craze4toys / goiscsi

A portable Go module for iSCSI operations.

goiscsi

A portable Go module for iscsi related operations such as discovery and login

Features

The following features are supported:

• Discover iSCSI targets provided by a specific portal, optionally log into eacj target
• Discover the iSCSI Initiators defined on the local system
• Log into a specific portal/target
• Log out of a specific portal/target
• Rescan all connected iSCSI sessions

Implementation options

Two implementations of the goiscsi.ISCSIinterface exist; one is for Linux based systems and one is a mock implementation. When instantiating an implementation of the goiscsi.ISCSIinterface interface, the factories accept a map[string]string option that allows the user to set specific key/values within the implementation.

The goiscsi.ISCSIinterface is defined as:

type ISCSIinterface interface {
	// Discover the targets exposed via a given portal
	// returns an array of ISCSITarget instances
	DiscoverTargets(address string, login bool) ([]ISCSITarget, error)

	// Get a list of iSCSI initiators defined in a specified file
	// To use the system default file of "/etc/iscsi/initiatorname.iscsi", provide a filename of ""
	GetInitiators(filename string) ([]string, error)

	// Log into a specified target
	PerformLogin(target ISCSITarget) error

	// Log out of a specified target
	PerformLogout(target ISCSITarget) error

	// Rescan current iSCSI sessions
	PerformRescan() error

	// generic implementations
	isMock() bool
	getOptions() map[string]string
}

Many operations deal with iSCSI Targets via a type of goiscsi.ISCSITarget, defined as:

type ISCSITarget struct {
	Portal   string
	GroupTag string
	Target   string
}

LinuxISCSI

When instantiating a Linux implementation via goiscsi.NewLinuxISCSI the following options are available

Key	Meaning
chrootDirectory	Run iscsiadm in a chrooted environment with the root set to this value.
	Default is to not chroot

MockISCSI

When instantiating a mock implementation via goiscsi.NewMockISCSI, the follwoing options are available:

Key	Meaning
numberOfInitiators	Defines the number of initiators that will be returned via the GetInitiators method.
	Default is "1"
--------------------	-----------------------------------------------------------------------------------------
numberOfTargets	Defines the number of targets that will be returned via the DiscoverTargets method.
	Default is "1"

Usage examples

The following example will instantiate a Linux based iSCSI client and Discover the targets exposed via the portal at address

import (
    "errors"
    
    "github.com/dell/goiscsi"
)

func printTargets(address string) {
    var c goiscsi.ISCSIinterface
    c := goiscsi.NewLinuxISCSI(map[string]string{})
    targets, err := c.DiscoverTargets(address, false)
    if err != nil {
        return
    }
    for _, t := range targets {
        fmt.Printf("Found target: %s", tgt.Target)
    }
}

The following example will instantiate a Mock iSCSI client, set the number of targets to 3, and Discover the mocked targets

import (
    "errors"
    
    "github.com/dell/goiscsi"
)

func printTargets(address string) {
    var c goiscsi.ISCSIinterface
    opts := make(map[string]string, 0)
    opts[goiscsi.MockNumberOfTargets] = "3"
    c := goiscsi.NewMockISCSI(opts)
    targets, err := c.DiscoverTargets(address, false)
    if err != nil {
        return
    }
    for _, t := range targets {
        fmt.Printf("Found target: %s", tgt.Target)
    }
}