF-8"},
+		"X-Test-Value1":  []string{"SaturnV"},
+		"X-Test-Value2":  []string{"Apollo11"},
+		"Retry-After":    []string{"2044"},
+		"Trace-Id":       []string{"123456789ABCDEF0"},
+	}
+
+	err := NewError(&http.Error{
+		StatusCode: ihttp.StatusBadRequest,
+		Code:       "bad request",
+		Message:    "this is just a test",
+		Err:        nil,
+		RetryAfter: 2044,
+		Header:     header,
+	}, "should be httpError")
+
+	var errTest *http.Error
+	assert.True(t, errors.As(err.Unwrap(), &errTest))
+	header, okh := err.HTTPHeader()
+	assert.NotNil(t, header)
+	assert.Nil(t, okh)
+	date, okd := err.GetHeaderValues("Date")
+	assert.Equal(t, []string{"2024-08-07T12:00:00.009"}, date)
+	assert.Nil(t, okd)
+	cType, okc := err.GetHeaderValues("Content-Type")
+	assert.Equal(t, []string{"application/json", "encoding UTF-8"}, cType)
+	assert.Nil(t, okc)
+	assert.Equal(t, "2024-08-07T12:00:00.009", err.GetHeader("Date"))
+	assert.Equal(t, "SaturnV", err.GetHeader("X-Test-Value1"))
+	assert.Equal(t, "Apollo11", err.GetHeader("X-Test-Value2"))
+	assert.Equal(t, "123456789ABCDEF0", err.GetHeader("Trace-Id"))
+	assert.Equal(t, "should be httpError:\n   bad request: this is just a test", err.Error())
+}

api/write_test.go

@@ -294,13 +294,15 @@ func TestWriteApiErrorHeaders(t *testing.T) {
 		for i := 0; i < 3; i++ {
 			recErr = <-errCh
 			assert.NotNil(t, recErr, "errCh should not run out of values")
-			assert.Len(t, recErr.(*http.Error).Header, 6)
-			assert.NotEqual(t, "", recErr.(*http.Error).Header.Get("Date"))
-			assert.NotEqual(t, "", recErr.(*http.Error).Header.Get("Content-Length"))
-			assert.NotEqual(t, "", recErr.(*http.Error).Header.Get("Content-Type"))
-			assert.Equal(t, strconv.Itoa(i+1), recErr.(*http.Error).Header.Get("X-Call-Count"))
-			assert.Equal(t, "Not All Correct", recErr.(*http.Error).Header.Get("X-Test-Val1"))
-			assert.Equal(t, "Atlas LV-3B", recErr.(*http.Error).Header.Get("X-Test-Val2"))
+			header, okh := recErr.(*write.Error).HTTPHeader()
+			assert.Nil(t, okh)
+			assert.Len(t, header, 6)
+			assert.NotEqual(t, "", recErr.(*write.Error).GetHeader("Date"))
+			assert.NotEqual(t, "", recErr.(*write.Error).GetHeader("Content-Length"))
+			assert.NotEqual(t, "", recErr.(*write.Error).GetHeader("Content-Type"))
+			assert.Equal(t, strconv.Itoa(i+1), recErr.(*write.Error).GetHeader("X-Call-Count"))
+			assert.Equal(t, "Not All Correct", recErr.(*write.Error).GetHeader("X-Test-Val1"))
+			assert.Equal(t, "Atlas LV-3B", recErr.(*write.Error).GetHeader("X-Test-Val2"))
 		}
 		wg.Done()
 	}()

internal/write/service.go

@@ -210,16 +210,7 @@ func (w *Service) HandleWrite(ctx context.Context, batch *Batch) error {
 						}
 						log.Error(logMessage)
 					}
-					return &http2.Error{
-						StatusCode: int(perror.StatusCode),
-						Code:       perror.Code,
-						Message: fmt.Errorf(
-							"write failed (attempts %d): %w", batchToWrite.RetryAttempts, perror,
-						).Error(),
-						Err:        perror.Err,
-						RetryAfter: perror.RetryAfter,
-						Header:     perror.Header,
-					}
+					return write.NewError(perror, fmt.Sprintf("write failed (retry attempts %d)", batchToWrite.RetryAttempts))
 				}
 			}
 

internal/write/service_test.go

@@ -339,7 +339,7 @@ func TestMaxRetryTime(t *testing.T) {
 	err = srv.HandleWrite(ctx, b)
 	require.NotNil(t, err)
 	// 1st Batch expires and writing 2nd trows error
-	assert.Equal(t, "write failed (attempts 1): Unexpected status code 429", err.Error())
+	assert.Equal(t, "write failed (retry attempts 1):\n   Unexpected status code 429", err.Error())
 	assert.Equal(t, 1, srv.retryQueue.list.Len())
 
 	//wait until remaining accumulated retryDelay has passed, because there hasn't been a successful write yet
@@ -715,7 +715,7 @@ func TestHttpErrorHeaders(t *testing.T) {
 		write.DefaultOptions())
 	err := svc.HandleWrite(context.Background(), NewBatch("1", 20))
 	assert.Error(t, err)
-	assert.Equal(t, "400 Bad Request: write failed (attempts 0): 400 Bad Request: { \"code\": \"bad request\", \"message\": \"test header\" }", err.Error())
-	assert.Equal(t, "Not All Correct", err.(*http.Error).Header.Get("X-Test-Val1"))
-	assert.Equal(t, "Atlas LV-3B", err.(*http.Error).Header.Get("X-Test-Val2"))
+	assert.Equal(t, "write failed (retry attempts 0):\n   400 Bad Request: { \"code\": \"bad request\", \"message\": \"test header\" }", err.Error())
+	assert.Equal(t, "Not All Correct", err.(*write.Error).GetHeader("X-Test-Val1"))
+	assert.Equal(t, "Atlas LV-3B", err.(*write.Error).GetHeader("X-Test-Val2"))
 }