Operate Vaultwarden with a local IP address.

[mememet]

This sentence just wrote "This is possible".
This is "my method" without any processing, Change it to suit your environment.
VW runs on Docker (docker-compose) on the Linux OS.

SSL is always required, so create a certificate.

Create a myconfig.conf file with the following contents.

# mkdir ssl
# cd ssl

myconfig.conf:

[req]
distinguished_name  = req_distinguished_name
x509_extensions     = v3_req
prompt              = no
string_mask         = utf8only
 
[req_distinguished_name]
C                   = JP
ST                  = Tokyo
L                   = Shinjuku-ku
O                   = vaultwarden.local
OU                  = Vaultwarden
CN                  = 10.0.0.209
 
[v3_req]
keyUsage            = nonRepudiation, digitalSignature, keyEncipherment
extendedKeyUsage    = serverAuth
subjectAltName      = @alt_names
 
[alt_names]
DNS.1               = vaultwarden.local
IP.1                = 10.0.0.209

Create the actual certificate.

# openssl req -x509 -nodes -days 18250 -newkey rsa:4096 -keyout mycert.key -out mycert.crt -config myconfig.conf

Copy the mycert.crt file and install it on your OS or browser.
For Windows OS, install it as a "Trusted Root Certificate Authority". (Requires a browser restart.)

Create a docker-compose.yml with:

services:
  vaultwarden:
    image: vaultwarden/server:testing-alpine
    container_name: vaultwarden
    restart: unless-stopped
    environment:
      DOMAIN: "https://10.0.0.209"
      SIGNUPS_ALLOWED: true
      ROCKET_TLS: '{certs="/ssl/mycert.crt", key="/ssl/mycert.key"}'
      ADMIN_TOKEN: "testtoken"
      TZ: "Asia/Tokyo"
      EXPERIMENTAL_CLIENT_FEATURE_FLAGS: "fido2-vault-credentials,ssh-key-vault-item,ssh-agent,inline-menu-totp,export-attachments"
      ORG_EVENTS_ENABLED: true
      EXTENDED_LOGGING: true
      LOG_LEVEL: debug
      LOG_FILE: /data/vaultwarden.log
    volumes:
      - ./vw-data:/data
      - ./ssl:/ssl
    ports:
      - 443:80

Start VW.

# docker-compose up -d

Access the https://10.0.0.209 in your browser.

That's it.
I hope it helps people who don't have a domain.

[maxdd]

does it work from android? Shall i install the certificate?