May 14, 2025 · May 13, 2025 · May 13, 2025 · May 13, 2025 · May 13, 2025
diff --git a/coderd/files/overlay.go b/coderd/files/overlay.go
 "io/fs"
 "path"
 "strings"

 "golang.org/x/xerrors"
 )

 // overlayFS allows you to "join" together the template files tar file fs.FS
 // with the Terraform modules tar file fs.FS. We could potentially turn this
 // into something more parameterized/configurable, but the requirements here are
 // a _bit_ odd, because every file in the modulesFS includes the
 // .terraform/modules/ folder at the beginning of it's path.
 // overlayFS allows you to "join" together multiple fs.FS. Files in any specific
 // overlay will only be accessible if their path starts with the base path
 // provided for the overlay. eg. An overlay at the path .terraform/modules
 // should contain files with paths inside the .terraform/modules folder.
 type overlayFS struct {
 baseFS   fs.FS
 overlays []Overlay
 fs.FS
 }

 func NewOverlayFS(baseFS fs.FS, overlays []Overlay) (fs.FS, error) {
 if err := valid(baseFS); err != nil {
 return nil, xerrors.Errorf("baseFS: %w", err)
 }

 for _, overlay := range overlays {
 if err := valid(overlay.FS); err != nil {
 return nil, xerrors.Errorf("overlayFS: %w", err)
 }
 }

 func NewOverlayFS(baseFS fs.FS, overlays []Overlay) fs.FS {
 return overlayFS{
 baseFS:   baseFS,
 overlays: overlays,
 }, nil
 }
 }

 func (f overlayFS) Open(p string) (fs.File, error) {
 func (f overlayFS) target(p string) fs.FS {
 target := f.baseFS
 for _, overlay := range f.overlays {
 if strings.HasPrefix(path.Clean(p), overlay.Path) {
 return overlay.FS.Open(p)
 target = overlay.FS
 break
 }
 }
 returnf.baseFS.Open(p)
 returntarget
 }

 func (f overlayFS) ReadDir(p string) ([]fs.DirEntry, error) {
 for _, overlay := range f.overlays {
 if strings.HasPrefix(path.Clean(p), overlay.Path) {
 //nolint:forcetypeassert
 return overlay.FS.(fs.ReadDirFS).ReadDir(p)
 }
 }
 //nolint:forcetypeassert
 return f.baseFS.(fs.ReadDirFS).ReadDir(p)
 func (f overlayFS) Open(p string) (fs.File, error) {
 return f.target(p).Open(p)
 }

 func (f overlayFS) ReadFile(p string) ([]byte, error) {
 for _, overlay := range f.overlays {
 if strings.HasPrefix(path.Clean(p), overlay.Path) {
 //nolint:forcetypeassert
 return overlay.FS.(fs.ReadFileFS).ReadFile(p)
 }
 }
 //nolint:forcetypeassert
 return f.baseFS.(fs.ReadFileFS).ReadFile(p)
 func (f overlayFS) ReadDir(p string) ([]fs.DirEntry, error) {
 return fs.ReadDir(f.target(p), p)
 }

 // valid checks that the fs.FS implements the required interfaces.
 // The fs.FS interface is not sufficient.
 func valid(fsys fs.FS) error {
 _, ok := fsys.(fs.ReadDirFS)
 if !ok {
 return xerrors.New("overlayFS does not implement ReadDirFS")
 }
 _, ok = fsys.(fs.ReadFileFS)
 if !ok {
 return xerrors.New("overlayFS does not implement ReadFileFS")
 }
 return nil
 func (f overlayFS) ReadFile(p string) ([]byte, error) {
 return fs.ReadFile(f.target(p), p)
 }
diff --git a/coderd/files/overlay_test.go b/coderd/files/overlay_test.go
 afero.WriteFile(b, ".terraform/modules/modules.json", []byte("{}"), 0o644)
 afero.WriteFile(b, ".terraform/modules/example_module/main.tf", []byte("terraform {}"), 0o644)

 it, err := files.NewOverlayFS(afero.NewIOFS(a), []files.Overlay{{
 it := files.NewOverlayFS(afero.NewIOFS(a), []files.Overlay{{
 Path: ".terraform/modules",
 FS:   afero.NewIOFS(b),
 }})
 require.NoError(t, err)

 content, err := fs.ReadFile(it, "main.tf")
 require.NoError(t, err)
diff --git a/coderd/parameters.go b/coderd/parameters.go
 return
 }
 defer api.FileCache.Release(tf.CachedModuleFiles.UUID)
 templateFS, err = files.NewOverlayFS(templateFS, []files.Overlay{{Path: ".terraform/modules", FS: moduleFilesFS}})
 if err != nil {
 httpapi.Write(ctx, rw, http.StatusInternalServerError, codersdk.Response{
 Message: "Internal error creating overlay filesystem.",
 Detail:  err.Error(),
 })
 return
 }
 templateFS = files.NewOverlayFS(templateFS, []files.Overlay{{Path: ".terraform/modules", FS: moduleFilesFS}})
 }
 } else if !xerrors.Is(err, sql.ErrNoRows) {
 httpapi.Write(ctx, rw, http.StatusInternalServerError, codersdk.Response{
Original file line number	Diff line number	Diff line change
Expand Up		@@ -4,15 +4,12 @@ import (
		"io/fs"
		"path"
		"strings"

