dzo

Run DayZ dedicated servers on Debian with rootless podman.

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dzo installs, configures, updates and watches one or more DayZ dedicated servers on a single Debian machine. It is one static binary: no Node.js, no shell-script fleet, no external RCon tool. Every server runs in a rootless podman container, started by systemd, and everything about your servers lives in a git repository you own.

Built with

What you get

• Servers as configuration. One instance.yaml per server (map, ports, mods, restart schedule) in a git "site" repository. dzo renders the mission and serverDZ.cfg from it, so a server can be rebuilt from git at any time, and changes to the Central Economy files are applied in place without wiping your live mission.
• Server builds and workshop mods that never change under a running server. Steam downloads go into immutable, shared "generations". A server switches to a new one only when it restarts, and old ones are cleaned up automatically. Server builds are updated by hand, never behind your back.
• Restarts players notice. Scheduled or manual restarts announce themselves in game, lock the server, kick the rest and start again with the new build or mods. A brake stops a server that fails to start from restarting in a loop.
• Snapshots and restores. On btrfs, dzo snapshots an instance before upgrades, mod updates and wipes, prunes old ones by a retention policy, and restores the whole instance or a single path.
• Monitoring and notifications. Prometheus /metrics, an Icinga/Nagios check, and Discord notifications for restarts, failed renders and failed downloads.
• An admin API, a web interface and a live map. See who is online, send a message, teleport a player, give an item, repair or delete a vehicle, and watch players and vehicles on the map. The in-game part is the dzo-admin servermod, which only connects out to dzo.
• A built-in BattlEye RCon client. Used for the graceful restart, dzo rcon and the player events.

The full documentation, including the quick start, the configuration reference and the operations guide, is at https://bzed.github.io/dayz-server-operator/. For the first setup there is also a two-page cheat sheet (PDF).

Install

From the apt repository (Debian 13 "trixie", amd64; signed, rebuilt from main):

dzo depends on steamcmd:i386, which is non-free and i386 only, so enable both first (see the installation guide for the details and the license prompt):

$ sudo dpkg --add-architecture i386
$ sudo sed -i /etc/apt/sources.list.d/debian.sources -e 's/^Components: main$/Components: main contrib non-free/'
$ sudo install -d -m 0755 /etc/apt/keyrings
$ sudo curl -fsSLo /etc/apt/keyrings/dzo-archive-keyring.asc https://bzed.github.io/dayz-server-operator/apt/dzo-archive-keyring.asc
$ sudo tee /etc/apt/sources.list.d/dzo.sources <<'EOF'
Types: deb
URIs: https://bzed.github.io/dayz-server-operator/apt
Suites: trixie
Components: main
Architectures: amd64
Signed-By: /etc/apt/keyrings/dzo-archive-keyring.asc
EOF
$ sudo apt update && sudo apt install dzo

The key's fingerprint is 184C DDC4 96A9 C739 D10F 67B0 FE4E E034 4431 4050.

Other ways: a .deb or a static binary from the CI artifacts, or build it yourself (a recent Go toolchain, see go.mod):

$ git clone https://github.com/bzed/dayz-server-operator.git && cd dayz-server-operator
$ make build && ./bin/dzo version                  # a static binary in ./bin
$ sudo apt install debhelper build-essential       # or the Debian package:
$ dpkg-buildpackage -us -uc -b && sudo apt install ../dzo_*.deb

Quick start

Run these as the service user (sudo -iu dayz). The quick start has every step with its explanation.

$ dzo setup                                      # directories, container images, the site checkout
$ dzo steam login --user <steam account>         # password and Steam Guard, once
$ dzo product install dayz-stable                # the server build, about 3 GB
$ # write instances/chernarus/instance.yaml in your site repository, push it, then:
$ dzo site pull && dzo site validate
$ dzo instance create chernarus                  # data volume and first mission
$ dzo instance apply chernarus                   # container units and timers
$ dzo start chernarus
$ dzo mod add 1559212036 --instance chernarus    # a workshop mod (Community Framework)
$ dzo restart chernarus --minutes 5              # announce, lock, kick, restart

Everyday commands

$ dzo status                                     # every instance: state, players, health, restarts
$ dzo logs chernarus -f                          # the server console
$ dzo mod update chernarus                       # new mod versions, applied at the next restart
$ dzo backup create chernarus && dzo backup list chernarus
$ dzo restore chernarus <snapshot>               # or one path of it

$ dzo token create web --role operator --delegate > /var/lib/dzo/secrets/web.token
$ dzo instance apply chernarus                   # starts dzo-serve (API, dzo-admin endpoint) and dzo-web:
                                                 # http://127.0.0.1:8081 (to try them by hand: dzo serve, dzo web)
$ dzo player list chernarus
$ dzo player msg chernarus all "restart in 5 minutes"
$ dzo rcon exec --instance chernarus players

$ dzo servercfg diff old/serverDZ.cfg new/serverDZ.cfg
$ dzo mod cfgpatches mods/@MyMod/addons/*.pbo    # CfgPatches and requiredAddons of a mod

dzo --help and dzo <command> --help list every flag.

