fix and add unit tests

Signed-off-by: Rakshit Gondwal <[email protected]>

cmd/oci/oci.go

@@ -36,7 +36,7 @@ func init() {
 	OCICmd.Flags().BoolVarP(&loadPodman, "load-podman", "", false, "Load the image into podman")
 	OCICmd.Flags().BoolVarP(&push, "push", "", false, "Push the image to the registry")
 	OCICmd.Flags().BoolVarP(&devDeps, "dev", "", false, "Build base image for Dev Dependencies")
-	OCICmd.Flags().BoolVarP(&dfSwap, "df-swap", "", false, "Build base image for Dev Dependencies")
+	OCICmd.Flags().BoolVarP(&dfSwap, "df-swap", "", false, "Modify base images in Dockerfile")
 	OCICmd.Flags().StringVarP(&tag, "tag", "t", "", "The tag that will be replaced with original tag in Dockerfile")
 	OCICmd.Flags().StringVar(&path, "path", "", "The path to Dockerfile")
 }
@@ -66,16 +66,14 @@ var OCICmd = &cobra.Command{
 
 		if dfSwap {
 			if tag != "" {
-				if err := builddocker.ModifyDockerfile(path, tag, devDeps); err != nil {
+				if err = modifyDockerfileWithTag(path, tag, devDeps); err != nil {
 					fmt.Println(styles.ErrorStyle.Render("error: ", err.Error()))
-					os.Exit(1)
 				}
 				fmt.Println(styles.SucessStyle.Render("dockerfile succesfully updated with tag:", tag))
-				os.Exit(1)
 			} else {
 				fmt.Println(styles.HintStyle.Render("hint:", "use --tag flag to define a tag"))
-				os.Exit(1)
 			}
+			os.Exit(1)
 		}
 
 		sc, fh, err := binit.GetBSFInitializers()
@@ -254,6 +252,38 @@ func ProcessPlatformAndConfig(plat string, envName string) (hcl2nix.OCIArtifact,
 	return artifact, plat, nil
 }
 
+func modifyDockerfileWithTag(path, tag string, devDeps bool) error {
+	var dockerfilePath string
+	if path != "" {
+		dockerfilePath = path + "/Dockerfile"
+	} else {
+		dockerfilePath = "./Dockerfile"
+	}
+
+	_, err := os.Stat(dockerfilePath)
+	if err != nil {
+		return err
+	}
+
+	file, err := os.Open(dockerfilePath)
+	if err != nil {
+		return err
+	}
+	defer file.Close()
+
+	resLines, err := builddocker.ModifyDockerfile(file, devDeps, tag)
+	if err != nil {
+		return err
+	}
+
+	err = os.WriteFile(dockerfilePath, []byte(strings.Join(resLines, "\n")), 0644)
+	if err != nil {
+		return err
+	}
+
+	return nil
+}
+
 func genOCIAttrName(env, platform string, artifact hcl2nix.OCIArtifact) string {
 	var arch string
 

pkg/builddocker/build.go

@@ -50,80 +50,74 @@ func GenerateDockerfile(w io.Writer, env hcl2nix.OCIArtifact, platform string) e
 }
 
 // ModifyDockerfile modifies the Dockerfile with the specified tag
-func ModifyDockerfile(path, tag string, dev bool) error {
-	var dockerfilePath string
-	if path != "" {
-		dockerfilePath = path + "/Dockerfile"
-	} else {
-		dockerfilePath = "./Dockerfile"
-	}
-
-	if _, err := os.Stat(dockerfilePath); os.IsNotExist(err) {
-		return fmt.Errorf("dockerfile not found")
+func ModifyDockerfile(file *os.File, dev bool, tag string) ([]string, error) {
+	lines, err := readDockerFile(file)
+	if err != nil {
+		return nil, err
 	}
 
-	file, err := os.Open(dockerfilePath)
+	reslines, err := editDockerfile(lines, dev, tag)
 	if err != nil {
-		return fmt.Errorf("error opening Dockerfile: %v", err)
+		return nil, err
 	}
-	defer file.Close()
 
+	return reslines, nil
+}
+
+func readDockerFile(file *os.File) ([]string, error) {
 	scanner := bufio.NewScanner(file)
 	lines := []string{}
 	for scanner.Scan() {
 		lines = append(lines, scanner.Text())
 	}
 	if err := scanner.Err(); err != nil {
-		return fmt.Errorf("error reading Dockerfile: %v", err)
-	}
-
-	var searchTag string
-	if dev {
-		searchTag = "# bsfimage:dev"
-	} else {
-		searchTag = "# bsfimage:runtime"
+		return nil, fmt.Errorf("error reading Dockerfile: %v", err)
 	}
+	return lines, nil
+}
 
