infra/AGENTS.md

# AGENTS.md
Guidance for coding agents working in this repository.
Project type: Ansible-driven infrastructure, workstation/server provisioning, and user dotfiles.

## Repository Map
- Entry playbook: `ansible/site.yml`
- Inventory: `ansible/inventory/hosts.yml`
- Group vars: `ansible/inventory/group_vars/*.yml`
- Host vars: `ansible/inventory/host_vars/*.yml`
- Roles: `ansible/roles/*`
- Role assets: `ansible/roles/*/{tasks,templates,files,handlers}/`
- Templates: `ansible/templates/**/*.j2`
- Dotfiles: `dotfiles/`
- Scripts: `scripts/`
- Secrets: `secrets/`

## Topology And Orchestration
- Void desktops: `ikaros`, `nymph`
- Ubuntu workstation: `deadalus`
- Ubuntu server: `prometheus`
- Most hosts use `ansible_connection: local`
- `all -> dotfiles_common`
- `void -> packages_void, services_runit, profile_desktop_common, profile_desktop_i3, profile_desktop_hyprland, profile_desktop_host`
- `ubuntu_workstation -> packages_ubuntu, services_systemd, profile_workstation_gnome`
- `ubuntu_server -> packages_ubuntu, services_systemd, profile_server`
- Present but unwired roles: `base`, `dotfiles`

## Local Instruction Files
Checked when this file was updated:
- `.cursorrules`: not present
- `.cursor/rules/`: not present
- `.github/copilot-instructions.md`: not present
If any appear later, treat them as higher-priority repo-local instructions.

## Working Principles
- Preserve the layering: `all -> OS -> profile -> host`
- Prefer minimal, targeted edits over broad cleanup
- Preserve idempotency and reproducibility
- Validate on one limited host before broad rollout
- Treat `secrets/` as sensitive; never print secret values
- Avoid editing vendored code under `dotfiles/common/.tmux/plugins/` unless explicitly asked
- Keep `ansible/site.yml` small; orchestration belongs there, implementation belongs in roles

## Build, Lint, And Test Commands
There is no compile/build pipeline. Confidence comes from syntax checks, dry runs, linting, and targeted script validation.

Install tooling if needed:
```bash
python3 -m pip install ansible ansible-lint yamllint
ansible-galaxy collection install community.general
```

Core validation:
```bash
ansible-playbook ansible/site.yml --syntax-check
ansible-playbook ansible/site.yml --limit ikaros --check --diff
ansible-playbook ansible/site.yml --limit nymph --check --diff
ansible-playbook ansible/site.yml --limit deadalus --check --diff
ansible-playbook ansible/site.yml --limit prometheus --check --diff
ansible-lint ansible/site.yml
ansible-lint ansible/roles
yamllint ansible/
```

Useful execution commands:
```bash
ansible-playbook ansible/site.yml
ansible-playbook ansible/site.yml --limit ikaros
ansible-playbook ansible/site.yml --limit nymph
ansible-playbook ansible/site.yml --limit deadalus
scripts/bootstrap_mail.sh
```

## Single-Test Equivalents
There is no pytest, Molecule, or unit-test suite. Use the narrowest command matching the changed area.
- Playbook syntax only: `ansible-playbook ansible/site.yml --syntax-check`
- Single host dry run: `ansible-playbook ansible/site.yml --limit <host> --check --diff`
- Single task restart point: `ansible-playbook ansible/site.yml --limit <host> --start-at-task "<task name>" --check --diff`
- Single role lint: `ansible-lint ansible/roles/<role>`
- Script syntax/lint: `sh -n scripts/bootstrap_mail.sh` and `shellcheck scripts/bootstrap_mail.sh`
- Prefer one limited-host dry run for vars, templates, dotfiles, packages, services, PAM, display manager, and firewall changes

## Code Style Guidelines
### General
- Keep orchestration in playbooks and implementation in roles
- Prefer declarative modules over imperative shell commands
- Make state transitions explicit
- Avoid unrelated refactors in the same change
- Keep comments sparse and only for non-obvious behavior

### YAML And Formatting
- Start YAML files with `---`
- Use 2-space indentation; never use tabs
- Keep existing ordering stable when editing lists and maps
- Quote file modes as strings such as `"0644"`, `"0755"`, `"0600"`, `"0700"`
- Avoid formatting-only churn in untouched sections

