LocalFileSource: support a custom fs.FS

Add fs.FS support to LocalFileSource, FileResource, and the commands that use them (deploy, diff, inspect). This is useful so these commands can be invoked programmatically. Signed-off-by: Andy Goldstein <[email protected]>
carvel-dev · Aug 14, 2023 · 2804e19 · 2804e19
1 parent a2e6064
commit 2804e19
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Showing 6 changed files with 265 additions and 20 deletions.
diff --git a/pkg/kapp/cmd/app/deploy.go b/pkg/kapp/cmd/app/deploy.go
@@ -5,12 +5,18 @@ package app
 
 import (
 	"fmt"
+	"io/fs"
 	"os"
 	"sort"
 	"strings"
 
 	"github.com/cppforlife/go-cli-ui/ui"
 	"github.com/spf13/cobra"
+	corev1 "k8s.io/api/core/v1"
+	"k8s.io/apimachinery/pkg/labels"
+	"k8s.io/apimachinery/pkg/runtime/schema"
+	"k8s.io/client-go/kubernetes"
+
 	ctlapp "github.com/vmware-tanzu/carvel-kapp/pkg/kapp/app"
 	ctlcap "github.com/vmware-tanzu/carvel-kapp/pkg/kapp/clusterapply"
 	cmdcore "github.com/vmware-tanzu/carvel-kapp/pkg/kapp/cmd/core"
@@ -23,10 +29,6 @@ import (
 	ctllogs "github.com/vmware-tanzu/carvel-kapp/pkg/kapp/logs"
 	ctlres "github.com/vmware-tanzu/carvel-kapp/pkg/kapp/resources"
 	ctlresm "github.com/vmware-tanzu/carvel-kapp/pkg/kapp/resourcesmisc"
-	corev1 "k8s.io/api/core/v1"
-	"k8s.io/apimachinery/pkg/labels"
-	"k8s.io/apimachinery/pkg/runtime/schema"
-	"k8s.io/client-go/kubernetes"
 )
 
 const (
@@ -47,6 +49,8 @@ type DeployOptions struct {
 	DeployFlags         DeployFlags
 	ResourceTypesFlags  ResourceTypesFlags
 	LabelFlags          LabelFlags
+
+	FileSystem fs.FS
 }
 
 func NewDeployOptions(ui ui.UI, depsFactory cmdcore.DepsFactory, logger logger.Logger) *DeployOptions {
@@ -329,7 +333,7 @@ func (o *DeployOptions) newResourcesFromFiles() ([]ctlres.Resource, error) {
 		return nil, fmt.Errorf("Expected at least one --file (-f) specified with a file or directory path")
 	}
 	for _, file := range o.FileFlags.Files {
-		fileRs, err := ctlres.NewFileResources(file)
+		fileRs, err := ctlres.NewFileResources(o.FileSystem, file)
 		if err != nil {
 			return nil, err
 		}

diff --git a/pkg/kapp/cmd/tools/diff.go b/pkg/kapp/cmd/tools/diff.go
@@ -4,8 +4,11 @@
 package tools
 
 import (
+	"io/fs"
+
 	"github.com/cppforlife/go-cli-ui/ui"
 	"github.com/spf13/cobra"
+
 	ctlcap "github.com/vmware-tanzu/carvel-kapp/pkg/kapp/clusterapply"
 	cmdcore "github.com/vmware-tanzu/carvel-kapp/pkg/kapp/cmd/core"
 	ctldiff "github.com/vmware-tanzu/carvel-kapp/pkg/kapp/diff"
@@ -19,6 +22,8 @@ type DiffOptions struct {
 	FileFlags  FileFlags
 	FileFlags2 FileFlags2
 	DiffFlags  DiffFlags
+
+	FileSystem fs.FS
 }
 
 func NewDiffOptions(ui ui.UI, depsFactory cmdcore.DepsFactory) *DiffOptions {
@@ -71,7 +76,7 @@ func (o *DiffOptions) fileResources(files []string) ([]ctlres.Resource, error) {
 	var newResources []ctlres.Resource
 
 	for _, file := range files {
-		fileRs, err := ctlres.NewFileResources(file)
+		fileRs, err := ctlres.NewFileResources(o.FileSystem, file)
 		if err != nil {
 			return nil, err
 		}

diff --git a/pkg/kapp/cmd/tools/inspect.go b/pkg/kapp/cmd/tools/inspect.go
@@ -4,8 +4,11 @@
 package tools
 
 import (
+	"io/fs"
+
 	"github.com/cppforlife/go-cli-ui/ui"
 	"github.com/spf13/cobra"
+
 	cmdcore "github.com/vmware-tanzu/carvel-kapp/pkg/kapp/cmd/core"
 	ctlres "github.com/vmware-tanzu/carvel-kapp/pkg/kapp/resources"
 )
@@ -17,6 +20,8 @@ type InspectOptions struct {
 	FileFlags           FileFlags
 	ResourceFilterFlags ResourceFilterFlags
 	Raw                 bool
+
+	FileSystem fs.FS
 }
 
 func NewInspectOptions(ui ui.UI, depsFactory cmdcore.DepsFactory) *InspectOptions {
@@ -49,7 +54,7 @@ func (o *InspectOptions) inspectFiles() error {
 	}
 
 	for _, file := range o.FileFlags.Files {
-		fileRs, err := ctlres.NewFileResources(file)
+		fileRs, err := ctlres.NewFileResources(o.FileSystem, file)
 		if err != nil {
 			return err
 		}

diff --git a/pkg/kapp/resources/file_resources.go b/pkg/kapp/resources/file_resources.go
@@ -5,6 +5,7 @@ package resources
 
 import (
 	"fmt"
+	"io/fs"
 	"os"
 	"path/filepath"
 	"sort"
@@ -19,7 +20,12 @@ type FileResource struct {
 	fileSrc FileSource
 }
 
