rds13 / dhcp_server

An ansible role to setup and configure a DHCP server under Debian/CentOS based distro's

dhcp_server

This role installs and configures a DHCP server.

Requirements

This role requires Ansible 1.4 or higher and platform requirements are listed in the metadata file.

Ubuntu AppArmor

Since Ubuntu 14.04, AppArmor is configured to not allow dhcpd to access files outside a certain list of paths. This prevents Ansible from running the check command on the template. The check is used to validate the correctness of the config file generated.

To prevent this, you can either disable AppArmor, manually configure it in such a way that it allows access to /root/.ansible/tmp for dhcpd or you can let this role do that for you:

If you specify the configure_apparmor: true variable for your host. This role will overwrite the /etc/apparmor.d/local/usr.bin.dhcpd file and specifically allow read-only access to /root/.ansible/tmp. It will first check if this file exists, if it does not, it will not do anything.

Difference between global and subnet interface options

Global dhcp_interfaces option makes listen on defined interfaces all subnets. Interface per subnet definition allows listen as much subnets as you want. Global dhcp_interfaces option does not work on systemd distros (ArchLinux, CentOS 7, Fedora), listen by default on interface with declared subnet. You cat rewrite systemd service, but is dirty. Instead this, describe interfaces in configuration. Is modern and properly.

Role Variables

The variables that can be passed to this role and a brief description about them are as follows. These are all based on the configuration variables of the DHCP server configuration.

# AppArmor configuration - important for Ubuntu 14.04
configure_apparmor: true

# Basic configuration information
dhcp_use_ansible_managed: true|false (default is true)
dhcp_interfaces: eth0
dhcp_common_domain: example.org
dhcp_common_domain_search: '"domain.aaa", "domain.bbb"'
dhcp_common_nameservers: ns1.example.org, ns2.example.org
dhcp_common_default_lease_time: 600
dhcp_common_max_lease_time: 7200
dhcp_common_ddns_update_style: none
dhcp_common_authoritative: true
dhcp_common_log_facility: local7
dhcp_common_options:
- opt66 code 66 = string
dhcp_common_parameters:
- filename "pxelinux.0"
dhcp_common_unknown_clients: true|false (default is true)

# DDNS configuration
dhcp_ddns_client_updates: true|false (default is false)
dhcp_ddns_updates: true|false (default is true)
dhcp_ddns_update_static_leases: true|false (default is false)
dhcp_ddns_update_style: interim
dhcp_ddns_keys:
  - the_key_name: the_key_value
dhcp_ddns_zones:
  -
    name:example.org
    primary: 192.168.0.1
    key: a_key_name_from_dhcp_ddns_keys_list

# Subnet configuration
dhcp_subnets:
# Required variables example
- base: 192.168.1.0
  netmask: 255.255.255.0
# Full list of possibilities
- base: 192.168.10.0
  netmask: 255.255.255.0
  interface: vlan100
  range_start: 192.168.10.150
  range_end: 192.168.10.200
  routers: 192.168.10.1
  broadcast_address: 192.168.10.255
  domain_nameservers: 192.168.10.1, 192.168.10.2
  domain_name: example.org
  ntp_servers: pool.ntp.org
  default_lease_time: 3600
  max_lease_time: 7200
  pools:
  - range_start: 192.168.100.10
    range_end: 192.168.100.20
    rule: 'allow members of "foo"'
    parameters:
    - filename "pxelinux.0"
  - range_start: 192.168.110.10
    range_end: 192.168.110.20
    rule: 'deny members of "foo"'
  parameters:
  - filename "pxelinux.0"

# Fixed lease configuration
dhcp_hosts:
- name: local-server
  mac_address: "00:11:22:33:44:55"
  fixed_address: 192.168.10.10
  default_lease_time: 43200
  max_lease_time: 86400
  parameters:
  - filename "pxelinux.0"

