The following commands require the tenant running the command to have an admin role.
Note | |
---|---|
Ensure that the following environment variables are set. These are used by the various clients to access Keystone. export OS_USERNAME=admin export OS_PASSWORD=adminpassword export OS_TENANT_NAME=admin export OS_AUTH_URL=http://controlnode:5000/v2.0/ |
Procedure 7.20. Settings
To experiment, you need VMs and a neutron network:
$ nova list +--------------------------------------+-----------+--------+---------------+ | ID | Name | Status | Networks | +--------------------------------------+-----------+--------+---------------+ | c394fcd0-0baa-43ae-a793-201815c3e8ce | myserver1 | ACTIVE | net1=10.0.1.3 | | 2d604e05-9a6c-4ddb-9082-8a1fbdcc797d | myserver2 | ACTIVE | net1=10.0.1.4 | | c7c0481c-3db8-4d7a-a948-60ce8211d585 | myserver3 | ACTIVE | net1=10.0.1.5 | +--------------------------------------+-----------+--------+---------------+ $ neutron net-list +--------------------------------------+------+--------------------------------------+ | id | name | subnets | +--------------------------------------+------+--------------------------------------+ | 89dca1c6-c7d4-4f7a-b730-549af0fb6e34 | net1 | f6c832e3-9968-46fd-8e45-d5cf646db9d1 | +--------------------------------------+------+--------------------------------------+
Procedure 7.21. Manage agents in neutron deployment
Every agent which supports these extensions will register itself with the neutron server when it starts up.
List all agents:
$ neutron agent-list +--------------------------------------+--------------------+-------+-------+----------------+ | id | agent_type | host | alive | admin_state_up | +--------------------------------------+--------------------+-------+-------+----------------+ | 1b69828d-6a9b-4826-87cd-1757f0e27f31 | Linux bridge agent | HostA | :-) | True | | a0c1c21c-d4f4-4577-9ec7-908f2d48622d | DHCP agent | HostA | :-) | True | | ed96b856-ae0f-4d75-bb28-40a47ffd7695 | Linux bridge agent | HostB | :-) | True | | f28aa126-6edb-4ea5-a81e-8850876bc0a8 | DHCP agent | HostB | :-) | True | +--------------------------------------+--------------------+-------+-------+----------------+
The output shows information for four agents. The
alive
field shows:-)
if the agent reported its state within the period defined by theagent_down_time
option in theneutron.conf
file. Otherwise thealive
isxxx
.List the DHCP agents that host a specified network
In some deployments, one DHCP agent is not enough to hold all network data. In addition, you must have a backup for it even when the deployment is small. The same network can be assigned to more than one DHCP agent and one DHCP agent can host more than one network.
List DHCP agents that host a specified network:
$ neutron dhcp-agent-list-hosting-net net1 +--------------------------------------+-------+----------------+-------+ | id | host | admin_state_up | alive | +--------------------------------------+-------+----------------+-------+ | a0c1c21c-d4f4-4577-9ec7-908f2d48622d | HostA | True | :-) | +--------------------------------------+-------+----------------+-------+
List the networks hosted by a given DHCP agent.
This command is to show which networks a given dhcp agent is managing.
$ neutron net-list-on-dhcp-agent a0c1c21c-d4f4-4577-9ec7-908f2d48622d +--------------------------------------+------+---------------------------------------------------+ | id | name | subnets | +--------------------------------------+------+---------------------------------------------------+ | 89dca1c6-c7d4-4f7a-b730-549af0fb6e34 | net1 | f6c832e3-9968-46fd-8e45-d5cf646db9d1 10.0.1.0/24 | +--------------------------------------+------+---------------------------------------------------+
Show agent details.
