openstack/ironic
Code Issues Proposed changes

Revise deploy process documentation

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Add more details about the node deployment process, when an instance
is booted by nova. This change covers iscsi and direct deploy methods
with PXE boot. This change also updates the sequence diagrams for
deploy process.

Co-Authored-By: Galyna Zholtkevych <galynazholtkevych1991@gmail.com>

Change-Id: Icaec14d10e702627bab0763e40efa77131564dec
This commit is contained in:
Vladyslav Drok 2017-05-22 16:09:13 +03:00
parent 5a5d485c1d
commit 9280560752
4 changed files with 193 additions and 2851 deletions
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10
doc/source/conf.py
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@ -11,12 +11,22 @@
# License for the specific language governing permissions and limitations
# under the License.
import eventlet
# NOTE(dims): monkey patch subprocess to prevent failures in latest eventlet
# See https://github.com/eventlet/eventlet/issues/398
try:
eventlet.monkey_patch(subprocess=True)
except TypeError:
pass
# -- General configuration ----------------------------------------------------
# Add any Sphinx extension module names here, as strings. They can be
# extensions coming with Sphinx (named 'sphinx.ext.*') or your custom ones.
extensions = ['sphinx.ext.autodoc',
'sphinx.ext.viewcode',
'sphinx.ext.graphviz',
'sphinxcontrib.httpdomain',
'sphinxcontrib.pecanwsme.rest',
'sphinxcontrib.seqdiag',

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doc/source/user/index.rst
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@ -183,111 +183,199 @@ These pre-requisites must be met before the deployment process:
+ user-image-initrd
- Hardware to be enrolled via Ironic RESTful API service.
.. figure:: ../images/deployment_steps.png
:alt: Deployment Steps
Deploy Process
-----------------
--------------
This describes a typical ironic node deployment using PXE and the Ironic
Python Agent (IPA). Depending on the ironic driver interfaces used, some of the
steps might be marginally different, however the majority of them will remain
the same.
#. A boot instance request comes in via the Nova API, through the message
queue to the Nova scheduler.
#. Nova scheduler applies filter and finds the eligible compute node. Nova
scheduler uses flavor extra_specs detail such as 'cpu_arch',
'baremetal:deploy_kernel_id', 'baremetal:deploy_ramdisk_id' etc to match
the target physical node.
#. Nova scheduler applies filters and finds the eligible hypervisor. The nova
scheduler also uses the flavor's ``extra_specs``, such as ``cpu_arch``, to
match the target physical node.
#. A spawn task is placed by the driver which contains all information such
as which image to boot from etc. It invokes the driver.spawn from the
virt layer of Nova compute.
#. Nova compute manager claims the resources of the selected hypervisor.
#. Information about the bare metal node is retrieved from the bare metal
database and the node is reserved.
#. Nova compute manager creates (unbound) tenant virtual interfaces (VIFs) in
the Networking service according to the network interfaces requested in the
nova boot request. A caveat here is, the MACs of the ports are going to be
randomly generated, and will be updated when the VIF is attached to some
node to correspond to the node network interface card's (or bond's) MAC.
#. Images from Glance are pulled down to the local disk of the Ironic
conductor servicing the bare metal node.
#. A spawn task is created by the nova compute which contains all
the information such as which image to boot from etc. It invokes the
``driver.spawn`` from the virt layer of Nova compute. During the spawn
process, the virt driver does the following:
#. For pxe_* drivers these include all images: both the deploy ramdisk and
user instance images.
#. Updates the target ironic node with the information about deploy image,
instance UUID, requested capabilities and various flavor properties.
#. For agent_* drivers only the deploy ramdisk is stored locally. Temporary
URLs in OpenStack's Object Storage service are created for user instance
images.
#. Validates node's power and deploy interfaces, by calling the ironic API.
#. Virtual interfaces are plugged in and Neutron API updates DHCP port to
support PXE/TFTP options.
#. Attaches the previously created VIFs to the node. Each neutron port can
be attached to any ironic port or port group, with port groups having
higher priority than ports. On ironic side, this work is done by the
network interface. Attachment here means saving the VIF identifier
into ironic port or port group and updating VIF MAC to match the port's
or port group's MAC, as described in bullet point 4.
#. Nova's ironic driver issues a deploy request via the Ironic API to the
#. Generates config drive, if requested.
#. Nova's ironic virt driver issues a deploy request via the Ironic API to the
Ironic conductor servicing the bare metal node.
#. PXE driver prepares tftp bootloader.