		"golang.org/x/xerrors"
		)

		// overlayFS allows you to "join" together the template files tar file fs.FS
		// with the Terraform modules tar file fs.FS. We could potentially turn this
		// into something more parameterized/configurable, but the requirements here are
		// a _bit_ odd, because every file in the modulesFS includes the
		// .terraform/modules/ folder at the beginning of it's path.
		// overlayFS allows you to "join" together multiple fs.FS. Files in any specific
		// overlay will only be accessible if their path starts with the base path
		// provided for the overlay. eg. An overlay at the path .terraform/modules
		// should contain files with paths inside the .terraform/modules folder.
		type overlayFS struct {
		baseFS fs.FS
		overlays []Overlay
Expand All		@@ -23,64 +20,32 @@ type Overlay struct {
		fs.FS
		}

		func NewOverlayFS(baseFS fs.FS, overlays []Overlay) (fs.FS, error) {
		if err := valid(baseFS); err != nil {
		return nil, xerrors.Errorf("baseFS: %w", err)
		}

		for _, overlay := range overlays {
		if err := valid(overlay.FS); err != nil {
		return nil, xerrors.Errorf("overlayFS: %w", err)
		}
		}

		func NewOverlayFS(baseFS fs.FS, overlays []Overlay) fs.FS {
		return overlayFS{
		baseFS: baseFS,
		overlays: overlays,
		}, nil
		}
		}

		func (f overlayFS) Open(p string) (fs.File, error) {
		func (f overlayFS) target(p string) fs.FS {
		target := f.baseFS
		for _, overlay := range f.overlays {
		if strings.HasPrefix(path.Clean(p), overlay.Path) {
		return overlay.FS.Open(p)
		target = overlay.FS
		break
		}
		}
		returnf.baseFS.Open(p)
		returntarget
		}

		func (f overlayFS) ReadDir(p string) ([]fs.DirEntry, error) {
		for _, overlay := range f.overlays {
		if strings.HasPrefix(path.Clean(p), overlay.Path) {
		//nolint:forcetypeassert
		return overlay.FS.(fs.ReadDirFS).ReadDir(p)
		}
		}
		//nolint:forcetypeassert
		return f.baseFS.(fs.ReadDirFS).ReadDir(p)
		func (f overlayFS) Open(p string) (fs.File, error) {
		return f.target(p).Open(p)
		}

		func (f overlayFS) ReadFile(p string) ([]byte, error) {
		for _, overlay := range f.overlays {
		if strings.HasPrefix(path.Clean(p), overlay.Path) {
		//nolint:forcetypeassert
		return overlay.FS.(fs.ReadFileFS).ReadFile(p)
		}
		}
		//nolint:forcetypeassert
		return f.baseFS.(fs.ReadFileFS).ReadFile(p)
		func (f overlayFS) ReadDir(p string) ([]fs.DirEntry, error) {
		return fs.ReadDir(f.target(p), p)
		}

		// valid checks that the fs.FS implements the required interfaces.
		// The fs.FS interface is not sufficient.
		func valid(fsys fs.FS) error {
		_, ok := fsys.(fs.ReadDirFS)
		if !ok {
		return xerrors.New("overlayFS does not implement ReadDirFS")
		}
		_, ok = fsys.(fs.ReadFileFS)
		if !ok {
		return xerrors.New("overlayFS does not implement ReadFileFS")
		}
		return nil
		func (f overlayFS) ReadFile(p string) ([]byte, error) {
		return fs.ReadFile(f.target(p), p)
		}
Original file line number	Diff line number	Diff line change
Expand Up		@@ -21,11 +21,10 @@ func TestOverlayFS(t *testing.T) {
		afero.WriteFile(b, ".terraform/modules/modules.json", []byte("{}"), 0o644)
		afero.WriteFile(b, ".terraform/modules/example_module/main.tf", []byte("terraform {}"), 0o644)

		it, err := files.NewOverlayFS(afero.NewIOFS(a), []files.Overlay{{
		it := files.NewOverlayFS(afero.NewIOFS(a), []files.Overlay{{
		Path: ".terraform/modules",
		FS: afero.NewIOFS(b),
		}})
		require.NoError(t, err)

		content, err := fs.ReadFile(it, "main.tf")
		require.NoError(t, err)
Expand Down
Original file line number	Diff line number	Diff line change
Expand Up		@@ -97,14 +97,7 @@ func (api API) templateVersionDynamicParameters(rw http.ResponseWriter, r http
		return
		}
		defer api.FileCache.Release(tf.CachedModuleFiles.UUID)
		templateFS, err = files.NewOverlayFS(templateFS, []files.Overlay{{Path: ".terraform/modules", FS: moduleFilesFS}})
		if err != nil {
		httpapi.Write(ctx, rw, http.StatusInternalServerError, codersdk.Response{
		Message: "Internal error creating overlay filesystem.",
		Detail: err.Error(),
		})
		return
		}
		templateFS = files.NewOverlayFS(templateFS, []files.Overlay{{Path: ".terraform/modules", FS: moduleFilesFS}})
		}
		} else if !xerrors.Is(err, sql.ErrNoRows) {
		httpapi.Write(ctx, rw, http.StatusInternalServerError, codersdk.Response{
Expand Down