memlock 73728 is the smallest limit that works for Alpine Linux 3.20.3 x86_64 build

[alopatindev]

It took... an embarrassingly long time for me to figure out what was not right. It'd be nice to update readme so it won't confuse anyone anymore.

Most of the time I was sure that the limit simply was not applied to the process which appeared to be false.

Alpine is an unusual distro: for instance it mostly doesn't use PAM, so /etc/security/limits.conf is mostly ignored.

Here's how to reproduce the issue:

#!/usr/bin/env sh

set -xeuo pipefail

#TARGET_CPU="native"
TARGET_CPU="nocona"

apk add --update --no-cache cargo clang17-libclang cmake findutils g++ git linux-headers liburing make rust

DISABLE_AVX512=$(rustc --print target-features | grep '    avx512' | grep -v 'avx512fp16' | awk '{print $1}'  | sed 's/^/-C target-feature=-/' | xargs)
export RUSTFLAGS="-C target-cpu=${TARGET_CPU} ${DISABLE_AVX512}"
export CFLAGS="-D_GNU_SOURCE -march=${TARGET_CPU}"
export PATH="${HOME}/.cargo/bin:${PATH}"

cargo install --force --locked bindgen-cli --version 0.70.1
cargo install --force --locked aquatic_ws --version 0.9.0
mv ~/.cargo/bin/aquatic_ws /usr/local/bin

mkdir -p /etc/init.d
echo "#!/sbin/openrc-run

rc_ulimit='-l 65536' # this will OOM, however it's suggested by the readme
#rc_ulimit='-l 73728' # this works

name='aquatic_ws'
command='/usr/local/bin/aquatic_ws'
command_args='--config-file /etc/aquatic_ws.conf'
command_user='nobody:nogroup'
pidfile='/run/aquatic_ws.pid'
command_background=true
output_logger='logger'
error_logger='logger'

depend() {
	need net
	use logger
}
" > /etc/init.d/aquatic_ws

echo 'socket_workers = 1
swarm_workers = 1
log_level = "info"

[network]
address = "[::ffff:127.0.0.1]:3000"
only_ipv6 = false
tcp_backlog = 1024
enable_tls = false
tls_certificate_path = ""
tls_private_key_path = ""
websocket_max_message_size = 65536
websocket_max_frame_size = 16384
websocket_write_buffer_size = 8192
enable_http_health_checks = false

[protocol]
max_scrape_torrents = 255
max_offers = 10
peer_announce_interval = 120

[cleaning]
torrent_cleaning_interval = 30
max_peer_age = 180
max_offer_age = 120
connection_cleaning_interval = 30
max_connection_idle = 180
close_after_tls_update_grace_period = 216000

[privileges]
drop_privileges = false

[access_list]
mode = "off"
path = "./access-list.txt"

[metrics]
run_prometheus_endpoint = false
prometheus_endpoint_address = "127.0.0.1:9000"
torrent_count_update_interval = 10
peer_clients = false
peer_id_prefixes = false
' > /etc/aquatic_ws.conf

chmod +x /etc/init.d/aquatic_ws
/etc/init.d/aquatic_ws start

tail -n 100 -F /var/log/messages