Authoring Site Topology¶
Drydock uses a YAML-formatted site topology definition to configure downstream drivers to provision baremetal nodes. This topology describes the networking configuration of a site as well as the set of node configurations that will be deployed. A node configuration consists of network attachment, network addressing, local storage, kernel selection and configuration and metadata.
The best source for a sample of the YAML schema for a topology is the unit
test input source in
./tests/yaml_samples/fullsite.yaml
.
Defining Networking¶
Network definitions in the topology are described by two document types: NetworkLink and Network. NetworkLink describes a physical or logical link between a node and switch. It is concerned with attributes that must be agreed upon by both endpoints: bonding, media speed, trunking, etc. A Network describes the layer 2 and layer 3 networks accessible over a link.
Network Links¶
The NetworkLink document defines layer 1 and layer 2 attributes that should be in-sync between the node and the switch. Each link can support a single untagged VLAN and 0 or more tagged VLANs.
Example YAML schema of the NetworkLink spec:
spec:
bonding:
mode: 802.3ad
hash: layer3+4
peer_rate: slow
mtu: 9000
linkspeed: auto
trunking:
mode: 802.1q
allowed_networks:
- public
- mgmt
bonding
describes combining multiple physical links into a single logical
link (aka LAG or link aggregation group).
mode
: What bonding mode to configuredisabled
: Do not configure a bond802.3ad
: Use 802.3ad dynamic aggregation (aka LACP)active-backup
: Use static active/standby bondingbalanced-rr
: Use static round-robin bonding
For a mode
of 802.3ad
the optional attributes below are available:
hash
: The link selection hash. Supported values arelayer3+4
,layer2+3
,layer2
. Default islayer3+4
peer_rate
: How frequently to send LACP control frames. Supported values arefast
andslow
. Default isfast
mon_rate
: Interval between checking link state in milliseconds. Default is100
up_delay
: Delay in milliseconds between a link coming up and being marked up in the bond. Must be greater thanmon_rate
. Default is200
down_delay
: Delay in milliseconds between a link going down and being marked down in the bond. Must be greater thanmon_rate
. Default is200
mtu
is the maximum transmission unit for the link. It must be equal or
greater than the MTU of any VLAN interfaces using the link. Default is 1500
.
linkspeed
is the physical layer speed and duplex. Recommended to always be
auto
trunking
describes how multiple layer 2 networks will be multiplexed on the
link.
mode
: Can bedisabled
for no trunking or802.1q
for standard VLAN taggingdefault_network
: Formode: disabled
, this is the single network on the link. Formode: 802.1q
this is optionally the network accessed by untagged frames.
allowed_networks
is a sequence of network names listing all networks allowed
on this link. Each Network can be listed on one and only one NetworkLink.
Network¶
The Network document defines the layer 2 and layer 3 networks nodes will access. Each Network is accessible over exactly one NetworkLink. However that NetworkLink can be attached to different interfaces on different nodes to support changing hardware configurations.
Example YAML schema of the Network spec:
spec:
vlan: '102'
mtu: 1500
cidr: 172.16.3.0/24
routedomain: storage
ranges:
- type: static
start: 172.16.3.15
end: 172.16.3.200
- type: dhcp
start: 172.16.3.201
end: 172.16.3.254
routes:
- subnet: 0.0.0.0/0
gateway: 172.16.3.1
metric: 10
- gateawy: 172.16.3.2
metric: 10
routedomain: storage
dns:
domain: sitename.example.com
servers: 8.8.8.8
If a Network is accessible over a NetworkLink using 802.1q VLAN tagging, the
vlan
attribute specified the VLAN tag for this Network. It should be omitted
for non-tagged Networks.
mtu
is the maximum transmission unit for this Network. Must be equal or less
than the mtu
defined for the hosting NetworkLink. Can be omitted to default
to the NetworkLink mtu
.
cidr
is the classless inter-domain routing address for the network.
routedomain
is a logical grouping of L3 networks such that a network that
describes a static route for accessing the route domain will yield a list of
static routes for all the networks in the routedomain. See the description
of routes
below for more information.
ranges
defines a sequence of IP addresses within the defined cidr
.
