mirror of
https://github.com/ceph/ceph
synced 2024-12-23 03:44:23 +00:00
235 lines
9.8 KiB
ReStructuredText
235 lines
9.8 KiB
ReStructuredText
==========================================
|
||
Configuring the iSCSI Target using Ansible
|
||
==========================================
|
||
|
||
The Ceph iSCSI gateway is the iSCSI target node and also a Ceph client
|
||
node. The Ceph iSCSI gateway can be a standalone node or be colocated on
|
||
a Ceph Object Store Disk (OSD) node. Completing the following steps will
|
||
install, and configure the Ceph iSCSI gateway for basic operation.
|
||
|
||
**Requirements:**
|
||
|
||
- A running Ceph Luminous (12.2.x) cluster or newer
|
||
|
||
- Red Hat Enterprise Linux/CentOS 7.5 (or newer); Linux kernel v4.16 (or newer)
|
||
|
||
- The ``ceph-iscsi`` package installed on all the iSCSI gateway nodes
|
||
|
||
**Installing:**
|
||
|
||
#. On the Ansible installer node, which could be either the administration node
|
||
or a dedicated deployment node, perform the following steps:
|
||
|
||
#. As ``root``, install the ``ceph-ansible`` package:
|
||
|
||
::
|
||
|
||
# yum install ceph-ansible
|
||
|
||
#. Add an entry in ``/etc/ansible/hosts`` file for the gateway group:
|
||
|
||
::
|
||
|
||
[iscsigws]
|
||
ceph-igw-1
|
||
ceph-igw-2
|
||
|
||
.. note::
|
||
If co-locating the iSCSI gateway with an OSD node, then add the OSD node to the
|
||
``[iscsigws]`` section.
|
||
|
||
**Configuring:**
|
||
|
||
The ``ceph-ansible`` package places a file in the ``/usr/share/ceph-ansible/group_vars/``
|
||
directory called ``iscsigws.yml.sample``. Create a copy of this sample file named
|
||
``iscsigws.yml``. Review the following Ansible variables and descriptions,
|
||
and update accordingly. See the ``iscsigws.yml.sample`` for a full list of
|
||
advanced variables.
|
||
|
||
+--------------------------------------+--------------------------------------+
|
||
| Variable | Meaning/Purpose |
|
||
+======================================+======================================+
|
||
| ``seed_monitor`` | Each gateway needs access to the |
|
||
| | ceph cluster for rados and rbd |
|
||
| | calls. This means the iSCSI gateway |
|
||
| | must have an appropriate |
|
||
| | ``/etc/ceph/`` directory defined. |
|
||
| | The ``seed_monitor`` host is used to |
|
||
| | populate the iSCSI gateway’s |
|
||
| | ``/etc/ceph/`` directory. |
|
||
+--------------------------------------+--------------------------------------+
|
||
| ``cluster_name`` | Define a custom storage cluster |
|
||
| | name. |
|
||
+--------------------------------------+--------------------------------------+
|
||
| ``gateway_keyring`` | Define a custom keyring name. |
|
||
+--------------------------------------+--------------------------------------+
|
||
| ``deploy_settings`` | If set to ``true``, then deploy the |
|
||
| | settings when the playbook is ran. |
|
||
+--------------------------------------+--------------------------------------+
|
||
| ``perform_system_checks`` | This is a boolean value that checks |
|
||
| | for multipath and lvm configuration |
|
||
| | settings on each gateway. It must be |
|
||
| | set to true for at least the first |
|
||
| | run to ensure multipathd and lvm are |
|
||
| | configured properly. |
|
||
+--------------------------------------+--------------------------------------+
|
||
| ``api_user`` | The user name for the API. The |
|
||
| | default is `admin`. |
|
||
+--------------------------------------+--------------------------------------+
|
||
| ``api_password`` | The password for using the API. The |
|
||
| | default is `admin`. |
|
||
+--------------------------------------+--------------------------------------+
|
||
| ``api_port`` | The TCP port number for using the |
|
||
| | API. The default is `5000`. |
|
||
+--------------------------------------+--------------------------------------+
|
||
| ``api_secure`` | True if TLS must be used. The |
|
||
| | default is `false`. If true the user |
|
||
| | must create the necessary |
|
||
| | certificate and key files. See the |
|
||
| | gwcli man file for details. |
|
||
+--------------------------------------+--------------------------------------+
|
||
| ``trusted_ip_list`` | A list of IPv4 or IPv6 addresses |
|
||
| | who have access to the API. By |
|
||
| | default, only the iSCSI gateway |
|
||
| | nodes have access. |
|
||
+--------------------------------------+--------------------------------------+
|
||
|
||
**Deploying:**
|
||
|
||
On the Ansible installer node, perform the following steps.
|
||
|
||
#. As ``root``, execute the Ansible playbook:
|
||
|
||
::
|
||
|
||
# cd /usr/share/ceph-ansible
|
||
# ansible-playbook site.yml --limit iscsigws
|
||
|
||
.. note::
|
||
The Ansible playbook will handle RPM dependencies, setting up daemons,
|
||
and installing gwcli so it can be used to create iSCSI targets and export
|
||
RBD images as LUNs. In past versions, ``iscsigws.yml`` could define the
|
||
iSCSI target and other objects like clients, images and LUNs, but this is
|
||
no longer supported.