# Class configuration
dhcp_classes:
- name: foo
  rule: 'match if substring (option vendor-class-identifier, 0, 4) = "SUNW"'
- name: CiscoSPA
  rule: 'match if (( substring (option vendor-class-identifier,0,13) = "Cisco SPA504G" ) or
         ( substring (option vendor-class-identifier,0,12) = "Cisco SPA303" ))'
  options:
  - opt: 'opt66 "http://distrib.local/cisco.php?mac=$MAU"'
  - opt: 'time-offset 21600'

# Shared network configurations
dhcp_shared_networks:
- name: shared-net
  interface: vlan100
  subnets:
  - base: 192.168.100.0
    netmask: 255.255.255.0
    routers: 192.168.10.1
  parameters:
  - filename "pxelinux.0"
  pools:
  - range_start: 192.168.100.10
    range_end: 192.168.100.20
    rule: 'allow members of "foo"'
    parameters:
    - filename "pxelinux.0"
  - range_start: 192.168.110.10
    range_end: 192.168.110.20
    rule: 'deny members of "foo"'

# Custom if else clause
  dhcp_ifelse:
  - condition: 'exists user-class and option user-class = "iPXE"'
    val: 'filename "http://my.web.server/real_boot_script.php";'
    else:
      - val: 'filename "pxeboot.0";'
      - val: 'filename "pxeboot.1";'

Examples

1. Install DHCP server on interface eth0 with one simple subnet:

   • hosts: all roles:
     • role: dhcp_server dhcp_interfaces: eth0 dhcp_common_domain: example.org dhcp_common_domain_search: '"domain.aaa", "domain.bbb"' dhcp_common_nameservers: ns1.example.org, ns2.example.org dhcp_common_default_lease_time: 600 dhcp_common_max_lease_time: 7200 dhcp_common_ddns_update_style: none dhcp_common_authoritative: true dhcp_common_log_facility: local7 dhcp_subnets:
       • base: 192.168.10.0 netmask: 255.255.255.0 range_start: 192.168.10.150 range_end: 192.168.10.200 routers: 192.168.10.1

2. Install DHCP server with subnet per interface:

   • hosts: all roles:
     • role: dhcp_server dhcp_common_domain: example.org dhcp_common_domain_search: '"domain.aaa", "domain.bbb"' dhcp_common_nameservers: ns1.example.org, ns2.example.org dhcp_common_default_lease_time: 600 dhcp_common_max_lease_time: 7200 dhcp_common_ddns_update_style: none dhcp_common_authoritative: true dhcp_common_log_facility: local7 dhcp_subnets:
       • base: 192.168.10.0 netmask: 255.255.255.0 interface: vlan10 range_start: 192.168.10.150 range_end: 192.168.10.200 routers: 192.168.10.1
       • base: 192.168.20.0 netmask: 255.255.255.0 interface: vlan20 range_start: 192.168.20.150 range_end: 192.168.20.200 routers: 192.168.20.1

3. Install DHCP server with one subnet on interface vlan10 and with shared network on interface vlan20

   • hosts: all roles:
     • role: dhcp_server dhcp_common_default_lease_time: 600 dhcp_common_max_lease_time: 7200 dhcp_common_ddns_update_style: none dhcp_common_authoritative: true dhcp_common_log_facility: local7 dhcp_subnets:
       • base: 192.168.10.0 netmask: 255.255.255.0 interface: vlan10 domain_nameserver: 192.168.10.1 domain_name: example.local range_start: 192.168.10.150 range_end: 192.168.10.200 routers: 192.168.10.1 dhcp_shared_networks:
       • name: sharednet interface: vlan20 subnets:
         • base: 10.7.0.0 netmask: 255.255.255.0 routers: 10.7.0.1 domain_nameserver: 10.7.0.1 domain_name: example.public0 ntp_servers: 10.7.0.1 pools:
           • range_start: 10.7.0.2 range_end: 10.7.0.254
         • base: 10.8.0.0 netmask: 255.255.255.0 routers: 10.8.0.1 domain_nameserver: 10.8.0.1 domain_name: example.public1 ntp_servers: 10.8.0.1 pools:
           • range_start: 10.8.0.2 range_end: 10.8.0.254

Dependencies

None

License

BSD

Author Information

Philippe Dellaert