EMQX add-on fails to set open file limit to 1048576

[walkeritgtech]

Describe the issue you are experiencing

I was testing dev builds so I could access the full 16GB of memory on the CM5 that I recently installed in my Home Assistant Yellow.

Sttarting with build 15.3.dev20250506, the EMQX add-on fails to start at boot or on demand, logging the following error message in the Core log:

[16:10:27] INFO: Starting EMQX...
s6-rc: info: service legacy-services successfully started
./run: line 28: ulimit: open files: cannot modify limit: Operation not permitted
[16:10:28] INFO: Service EMQX exited with code 1 (by signal 0)

I downgraded to 15.2 and EMQX was started successfully.

I then updated to the following dev builds to discover that they all exhibit the issue, and the same ulimit error is logged:

15.3.dev20250513
15.3.dev20250519
15.3.dev20250526
16.0.dev20250528

What operating system image do you use?

yellow (Home Assistant Yellow)

What version of Home Assistant Operating System is installed?

16.0.dev20250528

Did the problem occur after upgrading the Operating System?

Yes

Hardware details

Home Assistant Yellow with Aeotec Z-PI7 GPIO module, Sonoff 3.0 Zigbee stick

Steps to reproduce the issue

1. Update to any dev build from 15.3.dev20250506 or later
2. Check EMQX add-on, observe it is stopped and attempt to start.
3. Service attempts to start but logs ulimit error and fails.
   ...

Anything in the Supervisor logs that might be useful for us?

Did not see anything relevant.

Anything in the Host logs that might be useful for us?

Nothing relevant was observed.

System information

System Information

version	core-2025.5.3
installation_type	Home Assistant OS
dev	false
hassio	true
docker	true
user	root
virtualenv	false
python_version	3.13.3
os_name	Linux
os_version	6.12.25-haos-raspi
arch	aarch64
timezone	America/New_York
config_dir	/config

Home Assistant Community Store

GitHub API	ok
GitHub Content	ok
GitHub Web	ok
HACS Data	ok
GitHub API Calls Remaining	5000
Installed Version	2.0.5
Stage	running
Available Repositories	1982
Downloaded Repositories	48

Home Assistant Cloud

logged_in	true
subscription_expiration	April 29, 2026 at 8:00 PM
relayer_connected	true
relayer_region	us-east-1
remote_enabled	true
remote_connected	true
alexa_enabled	false
google_enabled	false
cloud_ice_servers_enabled	true
remote_server	us-east-1-7.ui.nabu.casa
certificate_status	ready
instance_id	a584795093fc4a25bb9be420db8ae280
can_reach_cert_server	ok
can_reach_cloud_auth	ok
can_reach_cloud	ok

Home Assistant Supervisor

host_os	Home Assistant OS 16.0.dev20250528
update_channel	stable
supervisor_version	supervisor-2025.05.3
agent_version	1.7.2
docker_version	28.0.4
disk_total	916.2 GB
disk_used	45.8 GB
healthy	true
supported	true
host_connectivity	true
supervisor_connectivity	true
ntp_synchronized	true
virtualization
board	yellow
supervisor_api	ok
version_api	ok
installed_addons	Z-Wave JS UI (4.3.1), phpMyAdmin (0.11.1), Terminal & SSH (9.17.0), MariaDB (2.7.2), Samba share (12.5.1), Node-RED (19.0.2), Studio Code Server (5.19.3), NGINX Home Assistant SSL proxy (3.11.1), Crowdsec (1.6.8), OpenThread Border Router (2.13.0), Log Viewer (0.17.1), Matter Server (8.0.0), ESPHome Device Builder (2025.5.1), File editor (5.8.0), AppDaemon (0.17.2), Crowdsec Firewall Bouncer (v0.0.31), diyHue (2.0.31), Network UPS Tools (0.14.1), ESPresense Companion (1.0.24), EMQX (0.7.5)