Ranges cannot overlap.
type
: The type of address range.static
: A range used for static, explicit address assignments for nodes.dhcp
: A range used for assigning DHCP addresses. Note that a network being used for PXE booting must have a DHCP range defined.reserved
: A range of addresses that will not be used by MaaS.
start
: The starting IP of the range, inclusive.end
: The last IP of the range, inclusive
routes
defines a list of static routes to be configured on nodes attached to
this network. The routes can defined in one of two ways: an explicit destination
subnet
where the route will be configured exactly as described or a destination
routedomain
where Drydock will calculate all the destination L3 subnets for the
routedomain and add routes for each of them using the gateway
and metric
defined.
subnet
: Destination CIDR for the routegateway
: The gateway IP on this Network to use for accessing the destinationmetric
: The metric or weight for this routeroutedomain
: Use this route’s gateway and metric for accessing networks in the- defined routedomain.
dns
is used for specifying the list of DNS servers to use if this network
is the primary network for the node.
servers
: A comma-separated list of IP addresses to use for DNS resolutiondomain
: A domain that can be used for automated registration of IP addresses assigned from this Network
DHCP Relay¶
DHCP relaying is used when a DHCP server is not attached to the same layer 2
broadcast domain as nodes that are being PXE booted. The DHCP requests from the
node are consumed by the relay (generally configured on a top-of-rack switch)
which then encapsulates the request in layer 3 routing and sends it to an
upstream DHCP server. The Network spec supports a dhcp_relay
key for
Networks that should relay DHCP requests.
- The Network must have a configured DHCP relay, this is not configured by Drydock or MaaS.
- The
upstream_target
IP address must be a host IP address for a MaaS rack controller - The Network must have a defined DHCP address range.
- The upstream target network must have a defined DHCP address range.
The dhcp_relay
stanza:
dhcp_relay:
upstream_target: 172.16.4.100
Defining Node Configuration¶
Node configuration is defined in three documents: HostProfile
,
HardwareProfile
and BaremetalNode
. HardwareProfile
defines
attributes directly related to hardware configuration such as card-slot layout
and firmware levels. HostProfile
is a generic definition for how a node
should be configured such that many nodes can reference a single HostProfile
and each will be configured identically. A BaremetalNode
is a concrete
reference to the particular physical node. The BaremetalNode
definition will
reference a HostProfile
and can then extend or override any of the
configuration values.
NOTE: Drydock does not support hostnames containing ‘__’ (double underscore)
Hardware Profile¶
The hardware profile is used to convert some abstractions in the HostProfile documents into concrete configurations based a particular hardware build. A host profile will designate how the bootdisk should be configured, but the hardware profile will designate which exact device is used for the bootdisk. This allows a heterogeneous mix of hardware in a site without duplicating definitions of how that hardware should be configured.
An example HardwareProfile document:
---
schema: 'drydock/HardwareProfile/v1'
metadata:
schema: 'metadata/Document/v1'
name: AcmeServer
storagePolicy: 'cleartext'
labels:
application: 'drydock'
data:
vendor: HP
generation: '8'
hw_version: '3'
bios_version: '2.2.3'
boot_mode: bios
bootstrap_protocol: pxe
pxe_interface: 0
device_aliases:
prim_nic01:
address: '0000:00:03.0'
dev_type: '82540EM Gigabit Ethernet Controller'
bus_type: 'pci'
prim_nic02:
address: '0000:00:04.0'
dev_type: '82540EM Gigabit Ethernet Controller'
bus_type: 'pci'
primary_boot:
address: '2:0.0.0'
dev_type: 'VBOX HARDDISK'
bus_type: 'scsi'
cpu_sets:
sriov: '2,4'
hugepages:
sriov:
size: '1G'
count: 300
dpdk:
size: '2M'
count: 530000
Device Aliases¶
Device aliases are a way of mapping a particular device bus address
to an alias. In the example above we map the PCI address 0000:00:03.0
to the alias prim_nic01
. A host profile or baremetal node definition
can then provide a configuration using prim_nic01
and Drydock will
translate that to the correct operating system device name for the NIC device
at PCI address 0000.00.03.0
. Currently device aliases are supported
for network interface slave devices and storage physical devices.