The agent-list command shows details for a specified agent:
$ neutron agent-show a0c1c21c-d4f4-4577-9ec7-908f2d48622d +---------------------+----------------------------------------------------------+ | Field | Value | +---------------------+----------------------------------------------------------+ | admin_state_up | True | | agent_type | DHCP agent | | alive | False | | binary | neutron-dhcp-agent | | configurations | { | | | "subnets": 1, | | | "use_namespaces": true, | | | "dhcp_driver": "neutron.agent.linux.dhcp.Dnsmasq", | | | "networks": 1, | | | "dhcp_lease_time": 120, | | | "ports": 3 | | | } | | created_at | 2013-03-16T01:16:18.000000 | | description | | | heartbeat_timestamp | 2013-03-17T01:37:22.000000 | | host | HostA | | id | 58f4ce07-6789-4bb3-aa42-ed3779db2b03 | | started_at | 2013-03-16T06:48:39.000000 | | topic | dhcp_agent | +---------------------+----------------------------------------------------------+
In this output,
heartbeat_timestamp
is the time on the neutron server. You do not need to synchronize all agents to this time for this extension to run correctly.configurations
describes the static configuration for the agent or run time data. This agent is a DHCP agent and it hosts one network, one subnet, and three ports.Different types of agents show different details. The following output shows information for a Linux bridge agent:
$ neutron agent-show ed96b856-ae0f-4d75-bb28-40a47ffd7695 +---------------------+--------------------------------------+ | Field | Value | +---------------------+--------------------------------------+ | admin_state_up | True | | binary | neutron-linuxbridge-agent | | configurations | { | | | "physnet1": "eth0", | | | "devices": "4" | | | } | | created_at | 2013-03-16T01:49:52.000000 | | description | | | disabled | False | | group | agent | | heartbeat_timestamp | 2013-03-16T01:59:45.000000 | | host | HostB | | id | ed96b856-ae0f-4d75-bb28-40a47ffd7695 | | topic | N/A | | started_at | 2013-03-16T06:48:39.000000 | | type | Linux bridge agent | +---------------------+--------------------------------------+
The output shows
bridge-mapping
and the number of virtual network devices on this L2 agent.
Procedure 7.22. Manage assignment of networks to DHCP agent
Now that you have run the net-list-on-dhcp-agent and dhcp-agent-list-hosting-net commands, you can add a network to a DHCP agent and remove one from it.
Default scheduling.
When you create a network with one port, you can schedule it to an active DHCP agent. If many active DHCP agents are running, select one randomly. You can design more sophisticated scheduling algorithms in the same way as
nova-schedule
later on.$ neutron net-create net2 $ neutron subnet-create net2 9.0.1.0/24 --name subnet2 $ neutron port-create net2 $ neutron dhcp-agent-list-hosting-net net2 +--------------------------------------+-------+----------------+-------+ | id | host | admin_state_up | alive | +--------------------------------------+-------+----------------+-------+ | a0c1c21c-d4f4-4577-9ec7-908f2d48622d | HostA | True | :-) | +--------------------------------------+-------+----------------+-------+
It is allocated to DHCP agent on HostA. If you want to validate the behavior through the dnsmasq command, you must create a subnet for the network because the DHCP agent starts the
dnsmasq
service only if there is a DHCP.Assign a network to a given DHCP agent.
To add another DHCP agent to host the network, run this command:
$ neutron dhcp-agent-network-add f28aa126-6edb-4ea5-a81e-8850876bc0a8 net2 Added network net2 to dhcp agent $ neutron dhcp-agent-list-hosting-net net2 +--------------------------------------+-------+----------------+-------+ | id | host | admin_state_up | alive | +--------------------------------------+-------+----------------+-------+ | a0c1c21c-d4f4-4577-9ec7-908f2d48622d | HostA | True | :-) | | f28aa126-6edb-4ea5-a81e-8850876bc0a8 | HostB | True | :-) | +--------------------------------------+-------+----------------+-------+
Both DHCP agents host the
net2
network.Remove a network from a specified DHCP agent.
This command is the sibling command for the previous one. Remove
net2
from the DHCP agent for HostA:$ neutron dhcp-agent-network-remove a0c1c21c-d4f4-4577-9ec7-908f2d48622d net2 Removed network net2 to dhcp agent $ neutron dhcp-agent-list-hosting-net net2 +--------------------------------------+-------+----------------+-------+ | id | host | admin_state_up | alive | +--------------------------------------+-------+----------------+-------+ | f28aa126-6edb-4ea5-a81e-8850876bc0a8 | HostB | True | :-) | +--------------------------------------+-------+----------------+-------+
You can see that only the DHCP agent for HostB is hosting the
net2
network.
Procedure 7.23. HA of DHCP agents
Boot a VM on net2. Let both DHCP agents host
net2
. Fail the agents in
turn to see if the VM can still get the desired
IP.
Boot a VM on net2.