keymaster

zwave_integration	zwave_js
network_status	on

Dashboards

dashboards	10
resources	28
views	51
mode	storage

Network Configuration

adapters	lo (disabled), end0 (enabled, default, auto), hassio (disabled), docker0 (disabled), veth233cd98 (disabled), vetha3a5193 (disabled), vethe0058c1 (disabled), vethb3bf13b (disabled), vethd2c83b2 (disabled), vethc87721b (disabled), veth927c471 (disabled), vethc869a3d (disabled), veth1040935 (disabled), vethad1ca30 (disabled), veth9520ac2 (disabled), wpan0 (disabled), veth7d8c380 (disabled), vethcd405a5 (disabled), veth4153f63 (disabled), veth0b0de9b (disabled), veth4595221 (disabled), vethffce66f (disabled)
ipv4_addresses	lo (127.0.0.1/8), end0 (10.118.40.65/24), hassio (172.30.32.1/23), docker0 (172.30.232.1/23), veth233cd98 (), vetha3a5193 (), vethe0058c1 (), vethb3bf13b (), vethd2c83b2 (), vethc87721b (), veth927c471 (), vethc869a3d (), veth1040935 (), vethad1ca30 (), veth9520ac2 (), wpan0 (), veth7d8c380 (), vethcd405a5 (), veth4153f63 (), veth0b0de9b (), veth4595221 (), vethffce66f ()
ipv6_addresses	lo (::1/128), end0 (fdb6:10ca:35c3:ee6a:87a7:b12e:a581:44f6/64, fe80::cddf:1f31:a5c9:d108/64), hassio (fe80::bcb8:c0ff:fe78:f6b/64), docker0 (fe80::f094:3ff:fe4f:77e2/64), veth233cd98 (fe80::3c42:57ff:fea2:3a11/64), vetha3a5193 (fe80::58d4:b7ff:fef0:b0b6/64), vethe0058c1 (fe80::508b:5dff:fe76:d438/64), vethb3bf13b (fe80::24c8:39ff:fea8:6ef0/64), vethd2c83b2 (fe80::b814:2ff:febd:f996/64), vethc87721b (fe80::78de:31ff:fe63:c428/64), veth927c471 (fe80::4b1:6cff:fefd:4319/64), vethc869a3d (fe80::18b1:57ff:fee7:a06e/64), veth1040935 (fe80::a0de:47ff:feb0:e6aa/64), vethad1ca30 (fe80::6cfd:9eff:fe43:9883/64), veth9520ac2 (fe80::60d6:58ff:feb8:e9b7/64), wpan0 (fd64:2644:9208:bb5d:0:ff:fe00:fc11/64, fd47:7ea6:e99f:1:4374:c99f:52a8:9470/64, fd64:2644:9208:bb5d:0:ff:fe00:fc10/64, fd64:2644:9208:bb5d:0:ff:fe00:fc38/64, fd64:2644:9208:bb5d:0:ff:fe00:fc00/64, fd64:2644:9208:bb5d:0:ff:fe00:dc00/64, fd64:2644:9208:bb5d:707b:6393:1594:8669/64, fe80::d465:3626:d7dd:ba0b/64), veth7d8c380 (fe80::142f:24ff:fec5:f7df/64), vethcd405a5 (fe80::4c3f:80ff:fed6:2daa/64), veth4153f63 (fe80::b056:21ff:fe04:efd0/64), veth0b0de9b (fe80::2481:a0ff:fe23:8525/64), veth4595221 (fe80::90cf:3eff:fe3b:1747/64), vethffce66f (fe80::f4bb:a1ff:fe40:7052/64)
announce_addresses	10.118.40.65, fdb6:10ca:35c3:ee6a:87a7:b12e:a581:44f6, fe80::cddf:1f31:a5c9:d108

Recorder

oldest_recorder_run	May 6, 2025 at 5:44 AM
current_recorder_run	May 28, 2025 at 4:23 PM
estimated_db_size	12031.72 MiB
database_engine	mysql
database_version	10.11.6

Additional information

EMQX Log file showing error on various dev builds attached.

a0d7b954_emqx_2025-05-28T20-21-53.755Z.log

[sairon]

Although the root cause lies in the OS update (brought by Containerd bump introduced on Buildroot update), this needs to be fixed on the add-on side - actually no add-ons should attempt to set the open file hard limit to anything higher than 524288. I opened a PR in the EMQX add-on repo, along with some further references explaining the issue.