Rm f symlink

pkg/filesystem/filesystem.go

@@ -2,13 +2,16 @@ package filesystem
 
 import (
 	"archive/zip"
+	"bytes"
+	"errors"
 	"fmt"
 	"io"
 	"io/fs"
 	"os"
 	"path"
 	"path/filepath"
 	"strings"
+	"text/template"
 
 	billy "github.com/go-git/go-billy/v5"
 )
@@ -253,6 +256,140 @@ func (m maskingFS) Readlink(link string) (string, error) {
 	return m.fs.Readlink(link)
 }
 
+// NewTemplatingFS creates a new filesystem that evaluates/expands Go templates from *.ftmpl files in the baseFS.
+// For example if the baseFS contains file go.mod.ftmpl then the new resultant FS will contain go.mod file instead,
+// and the file would be result of template execution with templateData as the template data.
+func NewTemplatingFS(baseFS Filesystem, templateData any) templatingFS {
+	return templatingFS{
+		fs:           baseFS,
+		templateData: templateData,
+	}
+}
+
+type templatingFS struct {
+	fs           Filesystem
+	templateData any
+}
+
+type templatingFI struct {
+	fs.FileInfo
+	size int64
+}
+
+func (t templatingFI) Size() int64 {
+	return t.size
+}
+
+func (t templatingFI) Name() string {
+	return strings.TrimSuffix(t.FileInfo.Name(), ".ftmpl")
+}
+
+type templatingFile struct {
+	fi   templatingFI
+	buff bytes.Buffer
+}
+
+func (t *templatingFile) Stat() (fs.FileInfo, error) {
+	return t.fi, nil
+}
+
+func (t *templatingFile) Read(i []byte) (int, error) {
+	return t.buff.Read(i)
+}
+
+func (t *templatingFile) Close() error {
+	return nil
+}
+
+func (t templatingFS) Open(name string) (fs.File, error) {
+	n := name + ".ftmpl"
+
+	if _, err := t.fs.Stat(n); errors.Is(err, fs.ErrNotExist) {
+		return t.fs.Open(name)
+	}
+
+	tmpl, err := template.ParseFS(t.fs, n)
+	if err != nil {
+		return nil, err
+	}
+
+	var f templatingFile
+	err = tmpl.Execute(&f.buff, t.templateData)
+	if err != nil {
+		return nil, err
+	}
+
+	fi, err := t.fs.Stat(n)
+	if err != nil {
+		return nil, err
+	}
+	f.fi = templatingFI{FileInfo: fi, size: int64(f.buff.Len())}
+
+	return &f, nil
+}
+
+func (t templatingFS) ReadDir(name string) ([]fs.DirEntry, error) {
+	des, err := t.fs.ReadDir(name)
+	if err != nil {
+		return nil, err
+	}
+
+	result := make([]fs.DirEntry, len(des))
+	for i, de := range des {
+		var fi fs.FileInfo
+		if !strings.HasSuffix(de.Name(), ".ftmpl") {
+			result[i] = de
+			continue
+		}
+
+		fi, err = t.Stat(path.Join(name, strings.TrimSuffix(de.Name(), ".ftmpl")))
+		if err != nil {
+			return nil, err
+		}
+		result[i] = dirEntry{fi}
+
+	}
+	return result, nil
+}
+
+func (t templatingFS) Stat(name string) (fs.FileInfo, error) {
+	n := name + ".ftmpl"
+
+	fi, err := t.fs.Stat(n)
+	if errors.Is(err, fs.ErrNotExist) {
+		return t.fs.Stat(name)
+	}
+
+	var tmpl *template.Template
+	tmpl, err = template.ParseFS(t.fs, n)
+	if err != nil {
+		return nil, err
+	}
+
+	var w wc
+	err = tmpl.Execute(&w, t.templateData)
+	if err != nil {
+		return nil, err
+	}
+	return templatingFI{
+		FileInfo: fi,
+		size:     w.written,
+	}, nil
+}
+
+type wc struct {
+	written int64
+}
+
+func (w *wc) Write(p []byte) (n int, err error) {
+	w.written += int64(len(p))
+	return len(p), nil
+}
+
+func (t templatingFS) Readlink(link string) (string, error) {
+	return t.fs.Readlink(link)
+}
+
 // CopyFromFS copies files from the `src` dir on the accessor Filesystem to local filesystem into `dest` dir.
 // The src path uses slashes as their separator.
 // The dest path uses OS specific separator.

