Neko with Docker Compose

What Neko needs

Only figures Neko's own documentation publishes, each linked to the page it is on. Where the project gives no number, this page does not invent one.

On top of this, Caddy (the reverse proxy in the file) is a single small container.

Which hardware Neko has images for

Read from each image's manifest list in its registry (anonymous, read-only) when this page was built. An app counts for a CPU only if every one of its images lists it.

• x86-64 PC or NAS (linux/amd64): every image has a build.
• Raspberry Pi 4/5, 64-bit OS (linux/arm64): every image has a build.
• Raspberry Pi 3 or Zero 2 W, 32-bit OS (linux/arm/v7): no image for neko. No image for this hardware; the builder leaves the app out.

A manifest says an image exists for a CPU, not how well Neko runs on it: a build for arm64 or arm/v7 can still be too slow or need more memory than the board has. The RAM and disk Neko publishes are in the table above and, for a whole set of apps against a Raspberry Pi, on Will it run on my machine?. A tag like latest can move to a new digest after the date checked.

docker-compose.yml

This is exactly what the builder writes for Neko alone on example.org: the official definition with its published ports removed except 52000:52000/udp and 52000:52000/tcp, which cannot go through a web proxy (see below), and Caddy added in front. Every ${VARIABLE} is defined in the .env below.

# docker-compose.yml built at dankhost.com for: Neko
# Each app block is its official compose definition. Only the names were prefixed with
# the app slug (services, containers, volumes, bind folders, .env variables) so any set of
# apps can share one file; other differences are listed under "Changed:" in each block.
# Caddy publishes 80 and 443. The only other published ports, each labelled where
# it is written: 52000/udp (Neko: WebRTC over UDP), 52000/tcp (Neko: WebRTC over TCP).
# Secrets live in .env next to this file.

services:
  # ---- Caddy: the one reverse proxy, HTTPS certificates from Let's Encrypt ----
  # Source: https://caddyserver.com/docs/running (checked 2026-09-23)
  # Source: https://github.com/dani-garcia/vaultwarden/wiki/Using-Docker-Compose (checked 2026-09-23)
  # Caddyfile goes in ./caddy/Caddyfile. Fixed address 172.30.0.2 so apps can trust it exactly.
  caddy:
    image: "caddy:2"
    container_name: "caddy"
    restart: "unless-stopped"
    ports:
      - "80:80"
      - "443:443"
      - "443:443/udp"
    volumes:
      - "./caddy:/etc/caddy"
      - "caddy-data:/data"
      - "caddy-config:/config"
    networks:
      proxy:
        ipv4_address: "172.30.0.2"

  # ---- Neko (neko.example.org) ----
  # Source: https://github.com/m1k1o/neko/blob/master/docker-compose.yaml (checked 2026-10-03)
  # Source: https://neko.m1k1o.net/docs/v3/quick-start (checked 2026-10-03)
  # Source: https://neko.m1k1o.net/docs/v3/configuration/webrtc (checked 2026-10-03)
  # Source: https://neko.m1k1o.net/docs/v3/reverse-proxy-setup (checked 2026-10-03)
  # Source: https://neko.m1k1o.net/docs/v3/customization/browsers (checked 2026-10-03)
  # Changed: Removed the documented '8080:8080' port; Caddy reaches neko:8080 on the proxy network.
  #          WebRTC uses the WebRTC page's other documented mode, UDP/TCP multiplexing, instead of the file's ephemeral range: NEKO_WEBRTC_EPR 52000-52100 with 101 published UDP ports becomes NEKO_WEBRTC_UDPMUX and NEKO_WEBRTC_TCPMUX on port 52000, published as 52000/udp and 52000/tcp. One port serves every viewer, so there is one port to open instead of 101.
  #          The example passwords (neko for users, admin for admins) are generated values in .env.
  #          NEKO_WEBRTC_NAT1TO1: <your-IP> is left out: without it, the WebRTC page says, Neko resolves the server's public address by itself. Set it to the server's LAN address if you use Neko only at home (Quick Start).
  #          NEKO_SERVER_PROXY=true is added, the Reverse Proxy page's server.proxy, so Neko trusts X-Forwarded-For and X-Real-IP from the proxy.
  #          The file's commented-out profile volume is switched on: ./profile at /home/neko/.mozilla/firefox/profile.default keeps bookmarks, settings, extensions and history when the container is recreated.
  # PORT OUTSIDE THE PROXY 52000/udp: the video, sound and input of the remote browser, all viewers multiplexed on one UDP port (NEKO_WEBRTC_UDPMUX). WebRTC is not HTTP, so it cannot go through the proxy (the WebRTC page: "it is not possible to use nginx or other reverse proxies to forward the WebRTC traffic"); the port must be published unchanged.
  # PORT OUTSIDE THE PROXY 52000/tcp: the same WebRTC traffic over TCP (NEKO_WEBRTC_TCPMUX), the fallback the WebRTC page recommends for networks that block UDP. Not HTTP either, so it is published beside the proxy, unchanged.
  neko:
    image: "ghcr.io/m1k1o/neko/firefox:latest"
    container_name: "neko"
    restart: "unless-stopped"
    shm_size: "2gb"
    volumes:
      - "./neko/profile:/home/neko/.mozilla/firefox/profile.default"
    environment:
      NEKO_WEBRTC_UDPMUX: "52000"
      NEKO_WEBRTC_TCPMUX: "52000"
      NEKO_DESKTOP_SCREEN: "1920x1080@30"
      NEKO_MEMBER_MULTIUSER_USER_PASSWORD: "${NEKO_USER_PASSWORD}"
      NEKO_MEMBER_MULTIUSER_ADMIN_PASSWORD: "${NEKO_ADMIN_PASSWORD}"
      NEKO_SERVER_PROXY: "true"
    ports:
      - "52000:52000/udp"  # WebRTC over UDP
      - "52000:52000/tcp"  # WebRTC over TCP
    networks:
      proxy: {}

