Remove not needed context pointers in container interface

Container interface is being extended right now, because we
build new things on top of it, such as bootstrap containers.

Current version of it, was delivered as MVP and is used only
in ISOGEN. During MVP stage we didn't bother too much about
the pointers and readability. However now when we built something
new on top of it, we want to make sure that it we dont make
matters worse, and building on solid foundation.

The pointers are not needed in any way, and they are dereferenced
on top of that, context.Context is an interface, and there is
very limited theoretical use of pointers to interfaces.

Change-Id: Iee1eeb89f058aa8e994cba685b49085707362ee1

pkg/bootstrap/isogen/executor.go

@@ -99,7 +99,7 @@ func (c *Executor) Run(evtCh chan events.Event, opts ifc.RunOptions) {
 	if c.builder == nil {
 		ctx := context.Background()
 		builder, err := container.NewContainer(
-			&ctx,
+			ctx,
 			c.imgConf.Container.ContainerRuntime,
 			c.imgConf.Container.Image)
 		c.builder = builder

pkg/container/container.go

@@ -36,7 +36,7 @@ type Container interface {
 // arguments (e.g. "docker").
 // Supported drivers:
 //   * docker
-func NewContainer(ctx *context.Context, driver string, url string) (Container, error) {
+func NewContainer(ctx context.Context, driver string, url string) (Container, error) {
 	switch driver {
 	case "":
 		return nil, ErrNoContainerDriver{}

pkg/container/container_docker.go

@@ -95,17 +95,17 @@ type DockerContainer struct {
 	imageURL     string
 	id           string
 	dockerClient DockerClient
-	ctx          *context.Context
+	ctx          context.Context
 }
 
 // NewDockerClient returns instance of DockerClient.
 // Function essentially returns new Docker API client with default values
-func NewDockerClient(ctx *context.Context) (DockerClient, error) {
+func NewDockerClient(ctx context.Context) (DockerClient, error) {
 	cli, err := client.NewClientWithOpts(client.FromEnv)
 	if err != nil {
 		return nil, err
 	}
-	cli.NegotiateAPIVersion(*ctx)
+	cli.NegotiateAPIVersion(ctx)
 	return cli, nil
 }
 
@@ -115,7 +115,7 @@ func NewDockerClient(ctx *context.Context) (DockerClient, error) {
 //
 // url format: <image_path>:<tag>. If tag is not specified "latest" is used
 // as default value
-func NewDockerContainer(ctx *context.Context, url string, cli DockerClient) (*DockerContainer, error) {
+func NewDockerContainer(ctx context.Context, url string, cli DockerClient) (*DockerContainer, error) {
 	t := "latest"
 	nameTag := strings.Split(url, ":")
 	if len(nameTag) == 2 {
@@ -155,7 +155,7 @@ func (c *DockerContainer) getCmd(cmd []string) ([]string, error) {
 		return nil, err
 	}
 
-	insp, _, err := c.dockerClient.ImageInspectWithRaw(*c.ctx, id)
+	insp, _, err := c.dockerClient.ImageInspectWithRaw(c.ctx, id)
 	if err != nil {
 		return nil, err
 	}
@@ -195,7 +195,7 @@ func (c *DockerContainer) getImageID(url string) (string, error) {
 		All:     false,
 		Filters: filter,
 	}
-	img, err := c.dockerClient.ImageList(*c.ctx, opts)
+	img, err := c.dockerClient.ImageList(c.ctx, opts)
 	if err != nil {
 		return "", err
 	}
@@ -217,12 +217,12 @@ func (c *DockerContainer) ImagePull() error {
 	// skip image download if already downloaded
 	// ImageInspectWithRaw returns err when image not found local and
 	//     in this case it will proceed for ImagePull.
-	_, _, err := c.dockerClient.ImageInspectWithRaw(*c.ctx, c.imageURL)
+	_, _, err := c.dockerClient.ImageInspectWithRaw(c.ctx, c.imageURL)
 	if err == nil {
 		log.Debug("Image Already exists, skip download")
 		return nil
 	}
-	resp, err := c.dockerClient.ImagePull(*c.ctx, c.imageURL, types.ImagePullOptions{})
+	resp, err := c.dockerClient.ImagePull(c.ctx, c.imageURL, types.ImagePullOptions{})
 	if err != nil {
 		return err
 	}
@@ -249,7 +249,7 @@ func (c *DockerContainer) RunCommand(
 
