CLOUD-535 Add cluster debug collector

src/go/debug-collector/dumper/dumper.go

@@ -0,0 +1,202 @@
+package dumper
+
+import (
+	"bytes"
+	"encoding/json"
+	"errors"
+	"log"
+	"os"
+	"os/exec"
+
+	corev1 "k8s.io/api/core/v1"
+)
+
+// Dumper struct is for dumping cluster
+type Dumper struct {
+	cmd       string
+	resources []string
+	location  string
+	Errors    map[string]string
+}
+
+// New return new Dumper object
+func New(location string) Dumper {
+	directory := "cluster-dump"
+	if len(location) > 0 {
+		directory = location + "/cluster-dump"
+	}
+	return Dumper{
+		cmd: "kubectl",
+		resources: []string{
+			"pods",
+			"replicasets",
+			"deployments",
+			"daemonsets",
+			"replicationcontrollers",
+			"events",
+		},
+		location: directory,
+		Errors:   make(map[string]string),
+	}
+}
+
+type k8sPods struct {
+	Items []corev1.Pod `json:"items"`
+}
+
+type namespaces struct {
+	Items []corev1.Namespace `json:"items"`
+}
+
+// DumpCluster create dump of a cluster in Dumper.location
+func (d *Dumper) DumpCluster() error {
+	output, err := d.runCmd("get", "namespaces", "-o", "json")
+	if err != nil {
+		return err
+	}
+	var nss namespaces
+	err = json.Unmarshal(output, &nss)
+	if err != nil {
+		return err
+	}
+
+	for _, ns := range nss.Items {
+		err = os.MkdirAll(d.location+"/"+ns.Name, 0755)
+		if err != nil {
+			return err
+		}
+
+		output, err = d.runCmd("get", "pods", "-o", "json", "--namespace", ns.Name)
+		if err != nil {
+			continue // runCmd already stored this error in Dumper.Errors
+		}
+		var pods k8sPods
+		err = json.Unmarshal(output, &pods)
+		if err != nil {
+			return err
+		}
+
+		for _, pod := range pods.Items {
+			output, err = d.runCmd("logs", pod.Name, "--namespace", ns.Name, "--all-containers")
+			if err != nil {
+				continue // runCmd already stored this error in Dumper.Errors
+			}
+			err = os.MkdirAll(d.location+"/"+ns.Name+"/"+pod.Name, 0755)
+			if err != nil {
+				return err
+			}
+
+			f, err := os.Create(d.location + "/" + ns.Name + "/" + pod.Name + "/logs.txt")
+			if err != nil {
+				return err
+			}
+			_, err = f.Write(output)
+			if err != nil {
+				return err
+			}
+
+		}
+
+		for _, resource := range d.resources {
+			err = d.getAndWriteToFile(resource, ns.Name)
+			if err != nil {
+				log.Println(err)
+			}
+		}
+	}
+
+	err = d.getAndWriteToFile("nodes", "")
+	if err != nil {
+		log.Println(err)
+	}
+
+	err = d.writeErrorsToFile()
+	if err != nil {
+		log.Println(err)
+	}
+
+	return nil
+}
+
+// runCmd run command (Dumper.cmd) with given args, return it output and save all errors in Dumper.errors
+func (d *Dumper) runCmd(args ...string) ([]byte, error) {
+	var outb, errb bytes.Buffer
+	cmd := exec.Command(d.cmd, args...)
+	cmd.Stdout = &outb
+	cmd.Stderr = &errb
+	err := cmd.Run()
+	if err != nil {
+		d.saveCommandError(err.Error()+" "+outb.String(), args...)
+		return outb.Bytes(), err
+	}
+	if len(errb.String()) > 0 {
+		d.saveCommandError(errb.String()+" "+outb.String(), args...)
+		return outb.Bytes(), err
+	}
+
+	return outb.Bytes(), nil
+}
+
+func (d *Dumper) getAndWriteToFile(name, namespace string) error {
+	location := d.location
+	args := []string{"get", name, "-o", "yaml"}
+	if len(namespace) > 0 {
+		args = append(args, "--namespace", namespace)
+		location = d.location + "/" + namespace
+	}
+	output, err := d.runCmd(args...)
+	if err != nil {
+		return nil // runCmd already stored this error in Dumper.Errors
+	}
+
+	f, err := os.Create(location + "/" + name + ".yaml")
+	if err != nil {
+		return err
+	}
+	_, err = f.Write(output)
+	if err != nil {
+		return err
+	}
+
+	return nil
+}
+
+func (d *Dumper) saveCommandError(err string, args ...string) {
+	command := d.cmd
+	for _, arg := range args {
+		command += " " + arg
+	}
+
+	d.Errors[command] = err
+}
+
+func (d *Dumper) writeErrorsToFile() error {
+	var errStr string
+	for cmd, errS := range d.Errors {
+		errStr += cmd + ": " + errS + "\n"
+	}
+	f, err := os.Create(d.location + "/errors.txt")
+	if err != nil {
+		return err
+	}
+	_, err = f.WriteString(errStr)
+	if err != nil {
+		return err
+	}
+
+	return nil
+}
+
+// DeleteDumpDir delete Dumper.location
+func (d *Dumper) DeleteDumpDir() error {
+	if d.location == "/" {
+		return errors.New("don't do this, please") // just for being sure
+	}
+
+	return os.RemoveAll(d.location)
+}
+
+// GetLocation return Dumper.location
+func (d *Dumper) GetLocation() string {
+	return d.location
+}