keepalived

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Table of Contents

  1. Description
  2. Usage - Configuration options and additional functionality
  3. Limitations - OS compatibility, etc.
  4. Development - Guide for contributing to the module

Description

This puppet module manages keepalived. The main goal of keepalived is to provide simple and robust facilities for loadbalancing and high-availability to Linux system and Linux based infrastructures.

Usage

Basic IP-based VRRP failover

This configuration will fail-over when:

a. Master node is unavailable

node /node01/ {
  include keepalived

  keepalived::vrrp::instance { 'VI_50':
    interface         => 'eth1',
    state             => 'MASTER',
    virtual_router_id => '50',
    priority          => '101',
    auth_type         => 'PASS',
    auth_pass         => 'secret',
    virtual_ipaddress => [ '10.0.0.1/29' ],
    track_interface   => ['eth1','tun0'], # optional, monitor these interfaces.
  }
}

node /node02/ {
  include keepalived

  keepalived::vrrp::instance { 'VI_50':
    interface         => 'eth1',
    state             => 'BACKUP',
    virtual_router_id => '50',
    priority          => '100',
    auth_type         => 'PASS',
    auth_pass         => 'secret',
    virtual_ipaddress => [ '10.0.0.1/29' ],
    track_interface   => ['eth1','tun0'], # optional, monitor these interfaces.
  }
}

or hiera:

---
keepalived::vrrp_instance:
  VI_50:
    interface: 'eth1'
    state: 'MASTER'
    virtual_router_id: '50'
    priority: '101'
    auth_type: 'PASS'
    auth_pass: 'secret'
    virtual_ipaddress: '10.0.0.1/29'
    track_interface:
      - 'eth1'
      - 'tun0'

Add floating routes

node /node01/ {
  include keepalived

  keepalived::vrrp::instance { 'VI_50':
    interface         => 'eth1',
    state             => 'MASTER',
    virtual_router_id => '50',
    priority          => '101',
    auth_type         => 'PASS',
    auth_pass         => 'secret',
    virtual_ipaddress => [ '10.0.0.1/29' ],
    virtual_routes    => [ { to  => '168.168.2.0/24', via => '10.0.0.2' },
                           { to  => '168.168.3.0/24', via => '10.0.0.3' } ]
  }
}

hiera:

---
keepalived::vrrp_instance:
  VI_50:
    interface: 'eth1'
    state: 'MASTER'
    virtual_router_id: '50'
    priority: '101'
    auth_type: 'PASS'
    auth_pass: 'secret'
    virtual_ipaddress: '10.0.0.1/29'
    virtual_routes:
      - to: '168.168.2.0/24'
        via: '10.0.0.2'
      - to: 168.168.3.0/24'
        via: '10.0.0.3'

Detect application level failure

This configuration will fail-over when:

a. NGinX daemon is not running
b. Master node is unavailable

node /node01/ {
  include ::keepalived

  keepalived::vrrp::script { 'check_nginx':
    script => '/usr/bin/killall -0 nginx',
  }

  keepalived::vrrp::instance { 'VI_50':
    interface         => 'eth1',
    state             => 'MASTER',
    virtual_router_id => '50',
    priority          => '101',
    auth_type         => 'PASS',
    auth_pass         => 'secret',
    virtual_ipaddress => '10.0.0.1/29',
    track_script      => 'check_nginx',
  }
}

node /node02/ {
  include ::keepalived

  keepalived::vrrp::script { 'check_nginx':
    script => '/usr/bin/killall -0 nginx',
  }

  keepalived::vrrp::instance { 'VI_50':
    interface         => 'eth1',
    state             => 'BACKUP',
    virtual_router_id => '50',
    priority          => '100',
    auth_type         => 'PASS',
    auth_pass         => 'secret',
    virtual_ipaddress => '10.0.0.1/29',
    track_script      => 'check_nginx',
  }
}

or hiera:

---
keepalived::vrrp_script:
  check_nginx:
    script: '/usr/bin/killall -0 nginx'

keepalived::vrrp_instance:
  VI_50:
    interface: 'eth1'
    state: 'MASTER'
    virtual_router_id: '50'
    priority: '101'
    auth_type: 'PASS'
    auth_pass: 'secret'
    virtual_ipaddress: '10.0.0.1/29'
    track_script: check_nginx

or using process tracking (keepalived 2.0.11+):

node /node01/ {
  include ::keepalived

  keepalived::vrrp::track_process { 'check_nginx':
    proc_name => 'nginx',
    weight    => 10,
    quorum    => 2,
    delay     => 10,
  }

  keepalived::vrrp::instance { 'VI_50':
    interface         => 'eth1',
    state             => 'MASTER',
    virtual_router_id => '50',
    priority          => '101',
    auth_type         => 'PASS',
    auth_pass         => 'secret',
    virtual_ipaddress => '10.0.0.1/29',
    track_process     => 'check_nginx',
  }
}

IPv4 and IPv6 virtual IP, with application level failure detection

This configuration will fail-over both the IPv4 address and the IPv6 address when:

a. NGINX daemon is not running b. Master node is unavailable

It is not possible to configure both IPv4 and IPv6 addresses as virtual_ipaddresses in a single vrrp_instance; the reason is that the VRRP protocol doesn't support it. The two VRRP instances can both use the same virtual_router_id since VRRP IPv4 and IPv6 instances are completely independent of each other. Both nodes have state set to BACKUP, which will prevent them from entering MASTER state until the check script(s) have succeeded and the election has been held.

To ensure that the IPv4 and IPv6 vrrp_instances are always in the same state as each other, configure a vrrp_sync_group to include both the instances. The vrrp_sync_group require the global_tracking flag to be enabled to prevent keepalived from ignoring the tracking scripts for the vrrp_sync_group's vrrp_instance members.