pkg/filesystem/filesystem_test.go

@@ -382,6 +382,74 @@ func TestCopy(t *testing.T) {
 	}
 }
 
+func TestTemplatingFS(t *testing.T) {
+	tfs := filesystem.NewTemplatingFS(
+		mockFS{files: []FileInfo{
+			{
+				Path: "src",
+				Typ:  fs.ModeDir,
+			},
+			{
+				Path:    "src/hello.txt.ftmpl",
+				Content: []byte("Hi {{.Name}}!"),
+			},
+		}},
+		struct{ Name string }{Name: "John"},
+	)
+
+	expectedContent := "Hi John!"
+
+	fi, err := tfs.Stat("src/hello.txt")
+	if err != nil {
+		t.Fatal(err)
+	}
+	if fi.Size() != int64(len(expectedContent)) {
+		t.Errorf("size missmatch")
+	}
+
+	des, err := tfs.ReadDir("src")
+	if err != nil {
+		t.Fatal(err)
+	}
+	if len(des) != 1 {
+		t.Fatal("expected exactly one item in directory")
+	}
+	if des[0].Name() != "hello.txt" {
+		t.Fatalf("unexpected file: %q", des[0].Name())
+	}
+	fi, err = des[0].Info()
+	if err != nil {
+		t.Fatal(err)
+	}
+	if fi.Size() != int64(len(expectedContent)) {
+		t.Error("size missmatch")
+	}
+
+	expectedFiles := []FileInfo{
+		{
+			Path: ".",
+			Typ:  fs.ModeDir,
+		},
+		{
+			Path: "src",
+			Typ:  fs.ModeDir,
+		},
+		{
+			Path:    "src/hello.txt",
+			Content: []byte(expectedContent),
+		},
+	}
+
+	actualFiles, err := loadFS(tfs)
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	if diff := cmp.Diff(expectedFiles, actualFiles); diff != "" {
+		t.Error("filesystem content missmatch (-want, +got):", diff)
+	}
+}
+
 // mock for testing symlink functionality
 type mockFS struct {
 	files []FileInfo

pkg/scaffolding/scaffold.go

@@ -2,7 +2,6 @@ package scaffolding
 
 import (
 	"fmt"
-	"os"
 	"path/filepath"
 
 	"knative.dev/func/pkg/filesystem"
@@ -43,6 +42,19 @@ func Write(out, src, runtime, invoke string, fs filesystem.Filesystem) (err erro
 		return ErrScaffoldingNotFound
 	}
 
+	rel, err := filepath.Rel(out, src)
+	if err != nil {
+		return ScaffoldingError{"error determining relative path to function source", err}
+	}
+
+	fs = filesystem.NewTemplatingFS(fs, struct {
+		ModuleName string
+		FuncPath   string
+	}{
+		ModuleName: "function",
+		FuncPath:   rel,
+	})
+
 	// Copy from d -> out from the filesystem
 	if err := filesystem.CopyFromFS(d, out, fs); err != nil {
 		return ScaffoldingError{"filesystem copy failed", err}
@@ -56,17 +68,6 @@ func Write(out, src, runtime, invoke string, fs filesystem.Filesystem) (err erro
 		return ScaffoldingError{"certs copy failed", err}
 	}
 
-	// Replace the 'f' link of the scaffolding (which is now incorrect) to
-	// link to the function's root.
-	rel, err := filepath.Rel(out, src)
-	if err != nil {
-		return ScaffoldingError{"error determining relative path to function source", err}
-	}
-	link := filepath.Join(out, "f")
-	_ = os.Remove(link)
-	if err = os.Symlink(rel, link); err != nil {
-		return fmt.Errorf("error linking scaffolding to source %w", err)
-	}
 	return
 }
 

templates/go/scaffolding/static-cloudevents/go.mod → templates/go/scaffolding/instanced-cloudevents/go.mod.ftmpl

@@ -1,6 +1,6 @@
 module s
 
-replace function => ./f
+replace {{.ModuleName}} => {{.FuncPath}}
 
 go 1.21
 

templates/go/scaffolding/static-http/go.mod → templates/go/scaffolding/instanced-http/go.mod.ftmpl

@@ -1,6 +1,6 @@
 module s
 
-replace function => ./f
+replace {{.ModuleName}} => {{.FuncPath}}
 
 go 1.21
 

templates/go/scaffolding/instanced-cloudevents/go.mod → templates/go/scaffolding/static-cloudevents/go.mod.ftmpl

@@ -1,6 +1,6 @@
 module s
 
-replace function => ./f
+replace {{.ModuleName}} => {{.FuncPath}}
 
 go 1.21
 

templates/go/scaffolding/instanced-http/go.mod → templates/go/scaffolding/static-http/go.mod.ftmpl

@@ -1,6 +1,6 @@
 module s
 
-replace function => ./f
+replace {{.ModuleName}} => {{.FuncPath}}
 
 go 1.21