fitme3070.pt/shared/platform-tools/PHILOSOPHY.md

How the andmore platforms are built

Seven sites — dance, design, fotografia, hub2, mstudio, quack, silver — share one VPS, one MariaDB, one reverse proxy, and this submodule. They are separate products with separate databases, but they are built the same way on purpose, so that knowing one means knowing all seven.

Two of them are worth naming as special cases, because they are the shape the conventions have to survive: mstudio is a second instance of fotografia's platform under different branding, and quack is a classroom game that grew up outside this submodule and was brought in later. Where this document says "every site", those two are included — that is the point of them.

This document records the reasoning behind that shape. It is descriptive, not aspirational: everything here is a decision already visible in the code. When a choice below stops being true, change the code or change this file — a convention nobody follows is worse than no convention.

---

1. Plain PHP, no framework, no build step

PHP 8.4 with PDO, server-side rendering, Bootstrap 5. Composer is used for autoloading and real libraries; there is no bundler, no transpiler, no node_modules in production.

The reason is maintenance horizon. These are small products that must keep working for years with long idle stretches between changes. A build step is a second thing that can rot — toolchain versions, lockfiles, a CI runner — and it rots silently while the site still appears fine. Editing a .php file and reloading is a workflow that cannot break.

The cost is real and accepted: no type checking beyond PHP's own, no component model, more repetition in templates. That trade is worth it at this size and would not be at ten times the size.

2. Comments explain why, never what

The code is unusually densely commented, and almost none of it restates the line below. A comment earns its place by recording something the reader cannot recover from the code: a constraint, a rejected alternative, a bug that a previous version had.

// MariaDB does not read cgroup limits -- without this it sizes its buffer
// pool against all 7.8GB of host RAM and then gets OOM-killed by mem_limit.
- --innodb-buffer-pool-size=1G

That comment is worth more than the line it sits above, because the line looks arbitrary without it and someone will eventually "clean it up".

Where a decision is a knowing compromise, it is labelled as one. The site containers mount their own source read-write so the backoffice updater can run git pull, and the compose file says so under an ACCEPTED RISK heading naming the exact exposure. A documented risk is a decision; an undocumented one is an accident waiting to be discovered by someone else.

3. Shared code lives here, once

Anything two platforms both need moves into platform-tools and is consumed as a git submodule. Edit one file, every platform gets it.

The failure mode this exists to prevent is genuine and has already happened: three sites independently grew their own AES-256-GCM secret helpers with three different key derivations, all writing the same enc:v1: prefix, all mutually unreadable, and nothing surfaced the divergence until something tried to read across sites. Copies do not stay identical. They stay similar, which is worse, because similar code invites the assumption that it is the same.

The corollary: a site must not reimplement something this submodule provides. If the shared version is wrong for one site, fix it here with a parameter, or say plainly in the site's own docs why it deviates.

Submodules have one sharp edge worth stating: git pull in a site advances the submodule pointer but leaves its working tree on the old commit, silently and with no error. Every deploy script therefore runs git submodule update --init --recursive as a separate, mandatory step.

4. Configuration has two homes, and a rule for choosing

.env for anything needed to reach or decrypt the database, or to repair the site when it is broken. The system_settings table for anything an operator should be able to change without shell access.

The test: can the system read this after a cold start with an empty database, and would I still need it if the app were broken?

This is why DB_* and APP_SECRET_KEY can never move to the database — the first is needed to reach it, the second to decrypt it. And it is why GIT_HTTP_TOKEN and HUB_OPS_SECRET stay in .env by choice rather than necessity: they are the credentials used to repair a platform, and a repair channel must not depend on the thing it repairs.

Full precedence rules and the secret-encryption contract are in README.md.

5. Secrets are encrypted at rest, because backups exist

The nightly job keeps many copies of each database. A plaintext SMTP password would therefore sit in every one of them, and the backups live on disk next to everything else. So secret-valued settings are encrypted, and the key lives only in .env — never in the database, never in git. A leaked dump alone is not enough to recover credentials.

Each platform keeps its own APP_SECRET_KEY. A secret encrypted on hub2 deliberately does not decrypt on dance: one compromised dump must not unlock the estate.

Which keys count as secret is decided centrally, by name, in platform_settings_is_secret() — never by the calling page. The previous arrangement had each site keeping its own list, and a credential added later on a different screen was simply missed.

6. Authentication is mechanism, not policy

Sessions, password hashing, login throttling, guards and password recovery live in functions_auth.php and functions_password_reset.php. None of it contains business logic, so there was never a reason for one version per site — and the separate versions had exactly the drift you would expect. dance ran a bare session_start() with no HttpOnly, no SameSite and no strict mode, never rotated the session id on login, kept the password hash in $_SESSION, and accepted unlimited login attempts. The other three had each solved some of that, separately.

Two things stay per-site, deliberately:

• The users table. The columns genuinely differ — fotografia's users carry CalDAV credentials, silver's carry a guardian. The shared code adapts through auth_schema() rather than demanding one shape, because renaming a column with 147 references is a migration and adapting is a function call.