networks:
  # Pinned so the trusted-proxy address given to each app (172.30.0.2) is exact.
  # If "docker compose up" reports "Pool overlaps", change 172.30.0 here, in Caddy's
  # ipv4_address and in every trusted-proxy value to a free 172.x.0 range.
  proxy:
    ipam:
      config:
        - subnet: "172.30.0.0/24"
          ip_range: "172.30.0.128/25"
          gateway: "172.30.0.1"

volumes:
  caddy-data:
  caddy-config:

Caddyfile save as caddy/Caddyfile

Caddy gets and renews the HTTPS certificate for neko.example.org by itself once the DNS record points at your server and ports 80 and 443 reach it.

# Caddyfile built at dankhost.com. Save it as ./caddy/Caddyfile next to docker-compose.yml.
# Caddy gets and renews a Let's Encrypt certificate for each name below by itself,
# once the DNS records point at this server and ports 80 and 443 reach it.

# Neko
neko.example.org {
	reverse_proxy neko:8080
}

Already running nginx, Nginx Proxy Manager, Caddy or Traefik? The reverse-proxy settings Neko needs, for all four, each cited to Neko's own docs.

.env

The secrets are left blank here on purpose: a password printed on a public page is the same for everyone who copies it. The builder fills them with random letters and digits made in your browser.

# .env for Neko, from dankhost.com/app/neko/. Fill the blank secrets before starting.
# Keep this file private (chmod 600).

# Neko
# 20 random letters and digits: the builder fills this in your browser
NEKO_USER_PASSWORD=
# 24 random letters and digits: the builder fills this in your browser
NEKO_ADMIN_PASSWORD=

What Neko needs beyond the proxy

Every other app in the builder is reached only through the proxy on ports 80 and 443. Neko also needs these ports on the server itself, because they carry traffic that is not HTTP. The compose file labels each with a # PORT OUTSIDE THE PROXY comment.

• 52000:52000/udp (WebRTC over UDP): the video, sound and input of the remote browser, all viewers multiplexed on one UDP port (NEKO_WEBRTC_UDPMUX). WebRTC is not HTTP, so it cannot go through the proxy (the WebRTC page: "it is not possible to use nginx or other reverse proxies to forward the WebRTC traffic"); the port must be published unchanged.
• 52000:52000/tcp (WebRTC over TCP): the same WebRTC traffic over TCP (NEKO_WEBRTC_TCPMUX), the fallback the WebRTC page recommends for networks that block UDP. Not HTTP either, so it is published beside the proxy, unchanged.
• Port 52000 (UDP, and TCP as the fallback) must reach this server from every viewer. For viewers outside your home, forward both on your router or open them in the VPS firewall; without them the page loads but the picture stays black.

