Note that discovery is an optional portion of confluent that may be skipped. Further, the discovery process does not require that the user log into the target and do anything like change password or network configuration. It is designed to specifically help when a target has not been configured at all and implements everything it needs to automatically change password and adjust networking as required. If you do adjust networking, user, and password through other means, then this portion may be skipped.

While it is possible to use confluent by directly specifying the pre-configured address, username, and password of a BMC, confluent also has the ability to automate the deployment of configuration of Integrated Management Module and xClarity Controller devices without knowing the addresses ahead of time. It is even possible to avoid ever provisioning a viable network configuration at all.

For optimal results, the confluent server should be on the same network as the management ports. Additionally, it is more robust if IPv6 is enabled, though no IPv6 addresses need to be configured (it can use the fe80:: addresseses that appear by default on network interfaces). Also, the general default configuration for Lenovo servers is to only have the dedicated management port enabled. As such, servers wired such that only the interface available to the OS is available will be unlikely to complete this procedure.

With the node definition complete, discovery can now be approached in one of two ways, automatic or manual. The automatic approach is good for environments that have a well defined map of servers or server enclosures to ethernet switch ports, and the manual approach is good for scenarios like matching nodes up by serial numbers or having a small number of servers to configure or replacing a server or system board.

Following the discovery process

Discovery can be followed by examining /var/log/confluent/events, Using tail -f for example:

May 25 16:28:25 {"info": "Discovered n1 (XCC)"} 
May 25 16:28:37 {"info": "Discovered n4 (XCC)"}
May 25 16:28:38 {"info": "Discovered n2 (XCC)"} 
May 25 16:28:40 {"info": "Discovered n3 (XCC)"}

Manual discovery

Manual discovery provides a more interactive approach to deploying systems. This can also aid in debugging attempts at setting up automatic discovery, or repairing the discovery state of a few miswired or misconfigured systems in an otherwise automatic, but locked down discovery configuration.

Using the nodediscover command

The nodediscover command is intended to aid in exploring available endpoints that may be discovered:

# nodediscover  list
           Node|          Model|         Serial|                                UUID|      Mac Address|        Type|                            Current IP Addresses
               |        5462AC1|        E2YV870|15e55533-8f37-300f-a5f6-f4954e1fec66|08:94:ef:00:f5:0d| lenovo-imm2|,fe80::a94:efff:fe00:f50d%eth0
               |        8869AC1|        J110D40|89fdadbc-3d0c-11e6-b9fa-0894ef1b4ed7|08:94:ef:1b:4e:dc| lenovo-imm2|,fe80::a94:efff:fe1b:4edc%eth0
               |        8869AC1|        J10VEKX|8be3221c-49e9-11e6-a963-0894ef222409|08:94:ef:22:24:0e| lenovo-imm2|                         
               |               |               |4980a05b-f2ec-e611-86af-c3c7e68a9e00|08:94:ef:3b:de:d4|  lenovo-smm|,fe80::a94:efff:fe3b:ded4%eth1
               |     7X07CTO1WW|       J30002HG|2b44751a-3481-11e7-bc9b-0a94ef3c8185|08:94:ef:3c:81:83|  lenovo-xcc|,fe80::a94:efff:fe3c:8183%eth1
               |     7X2104Z000|       DEV00003|cc099cf9-f9a5-11e6-84c7-db06face6280|08:94:ef:3f:e0:af|  lenovo-xcc|,fe80::a94:efff:fe3f:e0af%eth1
               |     7X2104Z000|       DEV00001|00b043c4-029b-11e7-ad41-c7027e3a94d2|08:94:ef:40:87:21|  lenovo-xcc|,fe80::a94:efff:fe40:8721%eth1
               |     7X2104Z000|       DEV00002|78b36a03-0356-11e7-9043-a5a2961a0e5c|08:94:ef:40:89:31|  lenovo-xcc|,fe80::a94:efff:fe40:8931%eth1
               |     7X2104Z000|       DEV00001|00b043c4-029b-11e7-ad41-c7027e3a94d2|08:94:ef:40:8a:96|  pxe-client|                                                
               |     7X2104Z000|       DEV00004|58962b3d-088b-11e7-b8b8-9e59e5cf61db|08:94:ef:41:01:b5|  lenovo-xcc|,fe80::a94:efff:fe41:1b5%eth1
               |     7X18CTO1WW|       J30007Y4|4dce618a-82f5-11e7-badd-0a94ef4a132f|08:94:ef:4a:13:2d|  lenovo-xcc|,fe80::a94:efff:fe4a:132d%eth1

Note in the above we have examples of Integrated Management Module 2, xClarity Controller, D2 SMM, and PXE client. Also note that it recognizes the relationship between a pxe-client and the managing xcc.

Assigning from a spreadsheet (.csv) based on serial numbers

One common scenario is having a spreadsheet of desired configuration together with the serial number. To do this, create a csv file with a header describing the available data followed by records to import. For example:


Then use the nodediscover assign command to deploy the requested configuration:

# nodediscover assign -i serials.csv 
Defined r1
Discovered r1
Defined r2
Discovered r2

At this point, the systems are ready for management:

# nodehealth everything|collate

Using /networking/macs

If there are switches defined, their mac address tables can be navigated through the /networking/macs interface. Using the mac address example from above:

/ -> show /networking/macs/by-mac/40-f2-e9-b9-10-1d
mac: 40:f2:e9:b9:10:1d
  "switch": "r8e1", 
  "macsonport": 1, 
  "port": "Ethernet28"
/ -> 

You may also use this to get the mac addresses from an ethernet port, if you do not know the mac address:

/ -> show /networking/macs/by-switch/r8e1/by-port/Ethernet13/by-mac

This can help provide additional context to a mac address observed in nodediscover or to debug or help formulate a way to use automatic discovery.