### Modules And Task Structure
- Use FQCN module names such as `ansible.builtin.copy` and `community.general.xbps`
- Prefer dedicated modules over `ansible.builtin.command` or `ansible.builtin.shell`
- Use `command` only when no module fits; use `shell` only for shell features
- When using `command` or `shell`, set `changed_when` and `failed_when` when defaults are misleading
- Keep task names imperative, descriptive, and stable enough for `--start-at-task`
- Tag tasks consistently with existing families such as `packages`, `services`, `dotfiles`, `gnome`, `nvidia`, `emptty`, and `dotfiles:*`
- Prefer `loop` with `loop_control.label` for multi-item tasks
- Use handlers for service restarts when configuration changes should trigger them

### Variables, Types, And Naming
- Use `snake_case` for vars, facts, and registered values
- Follow existing families such as `common_packages`, `profile_packages`, `host_packages`, `desktop_common_packages`, `desktop_i3_packages`, `desktop_hyprland_packages`, `desktop_common_dotfiles`, `desktop_i3_dotfiles`, `desktop_hyprland_dotfiles`, `host_i3_dotfiles`, `host_hyprland_dotfiles`, `enabled_services`, and `host_enabled_services`
- Keep booleans as booleans, not quoted strings
- Keep structured values as YAML lists/maps, not comma-separated strings
- Guard optional lists with `default([])`, mappings with `default({})`, and strings with `default('')`
- Build managed-user paths from `{{ user_home }}` where applicable
- Put host-specific overrides in `host_vars`, not shared `group_vars`

### Templates, Dotfiles, And Shell
- Keep secrets parameterized through vars; never hardcode them in templates
- Prefer role `templates/` for variable-driven config and role `files/` for static payloads
- Preserve destination paths and permissions unless the task requires a change
- Dotfiles should stay deployable on real machines; avoid repo-only hacks in `dotfiles/`
- Prefer POSIX `sh` for simple scripts; use Bash only when needed
- Use `set -eu` in POSIX shell scripts unless there is a clear reason not to
- Quote variable expansions unless intentional splitting is required

### Error Handling And Safety
- Fail early with `ansible.builtin.fail` when prerequisites are missing
- Guard OS-specific, DE-specific, and host-specific behavior with `when`
- Use `no_log: true` for passwords, tokens, and secret-bearing command results
- Use `failed_when: false` only for intentional probes
- Keep tasks non-interactive unless explicitly user-driven
- Avoid destructive changes in user homes unless clearly required
- For firewall changes, allow required access before enabling the firewall
- Be careful with display-manager/session changes on desktop hosts; validate on one host first

## Area-Specific Notes
- `profile_desktop_common` manages `emptty` and the shared Void desktop bootstrap; `profile_desktop_i3` adds the X11/i3 session; `profile_desktop_hyprland` adds the optional Wayland session on hosts that enable it; `profile_desktop_host` carries host-specific desktop overrides such as NVIDIA or host session dotfiles
- Do not auto-restart `emptty` during playbook runs on active desktop hosts; prefer a manual restart from SSH or another TTY after the run
- `dotfiles/desktop/.xinitrc` is part of the X11 session bootstrap path; changes there affect login behavior
- `dotfiles/desktop/.local/bin/start-hyprland-session` is the Wayland session bootstrap path; keep it aligned with DBus and keyring expectations
- `nymph` has special NVIDIA/PRIME handling; keep host-specific logic guarded by hostname or host vars
- `ikaros` is treated as the more stable personal desktop; prefer validating risky desktop changes elsewhere first

## Validation Expectations Before Finishing
Default minimum:
```bash
ansible-playbook ansible/site.yml --syntax-check
```
If you touched `scripts/bootstrap_mail.sh`, also run:
```bash
sh -n scripts/bootstrap_mail.sh
shellcheck scripts/bootstrap_mail.sh
```

## Agent Workflow Expectations
- Read the relevant inventory, vars, role tasks, templates, files, handlers, and dotfiles before editing
- Do not revert unrelated worktree changes made by the user
- Keep `README.md` and `AGENTS.md` aligned when workflows materially change
- If you add a new operational area, also add the validation command agents should run
- Prefer host-limited validation first, especially `ikaros` or `nymph` for Void desktop work, `deadalus` for Ubuntu workstation work, and `prometheus` for server work
- Call out checks you could not run and any follow-up verification needed