Moodle Development Kit (MDK)

Help the user work with MDK, Moodle’s developer CLI (mdk, installed as moodle-sdk). Discover commands from the project docs and with mdk <command> --help.

Who uses it

• Core contributors (Moodle HQ–style): many instances, integration remote, tracker—fix, backport, pull, rebase, push, tracker. Only assume this when the discussion is clearly upstream (MDL issues, stable branches, security workflow).
• Everyone else by default: one or a few local Moodle trees—create, install, upgrade, run, php, open, caches, tests, optional mdk docker.

Agent preferences

1. Prefer instance-scoped work: Prefer cd to the target Moodle root (version.php) so the active instance is unambiguous. If you need the path first, use mdk path <identifier>, then cd.
2. MDK settings: Prefer mdk config over reading or manipulating MDK config files directly.
3. Docker detection: Only infer Docker vs host when the workflow depends on it and the user has not said. Prefer MDK-native signals such as mdk config show docker.automaticContainerLookup, MDK_DOCKER_NAME, or clearly MDK-managed containers over generic guesses.
4. Risky / destructive commands: do not run mdk remove (or pass remove’s non-interactive flags) unless the user has explicitly confirmed they want that instance destroyed. See Risky commands.

Docker vs host (when it matters)

Guess only when the workflow depends on it (e.g. first-time setup path), and unclear from the user's instructions.

• Likely Docker:
  • mdk config show docker.automaticContainerLookup is true, or
  • docker ps shows moodlehq/moodle-php-apache containers tied to MDK.
• Likely host-only: Classic local Apache/nginx + DB on the machine.

Docker installed alone proves nothing.

Common goals

Goal	Direction
New checkout	mdk create …
New instance (host)	mdk create … → mdk install; optional mdk run dev
New instance (Docker)	mdk create … → mdk docker up … → mdk install with a db profile (see that section)
Update code	mdk update …; add --upgrade to run the upgrade
Run upgrade	mdk upgrade …
Caches	mdk purge …
Dev setup	mdk run mindev or mdk run dev; optionally follow with mdk run mincron
Tests	mdk phpunit, mdk behat
Cron	mdk cron; single task: -t <component>:<taskname>
Nuke instance	mdk remove (destructive—see Risky commands)
Uninstall only	mdk uninstall
Instance info	mdk info, mdk info -l, mdk info -v <field> [<identifier>]
Paths in the tree	mdk path, mdk path --component <component>
MDK settings	mdk config …

Tracker / git (core)

Command	Direction
mdk fix	Branch from tracker issue
mdk pull	Patch from issue
mdk push	Push; --update-tracker, --patch when relevant
mdk rebase, backport	Across branches/instances
mdk tracker	Issue summary

Commands

Rough groups:

• Lifecycle: create, install, remove, uninstall, info
• Day-to-day: path, php, run, upgrade, update, purge, cron, open
• Tests: phpunit, behat
• Docker: mdk docker — subcommands include:
  • Moodle PHP container: up, down, rm, stop, logs
  • Postgres (and other docker DB profiles): db up <profile> — profile name = a key under db in mdk config.
  • Adminer: adminer up, adminer down, adminer open
  • Selenium: selenium up, selenium down
• Toolbox: config
• HQ: fix, pull, push, rebase, backport, tracker

Moodle versions

Arguments requiring a Moodle version take a branch code (digits) or main, not a dotted release string: e.g. 411 → 4.11, 503 → 5.3, main → main branch.

New instance (Docker)

Use this when the goal is a new Moodle tree running in Docker.

1. Checkout — mdk create …
2. Choose a Docker DB profile — you must use an MDK DB profile (a key under db in MDK config). List them with mdk config show db and pick the profile you will install against.
3. Start the database container — start the DB container for that profile: mdk docker db up <profile> (if not already running).
4. Start the Moodle PHP container — from that instance’s Moodle root, run mdk docker up --port <n>.
5. Install — from that instance’s Moodle root, run mdk install --engine <profile> … using the same <profile> you started in step 3.

Flags for mdk docker up

• -p / --port — required until the instance is installed. Afterwards MDK can usually infer the host port from wwwroot.
• -v / --php — do not pass unless the user asks for a specific PHP version.

Behat (Docker)

Assume the Moodle instance is installed and usable, with Moodle running in Docker (mdk docker …) when relevant.

