added custom image name configuration

gnomock.go

@@ -92,6 +92,10 @@ func StartCustom(image string, ports NamedPorts, opts ...Option) (*Container, er
 		ports = config.CustomNamedPorts
 	}
 
+	if config.CustomImage != "" {
+		image = config.CustomImage
+	}
+
 	g.log.Infow("starting", "image", image, "ports", ports)
 	g.log.Infow("using config", "image", image, "ports", ports, "config", config)
 

gnomock_test.go

@@ -366,6 +366,16 @@ func TestGnomock_withExtraHosts(t *testing.T) {
 	require.NoError(t, gnomock.Stop(container))
 }
 
+func TestGnomock_withCustomImage(t *testing.T) {
+	t.Parallel()
+
+	p := &testutil.TestPreset{Img: "docker.io/orlangure/noimage"}
+	container, err := gnomock.Start(p, gnomock.WithCustomImage(testutil.TestImage))
+	require.NoError(t, err)
+	require.NotNil(t, container)
+	require.NoError(t, gnomock.Stop(container))
+}
+
 func initf(context.Context, *gnomock.Container) error {
 	return nil
 }

options.go

@@ -213,6 +213,14 @@ func WithExtraHosts(hosts []string) Option {
 	}
 }
 
+// WithCustomImage allows to define a custom image name. This option should be used to
+// override the image registry and repository defined by presets.
+func WithCustomImage(image string) Option {
+	return func(o *Options) {
+		o.CustomImage = image
+	}
+}
+
 // HealthcheckFunc defines a function to be used to determine container health.
 // It receives a host and a port, and returns an error if the container is not
 // ready, or nil when the container can be used. One example of HealthcheckFunc
@@ -307,6 +315,14 @@ type Options struct {
 	// its re-use in posterior executions.
 	Reuse bool `json:"reuse"`
 
+	// CustomImage allows to override the name of the image set by the presets
+	// with a custom image name. This option is useful for cases where it is
+	// required to pull the preset image from a custom registry and repository.
+	//
+	// Note that when using this option, you are responsible for verifying the
+	// validity of the provided image registry and repository.
+	CustomImage string `json:"customImage"`
+
 	ctx                 context.Context
 	init                InitFunc
 	healthcheck         HealthcheckFunc