feat: remove docker image on uninstall

Fixes #86

pkgmgr/docker.go

@@ -330,10 +330,7 @@ func (d *DockerService) refresh() error {
 
 func (d *DockerService) getClient() (*client.Client, error) {
 	if d.client == nil {
-		tmpClient, err := client.NewClientWithOpts(
-			client.WithAPIVersionNegotiation(),
-			client.WithHostFromEnv(),
-		)
+		tmpClient, err := NewDockerClient()
 		if err != nil {
 			return nil, err
 		}
@@ -342,10 +339,32 @@ func (d *DockerService) getClient() (*client.Client, error) {
 	return d.client, nil
 }
 
+func NewDockerClient() (*client.Client, error) {
+	tmpClient, err := client.NewClientWithOpts(
+		client.WithAPIVersionNegotiation(),
+		client.WithHostFromEnv(),
+	)
+	if err != nil {
+		return nil, err
+	}
+	return tmpClient, nil
+}
+
 func CheckDockerConnectivity() error {
-	tmpDockerService := &DockerService{}
-	if _, err := tmpDockerService.getClient(); err != nil {
+	if _, err := NewDockerClient(); err != nil {
 		return errors.New(dockerInstallError)
 	}
 	return nil
 }
+
+func RemoveDockerImage(image string) error {
+	client, err := NewDockerClient()
+	if err != nil {
+		return err
+	}
+	_, err = client.ImageRemove(context.Background(), image, types.ImageRemoveOptions{})
+	if err != nil {
+		return err
+	}
+	return nil
+}

pkgmgr/package.go

@@ -323,22 +323,36 @@ func (p *PackageInstallStepDocker) install(cfg Config, pkgName string) error {
 }
 
 func (p *PackageInstallStepDocker) uninstall(cfg Config, pkgName string) error {
-	// Nothing to uninstall if we were only fetching the image
-	if p.PullOnly {
-		return nil
-	}
-	containerName := fmt.Sprintf("%s-%s", pkgName, p.ContainerName)
-	svc, err := NewDockerServiceFromContainerName(containerName, cfg.Logger)
-	if err != nil {
-		return err
-	}
-	if running, _ := svc.Running(); running {
-		if err := svc.Stop(); err != nil {
+	if !p.PullOnly {
+		containerName := fmt.Sprintf("%s-%s", pkgName, p.ContainerName)
+		svc, err := NewDockerServiceFromContainerName(containerName, cfg.Logger)
+		if err != nil {
+			return err
+		}
+		if running, _ := svc.Running(); running {
+			if err := svc.Stop(); err != nil {
+				return err
+			}
+		}
+		if err := svc.Remove(); err != nil {
 			return err
 		}
 	}
-	if err := svc.Remove(); err != nil {
-		return err
+	if err := RemoveDockerImage(p.Image); err != nil {
+		cfg.Logger.Debug(
+			fmt.Sprintf(
+				"failed to delete image %q: %s",
+				p.Image,
+				err,
+			),
+		)
+	} else {
+		cfg.Logger.Debug(
+			fmt.Sprintf(
+				"removed unused image %q",
+				p.Image,
+			),
+		)
 	}
 	return nil
 }