diff --git a/client/request_test.go b/client/request_test.go
index 30de71382a..91d4b4b499 100644
--- a/client/request_test.go
+++ b/client/request_test.go
@@ -3,6 +3,7 @@ package client // import "github.com/docker/docker/client"
import (
"bytes"
"context"
+ "encoding/json"
"fmt"
"io"
"math/rand"
@@ -11,6 +12,7 @@ import (
"testing"
"time"
+ "github.com/docker/docker/api/types"
"github.com/docker/docker/api/types/container"
"github.com/docker/docker/errdefs"
"gotest.tools/v3/assert"
@@ -92,6 +94,136 @@ func TestPlainTextError(t *testing.T) {
assert.Check(t, is.ErrorType(err, errdefs.IsSystem))
}
+// TestResponseErrors tests handling of error responses returned by the API.
+// It includes test-cases for malformed and invalid error-responses, as well
+// as plain text errors for backwards compatibility with API versions <1.24.
+func TestResponseErrors(t *testing.T) {
+ errorResponse, err := json.Marshal(&types.ErrorResponse{
+ Message: "Some error occurred",
+ })
+ assert.NilError(t, err)
+
+ tests := []struct {
+ doc string
+ apiVersion string
+ contentType string
+ response string
+ expected string
+ }{
+ {
+ // Valid (types.ErrorResponse) error, but not using a fixture, to validate current implementation..
+ doc: "JSON error (non-fixture)",
+ contentType: "application/json",
+ response: string(errorResponse),
+ expected: `Error response from daemon: Some error occurred`,
+ },
+ {
+ // Valid (types.ErrorResponse) error.
+ doc: "JSON error",
+ contentType: "application/json",
+ response: `{"message":"Some error occurred"}`,
+ expected: `Error response from daemon: Some error occurred`,
+ },
+ {
+ // Valid (types.ErrorResponse) error with additional fields.
+ doc: "JSON error with extra fields",
+ contentType: "application/json",
+ response: `{"message":"Some error occurred", "other_field": "some other field that's not part of types.ErrorResponse"}`,
+ expected: `Error response from daemon: Some error occurred`,
+ },
+ {
+ // API versions before 1.24 did not support JSON errors, and return response as-is.
+ doc: "JSON error on old API",
+ apiVersion: "1.23",
+ contentType: "application/json",
+ response: `{"message":"Some error occurred"}`,
+ expected: `Error response from daemon: {"message":"Some error occurred"}`,
+ },
+ {
+ doc: "plain-text error",
+ contentType: "text/plain",
+ response: `Some error occurred`,
+ expected: `Error response from daemon: Some error occurred`,
+ },
+ {
+ // TODO(thaJeztah): consider returning (partial) raw response for these
+ doc: "malformed JSON",
+ contentType: "application/json",
+ response: `{"message":"Some error occurred`,
+ expected: `Error reading JSON: unexpected end of JSON input`,
+ },
+ {
+ // Server response that's valid JSON, but not the expected (types.ErrorResponse) scheme
+ // TODO(thaJeztah): consider returning (partial) raw response for these
+ doc: "incorrect JSON scheme",
+ contentType: "application/json",
+ response: `{"error":"Some error occurred"}`,
+ expected: `Error response from daemon: `,
+ },
+ {
+ // TODO(thaJeztah): improve handling of such errors; we can return the generic "502 Bad Gateway" instead
+ doc: "html error",
+ contentType: "text/html",
+ response: `
+
+
+ 502 Bad Gateway
+
+
+ Bad Gateway
+ The server was unable to complete your request. Please try again later.
+ If this problem persists, please contact support.
+
+`,
+ expected: `Error response from daemon:
+
+
+ 502 Bad Gateway
+
+
+ Bad Gateway
+ The server was unable to complete your request. Please try again later.
+ If this problem persists, please contact support.
+
+`,
+ },
+ {
+ // TODO(thaJeztah): improve handling of these errors (JSON: invalid character '<' looking for beginning of value)
+ doc: "html error masquerading as JSON",
+ contentType: "application/json",
+ response: `
+
+
+ 502 Bad Gateway
+
+
+ Bad Gateway
+ The server was unable to complete your request. Please try again later.
+ If this problem persists, please contact support.
+
+`,
+ expected: `Error reading JSON: invalid character '<' looking for beginning of value`,
+ },
+ }
+ for _, tc := range tests {
+ t.Run(tc.doc, func(t *testing.T) {
+ client := &Client{
+ version: tc.apiVersion,
+ client: newMockClient(func(req *http.Request) (*http.Response, error) {
+ return &http.Response{
+ StatusCode: http.StatusBadRequest,
+ Header: http.Header{"Content-Type": []string{tc.contentType}},
+ Body: io.NopCloser(bytes.NewReader([]byte(tc.response))),
+ }, nil
+ }),
+ }
+ _, err := client.Ping(context.Background())
+ assert.Check(t, is.Error(err, tc.expected))
+ assert.Check(t, is.ErrorType(err, errdefs.IsInvalidParameter))
+ })
+ }
+}
+
func TestInfiniteError(t *testing.T) {
infinitR := rand.New(rand.NewSource(42))
client := &Client{