Nextcloud is a suite of client-server software for creating and using file hosting services. Nextcloud is free and open-source, which means that anyone is allowed to install and operate it on their own private server devices.
This setup only works, when NextCloud is running with HTTPS enabled. See [here](https://docs.nextcloud.com/server/stable/admin_manual/configuration_server/reverse_proxy_configuration.html?highlight=overwriteprotocol#overwrite-parameters) on how to configure this.
In case something goes wrong with the configuration, you can use the URL `http://nextcloud.company/login?direct=1` to log in using the built-in authentication.
Create an application in authentik and note the slug you choose, as this will be used later. In the Admin Interface, go to Applications->Providers. Create a SAML provider with the following parameters:
- Optional display name of the identity provider (default: "SSO & SAML log in"): `authentik`
- Identifier of the IdP entity (must be a URI): `https://authentik.company`
- URL Target of the IdP where the SP will send the Authentication Request Message: `https://authentik.company/application/saml/<application-slug>/sso/binding/redirect/`
To do this you will need to add the line `'overwriteprotocol' => 'https'` to `config.php` in the Nextcloud `config\config.php` file
See https://docs.nextcloud.com/server/latest/admin_manual/configuration_server/reverse_proxy_configuration.html#overwrite-parameters for additional information
Create a group for each different level of quota you want users to have. Set a custom attribute, for example called `nextcloud_quota`, to the quota you want, for example `15 GB`.
Afterwards, create a custom SAML Property Mapping with the name `SAML NextCloud Quota`.
Set the *Expression* to `return user.group_attributes().get("nextcloud_quota", "1 GB")`, where `1 GB` is the default value for users that don't belong to another group (or have another value set).
To give authentik users admin access to your NextCloud instance, you need to create a custom Property Mapping that maps an authentik group to "admin". It has to be mapped to "admin" as this is static in NextCloud and cannot be changed.
Create a SAML Property mapping with the SAML Name "http://schemas.xmlsoap.org/claims/Group" and this expression:
```python
for group in user.ak_groups.all():
yield group.name
if ak_is_group_member(request.user, name="<authentiknextcloudadmingroup'sname>"):
yield "admin"
```
Then, edit the NextCloud SAML Provider, and replace the default Groups mapping with the one you've created above.