$ neutron net-list +--------------------------------------+------+--------------------------------------------------+ | id | name | subnets | +--------------------------------------+------+--------------------------------------------------+ | 89dca1c6-c7d4-4f7a-b730-549af0fb6e34 | net1 | f6c832e3-9968-46fd-8e45-d5cf646db9d1 10.0.1.0/24| | 9b96b14f-71b8-4918-90aa-c5d705606b1a | net2 | 6979b71a-0ae8-448c-aa87-65f68eedcaaa 9.0.1.0/24 | +--------------------------------------+------+--------------------------------------------------+ $ nova boot --image tty --flavor 1 myserver4 \ --nic net-id=9b96b14f-71b8-4918-90aa-c5d705606b1a $ nova list +--------------------------------------+-----------+--------+---------------+ | ID | Name | Status | Networks | +--------------------------------------+-----------+--------+---------------+ | c394fcd0-0baa-43ae-a793-201815c3e8ce | myserver1 | ACTIVE | net1=10.0.1.3 | | 2d604e05-9a6c-4ddb-9082-8a1fbdcc797d | myserver2 | ACTIVE | net1=10.0.1.4 | | c7c0481c-3db8-4d7a-a948-60ce8211d585 | myserver3 | ACTIVE | net1=10.0.1.5 | | f62f4731-5591-46b1-9d74-f0c901de567f | myserver4 | ACTIVE | net2=9.0.1.2 | +--------------------------------------+-----------+--------+---------------+
Make sure both DHCP agents hosting 'net2'.
Use the previous commands to assign the network to agents.
$ neutron dhcp-agent-list-hosting-net net2 +--------------------------------------+-------+----------------+-------+ | id | host | admin_state_up | alive | +--------------------------------------+-------+----------------+-------+ | a0c1c21c-d4f4-4577-9ec7-908f2d48622d | HostA | True | :-) | | f28aa126-6edb-4ea5-a81e-8850876bc0a8 | HostB | True | :-) | +--------------------------------------+-------+----------------+-------+
Procedure 7.24. Test the HA
Log in to the
myserver4
VM, and runudhcpc
,dhclient
or other DHCP client.Stop the DHCP agent on HostA. Besides stopping the
neutron-dhcp-agent
binary, you must stop the dnsmasq processes.Run a DHCP client in VM to see if it can get the wanted IP.
Stop the DHCP agent on HostB too.
Run udhcpc in the VM; it cannot get the wanted IP.
Start DHCP agent on HostB. The VM gets the wanted IP again.
Procedure 7.25. Disable and remove an agent
An administrator might want to disable an agent if a system hardware or software upgrade is planned. Some agents that support scheduling also support disabling and enabling agents, such as L3 and DHCP agents. After the agent is disabled, the scheduler does not schedule new resources to the agent. After the agent is disabled, you can safely remove the agent. Remove the resources on the agent before you delete the agent.
To run the following commands, you must stop the DHCP agent on HostA.
$ neutron agent-update --admin-state-up False a0c1c21c-d4f4-4577-9ec7-908f2d48622d $ neutron agent-list +--------------------------------------+--------------------+-------+-------+----------------+ | id | agent_type | host | alive | admin_state_up | +--------------------------------------+--------------------+-------+-------+----------------+ | 1b69828d-6a9b-4826-87cd-1757f0e27f31 | Linux bridge agent | HostA | :-) | True | | a0c1c21c-d4f4-4577-9ec7-908f2d48622d | DHCP agent | HostA | :-) | False | | ed96b856-ae0f-4d75-bb28-40a47ffd7695 | Linux bridge agent | HostB | :-) | True | | f28aa126-6edb-4ea5-a81e-8850876bc0a8 | DHCP agent | HostB | :-) | True | +--------------------------------------+--------------------+-------+-------+----------------+ $ neutron agent-delete a0c1c21c-d4f4-4577-9ec7-908f2d48622d Deleted agent: a0c1c21c-d4f4-4577-9ec7-908f2d48622d $ neutron agent-list +--------------------------------------+--------------------+-------+-------+----------------+ | id | agent_type | host | alive | admin_state_up | +--------------------------------------+--------------------+-------+-------+----------------+ | 1b69828d-6a9b-4826-87cd-1757f0e27f31 | Linux bridge agent | HostA | :-) | True | | ed96b856-ae0f-4d75-bb28-40a47ffd7695 | Linux bridge agent | HostB | :-) | True | | f28aa126-6edb-4ea5-a81e-8850876bc0a8 | DHCP agent | HostB | :-) | True | +--------------------------------------+--------------------+-------+-------+----------------+
After deletion, if you restart the DHCP agent, it appears on the agent list again.