ceph-iscsi

This project provides the common logic and CLI tools for creating and managing LIO gateways for Ceph.

It includes the rbd-target-gw daemon which is responsible for restoring the state of LIO following a gateway reboot/outage and replaces the existing 'target' service.

It also includes the CLI tool gwcli which can be used to configure and manage the Ceph iSCSI gateway, which replaces the existing targetcli CLI tool. This CLI tool utilizes the rbd-target-api server daemon to configure multiple gateways concurrently.

Usage

This package should be installed on each node that is intended to be an iSCSI gateway. The Python ceph_iscsi_config modules are used by:

• the rbd-target-gw daemon to restore LIO state at boot time
• Ansible modules defined in the ceph-iscsi-ansible project at https://github.com/pcuzner/ceph-ansible
• API/CLI configuration tools

Installation

Via RPM

Simply install the provided rpm with: rpm -ivh ceph-iscsi-<ver>.el7.noarch.rpm

Manually

The following packages are required by ceph-iscsi-config and must be installed before starting the rbd-target-gw service:

python-rados python-rbd python-netifaces python-rtslib python-configshell python-cryptography python-flask

To install the python package that provides the application logic, run the provided setup.py script i.e. > python setup.py install

For the daemons (rbd-target-gw and rbd-target-api), simply copy the following files into their equivalent places on each gateway:

• <archive_root>/usr/lib/systemd/system/rbd-target-gw.service --> /lib/systemd/system
• <archive_root>/usr/lib/systemd/system/rbd-target-api.service --> /lib/systemd/system
• <archive_root>/usr/bin/rbd-target-gw --> /usr/bin
• <archive_root>/usr/bin/rbd-target-api --> /usr/bin
• <archive_root>/usr/bin/gwcli --> /usr/bin

Once the daemon is in place, reload the configuration with

systemctl daemon-reload
systemctl enable rbd-target-gw
systemctl start rbd-target-gw
systemctl enable rbd-target-api
systemctl start rbd-target-api

Features

The functionality provided by each module in the python package is summarised below;

Module	Description
client	logic handling the create/update and remove of a NodeACL from a gateway
config	common code handling the creation and update mechanisms for the rados configuration object
gateway	definition of the iSCSI gateway (target plus target portal groups)
lun	rbd image management (create/resize), combined with mapping to the OS and LIO instance
utils	common code called by multiple modules

The rbd-target-gw daemon performs the following tasks;

1. At start up remove any osd blacklist entry that may apply to the running host
2. Read the configuration object from Rados
3. Process the configuration
   3.1 map rbd's to the host
   3.2 add rbd's to LIO
   3.3 Create the iscsi target, TPG's and port IP's
   3.4 Define clients (NodeACL's)
   3.5 add the required rbd images to clients