feat: add install method to plugin CLIManager

internal/file/file.go

@@ -13,9 +13,61 @@
 
 package file
 
-import "regexp"
+import (
+	"fmt"
+	"io"
+	"os"
+	"path/filepath"
+	"regexp"
+	"strings"
+)
 
 // IsValidFileName checks if a file name is cross-platform compatible
 func IsValidFileName(fileName string) bool {
 	return regexp.MustCompile(`^[a-zA-Z0-9_.-]+$`).MatchString(fileName)
 }
+
+// CopyToDir copies the src file to dst. Existing file will be overwritten.
+func CopyToDir(src, dst string) error {
+	sourceFileStat, err := os.Stat(src)
+	if err != nil {
+		return err
+	}
+
+	if !sourceFileStat.Mode().IsRegular() {
+		return fmt.Errorf("%s is not a regular file", src)
+	}
+
+	source, err := os.Open(src)
+	if err != nil {
+		return err
+	}
+	defer source.Close()
+
+	if err := os.MkdirAll(dst, 0700); err != nil {
+		return err
+	}
+	dstFile := filepath.Join(dst, filepath.Base(src))
+	destination, err := os.Create(dstFile)
+	if err != nil {
+		return err
+	}
+	defer destination.Close()
+	err = destination.Chmod(0600)
+	if err != nil {
+		return err
+	}
+	_, err = io.Copy(destination, source)
+	return err
+}
+
+// FileNameWithoutExtension returns the file name without extension.
+//
+// For example,
+//
+// when input is xyz.exe, output is xyz
+//
+// when input is xyz.tar.gz, output is xyz.tar
+func FileNameWithoutExtension(fileName string) string {
+	return strings.TrimSuffix(fileName, filepath.Ext(fileName))
+}

