Using Docker Compose

Docker Compose is a tool that allows the definition and configuration of multi-container applications. In our case, we want both the vaultwarden server and a proxy to redirect the WebSocket requests to the correct place.

Caddy with HTTP challenge

This example assumes that you have installed Docker Compose, that you have a domain name (e.g., vaultwarden.example.com) for your vaultwarden instance, and that it will be publicly accessible.

⚠️ Docker Compose might be run as docker-compose <command> ... (with a dash) or docker compose <command> ... (with a space), depending on how you have installed Docker Compose. docker-compose is the original syntax, when Docker Compose was distributed as a standalone executable. You can still choose to do a standalone installation, in which case you would continue to use this syntax. However, Docker currently recommends installing Docker Compose as a Docker plugin, where compose becomes a subcommand of docker, making the syntax docker compose <command> ....

Start by making a new directory and changing into it. Next, create the docker-compose.yml below, making sure to substitute appropriate values for the DOMAIN and EMAIL variables.

version: '3'

services:
  vaultwarden:
    image: vaultwarden/server:latest
    container_name: vaultwarden
    restart: always
    environment:
      DOMAIN: "https://vaultwarden.example.com"  # Your domain; vaultwarden needs to know it's https to work properly with attachments
    volumes:
      - ./vw-data:/data

  caddy:
    image: caddy:2
    container_name: caddy
    restart: always
    ports:
      - 80:80  # Needed for the ACME HTTP-01 challenge.
      - 443:443
    volumes:
      - ./Caddyfile:/etc/caddy/Caddyfile:ro
      - ./caddy-config:/config
      - ./caddy-data:/data
    environment:
      DOMAIN: "https://vaultwarden.example.com"  # Your domain.
      EMAIL: "admin@example.com"                 # The email address to use for ACME registration.
      LOG_FILE: "/data/access.log"

In the same directory, create the Caddyfile below. (This file does not need to be modified.)

{$DOMAIN}:443 {
  log {
    level INFO
    output file {$LOG_FILE} {
      roll_size 10MB
      roll_keep 10
    }
  }

  # Use the ACME HTTP-01 challenge to get a cert for the configured domain.
  tls {$EMAIL}

  # This setting may have compatibility issues with some browsers
  # (e.g., attachment downloading on Firefox). Try disabling this
  # if you encounter issues.
  encode gzip

  # Proxy everything Rocket
  reverse_proxy vaultwarden:80 {
       # Send the true remote IP to Rocket, so that vaultwarden can put this in the
       # log, so that fail2ban can ban the correct IP.
       header_up X-Real-IP {remote_host}
  }
}

Run

docker compose up -d  # or `docker-compose up -d` if using standalone Docker Compose

to create and start the containers. A private network for the services in this docker-compose.yml file will be created automatically, with only Caddy being publicly exposed.

docker compose down  # or `docker-compose down` if using standalone Docker Compose

stops and destroys the containers.

A similar Caddy-based example for Synology is available here.

Caddy with DNS challenge

This example is the same as the previous one, but for the case where you don't want your instance to be publicly accessible (i.e., you can access it only from your local network). This example uses Duck DNS as the DNS provider. Refer to Running a private vaultwarden instance with Let's Encrypt certs for more background, and details on how to set up Duck DNS.

Start by making a new directory and changing into it. Next, create the docker-compose.yml below, making sure to substitute appropriate values for the DOMAIN and EMAIL variables.

version: '3'

services:
  vaultwarden:
    image: vaultwarden/server:latest
    container_name: vaultwarden
    restart: always
    environment:
      DOMAIN: "https://vaultwarden.example.com"  # Your domain; vaultwarden needs to know it's https to work properly with attachments
    volumes:
      - ./vw-data:/data

  caddy:
    image: caddy:2
    container_name: caddy
    restart: always
    ports:
      - 80:80
      - 443:443
    volumes:
      - ./caddy:/usr/bin/caddy  # Your custom build of Caddy.
      - ./Caddyfile:/etc/caddy/Caddyfile:ro
      - ./caddy-config:/config
      - ./caddy-data:/data
    environment:
      DOMAIN: "https://vaultwarden.example.com"  # Your domain.
      EMAIL: "admin@example.com"                 # The email address to use for ACME registration.
      DUCKDNS_TOKEN: "<token>"                   # Your Duck DNS token.
      LOG_FILE: "/data/access.log"

The stock Caddy builds (including the one in the Docker image) don't include the DNS challenge modules, so next you'll need to get a custom Caddy build. Rename the custom build as caddy and move it under the same directory as docker-compose.yml. Make sure the caddy file is executable (e.g., chmod a+x caddy). The docker-compose.yml file above bind-mounts the custom build into the caddy:2 container, replacing the stock build.

In the same directory, create the Caddyfile below. (This file does not need to be modified.)

{$DOMAIN}:443 {
  log {
    level INFO
    output file {$LOG_FILE} {
      roll_size 10MB
      roll_keep 10
    }
  }

  # Use the ACME DNS-01 challenge to get a cert for the configured domain.
  tls {
    dns duckdns {$DUCKDNS_TOKEN}
  }

  # This setting may have compatibility issues with some browsers
  # (e.g., attachment downloading on Firefox). Try disabling this
  # if you encounter issues.
  encode gzip

  # Proxy everything to Rocket
  reverse_proxy vaultwarden:80
}

As with the HTTP challenge example, run

docker compose up -d  # or `docker-compose up -d` if using standalone Docker Compose

to create and start the containers.