common.yaml

company::sysctl::sysctls:
  'net.ipv4.tcp_keepalive_time':
    value: "30"
  'net.ipv4.tcp_keepalive_probes':
    value: "5"
  'net.ipv6.bindv6only':
    value: "0"
  'net.core.wmem_max':
    value: "16777216"
  'net.core.rmem_max':
    value: "16777216"
  'net.ipv4.tcp_rmem':
    value: "4096    87380   16777216"
  'net.ipv4.tcp_wmem':
    value: "4096    87380   16777216"
  'net.ipv4.tcp_window_scaling':
    value: "1"
  'net.ipv4.tcp_timestamps':
    value: "1"
  'net.ipv4.tcp_sack':
    value: "1"
  'net.ipv4.tcp_no_metrics_save':
    value: "1"
  'net.core.netdev_max_backlog':
    value: "5000"
  'net.ipv4.tcp_fin_timeout':
    value: "5"
  'fs.file-max':
    value: "398280"
  'vm.swappiness':
    value: "0"

company_sysctl.pp

class company::sysctl(
    $sysctls = {},
) {

    create_resources(sysctl, $sysctls)

}

hiera.yaml

---
:backends:
  - yaml

:hierarchy:
  - "%{::hostname}"
  - "%{::environment}"
  - common

:yaml:
  :datadir: /etc/puppet/nodes

:merge_behavior: deeper

my_role.yaml

company::sysctl::sysctls:
  'net.core.wmem_default':
    value: "8388608"
  'net.core.rmem_default':
    value: "8388608"
  'net.core.netdev_max_backlog':
    value: "10000"
  'net.core.somaxconn':
    value: "4000"
  'net.ipv4.tcp_max_syn_backlog':
    value: "40000"
  'net.ipv4.tcp_tw_reuse':
    value: "1"

sysctl.pp

define sysctl ( 
    $value  = undef, 
    $ensure = undef 
) {

    # ...

}