-	var selectedFrom string
-	var selectedIndex int
-	for i, line := range lines {
-		if strings.Contains(line, searchTag) {
-			selectedFrom = line
-			selectedIndex = i
-			break
+	func editDockerfile(lines []string, dev bool, tag string) ([]string, error) {
+		var searchTag string
+		if dev {
+			searchTag = "# bsfimage:dev"
+		} else {
+			searchTag = "# bsfimage:runtime"
 		}
-	}
 
-	if selectedFrom == "" {
-		return fmt.Errorf("no FROM command found with tag %s", searchTag)
-	}
+		var selectedFrom string
+		var selectedIndex int
+		for i, line := range lines {
+			if strings.Contains(line, searchTag) {
+				selectedFrom = line
+				selectedIndex = i
+				break
+			}
+		}
 
-	fromParts := strings.Fields(selectedFrom)
-	if len(fromParts) < 2 {
-		return fmt.Errorf("invalid FROM command format")
-	}
+		if selectedFrom == "" {
+			return nil, fmt.Errorf("no FROM command found with tag %s", searchTag)
+		}
 
-	var newFrom string
-	if strings.Contains(fromParts[1], ":") {
-		imageParts := strings.Split(fromParts[1], ":")
-		newFrom = fmt.Sprintf("FROM %s:%s", imageParts[0], tag)
-	} else {
-		newFrom = fmt.Sprintf("FROM %s:%s", fromParts[1], tag)
-	}
-	for _, part := range fromParts[2:] {
-		newFrom = fmt.Sprintf("%s %s", newFrom, part)
-	}
+		fromParts := strings.Fields(selectedFrom)
+		if len(fromParts) < 2 {
+			return nil, fmt.Errorf("invalid FROM command format")
+		}
 
-	lines[selectedIndex] = newFrom
+		var newFrom string
+		if strings.Contains(fromParts[1], ":") {
+			imageParts := strings.Split(fromParts[1], ":")
+			newFrom = fmt.Sprintf("FROM %s:%s", imageParts[0], tag)
+		} else {
+			newFrom = fmt.Sprintf("FROM %s:%s", fromParts[1], tag)
+		}
+		for _, part := range fromParts[2:] {
+			newFrom = fmt.Sprintf("%s %s", newFrom, part)
+		}
 
-	err = os.WriteFile(dockerfilePath, []byte(strings.Join(lines, "\n")), 0644)
-	if err != nil {
-		return fmt.Errorf("error writing to Dockerfile: %v", err)
+		lines[selectedIndex] = newFrom
+		return lines, nil
 	}
 
-	return nil
-}
-
 func convertExportCfgToDockerfileCfg(env hcl2nix.OCIArtifact, platform string) dockerfileCfg {
 	switch platform {
 	case "linux/amd64":

pkg/builddocker/build_test.go

@@ -0,0 +1,80 @@
+package builddocker
+
+import (
+	"testing"
+
+	"github.com/stretchr/testify/assert"
+)
+
+func TestEditDockerFile(t *testing.T) {
+	tests := []struct {
+		name        string
+		lines       []string
+		isDev       bool
+		tag         string
+		expectedRes []string
+		expectError bool
+	}{
+		{
+			name: "Dev",
+			lines: []string{
+				"FROM ubuntu:18.04 # bsfimage:dev",
+				"RUN apt-get update",
+			},
+			isDev: true,
+			tag:   "latest",
+			expectedRes: []string{
+				"FROM ubuntu:latest # bsfimage:dev",
+				"RUN apt-get update",
+			},
+			expectError: false,
+		},
+		{
+			name: "Runtime",
+			lines: []string{
+				"FROM ubuntu:18.04 # bsfimage:runtime",
+				"RUN apt-get update",
+			},
+			isDev: false,
+			tag:   "latest",
+			expectedRes: []string{
+				"FROM ubuntu:latest # bsfimage:runtime",
+				"RUN apt-get update",
+			},
+			expectError: false,
+		},
+		{
+			name: "No FROM Command with bsf tag",
+			lines: []string{
+				"FROM ubuntu:latest",
+				"RUN apt-get update",
+			},
+			isDev:       true,
+			tag:         "latest",
+			expectedRes: nil,
+			expectError: true,
+		},
+		{
+			name: "No FROM Command",
+			lines: []string{
+				"RUN apt-get update",
+			},
+			isDev:       true,
+			tag:         "latest",
+			expectedRes: nil,
+			expectError: true,
+		},
+	}
+
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			res, err := editDockerfile(tt.lines, tt.isDev, tt.tag)
+			if tt.expectError {
+				assert.Error(t, err)
+			} else {
+				assert.NoError(t, err)
+				assert.Equal(t, tt.expectedRes, res)
+			}
+		})
+	}
+}