feat: Reading Logs in daignose cli command

cli/cmd/diagnose.go

@@ -0,0 +1,148 @@
+package cmd
+
+import (
+	"compress/gzip"
+	"context"
+	"fmt"
+	"github.com/odigos-io/odigos/cli/cmd/resources"
+	"github.com/odigos-io/odigos/cli/pkg/kube"
+	"github.com/spf13/cobra"
+	"io"
+	v1 "k8s.io/api/core/v1"
+	metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
+	"os"
+	"path/filepath"
+)
+
+const (
+	mainDir       = "odigos-diagnose"
+	logDir        = "logs"
+	logBufferSize = 1024 * 1024 // 1MB buffer size for reading logs in chunks
+)
+
+var diagnozeCmd = &cobra.Command{
+	Use:   "diagnose",
+	Short: "Diagnose Client Cluster",
+	Long:  `Diagnose Client Cluster to identify issues and resolve them. This command is useful for troubleshooting and debugging.`,
+	Run: func(cmd *cobra.Command, args []string) {
+		ctx := cmd.Context()
+		client, err := kube.CreateClient(cmd)
+		if err != nil {
+			kube.PrintClientErrorAndExit(err)
+		}
+
+		err = startDiagnose(ctx, client)
+		if err != nil {
+			fmt.Printf("The diagnose script crashed on: %v\n", err)
+		}
+	},
+}
+
+func startDiagnose(ctx context.Context, client *kube.Client) error {
+	if err := createAllDirs(); err != nil {
+		return err
+	}
+
+	if err := fetchOdigosComponentsLogs(ctx, client); err != nil {
+		return err
+	}
+
+	return nil
+}
+
+func createAllDirs() error {
+	if err := os.RemoveAll(mainDir); err != nil {
+		return err
+	}
+	if err := os.MkdirAll(mainDir, 0755); err != nil {
+		return err
+	}
+
+	logsPath := filepath.Join(mainDir, logDir)
+	if err := os.MkdirAll(logsPath, 0755); err != nil {
+		return err
+	}
+
+	return nil
+}
+
+func fetchOdigosComponentsLogs(ctx context.Context, client *kube.Client) error {
+	odigosNamespace, err := resources.GetOdigosNamespace(client, ctx)
+	if err != nil {
+		return err
+	}
+
+	pods, err := client.CoreV1().Pods(odigosNamespace).List(context.TODO(), metav1.ListOptions{})
+	if err != nil {
+		return err
+	}
+
+	for _, pod := range pods.Items {
+		if err = fetchPodLogs(ctx, client, odigosNamespace, pod); err != nil {
+			return err
+		}
+	}
+
+	return nil
+}
+
+func fetchPodLogs(ctx context.Context, client *kube.Client, odigosNamespace string, pod v1.Pod) error {
+	for _, container := range pod.Spec.Containers {
+		fmt.Printf("Fetching logs for Pod: %s, Container: %s\n", pod.Name, container.Name)
+
+		// Define the log file path for saving compressed logs
+		logFilePath := filepath.Join(mainDir, logDir, pod.Name+"_"+container.Name+".log.gz")
+		logFile, err := os.OpenFile(logFilePath, os.O_APPEND|os.O_CREATE|os.O_WRONLY, 0666)
+		if err != nil {
+			return err
+		}
+
+		req := client.CoreV1().Pods(odigosNamespace).GetLogs(pod.Name, &v1.PodLogOptions{})
+		logStream, err := req.Stream(ctx)
+		if err != nil {
+			return err
+		}
+
+		if err = saveLogsToGzipFileInBatches(logFile, logStream, logBufferSize); err != nil {
+			return err
+		}
+
+		logStream.Close()
+		logFile.Close()
+	}
+
+	return nil
+}
+
+func saveLogsToGzipFileInBatches(logFile *os.File, logStream io.ReadCloser, bufferSize int) error {
+	// Create a gzip writer to compress the logs
+	gzipWriter := gzip.NewWriter(logFile)
+	defer gzipWriter.Close()
+
+	// Read logs in chunks and write them to the file
+	buffer := make([]byte, bufferSize)
+	for {
+		n, err := logStream.Read(buffer)
+		if n > 0 {
+			// Write the chunk to the gzip file
+			if _, err := gzipWriter.Write(buffer[:n]); err != nil {
+				return err
+			}
+		}
+
+		if err == io.EOF {
+			// End of the log stream; break out of the loop
+			break
+		}
+
+		if err != nil {
+			return err
+		}
+	}
+
+	return nil
+}
+
+func init() {
+	rootCmd.AddCommand(diagnozeCmd)
+}