-func NewFileResources(file string) ([]FileResource, error) {
+// NewFileResources inspects file and returns a slice of FileResource objects. If file is "-", a FileResource for STDIN
+// is returned. If it is prefixed with either http:// or https://, a FileResource that supports an HTTP transport is
+// returned. If file is a directory, one FileResource object is returned for each file in the directory with an allowed
+// extension (.json, .yml, .yaml). If file is not a directory, a FileResource object is returned for that one file. If
+// fsys is nil, NewFileResources uses the OS's file system. Otherwise, it uses the passed in file system.
+func NewFileResources(fsys fs.FS, file string) ([]FileResource, error) {
 	var fileRs []FileResource
 
 	switch {
@@ -30,16 +36,22 @@ func NewFileResources(file string) ([]FileResource, error) {
 		fileRs = append(fileRs, NewFileResource(NewHTTPFileSource(file)))
 
 	default:
-		fileInfo, err := os.Stat(file)
+		dir, err := isDir(fsys, file)
 		if err != nil {
-			return nil, fmt.Errorf("Checking file: %v", err)
+			return nil, err
 		}
 
-		if fileInfo.IsDir() {
-			var paths []string
+		if dir {
+			// The typical command line invocation won't set fsys. If it comes in nil, create a new DirFS rooted at
+			// file, then set file to '.' (current working directory) so the fs.WalkDir call below works correctly.
+			if fsys == nil {
+				fsys = os.DirFS(file)
+				file = "."
+			}
 
-			err := filepath.Walk(file, func(path string, fi os.FileInfo, err error) error {
-				if err != nil || fi.IsDir() {
+			var paths []string
+			err := fs.WalkDir(fsys, file, func(path string, d fs.DirEntry, err error) error {
+				if err != nil || d.IsDir() {
 					return err
 				}
 				ext := filepath.Ext(path)
@@ -51,16 +63,16 @@ func NewFileResources(file string) ([]FileResource, error) {
 				return nil
 			})
 			if err != nil {
-				return nil, fmt.Errorf("Listing files '%s'", file)
+				return nil, fmt.Errorf("error listing file %q", file)
 			}
 
 			sort.Strings(paths)
 
 			for _, path := range paths {
-				fileRs = append(fileRs, NewFileResource(NewLocalFileSource(path)))
+				fileRs = append(fileRs, NewFileResource(NewLocalFileSource(fsys, path)))
 			}
 		} else {
-			fileRs = append(fileRs, NewFileResource(NewLocalFileSource(file)))
+			fileRs = append(fileRs, NewFileResource(NewLocalFileSource(fsys, file)))
 		}
 	}
 
@@ -94,3 +106,38 @@ func (r FileResource) Resources() ([]Resource, error) {
 
 	return resources, nil
 }
+
+// isDir returns if path is a directory. If fsys is nil, isDir calls os.Stat(path); otherwise, it checks path inside
+// fsys.
+func isDir(fsys fs.FS, path string) (bool, error) {
+	if fsys == nil {
+		fileInfo, err := os.Stat(path)
+		if err != nil {
+			return false, fmt.Errorf("error stat'ing file %q: %v", path, err)
+		}
+		return fileInfo.IsDir(), nil
+	}
+
+	switch t := fsys.(type) {
+	case fs.StatFS:
+		fileInfo, err := t.Stat(path)
+		if err != nil {
+			return false, fmt.Errorf("error stat'ing file %q: %v", path, err)
+		}
+		return fileInfo.IsDir(), nil
+	case fs.FS:
+		f, err := t.Open(path)
+		if err != nil {
+			return false, fmt.Errorf("error opening file %q: %v", path, err)
+		}
+		defer f.Close()
+
+		fileInfo, err := f.Stat()
+		if err != nil {
+			return false, fmt.Errorf("error stat'ing file %q: %v", path, err)
+		}
+		return fileInfo.IsDir(), nil
+	default:
+		return false, fmt.Errorf("error determining if %q is a directory: unexpected FS type %T", path, fsys)
+	}
+}
diff --git a/pkg/kapp/resources/file_sources.go b/pkg/kapp/resources/file_sources.go
@@ -6,6 +6,7 @@ package resources
 import (
 	"fmt"
 	"io"
+	"io/fs"
 	"net/http"
 	"os"
 )
@@ -34,14 +35,31 @@ func (s StdinSource) Description() string    { return "stdin" }
 func (s StdinSource) Bytes() ([]byte, error) { return io.ReadAll(os.Stdin) }
 
 type LocalFileSource struct {
+	fsys fs.FS
 	path string
 }
 
 var _ FileSource = LocalFileSource{}
 
-func NewLocalFileSource(path string) LocalFileSource { return LocalFileSource{path} }
-func (s LocalFileSource) Description() string        { return fmt.Sprintf("file '%s'", s.path) }
-func (s LocalFileSource) Bytes() ([]byte, error)     { return os.ReadFile(s.path) }
+func NewLocalFileSource(fsys fs.FS, path string) LocalFileSource {
+	return LocalFileSource{fsys: fsys, path: path}
+}
+func (s LocalFileSource) Description() string { return fmt.Sprintf("file '%s'", s.path) }
+func (s LocalFileSource) Bytes() ([]byte, error) {
+	switch t := s.fsys.(type) {
+	case fs.ReadFileFS:
+		return t.ReadFile(s.path)
+	case fs.FS:
+		f, err := t.Open(s.path)
+		if err != nil {
+
+		}
+		defer f.Close()
+		return fs.ReadFile(s.fsys, s.path)
+	default:
+		return os.ReadFile(s.path)
+	}
+}
 
 type HTTPFileSource struct {
 	url    string