SearXNG with Docker Compose

What SearXNG needs

Only figures SearXNG'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. SearXNG itself runs as 2 containers: searxng-core, searxng-valkey.

Which hardware SearXNG 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): every image has a build.

A manifest says an image exists for a CPU, not how well SearXNG 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 SearXNG 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 SearXNG alone on example.org: the official definition with its published ports removed and Caddy added in front. Every ${VARIABLE} is defined in the .env below.

# docker-compose.yml built at dankhost.com for: SearXNG
# 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.
# Only Caddy publishes ports. 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"

  # ---- SearXNG (search.example.org) ----
  # Source: https://docs.searxng.org/admin/installation-docker.html (checked 2026-09-30)
  # Source: https://github.com/searxng/searxng/blob/master/container/docker-compose.yml (checked 2026-09-30)
  # Source: https://docs.searxng.org/admin/settings/settings_server.html (checked 2026-09-30)
  # Source: https://docs.searxng.org/admin/settings/settings_valkey.html (checked 2026-09-30)
  # Source: https://github.com/searxng/searxng/blob/master/container/entrypoint.sh (checked 2026-09-30)
  # Changed: Removed the documented port line (${SEARXNG_PORT:-8080}:${SEARXNG_PORT:-8080}); Caddy reaches searxng-core:8080 on the proxy network. Valkey stays on SearXNG's own network, which has no internet access. The container names are the documented ones, searxng-core and searxng-valkey.
  #          The documented file reads its settings from env_file: ./.env. Here the three variables it needs are written under environment: instead, because this .env holds every app's variables: SEARXNG_SECRET (the server's secret_key, a generated value in .env), SEARXNG_BASE_URL (https://search.example.org/) and SEARXNG_VALKEY_URL, which points SearXNG at the valkey service of the same file (settings_valkey: url, $SEARXNG_VALKEY_URL).
  #          The bind folder ./core-config/ is written ./core-config (the trailing slash dropped); it is the same folder, still mounted at /etc/searxng/ with the documented :Z SELinux label.
  searxng-core:
    image: "docker.io/searxng/searxng:latest"
    container_name: "searxng-core"
    restart: "always"
    environment:
      SEARXNG_BASE_URL: "https://search.example.org/"
      SEARXNG_SECRET: "${SEARXNG_SECRET}"
      SEARXNG_VALKEY_URL: "valkey://valkey:6379/0"
    volumes:
      - "./searxng/core-config:/etc/searxng/:Z"
      - "searxng-core-data:/var/cache/searxng/"
    networks:
      proxy: {}
      searxng-backend:
        aliases:
          - "core"
  searxng-valkey:
    image: "docker.io/valkey/valkey:9-alpine"
    container_name: "searxng-valkey"
    command: "valkey-server --save 30 1 --loglevel warning"
    restart: "always"
    volumes:
      - "searxng-valkey-data:/data/"
    networks:
      searxng-backend:
        aliases:
          - "valkey"

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"
  searxng-backend:
    internal: true

volumes:
  caddy-data:
  caddy-config:
  searxng-core-data:
  searxng-valkey-data:

Caddyfile save as caddy/Caddyfile

Caddy gets and renews the HTTPS certificate for search.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.

# SearXNG
search.example.org {
	reverse_proxy searxng-core:8080
}

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

.env

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

# .env for SearXNG, from dankhost.com/app/searxng/. Fill the blank secret before starting.
# Keep this file private (chmod 600).