Kernel Parameter References¶
Some kernel parameters specified in a host profile rely on particular hardware
builds, such as isolcpus
. To support the greatest flexibility in building
host profiles, you can specify a few values in a hardware profile that will then
be sourced when needed by a host profile or baremetal node definition.
cpu_sets
: Each key should have a value of a comma-separated list of CPUs/cores/hyperthreads that would be appropriate for theisolcpus
kernel parameters. A host profile can then select any one of these CPU sets for a host.hugepages
: Each key should have a value of a mapping containing two keys:size
andcount
. Again, a host profile can then select these values when defining kernel parameters for a host. Note thesize
field is a string and will be used as-is, so the format must be usable by the kernel.
Host Profiles and Baremetal Nodes¶
Example HostProfile
and BaremetalNode
configuration:
---
apiVersion: 'drydock/v1'
kind: HostProfile
metadata:
name: defaults
region: sitename
date: 17-FEB-2017
author: sh8121@att.com
spec:
# configuration values
---
apiVersion: 'drydock/v1'
kind: HostProfile
metadata:
name: compute_node
region: sitename
date: 17-FEB-2017
author: sh8121@att.com
spec:
host_profile: defaults
# compute_node customizations to defaults
---
apiVersion: 'drydock/v1'
kind: BaremetalNode
metadata:
name: compute01
region: sitename
date: 17-FEB-2017
author: sh8121@att.com
spec:
host_profile: compute_node
# configuration customization specific to single node compute01
In the above example, the compute_node HostProfile
adopts all values from
the defaults HostProfile
and can then override defined values or append
additional values. BaremetalNode
compute01 then adopts all values from the
compute_node HostProfile
(which includes all the configuration items it
adopted from defaults) and can then again override or append any
configuration that is specific to that node.
Defining Node Out-Of-Band Management¶
Drydock supports plugin-based OOB management. At a minimum a
OOB driver supports configuring a node to PXE boot during the next
boot cycle and power cycling the node to initiate the provisioning
process. Richer features might also be supported such as BIOS
configuration or BMC log analysis. The value of oob.type
in the
host profile or baremetal node definition will define what additional
parameters are required for that type and what capabilities are available
via OOB driver tasks.
IPMI¶
The ipmi
OOB type requires additional configuration to allow OOB
management:
- The
oob
parametersaccount
andcredential
must be populated with a valid account and password that can access the BMC via IPMI over LAN.- The
oob
parameternetwork
must reference which node network is used for OOB access.- The
addressing
section of the node definition must contain an IP address assignment for the network referenced inoob.network
.
Currently the IPMI driver supports only basic management by setting nodes to PXE boot and power-cycling the node.
Libvirt¶
The libvirt
OOB type requires additional configuration within the site definition
as well as particular configuration in the deployment of Drydock (and likely the node
provisioning driver.):
- A SSH public/private key-pair should be generated with the public key being added to the authorized_keys file on all hypervisors hosting libvirt-based VMs being deployed. The account for this must be in the
libvirt
group.- The private key should be provided in the Drydock and MAAS charts as an override to
conf.ssh.private_key
- The Drydock and MAAS chart should override
manifests.secret_ssh_key: true
.- In the site definition, each libvirt-based node must define
oob
parameterlibvirt_uri
of the formqemu+ssh://account@hostname/system
whereaccount
is an account in the libvirt group on the hypervisor with an authorized_key andhostname
is an IP address or FQDN for the hypervisor hosting the VM.
