Environment Variables¶

Every setting exposed by erseco/alpine-moodle. Defaults come from the Dockerfile and are applied unless you override them in docker run, docker-compose.yml, or your orchestration tool.

Site¶

Variable	Default	Description
`SITE_URL`	`http://localhost`	Public URL of the site. Becomes `$CFG->wwwroot`. Must match what users type in the browser.
`MOODLE_SITENAME`	`Dockerized_Moodle`	Full name shown on the Moodle front page.
`MOODLE_LANGUAGE`	`en`	Installer language. Sets `--lang` on `admin/cli/install.php`.
`LANG`	`en_US.UTF-8`	System locale.
`LANGUAGE`	`en_US:en`	System language fallback chain.

Admin user¶

Variable	Default	Description
`MOODLE_USERNAME`	`moodleuser`	Initial admin username.
`MOODLE_PASSWORD`	`PLEASE_CHANGEME`	Initial admin password. Always override.
`MOODLE_EMAIL`	`user@example.com`	Admin email address.

Warning

If the container finds an existing install, these values are re-applied to the admin user on every start via the image-resident helper /usr/local/lib/alpine-moodle/cli/update_admin_user.php. Keep them in sync with your secret store.

Database — primary¶

Variable	Default	Description
`DB_TYPE`	`pgsql`	`pgsql`, `mariadb`, `mysqli` or `sqlite3`.
`MOODLE_DATABASE_TYPE`	(empty)	Optional override for `DB_TYPE`. Set to `sqlite3` to enable the single-container mode.
`DB_HOST`	`postgres`	DB hostname (service name on the Docker network).
`DB_PORT`	`5432`	5432 for PostgreSQL, 3306 for MariaDB/MySQL.
`DB_NAME`	`moodle`	Database name.
`DB_USER`	`moodle`	Database user.
`DB_PASS`	`moodle`	Database password.
`DB_PREFIX`	`mdl_`	Table prefix. Must be non-numeric.
`DB_SQLITE_PATH`	`/var/www/moodledata/sqlite/moodle.sqlite`	SQLite file path. Must resolve inside `/var/www/moodledata/`.
`DB_FETCHBUFFERSIZE`	(empty)	Set to `0` when using PgBouncer in transaction mode.
`DB_DBHANDLEOPTIONS`	`false`	Set to `true` with PgBouncer (pool modes that reject `SET` options).

Database — read replica (optional)¶

Variable	Default	Description
`DB_HOST_REPLICA`	(empty)	Enables the read-only replica if set.
`DB_PORT_REPLICA`	(empty)	Falls back to `DB_PORT`.
`DB_USER_REPLICA`	(empty)	Falls back to `DB_USER`.
`DB_PASS_REPLICA`	(empty)	Falls back to `DB_PASS`.

Redis (optional)¶

Variable	Default	Description
`REDIS_HOST`	(empty)	When set, enables the Redis session handler and cache store.
`REDIS_PASSWORD`	(empty)	Redis password.
`REDIS_USER`	(empty)	Redis 6+ ACL user. Requires `REDIS_PASSWORD` or the container aborts at startup.

Reverse proxy / TLS¶

Variable	Default	Description
`REVERSEPROXY`	`false`	Set to `true` only if the site is intentionally served from multiple base URLs.
`SSLPROXY`	`false`	Set to `true` when a reverse proxy terminates TLS. Trusts `X-Forwarded-Proto`.
`MY_CERTIFICATES`	`none`	Base64-encoded trusted certificate bundle installed into the LDAP truststore (`/etc/openldap/my-certificates/extra.pem`). Use `none` to disable.

See Reverse Proxy for concrete examples.

Email / SMTP¶

Variable	Default	Description
`SMTP_HOST`	`smtp.gmail.com`	SMTP server hostname.
`SMTP_PORT`	`587`	SMTP server port.
`SMTP_USER`	`your_email@gmail.com`	SMTP username.
`SMTP_PASSWORD`	`your_password`	SMTP password.
`SMTP_PROTOCOL`	`tls`	`tls`, `ssl` or empty.
`MOODLE_MAIL_NOREPLY_ADDRESS`	`noreply@localhost`	Used as `noreplyaddress`.
`MOODLE_MAIL_PREFIX`	`[moodle]`	Email subject prefix.

PHP / web server tuning¶

Variable	Default	Description
`client_max_body_size`	`50M`	Nginx max request body size.
`post_max_size`	`50M`	PHP `post_max_size`.
`upload_max_filesize`	`50M`	PHP `upload_max_filesize`.
`max_input_vars`	`5000`	PHP `max_input_vars`. Keep high for Moodle course imports.
`memory_limit`	`256M`	PHP `memory_limit`. Increase to `512M` or more for big plugin installs / Moosh operations (#119).

Operational¶

Variable	Default	Description
`AUTO_UPDATE_MOODLE`	`true`	If `false`, skip the automatic `admin/cli/upgrade.php` on container start.
`SYNC_MOODLE_CODE`	`auto`	How to refresh Moodle PHP code from the image into `/var/www/html` when a volume is used. This is independent of `AUTO_UPDATE_MOODLE` (DB schema). Values: `auto` (default) — sync when the volume is empty or its Moodle `$version` differs from the image; `always` — rsync every start; `never` — leave the volume tree untouched (legacy). See Upgrading and #103.
`SYNC_PRESERVE_PLUGINS`	`true`	When `true`, the code sync automatically keeps third-party plugins — any directory containing a `version.php` that the image tree does not ship — matching Moodle's own upgrade procedure of carrying custom plugins over to the new code tree. Set to `false` to get a pristine image tree on every sync (third-party plugin code is then deleted unless listed in `EXTRA_PLUGIN_PATHS`). See #161.
`EXTRA_PLUGIN_PATHS`	(empty)	Space-separated paths relative to `/var/www/html` preserved across a code sync (e.g. `mod/attendance theme/space local/mytool`). Rejects absolute paths and `..`. With `SYNC_PRESERVE_PLUGINS=true` (default) real plugins are kept automatically; this is mainly for custom paths without a `version.php`. Prefer `PLUGINS` / Moosh when you can reinstall declaratively.

Note

When the image and the volume use different layouts (Moodle 5.1 moved the web root under public/), preserved paths are relocated automatically, e.g. mod/attendance → public/mod/attendance.

Code sync vs database upgrade¶

Knob	What it updates	When
`SYNC_MOODLE_CODE`	PHP files under `/var/www/html` (from `/usr/src/moodle`)	Before install/upgrade CLI runs
`AUTO_UPDATE_MOODLE`	Database schema via `admin/cli/upgrade.php`	After code is in place

Build-time argument¶

Build ARG	Default	Description
`MOODLE_VERSION`	`main`	Upstream Moodle tag to install (e.g. `v5.0.2`, `v4.5.7`). `main` installs the current development branch.

Full list of available Moodle tags: https://github.com/moodle/moodle/tags