#. Virtual interfaces are plugged in and Neutron API updates DHCP port to
set PXE/TFTP options. In case of using ``neutron`` network interface,
ironic creates separate provisioning ports in the Networking service, while
in case of ``flat`` network interface, the ports created by nova are used
both for provisioning and for deployed instance networking.
#. The IPMI driver issues command to enable network boot of a node and power
it on.
#. The ironic node's boot interface prepares (i)PXE configuration and caches
deploy kernel and ramdisk.
#. The DHCP boots the deploy ramdisk. Next, depending on the exact driver
used, either the conductor copies the image over iSCSI to the physical node
(pxe_* group of drivers) or the deploy ramdisk downloads the image from
a temporary URL (agent_* group of drivers), which can be generated by
a variety of object stores, e.g. *swift*, *radosgw*, etc, and uploaded
to OpenStack's Object Storage service. In the former case, the conductor
connects to the iSCSI end point, partitions volume, "dd" the image and
closes the iSCSI connection.
#. The ironic node's management interface issues commands to enable network
boot of a node.
The deployment is done. The Ironic conductor will switch pxe config to service
mode and notify ramdisk agent on the successful deployment.
#. The ironic node's deploy interface caches the instance image (in case of
``iscsi`` deploy interface or most ``pxe_*`` classic drivers), and kernel
and ramdisk if needed (it is needed in case of netboot for example).
#. The IPMI driver reboots the bare metal node. Note that there are 2 power
cycles during bare metal deployment; the first time when powered-on, the
images get deployed as mentioned in step 9. The second time as in this case,
after the images are deployed, the node is powered up.
#. The ironic node's power interface instructs the node to power on.
#. The bare metal node status is updated and the node instance is made
available.
#. The node boots the deploy ramdisk.
#. Depending on the exact driver used, either the conductor copies the image
over iSCSI to the physical node (``iscsi`` deploy interface or most
``pxe_*`` classic drivers) or the deploy ramdisk downloads the image from a
temporary URL (``direct`` deploy interface or ``agent_*`` classic drivers).
The temporary URL can be generated by Swift API-compatible object stores,
for example Swift itself or RadosGW.
The image deployment is done.
#. The node's boot interface switches pxe config to refer to instance images
(or, in case of local boot, sets boot device to disk), and asks the ramdisk
agent to soft power off the node. If the soft power off by the ramdisk agent
fails, the bare metal node is powered off via IPMI/BMC call.
#. The deploy interface triggers the network interface to remove provisioning
ports if they were created, and binds the tenant ports to the node if not
already bound. Then the node is powered on.
.. note:: There are 2 power cycles during bare metal deployment; the
first time the node is powered-on when ramdisk is booted, the
second time after the image is deployed.
#. The bare metal node's provisioning state is updated to ``active``.
Below is the diagram that describes the above process.
.. graphviz::
digraph "Deployment Steps" {
node [shape=box, style=rounded, fontsize=10];
edge [fontsize=10];
/* cylinder shape works only in graphviz 2.39+ */
{ rank=same; node [shape=cylinder]; "Nova DB"; "Ironic DB"; }
{ rank=same; "Nova API"; "Ironic API"; }
{ rank=same; "Nova Message Queue"; "Ironic Message Queue"; }
{ rank=same; "Ironic Conductor"; "TFTP Server"; }
{ rank=same; "Deploy Interface"; "Boot Interface"; "Power Interface";
"Management Interface"; }
{ rank=same; "Glance"; "Neutron"; }
"Bare Metal Nodes" [shape=box3d];
"Nova API" -> "Nova Message Queue" [label=" 1"];
"Nova Message Queue" -> "Nova Conductor" [dir=both];
"Nova Message Queue" -> "Nova Scheduler" [label=" 2"];
"Nova Conductor" -> "Nova DB" [dir=both, label=" 3"];
"Nova Message Queue" -> "Nova Compute" [dir=both];
"Nova Compute" -> "Neutron" [label=" 4"];
"Nova Compute" -> "Nova Ironic Virt Driver" [label=5];
"Nova Ironic Virt Driver" -> "Ironic API" [label=6];
"Ironic API" -> "Ironic Message Queue";
"Ironic Message Queue" -> "Ironic Conductor" [dir=both];
"Ironic API" -> "Ironic DB" [dir=both];
"Ironic Conductor" -> "Ironic DB" [dir=both, label=16];
"Ironic Conductor" -> "Boot Interface" [label="8, 14"];
"Ironic Conductor" -> "Management Interface" [label=" 9"];
"Ironic Conductor" -> "Deploy Interface" [label=10];
"Deploy Interface" -> "Network Interface" [label="7, 15"];
"Ironic Conductor" -> "Power Interface" [label=11];
"Ironic Conductor" -> "Glance";
"Network Interface" -> "Neutron";
"Power Interface" -> "Bare Metal Nodes";
"Management Interface" -> "Bare Metal Nodes";
"TFTP Server" -> "Bare Metal Nodes" [label=12];
"Ironic Conductor" -> "Bare Metal Nodes" [style=dotted, label=13];
"Boot Interface" -> "TFTP Server";
}
The following two examples describe what ironic is doing in more detail,
leaving out the actions performed by nova and some of the more advanced
options.