Configure the vrrp_instance with the native_ipv6 flag to force the instance to use IPv6. An IPv6 vrrp_instance without the "native_ipv6" keyword does not configure the virtual IPv6 address with the "deprecated nodad" options.

RFC 3484, “Default Address Selection for Internet Protocol version 6 (IPv6)”: Configure a /128 mask for the IPv6 address for keepliaved to set preferred_lft to 0 to avoid the VI to be used for outgoing connections.

RFC5798 section 5.2.9 requires that if the protocol is IPv6, then the first address must be the link local address of the virtual router.

IPv6 VRRP uses VRRP version 3, which does not support authentication, so the auth_type and auth_pass parameters are removed for the IPv6 VRRP instance.

node /node0x/ {
  keepalived::vrrp::script { 'check_nginx':
    script => '/usr/bin/pkill -0 nginx',
  }

  keepalived::vrrp::sync_group { 'VI_50':
    group               => [ 'VI_50_IPV4', 'VI_50_IPV6' ],
    global_tracking     => true,
  }

  keepalived::vrrp::instance { 'VI_50_IPV4':
    interface           => 'eth0',
    state               => 'BACKUP',
    virtual_router_id   => 50,
    priority            => 100,
    auth_type           => 'PASS',
    auth_pass           => 'secret',
    virtual_ipaddress   => '10.0.0.1/32',
    track_script        => 'check_nginx',
  }

  keepalived::vrrp::instance { 'VI_50_IPV6':
    interface           => 'eth0',
    state               => 'BACKUP',
    virtual_router_id   => 50,
    priority            => 100,
    virtual_ipaddress   => ['fe80::50/128', '2001:db8::50/128', ],
    track_script        => 'check_nginx',
    native_ipv6         => true,
  }
}

Global definitions

class { 'keepalived::global_defs':
  notification_email      => 'no@spam.tld',
  notification_email_from => 'no@spam.tld',
  smtp_server             => 'localhost',
  smtp_connect_timeout    => '60',
  router_id               => 'your_router_instance_id',
}

Soft-restart the Keepalived daemon

class { '::keepalived':
  service_restart => 'service keepalived reload',     # When using SysV Init
  # service_restart => 'systemctl reload keepalived', # When using SystemD
}

Opt out of having the service managed by the module

class { '::keepalived':
  service_manage => false,
}

Unicast instead of Multicast

caution: unicast support has only been added to Keepalived since version 1.2.8

By default Keepalived will use multicast packets to determine failover conditions. However, in many cloud environments it is not possible to use multicast because of network restrictions. Keepalived can be configured to use unicast in such environments:

  keepalived::vrrp::instance { 'VI_50':
    interface         => 'eth1',
    state             => 'BACKUP',
    virtual_router_id => '50',
    priority          => '100',
    auth_type         => 'PASS',
    auth_pass         => 'secret',
    virtual_ipaddress => '10.0.0.1/29',
    track_script      => 'check_nginx',
    unicast_source_ip => $::ipaddress_eth1,
    unicast_peers     => ['10.0.0.1', '10.0.0.2']
  }

The 'unicast_source_ip' parameter is optional as Keepalived will bind to the specified interface by default. The 'unicast_peers' parameter contains an array of ip addresses that correspond to the failover nodes.

Creating ip-based virtual server instances with two real servers

This sets up a virtual server www.example.com that directs traffic to example1.example.com and example2.example.com by matching on an IP address and port.

keepalived::lvs::virtual_server { 'www.example.com':
  ip_address          => '1.2.3.4',
  port                => '80',
  delay_loop          => '7',
  lb_algo             => 'wlc',
  lb_kind             => 'DR',
  persistence_timeout => 86400,
  virtualhost         => 'www.example.com',
  protocol            => 'TCP'
}

keepalived::lvs::real_server { 'example1.example.com':
  virtual_server => 'www.example.com',
  ip_address     => '1.2.3.8',
  port           => '80',
  options        => {
    weight      => '1000',
    'TCP_CHECK' => {
       connection_timeout => '3',
    }
  }
}

keepalived::lvs::real_server { 'example2.example.com':
  virtual_server => 'www.example.com',
  ip_address     => '1.2.3.9',
  port           => '80',
  options        => {
    weight      => '1000',
    'TCP_CHECK' => {
       connection_timeout => '3',
    }
  }
}

Creating firewall mark based virtual server instances with two real servers

This sets up a virtual server www.example.com that directs traffic to example1.example.com and example2.example.com by matching on a firewall mark set in iptables or something similar.

keepalived::lvs::virtual_server { 'www.example.com':
  fwmark              => '123',
  delay_loop          => '7',
  lb_algo             => 'wlc',
  lb_kind             => 'DR',
  persistence_timeout => 86400,
  virtualhost         => 'www.example.com',
  protocol            => 'TCP'
}

keepalived::lvs::real_server { 'example1.example.com':
  virtual_server => 'www.example.com',
  ip_address     => '1.2.3.8',
  port           => '80',
  options        => {
    weight      => '1000',
    'TCP_CHECK' => {
       connection_timeout => '3',
    }
  }
}

keepalived::lvs::real_server { 'example2.example.com':
  virtual_server => 'www.example.com',
  ip_address     => '1.2.3.9',
  port           => '80',
  options        => {
    weight      => '1000',
    'TCP_CHECK' => {
       connection_timeout => '3',
    }
  }
}

Reference

Reference documentation coming soon.

Limitations

Details in metadata.json.

Development

The contributing guide is in CONTRIBUTING.md.

Release Notes/Contributors/Etc.

Details in CHANGELOG.md.

Migrated from https://github.com/arioch/puppet-keepalived to Vox Pupuli.