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1575c03 Sep 27, 2018
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Installing faucet for the first time

This tutorial will run you through the steps of installing a complete faucet system for the first time.

We will be installing and configuring the following components:

Component Purpose
faucet Network controller
gauge Monitoring controller
prometheus Monitoring system & time series database
grafana Monitoring dashboard

This tutorial was written for Ubuntu 16.04, however the steps should work fine on any newer supported version of Ubuntu or Debian.

Package installation

  1. Add the faucet official repo to our system:

    sudo apt-get install curl gnupg apt-transport-https lsb-release
    echo "deb https://packagecloud.io/faucetsdn/faucet/$(lsb_release -si | awk '{print tolower($0)}')/ $(lsb_release -sc) main" | sudo tee /etc/apt/sources.list.d/faucet.list
    curl -L https://packagecloud.io/faucetsdn/faucet/gpgkey | sudo apt-key add -
    sudo apt-get update
  2. Install the required packages, we can use the faucet-all-in-one metapackage which will install all the correct dependencies.

    sudo apt-get install faucet-all-in-one

Configure prometheus

We need to configure prometheus to tell it how to scrape metrics from both the faucet and gauge controllers. To help make life easier faucet ships a sample configuration file for prometheus which sets it up to scrape a single faucet and gauge controller running on the same machine as prometheus. The configuration file we ship looks like:

.. literalinclude:: ../../etc/prometheus/prometheus.yml
  :language: shell
  :caption: prometheus.yml
  :name: prometheus.yml

To learn more about what this configuration file does you can look at the Prometheus Configuration Documentation. The simple explanation is that it includes an additional faucet.rules.yml file that performs some automatic queries in prometheus for generating some additional metrics as well as setting up scrape jobs every 15 seconds for faucet listening on localhost:9302 and gauge listening on localhost:9303.

Steps to make prometheus use the configuration file shipped with faucet:

  1. Change the configuration file prometheus loads by editing the file /etc/default/prometheus to look like:

  2. Restart prometheus to apply the changes:

    sudo systemctl restart prometheus

Configure grafana

Grafana running in it's default configuration will work just fine for our needs. We will however need to make it start on boot, configure prometheus as a data source and add our first dashboard:

  1. Make grafana start on boot and then start it manually for the first time:

    sudo systemctl daemon-reload
    sudo systemctl enable grafana-server
    sudo systemctl start grafana-server
  2. To finish setup we will configure grafana via the web interface.

    First load http://localhost:3000 in your web browser (by default both the username and password are admin).

  3. The web interface will first prompt us to add a data source. Use the following settings then click Save & Test:

    Name:   Prometheus
    Type:   Prometheus
    URL:    http://localhost:9090
    
  4. Next we want to add some dashboards so that we can later view the metrics from faucet.

    Hover over the + button on the left sidebar in the web interface and click Import.

    We will import the following dashboards, just download the following links and upload them through the grafana dashboard import screen:

Configure faucet

For this tutorial we will configure a very simple network topology consisting of a single switch with two ports.

  1. Configure faucet

    We need to tell faucet about our topology and VLAN information, we can do this by editing the faucet configuration /etc/faucet/faucet.yaml to look like:

    Note

    Tabs are forbidden in the YAML language, please use only spaces for indentation.

    This will create a single VLAN and a single datapath with two ports.

  2. Verify configuration

    The check_faucet_config command can be used to verify faucet has correctly interpreted your configuration before loading it. This can avoid shooting yourself in the foot by applying configuration with typos. We recommend either running this command by hand or with automation each time before loading configuration.

    check_faucet_config /etc/faucet/faucet.yaml

    This script will either return an error, or in the case of successfully parsing the configuration it will return a JSON object containing the entire faucet configuration that would be loaded (including any default settings), for example:

    {'drop_spoofed_faucet_mac': True, 'hardware': 'Open vSwitch', 'lowest_priority': 0, 'highest_priority': 9099, 'faucet_dp_mac': '0e:00:00:00:00:01', 'metrics_rate_limit_sec': 0, 'use_idle_timeout': False, 'max_resolve_backoff_time': 32, 'high_priority': 9001, 'timeout': 300, 'drop_lldp': True, 'learn_ban_timeout': 10, 'ofchannel_log': None, 'drop_broadcast_source_address': True, 'max_hosts_per_resolve_cycle': 5, 'proactive_learn': True, 'lldp_beacon': {}, 'cookie': 1524372928, 'stack': None, 'dp_id': 1, 'priority_offset': 0, 'description': 'sw1', 'max_host_fib_retry_count': 10, 'learn_jitter': 10, 'interfaces': {'p1': {'lldp_beacon': {}, 'unicast_flood': True, 'enabled': True, 'tagged_vlans': [], 'number': 1, 'description': 'port1', 'acls_in': None, 'mirror': None, 'acl_in': None, 'opstatus_reconf': True, 'hairpin': False, 'native_vlan': VLAN office vid:100 ports:Port 1,Port 2, 'loop_protect': False, 'stack': None, 'lacp': 0, 'override_output_port': None, 'receive_lldp': False, 'max_hosts': 255, 'permanent_learn': False, 'output_only': False}, 'p2': {'lldp_beacon': {}, 'unicast_flood': True, 'enabled': True, 'tagged_vlans': [], 'number': 2, 'description': 'port2', 'acls_in': None, 'mirror': None, 'acl_in': None, 'opstatus_reconf': True, 'hairpin': False, 'native_vlan': VLAN office vid:100 ports:Port 1,Port 2, 'loop_protect': False, 'stack': None, 'lacp': 0, 'override_output_port': None, 'receive_lldp': False, 'max_hosts': 255, 'permanent_learn': False, 'output_only': False}}, 'combinatorial_port_flood': True, 'packetin_pps': 0, 'ignore_learn_ins': 10, 'interface_ranges': {}, 'group_table_routing': False, 'advertise_interval': 30, 'group_table': False, 'low_priority': 9000, 'arp_neighbor_timeout': 30, 'drop_bpdu': True}
  3. Reload faucet