|
||
|
||
#. Verify the configuration from an iSCSI gateway node:
|
||
|
||
::
|
||
|
||
# gwcli ls
|
||
|
||
.. note::
|
||
See the `Configuring the iSCSI Target using the Command Line Interface`_
|
||
section to create gateways, LUNs, and clients using the `gwcli` tool.
|
||
|
||
.. important::
|
||
Attempting to use the ``targetcli`` tool to change the configuration will
|
||
result in the following issues, such as ALUA misconfiguration and path failover
|
||
problems. There is the potential to corrupt data, to have mismatched
|
||
configuration across iSCSI gateways, and to have mismatched WWN information,
|
||
which will lead to client multipath problems.
|
||
|
||
**Service Management:**
|
||
|
||
The ``ceph-iscsi`` package installs the configuration management
|
||
logic and a Systemd service called ``rbd-target-api``. When the Systemd
|
||
service is enabled, the ``rbd-target-api`` will start at boot time and
|
||
will restore the Linux IO state. The Ansible playbook disables the
|
||
target service during the deployment. Below are the outcomes of when
|
||
interacting with the ``rbd-target-api`` Systemd service.
|
||
|
||
::
|
||
|
||
# systemctl <start|stop|restart|reload> rbd-target-api
|
||
|
||
- ``reload``
|
||
|
||
A reload request will force ``rbd-target-api`` to reread the
|
||
configuration and apply it to the current running environment. This
|
||
is normally not required, since changes are deployed in parallel from
|
||
Ansible to all iSCSI gateway nodes
|
||
|
||
- ``stop``
|
||
|
||
A stop request will close the gateway’s portal interfaces, dropping
|
||
connections to clients and wipe the current LIO configuration from
|
||
the kernel. This returns the iSCSI gateway to a clean state. When
|
||
clients are disconnected, active I/O is rescheduled to the other
|
||
iSCSI gateways by the client side multipathing layer.
|
||
|
||
**Removing the Configuration:**
|
||
|
||
The ``ceph-ansible`` package provides an Ansible playbook to
|
||
remove the iSCSI gateway configuration and related RBD images. The
|
||
Ansible playbook is ``/usr/share/ceph-ansible/purge_gateways.yml``. When
|
||
this Ansible playbook is ran a prompted for the type of purge to
|
||
perform:
|
||
|
||
*lio* :
|
||
|
||
In this mode the LIO configuration is purged on all iSCSI gateways that
|
||
are defined. Disks that were created are left untouched within the Ceph
|
||
storage cluster.
|
||
|
||
*all* :
|
||
|
||
When ``all`` is chosen, the LIO configuration is removed together with
|
||
**all** RBD images that were defined within the iSCSI gateway
|
||
environment, other unrelated RBD images will not be removed. Ensure the
|
||
correct mode is chosen, this operation will delete data.
|
||
|
||
.. warning::
|
||
A purge operation is destructive action against your iSCSI gateway
|
||
environment.
|
||
|
||
.. warning::
|
||
A purge operation will fail, if RBD images have snapshots or clones
|
||
and are exported through the Ceph iSCSI gateway.
|
||
|
||
::
|
||
|
||
[root@rh7-iscsi-client ceph-ansible]# ansible-playbook purge_gateways.yml
|
||
Which configuration elements should be purged? (all, lio or abort) [abort]: all
|
||
|
||
|
||
PLAY [Confirm removal of the iSCSI gateway configuration] *********************
|
||
|
||
|
||
GATHERING FACTS ***************************************************************
|
||
ok: [localhost]
|
||
|
||
|
||
TASK: [Exit playbook if user aborted the purge] *******************************
|
||
skipping: [localhost]
|
||
|
||
|
||
TASK: [set_fact ] *************************************************************
|
||
ok: [localhost]
|
||
|
||
|
||
PLAY [Removing the gateway configuration] *************************************
|
||
|
||
|
||
GATHERING FACTS ***************************************************************
|
||
ok: [ceph-igw-1]
|
||
ok: [ceph-igw-2]
|
||
|
||
|
||
TASK: [igw_purge | purging the gateway configuration] *************************
|
||
changed: [ceph-igw-1]
|
||
changed: [ceph-igw-2]
|
||
|
||
|
||
TASK: [igw_purge | deleting configured rbd devices] ***************************
|
||
changed: [ceph-igw-1]
|
||
changed: [ceph-igw-2]
|
||
|
||
|
||
PLAY RECAP ********************************************************************
|
||
ceph-igw-1 : ok=3 changed=2 unreachable=0 failed=0
|
||
ceph-igw-2 : ok=3 changed=2 unreachable=0 failed=0
|
||
localhost : ok=2 changed=0 unreachable=0 failed=0
|
||
|
||
|
||
.. _Configuring the iSCSI Target using the Command Line Interface: ../iscsi-target-cli
|