Status

dzo runs real servers today, but it is young. The sections below say plainly what has been run against the real thing, what is not built, and what has not been checked yet.

Run for real

On a Debian 13 development host (rootless podman 5.4.2, a user systemd, btrfs) with a real Steam account, and on a workstation with the DayZ client:

• Servers. DayZ 1.29 (stable) and 1.30 (experimental) run in the runtime image from the generated quadlets, side by side, with workshop mods (CF-Test on experimental) and dzo-admin; builds and mods come from steamcmd by dzo. @<workshop id> directories work as mod folders, the Steam login and the workshop path layout match what the code expects, and the process name the health check looks for is enfMain.
• BattlEye player events from a real client with BattlEye (a signed test mod sends chat lines): connect, GUID, chat, kick and disconnect, on 1.29.
• dzo-admin with a real client, on both 1.29 and 1.30 (scripts/test-client.sh, a headless DayZ client against a local server and dzo serve): the player list, messages in all three styles, teleport (and its refusal in a vehicle), spawning an item into the inventory, the hands and the ground, an unknown class, the crew of a vehicle, class watch rules on items, vehicle repair and delete.
• The web interface and the map against a live server with a player, using Debian's own libjs-htmx 2.0.4 and libjs-leaflet 1.7.1 (trixie).
• The Central Economy mission is fetched from Bohemia's repository by branch or by bare commit id, rendered, applied in place, and booted by dzo test boot (also with CF-Test on the experimental server).
• Reading mod configs. dzo mod cfgpatches reads the CfgPatches of about 4,900 PBOs of real workshop mods (rapified config.bin, LZSS-compressed entries, per-folder configs, plain config.cpp) and agrees with armake2 on a random sample. Running it is what found and fixed the decoder bugs.
• Backups on btrfs, as the unprivileged user, on kernel 7.x and Debian 13's 6.12.
• Monitoring: the exporter runs on the development host against real systemd and podman, Prometheus metrics and /status included.
• Container images and setup: both images build on podman 5.4.2 and 5.8, the game server runs in them, and dzo setup ran on the development host.

Not built yet

• Web users with passwords and TOTP (the web interface expects an authenticating reverse proxy today).
• The player and ban database, and the database backup that goes with it.
• One-off restart timers and scheduled broadcasts.
• A web page for backups.
• Downloading map tiles from the client depot automatically (you point dzo at the client's world PBO).
• Golden-master tests for maps whose mission is not Bohemia's (three branches were compared as data by hand; see MILESTONES.md).
• A size-plausibility check of downloaded workshop items, and a check of real workshop PBOs for their prefix.
• The compat.yaml boot-test gate for the servermods (make servermods writes the file; server_build stays empty until the boot test fills it).

Limits worth knowing

• PlayerIdentity has no IP address, so dzo-admin cannot report one; IPs come from RCon.
• The restart counter in the metrics is systemd's and has no reasons.
• A few workshop mods ship an unreadable config.cpp (obfuscated, or built from macros): dzo mod cfgpatches reports an error for 10 of the ~4,900 PBOs. It is only a diagnostic and does not decide the load order, which is the order of the mods list.
• The package depends on Debian's libjs-htmx and libjs-leaflet. On trixie that is htmx 2.0.4, which the pages were written for; the htmx 4 beta of forky and sid has not been tried.
• The world sizes of sakhal and of unknown maps without tiles are guesses.

