authelia/BREAKING.md

Breaking changes
================

Since Authelia is still under active development, it is subject to breaking changes. We then recommend you don't blindly use the latest
Docker image but pick a version instead and read this documentation before upgrading. This is where you will get information about breaking
changes and about what you should do to overcome those changes.

## Breaking in v4.0.0

Authelia has been rewritten in Go for better code maintainability and for performance and security reasons.

The principles stay the same, Authelia is still an authenticating and authorizing proxy. Some major changes have been made though so
that the system is more reliable overall. This induced breaking the previous data model and the configuration to bring new features
but fortunately migration tools are provided to ease the task.

### Major updates

* The configuration mostly remained the same, only one major key has been added: `jwt_secret`
and one key removed: `secure` from the SMTP notifier as the Go SMTP library default to TLS
if available.
* The Hash router has been replaced by a Browser router. This means that the weird characters
/%23/ in the URL could now be safely removed.
* The local storage used for dev purpose was a `nedb` database which was implementing the
same interface as mongo but was not really standard. It has been replaced by a good old
sqlite3 database.
* The model of the database is not compatible with v3. This has been decided to better fit
with Golang libraries.
* Some features have been upgraded such as U2F in order to use the latest security features
available like allowing device cloning detection.
* Furthermore, a top-notch web server implementation (fasthttp) has been selected to allow a
large performance gain in order to use Authelia in demanding environments.

### Data migration tools

An authelia-scripts command is provided to perform the data model migration from a local database
or a mongo database created by Authelia v3 into a target SQL database (sqlite3, mysql, postgres)
supported by Authelia v4.

Example of usage:

    # Migrate a local database into the targeted database defined in config-v4.yml
    authelia-scripts migrate local --config=/path/to/config-v4.yml --db-path=/old/db/path

    # Migrate a mongo database into the targeted database defined in config-v4.yml
    authelia-scripts migrate mongo --config=/path/to/config-v4.yml --url=mongodb://myuser:mypassword@mymongo:27017 --database=authelia


Those commands migrate TOTP secrets, U2F devices, authentication traces and user preferences so
that the migration is almost seamless for your users.

The identity verification tokens are not migrated though since their format has changed. However they were
made to expire after a few minutes anyway. Consequently, the users who initiated a device registration process
which has not been completed before the migration will have to restart the device registration process for their
device. This is because their identity verification token will not be usable in v4.

## Breaking in v3.14.0

### Headers in nginx configuration

In order to support Traefik as a third party proxy interacting with Authelia some changes had to be made
to Authelia and the nginx proxy configuration.

The `Host` header is not used anymore by Authelia in any way. It was previously used to compute the url of the link that is
sent by Authelia for confirming the identity of the user. In the new version X-Forwarded-Proto, X-Forwarded-Host
headers are used to build the URL.

Authelia endpoint /api/verify does not produce the `Redirect` header containing the target URL the user is trying to visit.
This header was used in early versions to redirect the user to the login portal providing the target URL as a query parameter.
However this target URL can be computed automatically with the following statement:

    set                         $target_url $scheme://$http_host$request_uri;


## Breaking in v3.11.0

### ACL configuration

ACL definition in the configuration file has been updated to allow more authorization use cases.
The change basically removed the three categories "any", "groups" and "users" to introduce an
iptables-like format where the authorization policy is just an ordered list of rules with a few
attributes among which the attribute called `subject` used to map old categories.

So in order to upgrade from prior version, you simply need to flatten the rules you already have and
use the `subject` attribute to map your rules from the previous categories into the list. For `any`
rules, just don't specify the subject attribute, this rule will then apply to any user. For group-based
rules you can use `subject: 'group:mygroup'` where `mygroup` is the group you set authorizations for.
For user-based rules, use `subject: 'user:myuser'` where `myuser` is the user you set authorizations for.

Please note that in the new system, the first matching rule applies and the next ones are not taken into
account. If no rule apply, the default policy still applies and if no default policy is provided, the `deny`
policy applies.