NUT Web GUI

Lightweight web interface for Network UPS Tools.

Quickstart

Docker/Podman:

docker run -p 9000:9000 \
  -e UPSD_ADDR=10.0.0.1 \
  -e UPSD_USER=test \
  -e UPSD_PASS=strongpass \
  ghcr.io/superioone/nut_webgui:latest

Container image registries:

• Codeberg: codeberg.org/superiorone/nut_webgui:latest
• GitHub: ghcr.io/superioone/nut_webgui:latest

Features

• Monitors UPS variables with auto-refresh.
• Supports INSTCMD, SET VAR, and FSD calls from GUI.
• Potato PC friendly. Small footprint on both resource usage and disk size.
• Basic JSON API.
• Supports RISC-V and older ARM devices.

In order to run INSTCMD and FSD, make sure the configured user has the proper privileges in upsd.users. See man(upsd.users).

Examples/How-To's

• Volumes and args
• Docker/Podman compose
• Kubernetes - Basic
• Kubernetes - EndpointSlice
• Custom base path for reverse proxy
• Accessing localhost
• Using NUT with TLS
• Enabling Auth and API Keys
• Connecting multiple NUT servers
• Binary installation
• Events API
• OpenMetrics

CPU architecture support

Arch	Test Hardware	Notes
amd64	AM4 CPU	Works across all amd64 platforms.
amd64-v3	AM4 CPU	Snake-oil level optimizations with AVX. It mostly improves response compression, and TLS.
amd64-v4	Intel® SDE	Snake-oil level optimizations with AVX-512. It mostly improves response compression, and TLS.
arm64	Raspberry Pi 4 Model B
armv7	Qemu emulation	Uses software floating-point.
armv6	Qemu emulation	Uses software floating-point.
riscv64	Qemu emulation

amd64 v3 and v4 variants require certain CPU feature flags to run. If you are a crackhead min-max enjoyer (like me), you can use nut_webgui:latest-amd64-v3 and nut_webgui:latest-amd64-v4 images. See x86-64 Microarchitecture levels for more details.

Configuration

nut_webgui can be configured via args, environment variables, or config file. All configuration options are merged into single unified config based on their priority.

CLI arguments

CLI arguments hold the highest priority in configuration settings.

• --allow-env: Allows application to load configuration from environment variables.
• --base-path: Overrides HTTP server base path. Default is /.
• --config-file: config.toml path.
• --default-theme: Web UI default theme.
• --listen: Listen address for the HTTP server. Default is 0.0.0.0.
• --log-level: Log level for the HTTP server. Default is info.
• --port: Port used by the HTTP server. Default is 9000.
• --server-key: Private server key value. Default is randomly auto-generated value.
• --with-auth: Enables authentication with user.toml file.
• --worker-count: Sets HTTP server worker count.

Environment variables

Environment variables have the second-highest priority in configuration settings. Accepts direct values or file paths (automatically reads file contents).

General

Name	Alias (Container Only)	Default	Value Type	Description
NUTWG__CONFIG_FILE	CONFIG_FILE	/etc/nut_webgui/config.toml	File path	Custom config.toml file path.
NUTWG__DEFAULT_THEME	DEFAULT_THEME	None	See config.toml	Web UI default theme.
NUTWG__LOG_LEVEL	LOG_LEVEL	info	error, warn, info, debug, trace	Log level.
NUTWG__SERVER_KEY	SERVER_KEY	/etc/nut_webgui/server.key	File path, UTF-8 string	Server sign key used for signing session tokens.
NUTWG__AUTH__USERS_FILE	AUTH_USERS_FILE	None	File path	Enables authentication with the provided users.toml file.
NUTWG__HTTP_SERVER__BASE_PATH	BASE_PATH	/	URI path	Overrides HTTP server base path.
NUTWG__HTTP_SERVER__LISTEN	LISTEN	0.0.0.0	IPv4, IPv6	HTTP server listen address.
NUTWG__HTTP_SERVER__PORT	PORT	9000	1-65535	HTTP server listen port.
NUTWG__HTTP_SERVER__WORKER_COUNT		All CPU cores	1-usize::MAX	HTTP server worker count.

Default UPSD

If you only connect to a single NUT server and want to keep configurations simple as possible, connection details can be configured via NUTWG__UPSD__* environment variables.

Name	Alias (Container Only)	Default	Value Type	Description
NUTWG__UPSD__ADDRESS	UPSD_ADDR		IPv6, IPv4, hostname	UPS daemon address.
NUTWG__UPSD__MAX_CONNECTION		4	1-usize::Max	Allowed maximum connection for UPSD client.
NUTWG__UPSD__NAME		default	Text	Target namespace for the NUTWG__UPSD__* environment variables.
NUTWG__UPSD__PASSWORD	UPSD_PASS	None	Text	UPS daemon password.
NUTWG__UPSD__POLL_FREQ	POLL_FREQ	30	1-u64::Max	Non-critical ups variables update frequency in seconds.
NUTWG__UPSD__POLL_INTERVAL	POLL_INTERVAL	2	1-u64::Max	Critical ups variables (ups.status) update interval in seconds.
NUTWG__UPSD__PORT	UPSD_PORT	3493	1-65535	UPS daemon port.
NUTWG__UPSD__TLS_MODE	UPSD_TLS	disable	strict, disable, skip	Configures TLS communication between UPSD and client.
NUTWG__UPSD__USERNAME	UPSD_USER	None	Text	UPS daemon username.

Container only

The following environment variables are available only to container images and do not apply to binary installations.

Name	Default	Value Type	Description
UPSD_ROOT_CA	None	Path	Path to the Root CA certificate for TLS.
UID	1000	1-65535	User UID running the server. Ignored when container already starts with non-root user via --user option.
GID	Value of UID	1-65535	User GID running the server. Ignored when container already starts with non-root via --user option.

TOML config

Config.toml has the least priority, but it's recommended to use the config file as a baseline configuration and use environment variables and command-line arguments to override settings when needed.

version = "1"
log_level = "info"
default_theme = "tokyo-night"

[http_server]
base_path = "/"
listen = "0.0.0.0"
port = 9000
worker_count = 8

[upsd.default]
username = "admin"
password = "where an old man of Aran goes around and around"
address = "localhost"
port = 3493
max_connection = 4
poll_freq = 30
poll_interval = 2
tls_mode = "disable"

[upsd.reactor]
address = "10.0.12.10"
username = "observer"
password = "AbsoluteSecurity"

[auth]
users_file = "/etc/nut_webgui/users.toml"

For more detailed config template see ./dist/config.toml.

UniFi NUT Specific Configuration

The current UniFi NUT server supports up to 3 client connections, and when this limit is exceeded, the server restarts itself. To prevent this issue, set the maximum connection limit to 1 using one of the following methods:

• Set the NUTWG__UPSD__MAX_CONNECTION environment variable if you are using a single NUT server
• Configure max_connection in the config.toml file

JSON data API

A simple JSON-based API is available for general-purpose integrations.

OpenAPI 3.0.0 specification files: json | yaml

Events API

Real-time UPS events can read via WebSocket at /events. For more details see Events API.

Probes

nut_webgui has basic probe endpoints to check server health and readiness:

• /probes/health
• /probes/readiness

If you've multiple NUT server connections, you can also probe the individual connection:

• /probes/health/<namespace>
• /probes/readiness/<namespace>

OpenMetrics

UPS metrics can be scraped from /metrics endpoint. For more details see the OpenMetrics.

Building from source and debugging

Building and Debugging

Custom Build Pipeline