Docker
Docker is a platform that packages an application and everything it needs into a container image which behaves identically wherever it runs. For game servers it removes the gap between a build that works on one machine and the same build failing on another, and it is the unit most orchestration platforms deploy.
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Why Are Game Servers Packaged With Docker?
Docker is the tool that turns a server build into a container image and lets you run that image on your own machine. The image is what you ship. In production, a hosting platform or orchestrator runs the same image with its own container runtime, usually containerd, with no Docker installed.
That makes the image the build artifact. CI produces it, QA tests it, production runs it, and every version carries a tag. Rolling back a bad patch means redeploying the previous tag rather than rebuilding a machine.
A container is also not a virtual machine. It shares the host's operating system kernel instead of running its own on a hypervisor, so a server's simulation runs at close to native CPU speed and starts without booting an operating system. Each container also runs inside the CPU and memory limits it was given, so one match can't take another's share of the host. The trade-off is some overhead in networking and disk I/O.
What Breaks When You Containerize a Game Server?
Most problems come from the build, not from the container, and running the image locally with Docker catches them before anything is deployed. Four come up repeatedly:
The build targets the wrong OS. Container hosts run Linux, so the server needs a Linux build: a Linux Dedicated Server build in Unity, or a Linux target in Unreal, often cross-compiled from Windows.
The image targets the wrong CPU. Images built on an Apple Silicon Mac default to arm64, while most server hosts run amd64. Building with
--platform linux/amd64avoids an image that fails on start.The game port is TCP.
docker run -ppublishes TCP unless told otherwise, so a UDP game port needs/udp, as in-p 7777:7777/udp(Docker documentation). In production the platform assigns the external port, so the server should read its port from the environment rather than hardcode it.The image is too large. Every new host has to pull the image before a match can start there, so image size feeds directly into how long players wait for a fresh server.
Once the server runs cleanly in a container, the next question is what it costs to run. For Unreal, profiling a dedicated server build shows where CPU, memory and bandwidth go.
Can WebAssembly Replace Containers for Game Servers?
Not yet. WebAssembly's appeal is size. In May 2026, developer Ivan Bogomolov compiled a full Godot 4 engine to a 35 MB WebAssembly binary, against 421 MB for the default Node.js Docker image. Smaller binaries would mean faster pulls and faster starts.
The server side is where it stops. The WebAssembly System Interface (WASI) doesn't yet give reliable access to the UDP sockets game servers depend on, threading needs workarounds, and server runtimes fall back to WebSockets over TCP, which game netcode is built to avoid. Today WebAssembly fits single-player web games. Our full breakdown covers each limit.
For now, the portable unit is the container. Because an image runs the same on any provider's hardware, one build can deploy across a network the size of Edgegap's: 615+ locations across 17+ providers (platform data, as of 18 September 2026).
A word from our sponsor (ourselves!)
A region is a guess about where your players will be. Edgegap's Edge Cloud is a distributed, multi-cloud network of 615+ locations across 17+ providers, available on demand. Each server launches at the best available location on the network when the match starts, not at the nearest of a handful of regions.
