[ENHANCEMENT] support the go language

Signed-off-by: Augustin Husson <husson.augustin@gmail.com>

internal/cli/cmd/dac/build/testdata/go/go.mod

@@ -15,6 +15,6 @@ module dac
 
 go 1.21.6
 
-replace github.com/perses/perses => ../../../../../../ // Use current version
+replace github.com/perses/perses => ../../../../../../../ // Use current version
 
 require github.com/perses/perses v0.43.0

internal/cli/cmd/dac/setup/cue.go

@@ -0,0 +1,176 @@
+// Copyright 2024 The Perses 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 setup
+
+import (
+	"archive/tar"
+	"compress/gzip"
+	"fmt"
+	"io"
+	"net/http"
+	"os"
+	"strings"
+
+	"github.com/sirupsen/logrus"
+)
+
+const (
+	archiveName        = "sources.tar.gz"
+	cueDepsFolderName  = "cue/"
+	cueDepsRootDstPath = "cue.mod/pkg/github.com/perses/perses" // for more info see https://cuelang.org/docs/concepts/packages/
+	maxFileSize        = 10240                                  // = 10 KiB. Estimated max size for CUE files. Limit required by gosec.
+)
+
+func extractCUEDepsToDst() error {
+	file, err := os.Open(archiveName)
+	if err != nil {
+		return err
+	}
+	defer file.Close()
+
+	// Open the tar reader
+	gzipReader, err := gzip.NewReader(file)
+	if err != nil {
+		return err
+	}
+	defer gzipReader.Close()
+	tarReader := tar.NewReader(gzipReader)
+
+	// Extract each CUE dep to the destination path
+	// TODO simplify the code with https://github.com/mholt/archiver? Wait for stable release of v4 maybe
+	depsFolderFound := false
+	for {
+		header, tarErr := tarReader.Next()
+		if tarErr == io.EOF {
+			break
+		}
+		if tarErr != nil {
+			return tarErr
+		}
+
+		// Remove the wrapping folder for following evaluations
+		currentDepPath := removeFirstFolder(header.Name)
+
+		if currentDepPath == cueDepsFolderName {
+			depsFolderFound = true
+		}
+		if !strings.HasPrefix(currentDepPath, cueDepsFolderName) {
+			continue
+		}
+
+		newDepPath := fmt.Sprintf("%s/%s", cueDepsFolderName, currentDepPath)
+
+		switch header.Typeflag {
+		case tar.TypeDir:
+			if folderErr := os.Mkdir(newDepPath, 0666); err != nil {
+				return fmt.Errorf("can't create dir %s: %v", newDepPath, folderErr)
+			}
+			logrus.Debugf("dir %s created succesfully", newDepPath)
+		case tar.TypeReg:
+			outFile, createErr := os.Create(newDepPath)
+			if createErr != nil {
+				return fmt.Errorf("can't create file %s: %v", newDepPath, createErr)
+			}
+			defer outFile.Close()
+			if _, copyErr := io.CopyN(outFile, tarReader, maxFileSize); copyErr != nil {
+				if copyErr == io.EOF {
+					continue
+				}
+				return fmt.Errorf("can't copy content from %s: %v", header.Name, copyErr)
+			}
+			logrus.Debugf("file %s extracted succesfully", newDepPath)
+		default:
+			return fmt.Errorf("unknown type: %b in %s", header.Typeflag, header.Name)
+		}
+	}
+
+	if !depsFolderFound {
+		return fmt.Errorf("CUE dependencies not found in archive")
+	}
+
+	return nil
+}
+
+func removeFirstFolder(filePath string) string {
+	separatorChar := "/" // force the usage of forward slash for strings comparison
+
+	// Split the path into individual components
+	components := strings.Split(filePath, separatorChar)
+
+	// Remove the top folder if there is at least one folder in the path
+	if len(components) > 1 {
+		components = components[1:]
+	}
+
+	// Join the components back into a path
+	resultPath := strings.Join(components, separatorChar)
+
+	return resultPath
+}
+
+func (o *option) setupCue() error {
+	// Create the destination folder for the dependencies
+	if err := os.MkdirAll(cueDepsRootDstPath, os.ModePerm); err != nil {
+		return fmt.Errorf("error creating the dependencies folder structure: %v", err)
+	}
+
+	// Download the source code from the provided Perses version
+	if err := o.downloadSources(); err != nil {
+		return fmt.Errorf("error retrieving the Perses sources: %v", err)
+	}
+
+	defer func() {
+		// Cleanup
+		if err := os.Remove(archiveName); err != nil {
+			fmt.Printf("error removing the temp archive: %v\n", err)
+		}
+	}()
+
+	// Extract the CUE deps from the archive to the destination folder
+	if err := extractCUEDepsToDst(); err != nil {
+		return fmt.Errorf("error extracting the CUE dependencies: %v", err)
+	}
+	return nil
+}
+
+func (o *option) downloadSources() error {
+	// Download the sources
+	url := fmt.Sprintf("https://github.com/perses/perses/archive/refs/tags/%s.tar.gz", o.version)
+	// NB: wrongly spotted as unsecure by gosec; we are validating/sanitizing the string interpolated upfront thus no risk here
+	response, err := http.Get(url) // nolint: gosec
+	if err != nil {
+		return err
+	}
+	defer response.Body.Close()
+
+	if response.StatusCode != http.StatusOK {
+		return fmt.Errorf("error: Unable to fetch release. Status code: %d", response.StatusCode)
+	}
+
+	// Save the content to a local file
+	outFile, err := os.Create(archiveName)
+	if err != nil {
+		return fmt.Errorf("error creating file: %v", err)
+	}
+	defer outFile.Close()
+
+	_, err = io.Copy(outFile, response.Body)
+	if err != nil {
+		return fmt.Errorf("error copying content to file: %v", err)
+	}
+
+	logrus.Debug("Perses release archive downloaded successfully")
+
+	return nil
+}

internal/cli/cmd/dac/setup/golang.go

@@ -0,0 +1,33 @@
+// Copyright 2024 The Perses 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 setup
+
+import (
+	"fmt"
+	"os"
+	"os/exec"
+)
+
+func (o *option) setupGo() error {
+	if _, err := os.Stat("go.mod"); os.IsNotExist(err) {
+		return fmt.Errorf("unable to find the file 'go.mod'. Please run 'go mod init'")
+	} else if err != nil {
+		return err
+	}
+
+	if err := exec.Command("go", "get", fmt.Sprintf("github.com/perses/perses@%s", o.version)).Run(); err != nil {
+		return fmt.Errorf("unable to get the go dependencies github.com/perses/perses@%s : %w", o.version, err)
+	}
+	return nil
+}