1. docker
  2. Commit 1af30c50ca0ad81e2839ff4f2c5e70413f021d52
Browse code

Add httputils.FromStatusCode()

This utility allows a client to convert an API response
back to a typed error; allowing the client to perform
different actions based on the type of error, without
having to resort to string-matching the error.

Signed-off-by: Sebastiaan van Stijn <github@gone.nl>

Sebastiaan van Stijn authored on 2018/12/31 21:59:59
Showing 2 changed files
api/server/httputils/errors.go
History View file @ 1af30c5
... ... 
@@ -76,6 +76,52 @@ func GetHTTPErrorStatusCode(err error) int {
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 	return statusCode
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 }
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+// FromStatusCode creates an errdef error, based on the provided status-code
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+func FromStatusCode(err error, statusCode int) error {
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+	if err == nil {
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+		return err
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+	}
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+	switch statusCode {
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+	case http.StatusNotFound:
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+		err = errdefs.NotFound(err)
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+	case http.StatusBadRequest:
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+		err = errdefs.InvalidParameter(err)
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+	case http.StatusConflict:
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+		err = errdefs.Conflict(err)
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+	case http.StatusUnauthorized:
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+		err = errdefs.Unauthorized(err)
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+	case http.StatusServiceUnavailable:
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+		err = errdefs.Unavailable(err)
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+	case http.StatusForbidden:
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+		err = errdefs.Forbidden(err)
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+	case http.StatusNotModified:
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+		err = errdefs.NotModified(err)
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+	case http.StatusNotImplemented:
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+		err = errdefs.NotImplemented(err)
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+	case http.StatusInternalServerError:
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+		if !errdefs.IsSystem(err) && !errdefs.IsUnknown(err) && !errdefs.IsDataLoss(err) && !errdefs.IsDeadline(err) && !errdefs.IsCancelled(err) {
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+			err = errdefs.System(err)
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+		}
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+	default:
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+		logrus.WithFields(logrus.Fields{
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+			"module":      "api",
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+			"status_code": fmt.Sprintf("%d", statusCode),
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+		}).Debugf("FIXME: Got an status-code for which error does not match any expected type!!!: %d", statusCode)
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+
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+		switch {
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+		case statusCode >= 200 && statusCode < 400:
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+			// it's a client error
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+		case statusCode >= 400 && statusCode < 500:
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+			err = errdefs.InvalidParameter(err)
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+		case statusCode >= 500 && statusCode < 600:
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+			err = errdefs.System(err)
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+		default:
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+			err = errdefs.Unknown(err)
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+		}
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+	}
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+	return err
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+}
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+
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 func apiVersionSupportsJSONErrors(version string) bool {
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 	const firstAPIVersionWithJSONErrors = "1.23"
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 	return version == "" || versions.GreaterThan(version, firstAPIVersionWithJSONErrors)
api/server/httputils/errors_test.go
History View file @ 1af30c5
82 128 
new file mode 100644
... ... 
@@ -0,0 +1,93 @@
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+package httputils
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+
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+import (
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+	"fmt"
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+	"net/http"
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+	"testing"
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+
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+	"github.com/docker/docker/errdefs"
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+	"gotest.tools/assert"
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+)
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+
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+func TestFromStatusCode(t *testing.T) {
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+	testErr := fmt.Errorf("some error occurred")
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+
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+	testCases := []struct {
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+		err    error
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+		status int
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+		check  func(error) bool
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+	}{
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+		{
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+			err:    testErr,
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+			status: http.StatusNotFound,
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+			check:  errdefs.IsNotFound,
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+		},
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+		{
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+			err:    testErr,
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+			status: http.StatusBadRequest,
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+			check:  errdefs.IsInvalidParameter,
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+		},
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+		{
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+			err:    testErr,
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+			status: http.StatusConflict,
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+			check:  errdefs.IsConflict,
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+		},
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+		{
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+			err:    testErr,
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+			status: http.StatusUnauthorized,
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+			check:  errdefs.IsUnauthorized,
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+		},
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+		{
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+			err:    testErr,
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+			status: http.StatusServiceUnavailable,
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+			check:  errdefs.IsUnavailable,
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+		},
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+		{
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+			err:    testErr,
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+			status: http.StatusForbidden,
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+			check:  errdefs.IsForbidden,
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+		},
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+		{
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+			err:    testErr,
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+			status: http.StatusNotModified,
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+			check:  errdefs.IsNotModified,
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+		},
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+		{
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+			err:    testErr,
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+			status: http.StatusNotImplemented,
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+			check:  errdefs.IsNotImplemented,
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+		},
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+		{
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+			err:    testErr,
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+			status: http.StatusInternalServerError,
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+			check:  errdefs.IsSystem,
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+		},
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+		{
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+			err:    errdefs.Unknown(testErr),
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+			status: http.StatusInternalServerError,
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+			check:  errdefs.IsUnknown,
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+		},
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+		{
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+			err:    errdefs.DataLoss(testErr),
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+			status: http.StatusInternalServerError,
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+			check:  errdefs.IsDataLoss,
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+		},
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+		{
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+			err:    errdefs.Deadline(testErr),
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+			status: http.StatusInternalServerError,
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+			check:  errdefs.IsDeadline,
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+		},
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+		{
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+			err:    errdefs.Cancelled(testErr),
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+			status: http.StatusInternalServerError,
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+			check:  errdefs.IsCancelled,
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+		},
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+	}
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+
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+	for _, tc := range testCases {
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+		t.Run(http.StatusText(tc.status), func(t *testing.T) {
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+			err := FromStatusCode(tc.err, tc.status)
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+			assert.Check(t, tc.check(err), "unexpected error-type %T", err)
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+		})
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+	}
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+}