1. $CFG->behat_profiles in config.php — Required so Behat knows how to reach Selenium on the Docker network. Below matches mdk docker selenium … container names (selenium-firefox, selenium-chromium, selenium-chrome) and the usual variants; treat as recommended, not mandatory verbatim:

$CFG->behat_profiles = json_decode('{"default":{"browser":"firefox","wd_host":"http:\/\/selenium-firefox:4444\/wd\/hub"},"chromium":{"browser":"chrome","wd_host":"http:\/\/selenium-chromium:4444\/wd\/hub"},"chrome":{"browser":"chrome","wd_host":"http:\/\/selenium-chrome:4444\/wd\/hub"}}', true);

2. Start Selenium — mdk docker selenium up --variant <firefox|chrome|chromium>. If the user gave no preference, prefer chrome.

3. Initial Behat setup inside Moodle — from the instance root, run mdk behat without --run so MDK initialises Behat and prints the suggested command.

4. Run tests as requested — examples:

mdk behat -S -p chrome --run --skip-init --tags @<component>
mdk behat -S -p chrome --run --skip-init --feature relative/path/to/file.feature
mdk behat -S -p chrome --run --skip-init --feature relative/path/to/file.feature --testname "The scenario name"
mdk behat -S -p chrome --run --rerun

Flags:

• -S / --no-selenium — Skip MDK’s built-in handling for non-Docker Selenium (do use this when Selenium is already provided by mdk docker selenium).
• -p / --profile — Match $CFG->behat_profiles and the Selenium container you started (default, chrome, chromium, …).
• --skip-init — Faster reruns when Behat is already initialised on that instance.
• --rerun — Only scenarios that failed last time (implies --run in MDK).

PHPUnit

Assume the Moodle instance is installed and you are in that instance’s Moodle root (version.php).

1. Initial setup — mdk phpunit without -r initialises the PHPUnit test environment.

2. Run tests — use -r / --run. Narrow scope with a testsuite (-s / --testsuite, a file (-u / --unittest, path relative to the Moodle root), or PHPUnit’s --filter.

3. Faster reruns — when the environment is already initialised, pass -k / --skip-init.

Examples:

mdk phpunit -r -w -n -s enrol_manual
mdk phpunit -r --skip-init -u relative/path/tests/example_test.php
mdk phpunit -r -q

Flags:

• -r / --run — Run PHPUnit after setup; without it, MDK only initialises and prints the command line it would use.
• -k / --skip-init — Skip the init step when the instance is already set up.
• -s / --testsuite — Testsuite name, typically a component or subsystem.
• -u / --unittest — Test file to run, as a path relative to the Moodle root.
• -q / --stop-on-failure — Stop on the first failure or error.
• -w / --display-warnings — Show details for tests that triggered warnings.
• -n / --display-notices — Show details for tests that triggered notices.

Bundled mdk run scripts

Shipped scripts—invoke mdk run <name>. Summary:

Script	Role
dev, mindev, undev	Toggle dev-oriented Moodle settings
setup	Chain setup steps for a usable dev instance
setupsecurity	Security-remote clone helper (HQ-style)
users, enrol, makecourse	Test users, enrolment, sample course
webservices, external_functions, tokens	Webservices setup / definitions / tokens
version	Fix downgrade version clashes
jsconfig	Generate jsconfig.json for JS tooling

Example: mdk run dev then mdk run users (from the instance root per invariants).

Verbosity

The debug config key sets log level (mdk config show debug; default info). mdk --debug is equivalent to setting that key to debug for that run rather than the default info. MDK then logs more, including external commands it invokes (e.g. docker, git, php through MDK’s helpers).

Risky commands

Some MDK operations are irreversible and are not moved to a system trash folder.

• mdk remove — Permanently deletes the instance: it drops the instance’s database and deletes the instance directory tree (and related symlinks MDK created). Uncommitted work, local branches, and file customisations under that tree are gone unless they exist elsewhere (e.g. another remote or backup). This is the main “lose your work” footgun for developers.

Agents: never invoke mdk remove based on inference or convenience (e.g. “start fresh”). Only run it when the user has clearly and explicitly asked to remove / delete / destroy that MDK instance (by name or unambiguous reference). Do not use -y or -f on remove to skip confirmation unless the user has explicitly requested non-interactive removal as part of the same instruction.

Apply the same caution to other commands whose primary effect is destroying data or containers (for example Docker removal subcommands) when the outcome would be permanent loss of the user’s environment or data.