partial compose.yaml backup strategy

compose.yaml

services:
  backup:
    build:
      context: .
      dockerfile: Containerfile.restic
    command: "restic backup /data"
    deploy:
      replicas: 0
    environment:
      RESTIC_PASSWORD: snip
      RESTIC_REPOSITORY: sftp://backup/
    volumes:
    - ./config/restic/ssh_config:/root/.ssh/config:ro
    - ./config/restic/id_restic:/root/.ssh/id_ed25519:ro
    - ./config/restic/ssh_known_hosts:/root/.ssh/known_hosts
    - pg:/data/pg
    - caddy-data:/data/caddy-data
    - caddy-config:/data/caddy-config
    - synapse:/data/synapse
    - mautrix-telegram:/data/mautrix-telegram
    - mautrix-discord:/data/mautrix-discord
    - mautrix-signal:/data/mautrix-signal
    - signald:/data/signald
    - prometheus:/data/prometheus
    - grafana:/data/grafana
    - .:/data/self:ro

Containerfile.restic

# syntax=docker/dockerfile:1
FROM alpine:3.18

RUN apk add restic openssh