# SearXNG
# 64 random letters and digits: the builder fills this in your browser
SEARXNG_SECRET=

Changes from the official file

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

• Removed the documented port line (${SEARXNG_PORT:-8080}:${SEARXNG_PORT:-8080}); Caddy reaches searxng-core:8080 on the proxy network. Valkey stays on SearXNG's own network, which has no internet access. The container names are the documented ones, searxng-core and searxng-valkey.
• The documented file reads its settings from env_file: ./.env. Here the three variables it needs are written under environment: instead, because this .env holds every app's variables: SEARXNG_SECRET (the server's secret_key, a generated value in .env), SEARXNG_BASE_URL (https://search.example.org/) and SEARXNG_VALKEY_URL, which points SearXNG at the valkey service of the same file (settings_valkey: url, $SEARXNG_VALKEY_URL).
• The bind folder ./core-config/ is written ./core-config (the trailing slash dropped); it is the same folder, still mounted at /etc/searxng/ with the documented :Z SELinux label.

Notes for SearXNG behind the proxy

• On first start the container writes settings.yml into ./searxng/core-config from its template. Edit that file for engines, themes and plugins, then run docker compose restart searxng-core. The secret_key in it is overridden by SEARXNG_SECRET from .env.
• The limiter (bot protection, which needs Valkey) is off by default and meant for public instances. If you open this instance to everyone, set limiter: true (or SEARXNG_LIMITER=true) as the server: settings page describes.
• The docs' compose template uses the image tag 'latest' (SEARXNG_VERSION defaults to latest; the .env example shows a dated tag such as 2026.3.25-541c6c3cb for pinning).

Back it up

SearXNG publishes no backup procedure. It stores no searches: what is worth keeping is the configuration in /etc/searxng; the cache and Valkey data rebuild themselves.

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: SearXNG

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)

## SearXNG

SearXNG publishes no backup procedure. It stores no searches: what is worth keeping is the configuration in /etc/searxng; the cache and Valkey data rebuild themselves.

What this compose mounts:
- ./searxng/core-config (/etc/searxng in searxng-core)
  BACK UP: settings.yml and any limiter.toml or favicons.toml you add: your engines, theme and instance settings.
- searxng-core-data (named volume, /var/cache/searxng in searxng-core)
  SKIP: persistent cache such as faviconcache.db (the docs' example); rebuilt as people search.
- searxng-valkey-data (named volume, /data in searxng-valkey)
  SKIP: Valkey's snapshot of the limiter's counters; nothing SearXNG needs to start.

1. Copy (SearXNG keeps running):
   settings.yml only changes when you edit it, so the folder can be copied while SearXNG runs.

    tar czf "$BACKUP/searxng-core-config.tar.gz" ./searxng/core-config

Restore check:

    tar tzf "$BACKUP/searxng-core-config.tar.gz" > /dev/null && echo OK

Put a copy back (with SearXNG stopped):

    tar xzf "$BACKUP/searxng-core-config.tar.gz"   # recreates ./searxng/core-config; move the old folder aside first

Put ./searxng/core-config back and run docker compose up -d. Keep SEARXNG_SECRET in .env or signed preferences cookies stop matching.

Sources:
- SearXNG docs: Installation container (compose template, volumes, SEARXNG_* variables): https://docs.searxng.org/admin/installation-docker.html (checked 2026-09-30)
- 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 2026-09-30)

Sources

Every page below was fetched on the date shown.

• SearXNG README on GitHub checked 2026-09-30 (what it does)
• SearXNG docs: Installation container (compose template, volumes, SEARXNG_* variables) checked 2026-09-30 (compose definition and proxy settings, backup plan)
• SearXNG repository: container/docker-compose.yml (core and valkey services) checked 2026-09-30 (compose definition and proxy settings)
• SearXNG docs: settings.yml server: (secret_key as $SEARXNG_SECRET, base_url as $SEARXNG_BASE_URL, limiter) checked 2026-09-30 (compose definition and proxy settings)
• SearXNG docs: settings.yml valkey: (url as $SEARXNG_VALKEY_URL) checked 2026-09-30 (compose definition and proxy settings)
• SearXNG repository: container/entrypoint.sh (creates settings.yml from the template on first start) checked 2026-09-30 (compose definition and proxy settings)
• 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 2026-09-30 (backup plan)
• Caddy docs: Conventions, Data directory checked 2026-09-24 (backup plan)

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