Example 1: PXE Boot and iSCSI Deploy Process
--------------------------------------------
This process is used with pxe_* family of drivers.
This process is used with ``pxe_*`` family of drivers (the only exception
is ``pxe_agent_cimc`` driver).
.. seqdiag::
:scale: 80
:scale: 75
:alt: pxe_ipmi
diagram {
Nova; API; Conductor; Neutron; "TFTP/HTTPd"; Node;
Nova; API; Conductor; Neutron; HTTPStore; "TFTP/HTTPd"; Node;
activation = none;
span_height = 1;
edge_length = 250;
default_note_color = white;
default_fontsize = 14;
Nova -> API [label = "Set instance_info", note = "image_source\n,root_gb,etc."];
Nova -> API [label = "Set provision_state"];
Nova -> API [label = "Set instance_info\n(image_source,\nroot_gb, etc.)"];
Nova -> API [label = "Validate power and deploy\ninterfaces"];
Nova -> API [label = "Plug VIFs to the node"];
Nova -> API [label = "Set provision_state,\noptionally pass configdrive"];
API -> Conductor [label = "do_node_deploy()"];
Conductor -> Conductor [label = "Cache images"];
Conductor -> Conductor [label = "Build TFTP config"];
Conductor -> Neutron [label = "Update DHCPBOOT"];
Conductor -> Node [label = "IPMI power-on"];
Conductor -> Conductor [label = "Validate power and deploy interfaces"];
Conductor -> HTTPStore [label = "Store configdrive if configdrive_use_swift \noption is set"];
Conductor -> Node [label = "POWER OFF"];
Conductor -> Neutron [label = "Attach provisioning network to port(s)"];
Conductor -> Neutron [label = "Update DHCP boot options"];
Conductor -> Conductor [label = "Prepare PXE\nenvironment for\ndeployment"];
Conductor -> Node [label = "Set PXE boot device \nthrough the BMC"];
Conductor -> Conductor [label = "Cache deploy\nkernel, ramdisk,\ninstance images"];
Conductor -> Node [label = "REBOOT"];
Node -> Neutron [label = "DHCP request"];
Neutron -> Node [label = "next-server = Conductor"];
Node -> Conductor [label = "Attempts to tftpboot from Conductor"];
"TFTP/HTTPd" -> Node [label = "Send deploy kernel, ramdisk and config"];
Node -> Node [label = "Runs agent\nramdisk"];
Node -> API [label = "lookup()"];
API -> Conductor [label = "..."];
Conductor -> Node [label = "Pass UUID"];
API -> Node [label = "Pass UUID"];
Node -> API [label = "Heartbeat (UUID)"];
API -> Conductor [label = "Heartbeat"];
Conductor -> Node [label = "Continue deploy: Pass image, disk info"];
Node -> Node [label = "Exposes disks\nvia iSCSI"];
Conductor -> Node [label = "Send IPA a command to expose disks via iSCSI"];
Conductor -> Node [label = "iSCSI attach"];
Conductor -> Node [label = "Copies user image"];
Conductor -> Node [label = "Copies user image and configdrive, if present"];
Conductor -> Node [label = "iSCSI detach"];
Conductor -> Conductor [label = "Delete instance\nimage from cache"];
Conductor -> Node [label = "Install boot loader, if requested"];
Conductor -> Neutron [label = "Update DHCP boot options"];
Conductor -> Conductor [label = "Prepare PXE\nenvironment for\ninstance image"];
Conductor -> Node [label = "Set boot device either to PXE or to disk"];
Conductor -> Node [label = "Collect ramdisk logs"];
Conductor -> Node [label = "POWER OFF"];
Conductor -> Neutron [label = "Detach provisioning network\nfrom port(s)"];
Conductor -> Neutron [label = "Bind tenant port"];
Conductor -> Node [label = "POWER ON"];
Conductor -> Conductor [label = "Mark node as\nACTIVE"];
Conductor -> Neutron [label = "Clear DHCPBOOT"];
Conductor -> Node [label = "Reboot"];
Node -> Node [label = "Reboots into\nuser instance"];
}
(From a `talk`_ and `slides`_)
@ -295,48 +383,58 @@ This process is used with pxe_* family of drivers.