Changes from the official file

Besides prefixing every service, container, volume, folder and variable with neko (so any set of apps can share one file), these are all the differences from what the project documents:

• Removed the documented '8080:8080' port; Caddy reaches neko:8080 on the proxy network.
• WebRTC uses the WebRTC page's other documented mode, UDP/TCP multiplexing, instead of the file's ephemeral range: NEKO_WEBRTC_EPR 52000-52100 with 101 published UDP ports becomes NEKO_WEBRTC_UDPMUX and NEKO_WEBRTC_TCPMUX on port 52000, published as 52000/udp and 52000/tcp. One port serves every viewer, so there is one port to open instead of 101.
• The example passwords (neko for users, admin for admins) are generated values in .env.
• NEKO_WEBRTC_NAT1TO1: <your-IP> is left out: without it, the WebRTC page says, Neko resolves the server's public address by itself. Set it to the server's LAN address if you use Neko only at home (Quick Start).
• NEKO_SERVER_PROXY=true is added, the Reverse Proxy page's server.proxy, so Neko trusts X-Forwarded-For and X-Real-IP from the proxy.
• The file's commented-out profile volume is switched on: ./profile at /home/neko/.mozilla/firefox/profile.default keeps bookmarks, settings, extensions and history when the container is recreated.

Notes for Neko behind the proxy

• Open https://neko.example.org and log in with any display name and NEKO_USER_PASSWORD from .env (NEKO_ADMIN_PASSWORD gives admin rights: kick users, lock the room).
• Before the first start run sudo mkdir -p ./neko/profile && sudo chown -R 1000:1000 ./neko/profile: the Browsers page says the neko user (uid 1000) must own the profile folder.
• The profile alone does not keep you logged in: Neko's default Firefox policy clears cookies and sessions on shutdown. The Browsers page shows the policy change that allows persistent data.
• If the picture stays black, port 52000 is not reachable or the wrong address is announced: check the firewall, then set NEKO_WEBRTC_NAT1TO1 to the address viewers can reach.

Back it up

Neko publishes no backup procedure. With the profile volume it keeps one folder: the Firefox profile. Without it nothing survives a restart, by design.

Below is the BACKUP.md the builder writes next to the compose file above: which of its folders and volumes hold data, what to copy with which container stopped, and a restore check. Pick more apps in the builder and it covers them all in one file.

# BACKUP.md built at dankhost.com for: Neko

What to copy from the docker-compose.yml built with this file, the database dump each project documents (rewritten for the service names in that file), what to copy with which container stopped, and how to check the result. Run every command in the folder that holds docker-compose.yml.

The folders are owned by the containers' users: put sudo in front of tar if it says "Permission denied". Named volumes live under /var/lib/docker/volumes, not next to the compose file, so they are copied through a throwaway ubuntu container (Docker's documented --volumes-from method). tar makes a full copy each run; for large folders an incremental tool (restic, borg, rsync) saves time and space.

Never run "docker compose down -v" on this file: it deletes the named volumes of every app in it.

## Before you start

    BACKUP=/mnt/backup/selfhost   # change this: a disk or machine other than this server's system disk
    mkdir -p "$BACKUP"

## Every time: the three stack files

    tar czf "$BACKUP/stack-files.tar.gz" docker-compose.yml .env caddy

.env holds the database passwords and secret keys the apps were set up with; keep this archive as private as the data.

## Caddy (the reverse proxy)

Caddy's docs: 'The data directory must not be treated as a cache.' It holds the TLS certificates and their private keys; without it Caddy has to ask Let's Encrypt for every certificate again.

- caddy-data (named volume, /data in caddy)
  BACK UP: TLS certificates, private keys, OCSP staples.
- caddy-config (named volume, /config in caddy)
  SKIP: the last active configuration, kept for 'caddy run --resume', which this setup does not use: it starts from the Caddyfile.
- ./caddy (/etc/caddy in caddy)
  IN stack-files.tar.gz: the Caddyfile, copied with the stack files above.

Copy (Caddy keeps serving while you copy):

    docker run --rm --volumes-from caddy -v "$BACKUP":/backup ubuntu tar cvf /backup/caddy-data.tar /data

Restore check:

    tar tf "$BACKUP/caddy-data.tar" > /dev/null && echo OK
    docker run --rm --volumes-from caddy -v "$BACKUP":/backup ubuntu bash -c "cd /data && tar xvf /backup/caddy-data.tar --strip 1"

Sources:
- Caddy docs: Conventions, Data directory: https://caddyserver.com/docs/conventions#data-directory (checked 2026-09-24)
- Docker docs: Volumes, Back up, restore, or migrate data volumes: https://docs.docker.com/engine/storage/volumes/#back-up-restore-or-migrate-data-volumes (checked 2026-09-24)

## Neko

Neko publishes no backup procedure. With the profile volume it keeps one folder: the Firefox profile. Without it nothing survives a restart, by design.