Currently the Libvirt driver supports only basic management by setting nodes to PXE boot and power-cycling the node.
Defining Node Interfaces and Network Addressing¶
Node network attachment can be described in a HostProfile
or a
BaremetalNode
document. Node addressing is allowed only in a
BaremetalNode
document. If a HostProfile
or BaremetalNode
needs to
remove a defined interface from an inherited configuration, it can set the
mapping value for the interface name to null
.
Once the interface attachments to networks is defined, HostProfile
and
BaremetalNode
specs must define a primary_network
attribute to denote
which network the node should use as the primary route.
Interfaces¶
Interfaces for a node can be described in either a HostProfile
or
BaremetalNode
definition. This will attach a defined NetworkLink to a host
interface and define which Networks should be configured to use that interface.
Example interface definition YAML schema:
interfaces:
pxe:
device_link: pxe
labels:
pxe: true
slaves:
- prim_nic01
networks:
- pxe
bond0:
device_link: gp
slaves:
- prim_nic01
- prim_nic02
networks:
- mgmt
- private
Each key in the interfaces mapping is a defined interface. The key is the name
that will be used on the deployed node for the interface. The value must be a
mapping defining the interface configuration or null
to denote removal of
that interface for an inherited configuration.
device_link
: The name of the defined NetworkLink that will be attached to this interface. The NetworkLink definition includes part of the interface configuration such as bonding.labels
: Metadata for describing this interface.slaves
: The list of hardware interfaces used for creating this interface. This value can be a device alias defined in the HardwareProfile or the kernel name of the hardware interface. For bonded interfaces, this would list all the slaves. For non-bonded interfaces, this should list the single hardware interface used.networks
: This is the list of networks to enable on this interface. If multiple networks are listed, the NetworkLink attached to this interface must have trunking enabled or the design validation will fail.
Addressing¶
Addressing for a node can only be defined in a BaremetalNode
definition. The
addressing
stanza simply defines a static IP address or dhcp
for each
network a node should have a configured layer 3 interface on. It is a valid
design to omit networks from the addressing
stanza, in that case the
interface attached to the omitted network will be configured as link up with no
address.
Example addressing
YAML schema:
addressing:
- network: pxe
address: dhcp
- network: mgmt
address: 172.16.1.21
- network: private
address: 172.16.2.21
- network: oob
address: 172.16.100.21
Defining Node Storage¶
Storage can be defined in the storage
stanza of either a HostProfile or
BaremetalNode document. The storage configuration can describe the creation of
partitions on physical disks, the assignment of physical disks and/or partitions
to volume groups, and the creation of logical volumes. Drydock will make a best
effort to parse out system-level storage such as the root filesystem or boot
filesystem and take appropriate steps to configure them in the active node
provisioning driver. At a minimum, the storage configuration must contain
a root filesystem partition.
Example YAML schema of the storage
stanza:
storage:
physical_devices:
sda:
labels:
bootdrive: true
partitions:
- name: 'root'
size: '10g'
bootable: true
filesystem:
mountpoint: '/'
fstype: 'ext4'
mount_options: 'defaults'
- name: 'boot'
size: '1g'
filesystem:
mountpoint: '/boot'
fstype: 'ext4'
mount_options: 'defaults'
sdb:
volume_group: 'log_vg'
volume_groups:
log_vg:
logical_volumes:
- name: 'log_lv'
size: '500m'
filesystem:
mountpoint: '/var/log'
fstype: 'xfs'
mount_options: 'defaults'
Schema¶
The storage
stanza can contain two top-level keys: physical_devices
and
volume_groups
. The latter is optional.
