Merge pull request #138 from mallardduck/charts-debug

Author: mallardduck

.gitignore

@@ -18,4 +18,5 @@ dev/
 kubeconfig*.yaml
 get_helm.sh
 Dockerfile.dapper*
-!Dockerfile.dapper
+!Dockerfile.dapper
+/.debug

cmd/prometheus-federator/main.go

@@ -9,6 +9,7 @@ import (
 	_ "net/http/pprof"
 	"os"
 
+	"github.com/rancher/prometheus-federator/pkg/debug"
 	"github.com/rancher/prometheus-federator/pkg/helm-project-operator/controllers/common"
 	"github.com/rancher/prometheus-federator/pkg/helm-project-operator/operator"
 	"github.com/rancher/prometheus-federator/pkg/version"
@@ -84,5 +85,6 @@ func main() {
 		Version: version.FriendlyVersion(),
 	})
 	cmd = command.AddDebug(cmd, &debugConfig)
+	cmd.AddCommand(debug.ChartDebugSubCommand(base64TgzChart))
 	command.Main(cmd)
 }

pkg/debug/chart.go

@@ -0,0 +1,167 @@
+package debug
+
+import (
+	"archive/tar"
+	"bytes"
+	"compress/gzip"
+	"encoding/base64"
+	"fmt"
+	"io"
+	"os"
+	"path/filepath"
+
+	"github.com/sirupsen/logrus"
+
+	"github.com/spf13/cobra"
+)
+
+func ChartDebugSubCommand(base64ChartTarball string) *cobra.Command {
+	var chartOnly bool
+	chartDebug := &cobra.Command{
+		Use:   "debug-chart",
+		Short: "This command helps debug the internal chart files",
+		RunE: func(_ *cobra.Command, _ []string) error {
+			if chartOnly {
+				logrus.Info("Only the embedded chart's `Chart.yaml` will be exported.")
+			} else {
+				logrus.Info("The entire embedded chart wil be exported.")
+			}
+
+			tarReader, err := readEmbeddedHelmChart(base64ChartTarball)
+			if err != nil {
+				return err
+			}
+
+			// Extract files to the current working directory
+			cwd, err := os.Getwd()
+			if err != nil {
+				return fmt.Errorf("error getting current working directory: %v", err)
+			}
+			debugDir := filepath.Join(cwd, ".debug")
+			// Ensure the .debug directory exists
+			if err := os.MkdirAll(debugDir, 0755); err != nil {
+				return fmt.Errorf("error creating .debug directory: %v", err)
+			}
+
+			err = extractChartData(tarReader, debugDir, chartOnly)
+			if err != nil {
+				return err
+			}
+
+			logrus.Infof("Chart files successfully extracted to: %s", debugDir)
+			return nil
+		},
+	}
+	chartDebug.Flags().BoolVarP(&chartOnly, "chart-only", "C", false, "When set, only the `Chart.yaml` will be exported.")
+	return chartDebug
+}
+
+func readEmbeddedHelmChart(base64ChartTarball string) (*tar.Reader, error) {
+	chartTarballData, err := base64.StdEncoding.DecodeString(base64ChartTarball)
+	if err != nil {
+		return nil, fmt.Errorf("error reading embedded chart data from base64: %v", err)
+	}
+
+	gzipReader, err := gzip.NewReader(bytes.NewReader(chartTarballData))
+	if err != nil {
+		return nil, fmt.Errorf("error creating gzip reader: %v", err)
+	}
+	defer gzipReader.Close()
+
+	// Create a tar reader
+	tarReader := tar.NewReader(gzipReader)
+	return tarReader, nil
+}
+
+func extractChartData(tarReader *tar.Reader, debugDir string, chartOnly bool) error {
+	// Extract files to the .debug directory
+	for {
+		header, err := tarReader.Next()
+		if err == io.EOF {
+			// End of archive
+			break
+		}
+		if err != nil {
+			return fmt.Errorf("error reading tarball: %v", err)
+		}
+
+		// Determine the path to extract the file to
+		filePath := filepath.Join(debugDir, header.Name)
+
+		if chartOnly {
+			err = extractChartYamlFile(tarReader, header, filePath)
+		} else {
+			err = extractAllChartData(tarReader, header, filePath)
+		}
+
+		if err != nil {
+			return err
+		}
+	}
+	return nil
+}
+
+func extractChartYamlFile(tarReader *tar.Reader, header *tar.Header, filePath string) error {
+	switch header.Typeflag {
+	case tar.TypeReg:
+		if header.Name == "rancher-project-monitoring/Chart.yaml" {
+			logrus.Info("Found a `Chart.yaml` file to export.")
+			// Ensure the parent directory exists
+			parentDir := filepath.Dir(filePath)
+			if err := os.MkdirAll(parentDir, 0755); err != nil {
+				return fmt.Errorf("error creating parent directory: %v", err)
+			}
+
+			// Create regular file
+			outFile, err := os.Create(filePath)
+			if err != nil {
+				return fmt.Errorf("error creating file: %v", err)
+			}
+
+			// Copy file content
+			if _, err := io.Copy(outFile, tarReader); err != nil {
+				outFile.Close()
+				return fmt.Errorf("error writing file content: %v", err)
+			}
+			logrus.Info("The `Chart.yaml` file was exported")
+			outFile.Close()
+		} else {
+			logrus.Debugf("Skipping file: %s\n", header.Name)
+		}
+	default:
+		logrus.Debugf("Skipping file: %s\n", header.Name)
+	}
+	return nil
+}
+
+func extractAllChartData(tarReader *tar.Reader, header *tar.Header, filePath string) error {
+	switch header.Typeflag {
+	case tar.TypeDir:
+		// Create directory
+		if err := os.MkdirAll(filePath, os.FileMode(header.Mode)); err != nil {
+			return fmt.Errorf("error creating directory: %v", err)
+		}
+	case tar.TypeReg:
+		// Ensure the parent directory exists
+		parentDir := filepath.Dir(filePath)
+		if err := os.MkdirAll(parentDir, 0755); err != nil {
+			return fmt.Errorf("error creating parent directory: %v", err)
+		}
+
+		// Create regular file
+		outFile, err := os.Create(filePath)
+		if err != nil {
+			return fmt.Errorf("error creating file: %v", err)
+		}
+
+		// Copy file content
+		if _, err := io.Copy(outFile, tarReader); err != nil {
+			outFile.Close()
+			return fmt.Errorf("error writing file content: %v", err)
+		}
+		outFile.Close()
+	default:
+		logrus.Debugf("Skipping unsupported file type: %s\n", header.Name)
+	}
+	return nil
+}