    To apply this configuration we can reload faucet which will cause it to compute the difference between the old and new configuration and apply the minimal set of changes to the network in a hitless fashion (where possible).

    sudo systemctl reload faucet
  4. Check logs

    To verify the configuration reload was successful we can check /var/log/faucet/faucet.log and make sure faucet successfully loaded the configuration we can check the faucet log file /var/log/faucet/faucet.log:

    If there were any issues (say faucet wasn't able to find a valid pathway from the old config to the new config) we could issue a faucet restart now which will cause a cold restart of the network.

Configure gauge

We will not need to edit the default gauge configuration that is shipped with faucet as it will be good enough to complete the rest of this tutorial. If you did need to modify it the path is /etc/faucet/gauge.yaml and the default configuration looks like:

.. literalinclude:: ../../etc/faucet/gauge.yaml
  :language: yaml
  :caption: gauge.yaml
  :name: tutorial-gauge.yaml

This default configuration will setup a prometheus exporter listening on port 0.0.0.0:9303 and write all the different kind of gauge metrics to this exporter.

We will however need to restart the current gauge instance so it can pick up our new faucet configuration:

sudo systemctl restart gauge

Connect your first datapath

Now that we've set up all the different components let's connect our first switch (which we call a datapath) to faucet. We will be using Open vSwitch for this which is a production-grade software switch with very good OpenFlow support.

  1. Add WAND Open vSwitch repo

    The bundled version of Open vSwitch in Ubuntu 16.04 is quite old so we will use WAND's package repo to install a newer version (if you're using a more recent debian or ubuntu release you can skip this step).

    Note

    If you're using a more recent debian or ubuntu release you can skip this step

    sudo apt-get install apt-transport-https
    echo "deb https://packages.wand.net.nz $(lsb_release -sc) main" | sudo tee /etc/apt/sources.list.d/wand.list
    sudo curl https://packages.wand.net.nz/keyring.gpg -o /etc/apt/trusted.gpg.d/wand.gpg
    sudo apt-get update
  2. Install Open vSwitch

    sudo apt-get install openvswitch-switch
  3. Add network namespaces to simulate hosts

    We will use two linux network namespaces to simulate hosts and this will allow us to generate some traffic on our network.

    First let's define some useful bash functions by coping and pasting the following definitions into our bash terminal:

    create_ns () {
        NETNS=$1
        IP=$2
        sudo ip netns add ${NETNS}
        sudo ip link add dev veth-${NETNS} type veth peer name veth0 netns $NETNS
        sudo ip link set dev veth-${NETNS} up
        sudo ip netns exec $NETNS ip link set dev veth0 up
        sudo ip netns exec $NETNS ip addr add dev veth0 $IP
        sudo ip netns exec $NETNS ip link set dev lo up
    }
    
    as_ns () {
        NETNS=$1
        shift
        sudo ip netns exec $NETNS $@
    }

    Now we will create host1 and host2 and assign them some IPs:

    create_ns host1 192.168.0.1/24
    create_ns host2 192.168.0.2/24
  1. Configure Open vSwitch

    We will now configure a single Open vSwitch bridge (which will act as our datapath) and add two ports to this bridge:

    sudo ovs-vsctl add-br br0 \
    -- set bridge br0 other-config:datapath-id=0000000000000001 \
    -- set bridge br0 other-config:disable-in-band=true \
    -- set bridge br0 fail_mode=secure \
    -- add-port br0 veth-host1 -- set interface veth-host1 ofport_request=1 \
    -- add-port br0 veth-host2 -- set interface veth-host2 ofport_request=2 \
    -- set-controller br0 tcp:127.0.0.1:6653 tcp:127.0.0.1:6654

    The Open vSwitch documentation is very good if you wish to find out more about configuring Open vSwitch.

  2. Verify datapath is connected to faucet

    At this point everything should be working, we just need to verify that is the case. If we now load up some of the grafana dashboards we imported earlier, we should see the datapath is now listed in the Faucet Inventory dashboard.

    If you don't see the new datapath listed you can look at the faucet log files /var/log/faucet/faucet.log or the Open vSwitch log /var/log/openvswitch/ovs-vswitchd.log for clues.

  3. Generate traffic between virtual hosts

    With host1 and host2 we can now test our network works and start generating some traffic which will show up in grafana.

    Let's start simple with a ping:

    as_ns host1 ping 192.168.0.2

    If this test is successful this shows our Open vSwitch is forwarding traffic under faucet control, /var/log/faucet/faucet.log should now indicate those two hosts have been learnt:

    We can also use iperf to generate a large amount of traffic which will show up on the Port Statistics dashboard in grafana, just select sw1 as the Datapath Name and All for the Port.

    sudo apt-get install iperf3
    as_ns host1 iperf3 -s &
    as_ns host2 iperf3 -c 192.168.0.1

Further steps

Now that you know how to setup and run faucet in a self-contained virtual environment you can build on this tutorial and start to make more interesting topologies by adding more Open vSwitch bridges, ports and network namespaces. Check out the faucet :doc:`../configuration` document for more information on features you can turn on and off. In future we will publish additional tutorials on layer 3 routing, inter-vlan routing, ACLs.

You can also easily add real hardware into the mix as well instead of using a software switch. See the :doc:`../vendors/index` section for information on how to configure a wide variety of different vendor devices for faucet.