Needs live verification

Things that could not be checked yet, roughly in the order they would bite:

• BattlEye's Verified GUID line. The other player events (connect, GUID, chat, kick, disconnect) were captured from a real client with BattlEye and the patterns fixed; the verified-GUID line needs a BattlEye master that answers, which it did not from the development host or the workstation (Ban check timed out). See the FAQ.
• steamcmd's failure paths. A real login, server install, workshop download and forced refresh have worked. The wording of the other prompts (wrong password, Steam Guard by mail or by mobile confirmation, rate limiting) and of failed jobs is from community reports.
• The weekly image refresh. Its command rebuilds both images on podman 5.4.2, but the timer has not fired by itself yet, and the unit on the development host predates a fix: the generated unit lacked --images-dir and --config, which broke it on any host with a non-default layout.
• dzo test boot in some modes: --container, cfggameplay.json (the server only reads it with enableCfgGameplayFile = 1) and Windows. It has passed on 1.29 and 1.30, on a good instance, and fails on a mission script error, an XML file that does not parse and a missing <ce folder>.
• The web interface's buttons in a browser. The pages, the map and the API actions behind the buttons work; the htmx forms were not clicked.
• Other podman versions than 5.4.2 and 5.8 for the quadlet keys (HealthStartup*, HealthOnFailure=kill, Notify=healthy, StopTimeout, Volume=…:O), which spike S6 confirmed on 5.4.2.

Developing

$ make lint      # gofmt, go vet, golangci-lint
$ make reuse     # SPDX/REUSE licence header check
$ make test      # unit tests
$ make cover     # tests + the 85% coverage gate (D20)
$ make licenses  # dependency licence allow-list check (D15)

.github/workflows/ci.yml runs all of the above on every push, plus cross-compiled binary and .deb builds, and uploads coverage and JUnit test results to Codecov. Tests that need a real DayZ server and client (make test-findfile, make test-client) run on a development machine only; see the development guide and the testing strategy. The full design, with decisions, legacy analysis and the phased roadmap, is in IMPLEMENTATION_PLAN.md.

The packages

Package	What it does
cmd/dzo	The CLI that wires everything together
internal/config	Loads and validates /etc/dzo/config.yaml (data paths, products, notification targets)
internal/site	The site repository's schema types (site.yaml, instance.yaml, overlays) and its git plumbing
internal/resolve	Combines config.yaml, the site checkout and the cache into one resolved instance, including its quadlet spec (dzo instance show)
internal/instance	One instance's lifecycle: the failed-render gate, quadlet and timer materialization, systemd start/stop/restart, the BattlEye lock/kick graceful restart
internal/quadlet	Renders podman quadlet .container units (health checks, networking, mounts, the start-rate limit)
internal/mission	The mission render/apply pipeline: pristine fetch, staging, apply plan, atomic writes with a file history
internal/ce	JSON and XML merge primitives for mission, mod and overlay data, and <ce folder> registration
internal/servercfg	Parses and writes serverDZ.cfg and diffs two versions
internal/runfiles	The keys, serverDZ.cfg and BattlEye config an instance needs besides its mission
internal/cache	The immutable, generation-based download cache with atomic activation and safe garbage collection
internal/steam	The steamcmd login state machine (pty-driven) and a non-interactive mode for scheduled jobs
internal/product	Update scheduling, the Steam Web API freshness client, the steamcmd job runner and the install flow for server builds, workshop mods and local servermods
internal/moddeps	Reads CfgPatches and requiredAddons from a PBO or a config.cpp (diagnostics)
internal/battleye	The native BattlEye RCon client: login, commands, multi-packet answers, the event stream
internal/a2s	The Valve A2S server-query client
internal/health	dzo health startup and live: process, A2S and optional RCon probes
internal/hooks	Runs the extension-point scripts (pre_start, post_stop, …) with a DZO_* environment
internal/notify	Discord notifications, per-event templates and event coalescing
internal/monitor, internal/exporter	Prometheus /metrics, JSON /status, Icinga/Nagios checks, served over HTTP or TLS with mutual TLS, a bearer token or an IP allow-list
internal/btrfs, internal/backup	Snapshots by ioctl as the unprivileged user; the snapshot index, retention policy and full or partial restore
internal/admin, internal/api, internal/apiclient, internal/serve	The operator side of dzo-admin (protocol, hub, audit log, spawn limits), the /api/v1 JSON API with scoped tokens, its Go client, and dzo serve
internal/web, internal/maptiles	The web interface (server-rendered pages, htmx, a Leaflet map) and the map tiles built from the game's world PBOs
internal/servermods	make servermods: packs servermods/*/src/* into reproducible PBOs with WoozyMasta/pbo (MIT) and writes compat.yaml
internal/boottest	dzo test boot: boots a real DayZServer from a disposable tree and checks the logs
internal/setup	dzo setup: data directories, the two container images (images/), the Steam login hand-off, the site clone and the weekly image refresh timer
servermods/dzo-admin	The Enforce Script servermod (a submodule): state push, admin actions, marker API

Licence

AGPL-3.0-or-later. This repository follows the REUSE specification — every file carries an SPDX header, and licence texts live under LICENSES/. See LICENSE and debian/copyright for details.