Using ENV vars on fortrabbit

The input supports the dotenv file format and allows you to create or update multiple variables at once. The changes will be distributed after you save the page. That may take around 60 seconds.

# ENV var types on fortrabbit

There are four different kinds of ENV vars here on fortrabbit which are available to your environment at runtime.

# Software template ENV vars

Depending on the detected or chosen software, additional ENV vars will be seeded for you. This selection will configure the server ENV vars in ways the software can work with. For example, for Laravel and Craft, an ENV var like DB_PASSWORD will be populated with the database password. Most likely, the environment will work out of the box. You can also reset the database password without touching any configurations.

# System ENV vars

System ENV vars are automatically updated values that contain access details for services offered by fortrabbit. These are the ones every environment gets:

Reference one from a custom ENV var rather than copying its value, so a rotated password keeps working:

MY_DB_PASSWORD=${FORTRABBIT_DB_PASSWORD}
# MY_DB_PASSWORD is the key
# ${FORTRABBIT_DB_PASSWORD} is an alias for a value populated by fortrabbit

System ENV vars will not overwrite existing, manually created ENV vars. This means: if you manually create an ENV var, we guarantee that we won't replace its value with a dynamically generated ENV var.

# Custom ENV vars

Those are the ones you add yourself in the dashboard.

# Nested ENV vars

You can use simple, nested variables↗ in your custom ENV vars. Simple means, that you can set variables which reference other variables, which contain a value, for example:

# will work:
OTHER_VAR=something
MY_VAR=${OTHER_VAR}

Order matters. First define something before referencing. Multiple levels of interpolation are not supported. That means that you cannot use variables, which reference other variables, which again reference other variables, for example:

# will not work:
MY_VAR=${OTHER_VAR}
OTHER_VAR=${ANOTHER_VAR}
ANOTHER_VAR=something

# ENV var validation

Strict validation rules for ENV vars are in use in the dashboard while entering. Chars like the "$" sign can be harmful in Linux systems. Here is the regex we use to validate the ENV var input in the dashboard:

/^[\p{L}\p{N}\ _\-\+=\.,:;\?!@~%&\*\(\)\[\]\{\}<>\/\\#]+$/u

So sometimes, when you want to store an external API key as an ENV var, you might get a validation error like: "Variable value contains invalid characters".

# Base64 encoding and decoding

Use the Base64 helper in the dashboard to handle special characters, multi-line values, or long strings.

# Can NOT save this due to special characters
MOTTO=$$$$ Rules Everything Around Me

# The tool converts it to Base64 with a prefix
MOTTO=fr+base64:JCQkJCBSdWxlcyBFdmVyeXRoaW5nIEFyb3VuZCBNZQ==

# The environment receives the original value
MOTTO=$$$$ Rules Everything Around Me

The tool encodes your value to Base64 and adds the fr+base64: prefix. This encoded value is stored safely. At runtime, the platform automatically decodes it, so your application receives the original value without any extra work.

Laravel and Symfony have similar built-in functionality for variables prefixed with base64:. If you use that, the framework handles the decoding. The fr+base64: prefix is a platform-level feature that works for any application, regardless of the framework.

# Reserved environment variable names

There are some names you can not use here:

, __FRBIT__, argc, argv, AUTHTYPE, CHARSET, CONTEXT_DOCUMENT_ROOT, CONTEXT_PREFIX, DOCUMENT_ROOT, FCGI_ROLE, FORTRABBIT, GATEWAYINTERFACE, GROUP, HOME, HTTP_, HTTPS, LANG, LC__, LOGNAME, MAIL, MUSL_LOCPATH, OLDPWD, ORIG_PATH_INFO, PAGER, PATH, PATH_INFO, PATH_TRANSLATED, PHP_AUTH_DIGEST, PHP_AUTH_PW, PHP_AUTH_USER, PHP_SELF, PS0, PS1, PS2, PS3, PS4, PWD, QUERY_STRING, REDIRECT_REMOTE_USER, REMOTE_ADDR, REMOTE_HOST, REMOTE_PORT, REMOTE_USER, REQUEST_METHOD, REQUEST_SCHEME, REQUEST_TIME, REQUEST_TIME_FLOAT, REQUEST_URI, SCRIPT_FILENAME, SCRIPT_NAME, SCRIPT_URI, SCRIPT_URL, SERVER_ADDR, SERVER_ADMIN, SERVER_NAME, SERVER_PORT, SERVER_PROTOCOL, SERVER_SIGNATURE, SERVER_SOFTWARE, SHELL, SHLVL, SSH_CLIENT, SSH_CONNECTION, SSH_TTY, TERM, USER