internal/file/file_test.go

@@ -0,0 +1,179 @@
+// Copyright The Notary Project Authors.
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package file
+
+import (
+	"bytes"
+	"os"
+	"path/filepath"
+	"runtime"
+	"testing"
+)
+
+func TestCopyToDir(t *testing.T) {
+	t.Run("copy file", func(t *testing.T) {
+		tempDir := t.TempDir()
+		data := []byte("data")
+		filename := filepath.Join(tempDir, "a", "file.txt")
+		if err := writeFile(filename, data); err != nil {
+			t.Fatal(err)
+		}
+
+		destDir := filepath.Join(tempDir, "b")
+		if err := CopyToDir(filename, destDir); err != nil {
+			t.Fatal(err)
+		}
+	})
+
+	t.Run("source directory permission error", func(t *testing.T) {
+		if runtime.GOOS == "windows" {
+			t.Skip("skipping test on Windows")
+		}
+
+		tempDir := t.TempDir()
+		destDir := t.TempDir()
+		data := []byte("data")
+		filename := filepath.Join(tempDir, "a", "file.txt")
+		if err := writeFile(filename, data); err != nil {
+			t.Fatal(err)
+		}
+
+		if err := os.Chmod(tempDir, 0000); err != nil {
+			t.Fatal(err)
+		}
+		defer os.Chmod(tempDir, 0700)
+
+		if err := CopyToDir(filename, destDir); err == nil {
+			t.Fatal("should have error")
+		}
+	})
+
+	t.Run("not a regular file", func(t *testing.T) {
+		tempDir := t.TempDir()
+		destDir := t.TempDir()
+		if err := CopyToDir(tempDir, destDir); err == nil {
+			t.Fatal("should have error")
+		}
+	})
+
+	t.Run("source file permission error", func(t *testing.T) {
+		if runtime.GOOS == "windows" {
+			t.Skip("skipping test on Windows")
+		}
+
+		tempDir := t.TempDir()
+		destDir := t.TempDir()
+		data := []byte("data")
+		// prepare file
+		filename := filepath.Join(tempDir, "a", "file.txt")
+		if err := writeFile(filename, data); err != nil {
+			t.Fatal(err)
+		}
+		// forbid reading
+		if err := os.Chmod(filename, 0000); err != nil {
+			t.Fatal(err)
+		}
+		defer os.Chmod(filename, 0600)
+		if err := CopyToDir(filename, destDir); err == nil {
+			t.Fatal("should have error")
+		}
+	})
+
+	t.Run("dest directory permission error", func(t *testing.T) {
+		if runtime.GOOS == "windows" {
+			t.Skip("skipping test on Windows")
+		}
+
+		tempDir := t.TempDir()
+		destTempDir := t.TempDir()
+		data := []byte("data")
+		// prepare file
+		filename := filepath.Join(tempDir, "a", "file.txt")
+		if err := writeFile(filename, data); err != nil {
+			t.Fatal(err)
+		}
+		// forbid dest directory operation
+		if err := os.Chmod(destTempDir, 0000); err != nil {
+			t.Fatal(err)
+		}
+		defer os.Chmod(destTempDir, 0700)
+		if err := CopyToDir(filename, filepath.Join(destTempDir, "a")); err == nil {
+			t.Fatal("should have error")
+		}
+	})
+
+	t.Run("dest directory permission error 2", func(t *testing.T) {
+		if runtime.GOOS == "windows" {
+			t.Skip("skipping test on Windows")
+		}
+
+		tempDir := t.TempDir()
+		destTempDir := t.TempDir()
+		data := []byte("data")
+		// prepare file
+		filename := filepath.Join(tempDir, "a", "file.txt")
+		if err := writeFile(filename, data); err != nil {
+			t.Fatal(err)
+		}
+		// forbid writing to destTempDir
+		if err := os.Chmod(destTempDir, 0000); err != nil {
+			t.Fatal(err)
+		}
+		defer os.Chmod(destTempDir, 0700)
+		if err := CopyToDir(filename, destTempDir); err == nil {
+			t.Fatal("should have error")
+		}
+	})
+
+	t.Run("copy file and check content", func(t *testing.T) {
+		tempDir := t.TempDir()
+		data := []byte("data")
+		filename := filepath.Join(tempDir, "a", "file.txt")
+		if err := writeFile(filename, data); err != nil {
+			t.Fatal(err)
+		}
+
+		destDir := filepath.Join(tempDir, "b")
+		if err := CopyToDir(filename, destDir); err != nil {
+			t.Fatal(err)
+		}
+		validFileContent(t, filepath.Join(destDir, "file.txt"), data)
+	})
+}
+
+func TestFileNameWithoutExtension(t *testing.T) {
+	input := "testfile.tar.gz"
+	expectedOutput := "testfile.tar"
+	actualOutput := FileNameWithoutExtension(input)
+	if actualOutput != expectedOutput {
+		t.Errorf("expected '%s', but got '%s'", expectedOutput, actualOutput)
+	}
+}
+
+func validFileContent(t *testing.T, filename string, content []byte) {
+	b, err := os.ReadFile(filename)
+	if err != nil {
+		t.Fatal(err)
+	}
+	if !bytes.Equal(content, b) {
+		t.Fatal("file content is not correct")
+	}
+}
+
+func writeFile(path string, data []byte) error {
+	if err := os.MkdirAll(filepath.Dir(path), 0700); err != nil {
+		return err
+	}
+	return os.WriteFile(path, data, 0600)
+}

