Docker

Overview

Self-Hosted SimpleLogin runs on Docker.

Dependencies

The containers run in the following dependency tree:

├─ postgres
|  └─ migration
│     └─ init
│        └─ app
│           └─ traefik-certificate-exporter
│              └─ postfix
│                 └─ email
│                    └─ job_runner
├─ dns
|  └─ postfix
└─ traefik

It could be argued that postfix depends on email to process incoming messages, whereas email depends on postfix to process outgoing and forwarded messages.

For simplicify, this setup makes sure that the email handler only starts when postfix is running. On the other hand, the postfix container runs a healthcheck task to periodically check that the email handler is running. This ensures both services can safely rely on one another.

Likewise, postfix uses the pgsql-relay-domains.cf and pgsql-transport-maps.cf configuration as part of its configuration.

This means postfix needs postgres to run and be healthy, which this setup implicitly ensures. This project enforces strong dependency (not shown in the tree) by explicitly added the following directive in postfix-compose.yaml:

  postfix:
    image: private/postfix:latest
    …
    depends_on:
      dns:
        condition: service_healthy
+     postgres:
+       condition: service_healthy
      traefik-certificate-exporter:
        condition: service_healthy