#!/bin/bash

set -eu
set -o pipefail

sysctl-write-value net.ipv4.tcp_max_tw_buckets 5800000
sysctl-write-value net.ipv4.tcp_max_orphans 5800000
sysctl-write-value net.ipv4.tcp_max_syn_backlog 100000
sysctl-write-value net.ipv4.tcp_keepalive_time 300
sysctl-write-value net.ipv4.tcp_tw_reuse 1
sysctl-write-value net.core.somaxconn 65534  # netns aware
sysctl-write-value net.ipv4.tcp_synack_retries 3
sysctl-write-value net.core.netdev_max_backlog 100000
# This should allow HAProxy maxconn to be 1,000,000
sysctl-write-value fs.file-max 2600000  # netns aware
sysctl-write-value fs.nr_open 2600000  # netns aware

# It's ok for these to fail if conntrack module isn't loaded
sysctl-write-value net.netfilter.nf_conntrack_tcp_timeout_time_wait 5 || true
sysctl-write-value net.netfilter.nf_conntrack_tcp_timeout_fin_wait 5 || true

# Enable MTU icmp black hole detection (RFC4821)
sysctl-write-value net.ipv4.tcp_mtu_probing 1

sysctl-write-value net.ipv4.tcp_fin_timeout 5
sysctl-write-value net.ipv4.ip_nonlocal_bind 1
sysctl-write-value net.ipv6.ip_nonlocal_bind 1
sysctl-write-value net.core.rmem_max 67108864
sysctl-write-value net.core.wmem_max 67108864
sysctl-write-value net.ipv4.tcp_rmem "4096 87380 33554432"
sysctl-write-value net.ipv4.tcp_wmem "4096 87380 33554432"
sysctl-write-value net.ipv4.ip_local_port_range "1025 65534"

# Allow unprivileged users to send ICMP echo requests
# https://bugzilla.redhat.com/show_bug.cgi?id=2037807
# This sysctl is already included in /usr/lib/sysctl.d/50-default.conf on Centos
# 8 Stream (with a '-'' prefix that prevents sysctl from throwing an error if
# the setting doesn't exist in the kernel), but sysctl --system doesn't apply it
# correctly when creating the amphora-haproxy namespace.
sysctl-write-value net.ipv4.ping_group_range "0 2147483647"