  The same map covers what you sign in with. Six sites match on email; quack matches on username and keeps email as the address recovery mails to, so auth_schema() carries a login key separate from email. It defaults to null, meaning "same as email" — a site that never thought about it gets the behaviour it already had.

• The roles. sysadmin, admin and user are common and mean the same everywhere. Past that the vocabulary is the product's: teacher, student, parent, staff, client, formador, aluno. A site registers its own with a rank, so auth_at_least('admin') works without anyone hardcoding a list, and an unrecognised role ranks zero — a typo can never grant access.

Password recovery goes out over the same SMTP transport as everything else, and stores only the SHA-256 of its token: a leaked database dump must not be usable to reset anyone's password.

7. Fail loudly; silence must mean healthy

The most expensive bug in this estate's history was not a crash. dance's nightly backup ran every night, printed DB backup FAILED, exited 0, and touched its success heartbeat. Both monitoring signals — an empty error log and a fresh heartbeat — reported health while zero backups existed. It took four independent faults to produce that, and every one of them was individually survivable; what made it invisible was the exit code.

A related habit from the same incident: dance ran error_reporting(0) in production, which silences the log as well as the screen. Suppress display, never logging — the log is the only thing that can explain a production failure after the fact.

Two rules come from that:

• An operation that failed must exit non-zero. Printing the failure is not reporting it; nothing downstream reads stdout.
• Health signals must be positive, not the absence of a negative. An empty log is ambiguous between "everything succeeded" and "it never ran". Cron jobs therefore touch a heartbeat file only on real success, and the check is the heartbeat's freshness rather than the log's emptiness.

The same instinct applies in code: a missing configuration value should be a loud error, not a quiet default that happens to be empty.

8. Expose the minimum

Only the reverse proxy publishes ports. MariaDB publishes none and is reachable only on an internal Docker network. Each site has its own database user with access to its own schema and nothing else.

Where a control surface must exist, it is bound to loopback and reached over an SSH tunnel rather than firewalled — because Docker writes iptables rules directly and a ufw rule would not actually apply. That distinction is written into the compose file, since the safe-looking alternative is the one people reach for.

Every container runs with no-new-privileges, a memory limit and a pid cap, sized to its workload rather than copied between sites.

Application code sits outside the document root: the web root is public/, and shared/, config/ and src/ are not reachable over HTTP. Anything that genuinely must be callable is a thin, explicit stub in public/api/.

9. Migrations are append-only

A migration that has been applied is never edited. If it seeded a value that later turns out wrong, a new migration corrects it. The applied set is tracked in applied_migrations, and the schema is exported deterministically to database/schema.sql so that a git diff on that file is a real changelog.

Editing an applied migration produces a database that matches no known state — recoverable on the machine where it happened, and nowhere else.

The filename is the order. The runner globs database/migration_*.sql and sorts by name, so the numeric prefix is not decoration — it is the only thing saying what runs when. quack's were originally named after what they did, and alphabetically migration_multi_deck (which creates decks) sorted after migration_anti_hoarding (which updates it). Thirteen of thirty-five failed on a fresh install, and nobody noticed for months because the only database that mattered had been built incrementally, in the order the files were written. A migration set that cannot rebuild the database from scratch is not a migration set; it is a changelog that happens to be executable.

10. The page works without JavaScript

Pages render complete from the server. JavaScript filters, copies, reorders and warns — it does not fetch the content. Without it a page degrades to more information rather than less: a filter simply stays off and everything shows.

Vendoring is the goal, not yet the practice. hub2 serves every front-end asset from itself and says so in its own code. quack does the same by a different route — composer post-install-cmd downloads Bootstrap, jQuery, DataTables and A-Frame into public/assets/vendor/ at deploy time, and each <script> falls back to the CDN only when the local file is absent, so the fallback is visible in the page rather than assumed. dance, fotografia and silver still load Bootstrap and Bootstrap Icons from cdn.jsdelivr.net — 12, 11 and 8 files respectively. So this is a direction, not yet a description: new pages should vendor, and the remaining CDN links are debt worth paying down, because a third party host is a runtime dependency the container isolation cannot protect.

11. Portuguese for people, English for machines

User-facing text is European Portuguese (pt-PT). Code identifiers, commit subjects and the infrastructure documentation are English. In-code comments are written in whichever language the surrounding file already uses — consistency within a file matters more than uniformity across the estate.

12. Data lives outside the checkout

Uploads, logs, caches and backups are bind-mounted from /srv/data/<host>/ and never live inside the git working tree. The checkout should be disposable: a git pull, a rebuild, or a fresh clone must never risk user data, and git status on a production site should be quiet enough that real drift stands out.

---

When these conflict

They will. The ordering that has held so far:

1. Do not lose data. Backups and migrations win over convenience.
2. Do not hide failure. A loud error beats a graceful degradation nobody sees.
3. Do not duplicate. One implementation, parameterised, beats two that agree today.
4. Do not surprise. A boring, obvious solution beats a clever one, because the reader six months from now is the constraint.