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Anish Bhatt 6d9e9561e8 Fix extraneous entries in iscsi path format 
Code comments currently claim the default iscsi mount path as

kubernetes.io/pod/iscsi/<portal>-iqn-<iqn>-lun-<id>, however actual
path being used is
kubernetes.io/iscsi/iscsi/<portal>-iqn-<iqn>-lun-<id>

This leads to ultimate path being similar to this :

kubernetes.io/iscsi/iscsi/...iqn-iqn...-lun-N

Both iscsi and iqn are repated twice for no reason, since "iqn" is
required by spec to be part of an iqn. This is also  wrong on
multiple leves as actual allowed naming formats are :

iqn.2001-04.com.example:storage:diskarrays-sn-a8675309
eui.02004567A425678D
(RFC 3720 3.2.6.3)

and in the second case "iqn-eui" in the path would be misleading.

Change this to a more reasonable path of
kubernetes.io/iscsi/<portal>-<iqn>-lun-<id>

which also aligns up with how the /dev/by-path and sysfs entries
are created for iscsi devices on linux

  * -- *

Update iSCSI README and sample json file

There seems to have been quite a skew in recent updates to these
files adding in wrong info or info that no longer lines up the
sample config with the README.

Fixed the following issues :
* Fix discrepancy in samples json using initiator iqn from previous
  linked example as target iqn (which was just wrong)
* Generate sample output and README from the same json config provided.
* Remove recommendation to edit initiator name, this is not required
  (open-iscsi warns against editing this manually and provides a utility
   for the same)
* Update docker inspect command to one that works.
* Use separate LUNs for separate mount points instead of re-using.
 		2015-10-13 10:08:52 -07:00
..
README.md Fix extraneous entries in iscsi path format 2015-10-13 10:08:52 -07:00
iscsi.json Fix extraneous entries in iscsi path format 2015-10-13 10:08:52 -07:00

README.md

WARNING WARNING WARNING WARNING WARNING

PLEASE NOTE: This document applies to the HEAD of the source tree

If you are using a released version of Kubernetes, you should refer to the docs that go with that version.

The latest 1.0.x release of this document can be found [here](http://releases.k8s.io/release-1.0/examples/iscsi/README.md).

Documentation for other releases can be found at releases.k8s.io.

Step 1. Setting up iSCSI target and iSCSI initiator

Setup A. On Fedora 21 nodes

If you use Fedora 21 on Kubernetes node, then first install iSCSI initiator on the node:

# yum -y install iscsi-initiator-utils

then edit /etc/iscsi/iscsid.conf to match your iSCSI target configuration.

I mostly followed these instructions to setup iSCSI target. and these instructions to setup iSCSI initiator.

Setup B. On Unbuntu 12.04 and Debian 7 nodes on Google Compute Engine (GCE)

GCE does not provide preconfigured Fedora 21 image, so I set up the iSCSI target on a preconfigured Ubuntu 12.04 image, mostly following these instructions. My Kubernetes cluster on GCE was running Debian 7 images, so I followed these instructions to set up the iSCSI initiator.

Step 2. Creating the pod with iSCSI persistent storage

Once you have installed iSCSI initiator and new Kubernetes, you can create a pod based on the example iscsi.json. In the pod JSON, you need to provide targetPortal (the iSCSI target's IP address and port if not the default port 3260), target's iqn, lun, and the type of the filesystem that has been created on the lun, and readOnly boolean. No initiator information is required.

Note: If you have followed the instructions in the links above you may have partitioned the device, the iSCSI volume plugin does not currently support partitions so format the device as one partition. Make sure you have the correct device name then run the following as root to format it:

mkfs.ext4 /dev/<name of device>

Once your pod is created, run it on the Kubernetes master:

kubectl create -f ./your_new_pod.json

Here is my command and output:

# kubectl create -f examples/iscsi/iscsi.json
# kubectl get pods
NAME      READY     STATUS    RESTARTS   AGE
iscsipd   2/2       RUNNING   0           2m

On the Kubernetes node, verify the mount output

# mount |grep kub
/dev/sdb on /var/lib/kubelet/plugins/kubernetes.io/iscsi/10.0.2.15:3260-iqn.2001-04.com.example:storage.kube.sys1.xyz-lun-0 type ext4 (ro,relatime,data=ordered)
/dev/sdb on /var/lib/kubelet/pods/f527ca5b-6d87-11e5-aa7e-080027ff6387/volumes/kubernetes.io~iscsi/iscsipd-ro type ext4 (ro,relatime,data=ordered)
/dev/sdc on /var/lib/kubelet/plugins/kubernetes.io/iscsi/10.0.2.15:3260-iqn.2001-04.com.example:storage.kube.sys1.xyz-lun-1 type ext4 (rw,relatime,data=ordered)
/dev/sdc on /var/lib/kubelet/pods/f527ca5b-6d87-11e5-aa7e-080027ff6387/volumes/kubernetes.io~iscsi/iscsipd-rw type ext4 (rw,relatime,data=ordered)

If you ssh to that machine, you can run docker ps to see the actual pod.

# docker ps
CONTAINER ID        IMAGE                                  COMMAND             CREATED             STATUS              PORTS               NAMES
f855336407f4        kubernetes/pause                       "/pause"            6 minutes ago       Up 6 minutes                            k8s_iscsipd-ro.d130ec3e_iscsipd_default_f527ca5b-6d87-11e5-aa7e-080027ff6387_5409a4cb
3b8a772515d2        kubernetes/pause                       "/pause"            6 minutes ago       Up 6 minutes                            k8s_iscsipd-rw.ed58ec4e_iscsipd_default_f527ca5b-6d87-11e5-aa7e-080027ff6387_d25592c5

Run docker inspect and verify the container mounted the host directory into the their /mnt/iscsipd directory.

# docker inspect --format '{{ range .Mounts }}{{ if eq .Destination "/mnt/iscsipd" }}{{ .Source }}{{ end }}{{ end }}' f855336407f4
/var/lib/kubelet/pods/f527ca5b-6d87-11e5-aa7e-080027ff6387/volumes/kubernetes.io~iscsi/iscsipd-ro

# docker inspect --format '{{ range .Mounts }}{{ if eq .Destination "/mnt/iscsipd" }}{{ .Source }}{{ end }}{{ end }}' 3b8a772515d2
/var/lib/kubelet/pods/f527ca5b-6d87-11e5-aa7e-080027ff6387/volumes/kubernetes.io~iscsi/iscsipd-rw

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