fix: support building features that call bundled scripts (#64)

Co-authored-by: Aaron Lehmann <aaronl@vitelus.com>

devcontainer/devcontainer_test.go

@@ -91,19 +91,21 @@ func TestCompileWithFeatures(t *testing.T) {
 
 	// We have to SHA because we get a different MD5 every time!
 	featureOneMD5 := md5.Sum([]byte(featureOne))
-	featureOneSha := fmt.Sprintf("%x", featureOneMD5[:4])
+	featureOneDir := fmt.Sprintf(".envbuilder/features/one-%x", featureOneMD5[:4])
 	featureTwoMD5 := md5.Sum([]byte(featureTwo))
-	featureTwoSha := fmt.Sprintf("%x", featureTwoMD5[:4])
+	featureTwoDir := fmt.Sprintf(".envbuilder/features/two-%x", featureTwoMD5[:4])
 
 	require.Equal(t, `FROM codercom/code-server:latest
 
 USER root
 # Rust tomato - Example description!
+WORKDIR `+featureOneDir+`
 ENV TOMATO=example
-RUN .envbuilder/features/one-`+featureOneSha+`/install.sh
+RUN ./install.sh
 # Go potato - Example description!
+WORKDIR `+featureTwoDir+`
 ENV POTATO=example
-RUN VERSION=potato .envbuilder/features/two-`+featureTwoSha+`/install.sh
+RUN VERSION=potato ./install.sh
 USER 1000`, params.DockerfileContent)
 }
 

devcontainer/features/features.go

@@ -137,7 +137,7 @@ func Extract(fs billy.Filesystem, directory, reference string) (*Spec, error) {
 		return nil, errors.New(`devcontainer-feature.json: name is required`)
 	}
 
-	spec.InstallScriptPath = installScriptPath
+	spec.Directory = directory
 	return spec, nil
 }
 
@@ -164,7 +164,7 @@ type Spec struct {
 	Options          map[string]Option `json:"options"`
 	ContainerEnv     map[string]string `json:"containerEnv"`
 
-	InstallScriptPath string `json:"-"`
+	Directory string `json:"-"`
 }
 
 // Extract unpacks the feature from the image and returns a set of lines
@@ -189,7 +189,7 @@ func (s *Spec) Compile(options map[string]any) (string, error) {
 	sort.Strings(runDirective)
 	// See https://containers.dev/implementors/features/#invoking-installsh
 	runDirective = append([]string{"RUN"}, runDirective...)
-	runDirective = append(runDirective, s.InstallScriptPath)
+	runDirective = append(runDirective, "./install.sh")
 
 	comment := ""
 	if s.Name != "" {
@@ -205,6 +205,7 @@ func (s *Spec) Compile(options map[string]any) (string, error) {
 	if comment != "" {
 		lines = append(lines, comment)
 	}
+	lines = append(lines, "WORKDIR "+s.Directory)
 	envKeys := make([]string, 0, len(s.ContainerEnv))
 	for key := range s.ContainerEnv {
 		envKeys = append(envKeys, key)

devcontainer/features/features_test.go

@@ -81,28 +81,28 @@ func TestCompile(t *testing.T) {
 	t.Run("Basic", func(t *testing.T) {
 		t.Parallel()
 		spec := &features.Spec{
-			InstallScriptPath: "install.sh",
+			Directory: "/",
 		}
 		directive, err := spec.Compile(nil)
 		require.NoError(t, err)
-		require.Equal(t, "RUN install.sh", strings.TrimSpace(directive))
+		require.Equal(t, "WORKDIR /\nRUN ./install.sh", strings.TrimSpace(directive))
 	})
 	t.Run("ContainerEnv", func(t *testing.T) {
 		t.Parallel()
 		spec := &features.Spec{
-			InstallScriptPath: "install.sh",
+			Directory: "/",
 			ContainerEnv: map[string]string{
 				"FOO": "bar",
 			},
 		}
 		directive, err := spec.Compile(nil)
 		require.NoError(t, err)
-		require.Equal(t, "ENV FOO=bar\nRUN install.sh", strings.TrimSpace(directive))
+		require.Equal(t, "WORKDIR /\nENV FOO=bar\nRUN ./install.sh", strings.TrimSpace(directive))
 	})
 	t.Run("OptionsEnv", func(t *testing.T) {
 		t.Parallel()
 		spec := &features.Spec{
-			InstallScriptPath: "install.sh",
+			Directory: "/",
 			Options: map[string]features.Option{
 				"foo": {
 					Default: "bar",
@@ -111,6 +111,6 @@ func TestCompile(t *testing.T) {
 		}
 		directive, err := spec.Compile(nil)
 		require.NoError(t, err)
-		require.Equal(t, "RUN FOO=bar install.sh", strings.TrimSpace(directive))
+		require.Equal(t, "WORKDIR /\nRUN FOO=bar ./install.sh", strings.TrimSpace(directive))
 	})
 }