Physical Devices and Partitions¶
A physical device can either be carved up in partitions (including a single
partition consuming the entire device) or added to a volume group as a physical
volume. Each key in the physical_devices
mapping represents a device on a
node. The key should either be a device alias defined in the HardwareProfile or
the name of the device published by the OS. The value of each key must be a
mapping with the following keys
labels
: A mapping of key/value strings providing generic labels for the devicepartitions
: A sequence of mappings listing the partitions to be created on the device. The mapping is described below. Incompatible with thevolume_group
specification.volume_group
: A volume group name to add the device to as a physical volume. Incompatible with thepartitions
specification.
Partition¶
A partition mapping describes a GPT partition on a physical disk. It can be left as a raw block device or formatted and mounted as a filesystem.
name
: Metadata describing the partition in the topologysize
: The size of the partition. See the Size Format section belowbootable
: Boolean whether this partition should be the bootable devicepart_uuid
: A UUID4 formatted UUID to assign to the partition. If not specified one will be generatedfilesystem
: An optional mapping describing how the partition should be formatted and mountedmountpoint
: Where the filesystem should be mounted. If not specified the partition will be left as a raw devicefstype
: The format of the filesystem. Defaults to ext4mount_options
: fstab style mount options. Default is ‘defaults’fs_uuid
: A UUID4 formatted UUID to assign to the filesystem. If not specified one will be generatedfs_label
: A filesystem label to assign to the filesystem. Optional.
Size Format¶
The size specification for a partition or logical volume is formed from three parts:
The first character can optionally be
>
indicating that the size specified is a minimum and the calculated size should be at least the minimum and should take the rest of the available space on the physical device or volume group.The second part is the numeric portion and must be an integer
The third part is a label
- m|M|mb|MB: Megabytes or 10^6 * the numeric
- g|G|gb|GB: Gigabytes or 10^9 * the numeric
- t|T|tb|TB: Terabytes or 10^12 * the numeric
- %: The percentage of total device or volume group space
Volume Groups and Logical Volumes¶
Logical volumes can be used to create RAID-0 volumes spanning multiple physical
disks or partitions. Each key in the volume_groups
mapping is a name
assigned to a volume group. This name must be specified as the volume_group
attribute on one or more physical devices or partitions or the configuration is
invalid. Each mapping value is another mapping describing the volume group.
vg_uuid
: A UUID4 format uuid applied to the volume group. If not specified, one is generatedlogical_volumes
: A sequence of mappings listing the logical volumes to be created in the volume group
Logical Volume¶
A logical volume is a RAID-0 volume. Using logical volumes for /
and
/boot
is supported
name
: Required field. Used as the logical volume name.size
: The logical volume size. See Size Format above for details.lv_uuid
: A UUID4 format uuid applied to the logical volume: If not specified, one is generatedfilesystem
: A mapping specifying how the logical volume should be formatted and mounted. See the Partition section above for filesystem details.
Platform Configuration¶
In the platform
stanza you can define the operating system image
and kernel
to use as well as customize the kernel configuration with
kernel_params
.
The valid image
and kernel
values are dependent on what is supported
by your node provisioner. In the example of Canonical MaaS using the 16.04 LTS
image, the values would be image: 'xenial'
and kernel: 'ga-16.04'
for the
LTS kernel or kernel: hwe-16.04
for the hardware-enablement kernel.
The kernel_params
configuration is a mapping. Each key should either be a string
or boolean value. For boolean true
values, the key will be added to the kernel
parameter list as a flag. For string values, the key:value pair will be added to the
kernel parameter list as key=value
.
One special case is supported for values that match a hardware profile reference. When the parameter is rendered for a particular node, the value included in the kernel parameter list will be sourced from the effective HardwareProfile assigned to the node.
hardwareprofile:cpuset.<name>
: Sourced from the hardware profilecpu_sets.<name>
value.hardwareprofile.hugepages.<name>.size
: Source from the hardware profilehugepages.<name>.size
value.hardwareprofile.hugepages.<name>.count
: Source from the hardware profilehugepages.<name>.count
value.