Merge pull request #1 from j-griffith/initial_code_add

Initial commit

Author: k8s-ci-robot

.gitignore

@@ -0,0 +1,3 @@
+*.out
+_output
+example/example

Makefile

@@ -0,0 +1,15 @@
+.PHONY: all build clean install
+
+all: clean build install
+
+clean:
+	go clean -r -x
+	-rm -rf _output
+
+build:
+	go build ./iscsi/
+	go build -o _output/example ./example/main.go
+
+install:
+	go install ./iscsi/
+

README.md

@@ -1,16 +1,39 @@
-# Kubernetes Template Project
+# csi lib-iscsi
 
-The Kubernetes Template Project is a template for starting new projects in the GitHub organizations owned by Kubernetes. All Kubernetes projects, at minimum, must have the following files:
+A simple go package intended to assist CSI plugin authors by providing a tool set to manage iscsi connections.
 
-- a `README.md` outlining the project goals, sponsoring sig, and community contact information
-- an `OWNERS` with the project leads listed as approvers ([docs on `OWNERS` files][owners])
-- a `CONTRIBUTING.md` outlining how to contribute to the project
-- an unmodified copy of `code-of-conduct.md` from this repo, which outlines community behavior and the consequences of breaking the code
-- a `LICENSE` which must be Apache 2.0 for code projects, or [Creative Commons 4.0] for documentation repositories, without any custom content
-- a `SECURITY_CONTACTS` with the contact points for the Product Security Team 
-  to reach out to for triaging and handling of incoming issues. They must agree to abide by the
-  [Embargo Policy](https://github.com/kubernetes/sig-release/blob/master/security-release-process-documentation/security-release-process.md#embargo-policy) 
-  and will be removed and replaced if they violate that agreement.
+## Goals
+
+Provide a basic, lightweight library for CSI Plugin Authors to leverage some of the common tasks like connecting
+and disconnecting iscsi devices to a node.  This library includes a high level abstraction for iscsi that exposes
+simple Connect and Disconnect functions.  These are built on top of exported iscsiadm calls, so if you need more
+control you can access the iscsiadm calls directly.
+
+## Design Philosophy
+
+The idea is to keep this as lightweight and generic as possible.  We intentionally avoid the use of any third party
+libraries or packages in this project.  We don't have a vendor directory, because we attempt to rely only on the std
+golang libs.  This may prove to not be ideal, and may be changed over time, but initially it's a worthwhile goal.
+
+## Logging and Debug
+
+By default the library does not provide any logging, but provides an error message that includes any messages from
+iscsiadm as well as exit-codes.  In the event that you need to debug the library, we provide a function:
+
+```
+func EnableDebugLogging(writer io.Writer)
+```
+
+This will turn on verbose logging directed to the provided io.Writer and include the response of every iscsiadm command
+issued.
+
+## Intended Usage
+
+Curently the intended usage of this library is simply to provide a golang package to standardize how plugins are implementing
+iscsi connect and disconnect.  It's not intended to be  a "service", although that's a possible next step.  It's currenty been
+used for plugins where iscsid is installed in containers only, as well as designs where it uses the nodes iscsid.  Each of these
+approaches has their own pros and cons.  Currently, it's up to the plugin author to determine which model suits them best
+and to deploy their node plugin appropriately.
 
 ## Community, discussion, contribution, and support
 
@@ -19,6 +42,7 @@ Learn how to engage with the Kubernetes community on the [community page](http:/
 You can reach the maintainers of this project at:
 
 - [Slack](http://slack.k8s.io/)
+  * sig-storage
 - [Mailing List](https://groups.google.com/forum/#!forum/kubernetes-dev)
 
 ### Code of conduct

example/main.go

@@ -0,0 +1,75 @@
+package main
+
+import (
+	"flag"
+	"log"
+	"os"
+	"strings"
+	"time"
+
+	"github.com/kubernetes-csi/csi-lib-iscsi/iscsi"
+)
+
+var (
+	portals   = flag.String("portals", "192.168.1.112:3260", "Comma delimited.  Eg: 1.1.1.1,2.2.2.2")
+	iqn       = flag.String("iqn", "iqn.2010-10.org.openstack:volume-95739000-1557-44f8-9f40-e9d29fe6ec47", "")
+	multipath = flag.Bool("multipath", false, "")
+	username  = flag.String("username", "3aX7EEf3CEgvESQG75qh", "")
+	password  = flag.String("password", "eJBDC7Bt7WE3XFDq", "")
+	lun       = flag.Int("lun", 1, "")
+	debug     = flag.Bool("debug", false, "enable logging")
+)
+
+func main() {
+	flag.Parse()
+	tgtp := strings.Split(*portals, ",")
+	if *debug {
+		iscsi.EnableDebugLogging(os.Stdout)
+	}
+
+	// You can utilize the iscsiadm calls directly if you wish, but by creating a Connector
+	// you can simplify interactions to simple calls like "Connect" and "Disconnect"
+	c := iscsi.Connector{
+		// Our example uses chap
+		AuthType: "chap",
+		// Specify the target iqn we're dealing with
+		TargetIqn: *iqn,
+		// List of portals must be >= 1 (>1 signals multipath/mpio)
+		TargetPortals: tgtp,
+		// CHAP can be setup up for discovery as well as sessions, our example
+		// device only uses CHAP security for sessions, for those that use Discovery
+		// as well, we'd add a DiscoverySecrets entry the same way
+		SessionSecrets: iscsi.Secrets{
+			UserName:    *username,
+			Password:    *password,
+			SecretsType: "chap"},
+		// Lun is the lun number the devices uses for exports
+		Lun: int32(*lun),
+		// Multipath indicates that we want to configure this connection as a multipath device
+		Multipath: *multipath,
+		// Number of times we check for device path, waiting for CheckInterval seconds inbetween each check (defaults to 10 if omitted)
+		RetryCount: 11,
+		// CheckInterval is the time in seconds to wait inbetween device path checks when logging in to a target
+		CheckInterval: 1,
+	}
+
+	// Now we can just issue a connection request using our Connector
+	// A succesful connection will include the device path to access our iscsi volume
+	path, err := iscsi.Connect(c)
+	if err != nil {
+		log.Printf("Error returned from iscsi.Connect: %s", err.Error())
+		os.Exit(1)
+	}
+
+	if path == "" {
+		log.Printf("Failed to connect, didn't receive a path, but also no error!")
+		os.Exit(1)
+	}
+
+	log.Printf("Connected device at path: %s\n", path)
+	time.Sleep(3 * time.Second)
+
+	// Disconnect is easy as well, we don't need the full Connector any more, just the Target IQN and the Portals
+	/// this should disconnect the volume as well as clear out the iscsi DB entries associated with it
+	iscsi.Disconnect(c.TargetIqn, c.TargetPortals)
+}