Automatic discovery

As a prelude for automatic discovery, first define the node using the values that it should be configured with at the end, regardless of current configuration. For example, we will define 42 nodes (n1 through n42) that upon completion should have an xClarity Controller with the address ‘10.2.3.(node number)’, and the username and password of your choice. Here we will use a group to hold the patterns and just define the nodes with just the single group membership:

nodegroupdefine compute bmc=10.2.3.{n1}
nodegroupattrib compute -p bmcuser bmcpass
nodegroupattrib compute net.<name>.ipv4_gateway=<IP of gateway for xClarity Controllers to use)
nodedefine n1-n42 groups=compute

This will interactively prompt for username and password. This is the desired username and password not necessarily the current. If the devices are at factory default, then they will be changed automatically to the password and username given.

If no value is provided for bmc it will not try to program IPv4 addresses, but will instead collect fe80:: ip addresses. This is useful to have confluent commands work regardless of IPv4 misconfiguration, but may not be obvious to all users. Setting net.. ipv4_gateway setting is optional, but needs to be set for the IPV4 gateway setting of the xClarity Controller to be configured by confluent on discovery of the xClarity Controller. The value is arbitrary, but it is useful to use the name of a network, e.g., "mgt" for a management network (IPv4 subnet). The value of this IPv4 gateway address is determined not by this network name in confluent, but by whether it matches in the same IP subnet of the IPv4 addresses set for the "bmc" value. Note that the subnet is typically automatically determined based on the subnet of the interface on the management node for this network (the subnet mask of this inteface is leveraged to determine the subnet mask of the bmc.) If using xCAT's `makeconfluentcfg` and you want to mandate IPv4 configuration rather than configuring confluent directly, ensure that `ipmi. bmc` is set on nodes in xCAT. This is normally a natural thing to do, but might not be done for certain nodes like ThinkSystem D2 SMMs.

Selecting a discovery policy

The first step is to opt into an automatic discovery policy. There are three policies:

  • manual disables automatic discovery, this is the default behavior.
  • open will always allow a candidate node to be configured as the actual node, regardless of current certificate. This allows the most hands off automation in the face of actions such as replacing a server or system board, but if an attacker can spoof the mac address of a valid management device they could use the discovery process to get the username and password intended for a management device as well as install a certificate of their choosing as trusted to be that node.
  • permissive will allow automatic discovery only if the proposed node identity does not already have a known certificate (in the nodes pubkeys.tls_hardwaremanager attribute), allowing new nodes to fill out defined nodes not yet bound to an actual node. Note that nodes that are defined, but not yet discovered are a risk to the same scenario as described in open
  • pxe allows free replacement of PXE related data (mac addresses and UUID), but will not allow free replacement of secure data. This can be a standalone policy or combined with permissive by using the value permissive,pxe. This allows relaxing the policy to open, but only for PXE data, which cannot have meaningful protections to automate. In this mode, ethernet mac addresses will be collected to a net.<n>.hwaddr field if the corresponding net.<n>.bootable is true.

The policy can be defined on a per node basis or by group. Here we will select permissive,pxe across the board, and enable PXE collection to a field called net.pxe.hwaddr:

nodegroupattrib everything discovery.policy=permissive,pxe net.pxe.bootable=true

The policy can be changed on the fly, if for example you want open or permissive during initial deployment, but change to manual after systems are up:

nodegroupattrib everything discovery.policy=manual

If you have a system that needs to be replaced, you can use manual discovery as documented in the previous section or temporarily override the policy for just the one node:

nodeattrib n3 discovery.policy=open

Defining required attributes on the nodes, enclosure managers, and switches

In this example, we have 4 ThinkSystem SD530 servers in a D2 enclosure. That enclosure has a management port plugged into a switch called r8e1 on port 8.

First we set the enclosure attributes on the nodes:

nodeattrib n1-n4 enclosure.manager=enc1 enclosure.bay={n1}

We then make sure the enclosure manager is a node and configure the location of it’s switch port:

nodeattrib enc1 net.switchport=8 net.switch=r8e1

By default, confluent will assume it can use SNMPv1/v2c, community string public to communicate with the switch. To use a different SNMP community string, make sure the ethernet switch is defined as a node and set a value for secret.snmpcommunity:

nodedefine r8e1 secret.snmpcommunity=otherpublic

Or for SNMPv3, use secret.hardwaremanagementuser and hardwaremanagementpassword:

nodedefine r8e1 secret.hardwaremanagementuser=snmpv3user secret.hardwaremanagementpassword=snmpv3password

In the event of a rackmount system, such as the Thinksystem SD650, simply assign net attributes directly to the node:

nodeattrib n1-n20 net.switchport={n1} net.switch=r8e1

Resetting automatic discovery process for nodes

If the wiring or configuration of set of nodes was incorrect at time of discovery, the situation can be corrected by doing manual discovery or by resetting the discovery process for the nodes. Resetting the automatic discovery process can be done by clearing the pubkeys.tls_hardwaremanager attribute:

nodeattrib n1-n4 pubkeys.tls_hardwaremanager=

This can be combined with a configuration change. For example, if we decide that the previous scheme of 10.2.3.{n1} really should be 10.2.4.{n1}:

nodeattrib n1-n42 hardwaremanagement.manager=10.2.4.{n1} pubkeys.tls_hardwaremanager=

This will change the desired ip address and reset the discovery process for those nodes to apply the requested change.