Initial commit

pkg/driver/initiator.go

@@ -0,0 +1,162 @@
+// Copyright 2021 Synology Inc.
+
+package driver
+
+import (
+	"errors"
+	"fmt"
+	"strings"
+
+	log "github.com/sirupsen/logrus"
+	utilexec "k8s.io/utils/exec"
+)
+
+type initiatorDriver struct {
+	chapUser string
+	chapPassword string
+}
+
+const (
+	ISCSIPort = 3260
+)
+
+func iscsiadm(cmdArgs ...string) utilexec.Cmd {
+	executor := utilexec.New()
+
+	return executor.Command("iscsiadm", cmdArgs...)
+}
+
+func iscsiadm_session() string {
+	cmd := iscsiadm("-m", "session")
+	out, err := cmd.CombinedOutput()
+	if err != nil {
+		exitErr, ok := err.(utilexec.ExitError)
+		if ok && exitErr.ExitStatus() == 21 { // iscsiadm: No active sessions
+			log.Info("No active iscsi session found.")
+		} else {
+			log.Errorf("Failed to run iscsiadm session: %v", err)
+		}
+		return ""
+	}
+
+	return string(out)
+}
+
+func iscsiadm_discovery(ip string) error {
+	cmd := iscsiadm(
+		"-m", "discoverydb",
+		"--type", "sendtargets",
+		"--portal", ip,
+		"--discover")
+	out, err := cmd.CombinedOutput()
+	if err != nil {
+		return fmt.Errorf("%s (%v)", string(out), err)
+	}
+	return nil
+}
+
+func iscsiadm_login(iqn, portal string) error {
+	cmd := iscsiadm(
+		"-m", "node",
+		"--targetname", iqn,
+		"--portal", portal,
+		"--login")
+	out, err := cmd.CombinedOutput()
+	if err != nil {
+		return fmt.Errorf("%s (%v)", string(out), err)
+	}
+	return nil
+}
+
+func iscsiadm_logout(iqn string) error {
+	cmd := iscsiadm(
+		"-m", "node",
+		"--targetname", iqn,
+		"--logout")
+	if _, err := cmd.CombinedOutput(); err != nil {
+		return err
+	}
+	return nil
+}
+
+func iscsiadm_rescan(iqn string) error {
+	cmd := iscsiadm(
+		"-m", "node",
+		"--targetname", iqn,
+		"-R")
+	if _, err := cmd.CombinedOutput(); err != nil {
+		return err
+	}
+	return nil
+}
+
+func hasSession(targetIqn string) bool{
+	sessions := iscsiadm_session();
+
+	for _, line := range strings.Split(sessions, "\n") {
+		if strings.Contains(line, targetIqn) {
+			return true
+		}
+	}
+
+	return false
+}
+
+func (d *initiatorDriver) login(targetIqn string, ip string) error{
+	portal := fmt.Sprintf("%s:%d", ip, ISCSIPort)
+
+	if (hasSession(targetIqn)) {
+		log.Infof("Session[%s] already exists.", targetIqn)
+		return nil
+	}
+
+	if err := iscsiadm_discovery(ip); err != nil {
+		log.Errorf("Failed in discovery of the target: %v", err)
+		return err
+	}
+
+	if err := iscsiadm_login(targetIqn, portal); err != nil {
+		log.Errorf("Failed in login of the target: %v", err)
+		return err
+	}
+
+	log.Infof("Login target portal [%s], iqn [%s].", portal, targetIqn)
+
+	return nil
+}
+
+func (d *initiatorDriver) logout(targetIqn string, ip string) error{
+	if (!hasSession(targetIqn)) {
+		log.Infof("Session[%s] doesn't exist.", targetIqn)
+		return nil
+	}
+
+	portal := fmt.Sprintf("%s:%d", ip, ISCSIPort)
+	if err := iscsiadm_logout(targetIqn); err != nil {
+		log.Errorf("Failed in logout of the target.\nTarget [%s], Portal [%s], Err[%v]",
+			targetIqn, portal, err)
+		return err
+	}
+
+	log.Infof("Logout target portal [%s], iqn [%s].", portal, targetIqn)
+
+	return nil
+}
+
+func (d *initiatorDriver) rescan(targetIqn string) error{
+	if (!hasSession(targetIqn)) {
+		msg := fmt.Sprintf("Session[%s] doesn't exist.", targetIqn)
+		log.Error(msg)
+		return errors.New(msg)
+	}
+
+	if err := iscsiadm_rescan(targetIqn); err != nil {
+		log.Errorf("Failed in rescan of the target.\nTarget [%s], Err[%v]",
+			targetIqn, err)
+		return err
+	}
+
+	log.Infof("Rescan target iqn [%s].", targetIqn)
+
+	return nil
+}