What this compose mounts:
- ./neko/profile (/home/neko/.mozilla/firefox/profile.default in neko)
  BACK UP: Firefox's profile: bookmarks, settings, extensions, history and (if the policy allows it) cookies and saved logins.

1. Stop neko. Firefox keeps its profile databases open while it runs; stopping Neko first gives a consistent copy.

    docker compose stop neko

2. Copy while neko is stopped:

    tar czf "$BACKUP/neko-profile.tar.gz" ./neko/profile

3. Start it again:

    docker compose start neko

Restore check:

    tar tzf "$BACKUP/neko-profile.tar.gz" > /dev/null && echo OK

Put a copy back (with neko stopped):

    tar xzf "$BACKUP/neko-profile.tar.gz"   # recreates ./neko/profile; move the old folder aside first

Stop it, put ./neko/profile back (owned by 1000:1000), start it.

Sources:
- Neko docs: Browsers (persistent profile at /home/neko/.mozilla/firefox/profile.default, uid 1000, policies): https://neko.m1k1o.net/docs/v3/customization/browsers (checked 2026-10-03)
- Docker docs: Volumes, Back up, restore, or migrate data volumes: https://docs.docker.com/engine/storage/volumes/#back-up-restore-or-migrate-data-volumes (checked 2026-10-03)

Update it

What docker compose pull does depends only on how each image line in the compose file above is tagged. For Neko as this page writes it:

What Neko's docs say about updating

Neko publishes no update procedure for this setup; the steps below are Docker's generic method.

The steps

1. Back up first, as in Back it up above. An update can migrate Neko's data on its first start; the copy is the way back.
2. Download the new images. Running containers are not touched yet:

   docker compose pull

3. Recreate the containers whose image changed. Volumes and bind-mounted folders stay as they are:

   docker compose up -d

4. Watch Neko start (Ctrl+C stops following the log, not the app):

   docker compose logs -f neko

5. Optional: remove the old images the pull left without a tag. This covers every stack on the machine, not only this one:

   docker image prune

Docker's reference for these commands: Docker docs: docker compose pull checked 2026-09-30; Docker docs: docker compose up (recreates changed containers, keeps volumes) checked 2026-09-30; Docker docs: docker image prune checked 2026-09-30

Sources

Every page below was fetched on the date shown.

• Neko on GitHub (repository description) checked 2026-10-03 (what it does)
• Neko: docker-compose.yaml (Firefox image, shm_size 2gb, port 8080, UDP 52000-52100) checked 2026-10-03 (compose definition and proxy settings)
• Neko docs: Quick Start (download the compose file, NAT1TO1 on a local network) checked 2026-10-03 (compose definition and proxy settings)
• Neko docs: WebRTC Configuration (ephemeral UDP port range or UDP/TCP multiplexing, server IP address, no reverse proxy for WebRTC) checked 2026-10-03 (compose definition and proxy settings)
• Neko docs: Reverse Proxy Setup (server.proxy, WebSocket, Nginx and Caddy examples) checked 2026-10-03 (compose definition and proxy settings)
• Neko docs: Browsers (persistent profile at /home/neko/.mozilla/firefox/profile.default, uid 1000, policies) checked 2026-10-03 (compose definition and proxy settings, backup plan)
• Caddy docs: Keep Caddy running (Docker Compose section) checked 2026-09-23 (Caddy)
• Vaultwarden wiki: Caddy with HTTP challenge (uses the caddy:2 image) checked 2026-09-23 (Caddy)
• Docker docs: Volumes, Back up, restore, or migrate data volumes checked 2026-10-03 (backup plan)
• Caddy docs: Conventions, Data directory checked 2026-09-24 (backup plan)
• Docker docs: docker compose pull checked 2026-09-30 (update steps)
• Docker docs: docker compose up (recreates changed containers, keeps volumes) checked 2026-09-30 (update steps)
• Docker docs: docker image prune checked 2026-09-30 (update steps)

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