 	containerConfig, hostConfig := c.getConfig(realCmd, volumeMounts, envVars)
 	resp, err := c.dockerClient.ContainerCreate(
-		*c.ctx,
+		c.ctx,
 		&containerConfig,
 		&hostConfig,
 		nil,
@@ -262,7 +262,7 @@ func (c *DockerContainer) RunCommand(
 	c.id = resp.ID
 
 	if containerInput != nil {
-		conn, attachErr := c.dockerClient.ContainerAttach(*c.ctx, c.id, types.ContainerAttachOptions{
+		conn, attachErr := c.dockerClient.ContainerAttach(c.ctx, c.id, types.ContainerAttachOptions{
 			Stream: true,
 			Stdin:  true,
 		})
@@ -274,7 +274,7 @@ func (c *DockerContainer) RunCommand(
 		}
 	}
 
-	if err = c.dockerClient.ContainerStart(*c.ctx, c.id, types.ContainerStartOptions{}); err != nil {
+	if err = c.dockerClient.ContainerStart(c.ctx, c.id, types.ContainerStartOptions{}); err != nil {
 		return err
 	}
 
@@ -284,13 +284,13 @@ func (c *DockerContainer) RunCommand(
 
 // GetContainerLogs returns logs from the container as io.ReadCloser
 func (c *DockerContainer) GetContainerLogs() (io.ReadCloser, error) {
-	return c.dockerClient.ContainerLogs(*c.ctx, c.id, types.ContainerLogsOptions{ShowStdout: true, Follow: true})
+	return c.dockerClient.ContainerLogs(c.ctx, c.id, types.ContainerLogsOptions{ShowStdout: true, Follow: true})
 }
 
 // RmContainer kills and removes a container from the docker host.
 func (c *DockerContainer) RmContainer() error {
 	return c.dockerClient.ContainerRemove(
-		*c.ctx,
+		c.ctx,
 		c.id,
 		types.ContainerRemoveOptions{
 			Force: true,
@@ -300,7 +300,7 @@ func (c *DockerContainer) RmContainer() error {
 
 // WaitUntilFinished waits unit container command is finished, return an error if failed
 func (c *DockerContainer) WaitUntilFinished() error {
-	statusCh, errCh := c.dockerClient.ContainerWait(*c.ctx, c.id, container.WaitConditionNotRunning)
+	statusCh, errCh := c.dockerClient.ContainerWait(c.ctx, c.id, container.WaitConditionNotRunning)
 	log.Debugf("waiting until command is finished...")
 	select {
 	case err := <-errCh:

pkg/container/container_docker_test.go

@@ -123,7 +123,7 @@ func getDockerContainerMock(mdc mockDockerClient) *DockerContainer {
 	ctx := context.Background()
 	cnt := &DockerContainer{
 		dockerClient: &mdc,
-		ctx:          &ctx,
+		ctx:          ctx,
 	}
 	return cnt
 }
@@ -520,7 +520,7 @@ func TestNewDockerContainer(t *testing.T) {
 		},
 	}
 	for _, tt := range tests {
-		actualRes, actualErr := NewDockerContainer(&(tt.ctx), tt.url, &(tt.cli))
+		actualRes, actualErr := NewDockerContainer((tt.ctx), tt.url, &(tt.cli))
 
 		assert.Equal(t, tt.expectedErr, actualErr)
 

pkg/container/container_test.go

@@ -27,13 +27,13 @@ func TestNewContainer(t *testing.T) {
 	ctx := context.Background()
 
 	t.Run("not-supported-container", func(t *testing.T) {
-		cnt, err := NewContainer(&ctx, "test_drv", "")
+		cnt, err := NewContainer(ctx, "test_drv", "")
 		assert.Equal(nil, cnt)
 		assert.Equal(ErrContainerDrvNotSupported{Driver: "test_drv"}, err)
 	})
 
 	t.Run("empty-container", func(t *testing.T) {
-		cnt, err := NewContainer(&ctx, "", "")
+		cnt, err := NewContainer(ctx, "", "")
 		assert.Equal(nil, cnt)
 		assert.Equal(ErrNoContainerDriver{}, err)
 	})