(GH-85) Add alwaysBuild flag and functionality

In this commit the `alwaysBuild` flag and its functionality were added
to the `prm exec` command. `alwaysBuild` will cause the docker
image pertaining to the executed tool and puppet version to
rebuild on tool execution.

cmd/exec/exec.go

@@ -21,9 +21,10 @@ var (
 	format        string
 	selectedTool  string
 	// selectedToolInfo    string
-	listTools bool
-	prmApi    *prm.Prm
-	toolArgs  string
+	listTools   bool
+	prmApi      *prm.Prm
+	toolArgs    string
+	alwaysBuild bool
 )
 
 func CreateCommand(parent *prm.Prm) *cobra.Command {
@@ -72,6 +73,10 @@ func CreateCommand(parent *prm.Prm) *cobra.Command {
 	err = viper.BindPFlag("toolArgs", tmp.Flags().Lookup("toolArgs"))
 	cobra.CheckErr(err)
 
+	tmp.Flags().BoolVarP(&alwaysBuild, "alwaysBuild", "a", false, "Rebuild the docker image for each tool execution, even if it already exists")
+	err = viper.BindPFlag("alwaysBuild", tmp.Flags().Lookup("alwaysBuild"))
+	cobra.CheckErr(err)
+
 	return tmp
 }
 
@@ -82,9 +87,9 @@ func preExecute(cmd *cobra.Command, args []string) error {
 
 	switch prmApi.RunningConfig.Backend {
 	case prm.DOCKER:
-		prmApi.Backend = &prm.Docker{AFS: prmApi.AFS, IOFS: prmApi.IOFS}
+		prmApi.Backend = &prm.Docker{AFS: prmApi.AFS, IOFS: prmApi.IOFS, AlwaysBuild: alwaysBuild}
 	default:
-		prmApi.Backend = &prm.Docker{AFS: prmApi.AFS, IOFS: prmApi.IOFS}
+		prmApi.Backend = &prm.Docker{AFS: prmApi.AFS, IOFS: prmApi.IOFS, AlwaysBuild: alwaysBuild}
 	}
 
 	// handle the default cachepath
@@ -188,6 +193,7 @@ func execute(cmd *cobra.Command, args []string) error {
 			if !ok {
 				return fmt.Errorf("Tool %s not found in cache", tool)
 			}
+
 			err := prmApi.Exec(cachedTool, tool.Args)
 			if err != nil {
 				return err

internal/pkg/mock/docker.go

@@ -64,3 +64,7 @@ func (m *DockerClient) ImageBuild(ctx context.Context, buildContext io.Reader, o
 func (m *DockerClient) ImageList(ctx context.Context, options types.ImageListOptions) ([]types.ImageSummary, error) {
 	return []types.ImageSummary{}, nil
 }
+
+func (m *DockerClient) ImageRemove(ctx context.Context, imageID string, options types.ImageRemoveOptions) ([]types.ImageDeleteResponseItem, error) {
+	return []types.ImageDeleteResponseItem{{Deleted: "test_id"}}, nil
+}

pkg/prm/docker.go

@@ -31,6 +31,7 @@ type Docker struct {
 	ContextCancel func()
 	AFS           *afero.Afero
 	IOFS          *afero.IOFS
+	AlwaysBuild   bool
 }
 
 type DockerClientI interface {
@@ -42,6 +43,7 @@ type DockerClientI interface {
 	ContainerWait(ctx context.Context, containerID string, condition container.WaitCondition) (<-chan container.ContainerWaitOKBody, <-chan error)
 	ImageBuild(ctx context.Context, buildContext io.Reader, options types.ImageBuildOptions) (types.ImageBuildResponse, error)
 	ImageList(ctx context.Context, options types.ImageListOptions) ([]types.ImageSummary, error)
+	ImageRemove(ctx context.Context, imageID string, options types.ImageRemoveOptions) ([]types.ImageDeleteResponseItem, error)
 	ServerVersion(context.Context) (types.Version, error)
 }
 
@@ -64,16 +66,33 @@ func (d *Docker) GetTool(tool *Tool, prmConfig Config) error {
 		return err
 	}
 
+	foundImage := ""
 	for _, image := range list {
 		for _, tag := range image.RepoTags {
 			if tag == toolImageName {
 				log.Info().Msgf("Found image: %s", image.ID)
-				return nil
+				if !d.AlwaysBuild {
+					return nil
+				}
+				foundImage = image.ID
+				break
 			}
 		}
+		if foundImage != "" {
+			break
+		}
 	}
 
-	log.Info().Msg("Creating new image. Please wait...")
+	if d.AlwaysBuild && foundImage != "" {
+		log.Info().Msg("Rebuilding image. Please wait...")
+		_, err = d.Client.ImageRemove(d.Context, foundImage, types.ImageRemoveOptions{Force: true})
+		if err != nil {
+			log.Error().Msgf("Error removing docker image: %v", err)
+			return err
+		}
+	} else {
+		log.Info().Msg("Creating new image. Please wait...")
+	}
 
 	// No image found with that configuration
 	// we must create it