internal/semver/semver.go

@@ -0,0 +1,51 @@
+// Copyright The Notary Project Authors.
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+// Package semver provides functions related to semanic version.
+// This package is based on "golang.org/x/mod/semver"
+package semver
+
+import (
+	"fmt"
+	"regexp"
+
+	"golang.org/x/mod/semver"
+)
+
+// SemVerRegEx is takenfrom https://semver.org/#is-there-a-suggested-regular-expression-regex-to-check-a-semver-string
+var SemVerRegEx = regexp.MustCompile(`^(0|[1-9]\d*)\.(0|[1-9]\d*)\.(0|[1-9]\d*)(?:-((?:0|[1-9]\d*|\d*[a-zA-Z-][0-9a-zA-Z-]*)(?:\.(?:0|[1-9]\d*|\d*[a-zA-Z-][0-9a-zA-Z-]*))*))?(?:\+([0-9a-zA-Z-]+(?:\.[0-9a-zA-Z-]+)*))?$`)
+
+// IsVersionSemverValid returns true if version is a valid semantic version
+func IsVersionSemverValid(version string) bool {
+	return SemVerRegEx.MatchString(version)
+}
+
+// ComparePluginVersion validates and compares two plugin semantic versions.
+//
+// The result will be 0 if v == w, -1 if v < w, or +1 if v > w.
+func ComparePluginVersion(v, w string) (int, error) {
+	// sanity check
+	// a valid semantic version should not have prefix `v`
+	// Reference: https://semver.org/#semantic-versioning-200
+	if !IsVersionSemverValid(v) {
+		return 0, fmt.Errorf("%s is not a valid semantic version", v)
+	}
+	if !IsVersionSemverValid(w) {
+		return 0, fmt.Errorf("%s is not a valid semantic version", w)
+	}
+
+	// golang.org/x/mod/semver requires semantic version strings must begin
+	// with a leading "v". Adding prefix "v" to the inputs.
+	// Reference: https://pkg.go.dev/golang.org/x/mod/semver#pkg-overview
+	return semver.Compare("v"+v, "v"+w), nil
+}

internal/semver/semver_test.go

@@ -0,0 +1,40 @@
+// Copyright The Notary Project Authors.
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package semver
+
+import "testing"
+
+func TestComparePluginVersion(t *testing.T) {
+	t.Run("compare with lower version", func(t *testing.T) {
+		comp, err := ComparePluginVersion("1.0.0", "1.0.1")
+		if err != nil || comp >= 0 {
+			t.Fatal("expected nil err and negative comp")
+		}
+	})
+
+	t.Run("compare with equal version", func(t *testing.T) {
+		comp, err := ComparePluginVersion("1.0.1", "1.0.1")
+		if err != nil || comp != 0 {
+			t.Fatal("expected nil err and comp equal to 0")
+		}
+	})
+
+	t.Run("failed due to invalid semantic version", func(t *testing.T) {
+		expectedErrMsg := "v1.0.0 is not a valid semantic version"
+		_, err := ComparePluginVersion("v1.0.0", "1.0.1")
+		if err == nil || err.Error() != expectedErrMsg {
+			t.Fatalf("expected err %s, but got %s", expectedErrMsg, err)
+		}
+	})
+}

plugin/errors.go

@@ -0,0 +1,49 @@
+// Copyright The Notary Project Authors.
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package plugin
+
+import "errors"
+
+// ErrNotCompliant is returned by plugin methods when the response is not
+// compliant.
+var ErrNotCompliant = errors.New("plugin not compliant")
+
+// ErrNotRegularFile is returned when the plugin file is not an regular file.
+var ErrNotRegularFile = errors.New("not regular file")
+
+// ErrPluginDowngrade is returned when installing a plugin with version
+// lower than the exisiting plugin version.
+type ErrPluginDowngrade struct {
+	Msg string
+}
+
+func (e ErrPluginDowngrade) Error() string {
+	if e.Msg != "" {
+		return e.Msg
+	}
+	return "installing plugin with version lower than the existing plugin version"
+}
+
+// ErrInstallEqualVersion is returned when installing a plugin with version
+// equal to the exisiting plugin version.
+type ErrInstallEqualVersion struct {
+	Msg string
+}
+
+func (e ErrInstallEqualVersion) Error() string {
+	if e.Msg != "" {
+		return e.Msg
+	}
+	return "installing plugin with version equal to the existing plugin version"
+}