Example 2: PXE Boot and Direct Deploy Process
---------------------------------------------
This process is used with agent_* family of drivers.
This process is used with ``agent_*`` family of drivers.
.. seqdiag::
:scale: 80
:scale: 75
:alt: pxe_ipmi_agent
diagram {
Nova; API; Conductor; Neutron; "TFTP/HTTPd"; Node;
Nova; API; Conductor; Neutron; HTTPStore; "TFTP/HTTPd"; Node;
activation = none;
edge_length = 250;
span_height = 1;
default_note_color = white;
default_fontsize = 14;
Nova -> API [label = "Set instance_info", note = "image_source\n,root_gb,etc."];
Nova -> API [label = "Set provision_state"];
Nova -> API [label = "Set instance_info\n(image_source,\nroot_gb, etc.)"];
Nova -> API [label = "Validate power and deploy\ninterfaces"];
Nova -> API [label = "Plug VIFs to the node"];
Nova -> API [label = "Set provision_state,\noptionally pass configdrive"];
API -> Conductor [label = "do_node_deploy()"];
Conductor -> Conductor [label = "Cache images"];
Conductor -> Conductor [label = "Update pxe,\ntftp configs"];
Conductor -> Neutron [label = "Update DHCPBOOT"];
Conductor -> Node [label = "power on"];
Conductor -> Conductor [label = "Validate power and deploy interfaces"];
Conductor -> HTTPStore [label = "Store configdrive if configdrive_use_swift \noption is set"];
Conductor -> Node [label = "POWER OFF"];
Conductor -> Neutron [label = "Attach provisioning network to port(s)"];
Conductor -> Neutron [label = "Update DHCP boot options"];
Conductor -> Conductor [label = "Prepare PXE\nenvironment for\ndeployment"];
Conductor -> Node [label = "Set PXE boot device \nthrough the BMC"];
Conductor -> Conductor [label = "Cache deploy\nand instance\nkernel and ramdisk"];
Conductor -> Node [label = "REBOOT"];
Node -> Neutron [label = "DHCP request"];
Neutron -> Node [label = "next-server = Conductor"];
Node -> Conductor [label = "Attempts tftpboot"];
"TFTP/HTTPd" -> Node [label = "Send deploy kernel, ramdisk and config"];
Node -> Node [label = "Runs agent\nramdisk"];
Node -> API [label = "lookup()"];
API -> Conductor [label = "..."];
Conductor -> Node [label = "Pass UUID"];
API -> Node [label = "Pass UUID"];
Node -> API [label = "Heartbeat (UUID)"];
API -> Conductor [label = "Heartbeat"];
Conductor -> Node [label = "Continue deploy: Pass image, disk info"];
=== Node downloads image, writes to disk ===
Node -> API [label = "Heartbeat periodically"];
API -> Conductor [label = "..."];
Conductor -> Node [label = "Is deploy done yet?"];
Conductor -> Node [label = "Continue deploy asynchronously: Pass image, disk info"];
Node -> HTTPStore [label = "Downloads image, writes to disk, \nwrites configdrive if present"];
=== Heartbeat periodically ===
Conductor -> Node [label = "Is deploy done?"];
Node -> Conductor [label = "Still working..."];
=== When deploy is done ===
Conductor -> Neutron [label = "Clear DHCPBOOT"];
Conductor -> Node [label = "Set bootdev HDD"];
Conductor -> Node [label = "Reboot"];
Node -> Node [label = "Reboots into\nuser instance"];
=== ... ===
Node -> Conductor [label = "Deploy is done"];
Conductor -> Node [label = "Install boot loader, if requested"];
Conductor -> Neutron [label = "Update DHCP boot options"];
Conductor -> Conductor [label = "Prepare PXE\nenvironment for\ninstance image\nif needed"];
Conductor -> Node [label = "Set boot device either to PXE or to disk"];
Conductor -> Node [label = "Collect ramdisk logs"];
Conductor -> Node [label = "POWER OFF"];
Conductor -> Neutron [label = "Detach provisioning network\nfrom port(s)"];
Conductor -> Neutron [label = "Bind tenant port"];
Conductor -> Node [label = "POWER ON"];
Conductor -> Conductor [label = "Mark node as\nACTIVE"];
}
(From a `talk`_ and `slides`_)