sshd

Description

This Ansible role configures the OpenSSH daemon (sshd) by deploying a templated sshd_config file. It applies secure, best-practice settings to harden remote access and reduce the risk of misconfiguration or lockout. Settings include disabling root login, enforcing public-key authentication, and setting appropriate logging levels.

Overview

  • Renders sshd_config.j2 into /etc/ssh/sshd_config with customizable options

  • Sets file ownership (root:root) and permissions (0644)

  • Automatically reloads and restarts the SSH service via a systemd handler

  • Uses a run_once_sys_svc_sshd fact to ensure idempotent execution

Key variable: SYS_SVC_SSHD_PASSWORD_AUTHENTICATION (default: false) enables password authentication when explicitly required by controlled environments such as local E2E test targets.

Cosmos

The diagram places sshd in the Infinito.Nexus cosmos: the components it deploys (capabilities), the central services it consumes (dependencies), and its outward reach (federation and bridged external networks).

flowchart LR
    subgraph role [sys-svc-sshd 💻]
        svc_svc_sshd["svc-sshd"]
    end

Solid 1:1 edges are fixed relationships; dashed 0..1 edges are conditional (enabled only in matching deployments); red 0..0 edges are turned off in this role. Node markers show the role’s deploy modes (💻 host, 🐳 compose, 🐝 swarm); ❌ marks a service that is explicitly turned off, and ⚙️ an Ansible role dependency declared in meta/main.yml.

Features

  • Templated Configuration: Delivers a Jinja2-based sshd_config with variables for debug logging, PAM support, and password-auth overrides.

  • Security Defaults: Disables password authentication and root login; enforces public-key authentication; conditionally sets LogLevel to DEBUG3 when MODE_DEBUG is true.

  • Systemd Integration: Handles daemon reload and service restart seamlessly on configuration changes.

  • Idempotency: Ensures tasks run only once per play by setting the run_once_sys_svc_sshd fact.

Further Resources

Credits

Implemented by Kevin Veen-Birkenbach. Part of the Infinito.Nexus Project and maintained by Kevin Veen-Birkenbach. Licensed under the Infinito.Nexus Community License (Non-Commercial).