website/docs: add General Setup instructions for LDAP Provider (#3680)

* Added General Setup instructions for LDAP Provider

* Added General Setup instructions for LDAP Provider and updated relative links

* updated LDAP Outpost note verbiage

* Corrected the case for LDAP and renamed to Generic Setup

* removed ldapsearch example from index page

* updated verbiage around multifactor authentication

* removed note about local LDAP provider

* updated sidebar to reflect generic_setup

* updated logging info

* corrected typo

* updated stage creation instructions and screenshot

* corrected another typo

* corrected another typo

* reword some things

Signed-off-by: Jens Langhammer <jens.langhammer@beryju.org>

Signed-off-by: Jens Langhammer <jens.langhammer@beryju.org>
Co-authored-by: Jens Langhammer <jens.langhammer@beryju.org>

website/docs/providers/ldap/generic_setup.md

@@ -0,0 +1,93 @@
+---
+title: Generic Setup
+---
+
+### Create User/Group
+
+1. Create a new user account to test LDAP bind under _Directory_ -> _Users_ -> _Create_, in this example called `ldapservice`.
+
+    Note the DN of this user will be `cn=ldapservice,ou=users,dc=ldap,dc=goauthentik,dc=io`
+
+2. Create a new group for LDAP searches. In this example `ldapsearch`. Add the `ldapservice` user to this new group.
+
+:::info
+Note: The `default-authentication-flow` validates MFA by default, and currently only Duo-based MFA devices are supported by LDAP. If you plan to use only dedicated service accounts to bind to LDAP, then you can use the default flow and skip the extra steps below and continue at [Create LDAP Provider](#create-ldap-provider)
+:::
+
+### LDAP Flow
+
+#### Create Custom Stages
+
+1. Create a new identification stage. _Flows & Stage_ -> _Stages_ -> _Create_
+   ![](./general_setup1.png)
+2. Name it something meaningful like `ldap-identification-stage`. Select User fields Username and Email (and UPN if it is relevant to your setup).
+   ![](./general_setup2.png)
+3. Create a new password stage. _Flows & Stage_ -> _Stages_ -> _Create_
+   ![](./general_setup3.png)
+4. Name it something meaningful like `ldap-authentication-password`. Leave the defaults for Backends.
+   ![](./general_setup4.png)
+5. Create a new user login stage. _Flows & Stage_ -> _Stages_ -> _Create_
+   ![](./general_setup5.png)
+6. Name it something meaningful like `ldap-authentication-login`.
+   ![](./general_setup6.png)
+
+#### Create Custom Flow
+
+1. Create a new authentication flow under _Flows & Stage_ -> _Flows_ -> _Create_, and name it something meaningful like `ldap-authentication-flow`
+   ![](./general_setup7.png)
+2. Click the newly created flow and choose _Stage Bindings_.
+   ![](./general_setup8.png)
+3. Click `Bind Stage` choose `ldap-identification-stage` and set the order to `10`.
+   ![](./general_setup9.png)
+4. Click `Bind Stage` choose `ldap-authentication-login` and set the order to `30`.
+   ![](./general_setup11.png)
+5. Edit the `ldap-identification-stage`.
+   ![](./general_setup12.png)
+6. Change the Password stage to `ldap-authentication-password`.
+   ![](./general_setup13.png)
+
+### Create LDAP Provider
+
+1. Create the LDAP Provider under _Applications_ -> _Providers_ -> _Create_.
+   ![](./general_setup14.png)
+2. Name is something meaningful like `LDAP`, bind the custom flow created previously (or the default flow, depending on setup) and specify the search group created earlier.
+   ![](./general_setup15.png)
+
+### Create LDAP Application
+
+1. Create the LDAP Application under _Applications_ -> _Applications_ -> _Create_ and name it something meaningful like `LDAP`. Choose the provider created in the previous step.
+   ![](./general_setup16.png)
+
+### Create LDAP Outpost
+
+1. Create (or update) the LDAP Outpost under _Applications_ -> _Outposts_ -> _Create_. Set the Type to `LDAP` and choose the `LDAP` application created in the previous step.
+   ![](./general_setup17.png)
+
+### ldapsearch Test
+
+Test connectivity by using ldapsearch.
+
+:::info
+ldapsearch can be installed on Linux system with these commands
+
+```
+sudo apt-get install ldap-utils -y # Debian-based systems
+sudo yum install openldap-clients -y # CentOS-based systems
+```
+
+:::
+
+```
+ldapsearch \
+  -x \
+  -h <LDAP Outpost IP address> \
+  -p 389 \ # Production should use SSL 636
+  -D 'cn=ldapservice,ou=users,DC=ldap,DC=goauthentik,DC=io' \
+  -w '<ldapuserpassword>' \
+  -b 'DC=ldap,DC=goauthentik,DC=io' \
+  '(objectClass=user)'
+```
+
+:::info
+This query will log the first successful attempt in an event in the _Events_ -> _Logs_ area, further successful logins from the same user are not logged as they are cached in the outpost.
+:::

website/docs/providers/ldap/index.md

@@ -0,0 +1,93 @@
+---
+title: LDAP Provider
+---
+
+You can configure an LDAP Provider for applications that don't support any newer protocols or require LDAP.
+
+:::info
+Note: This provider requires the deployment of the [LDAP Outpost](../../outposts/)
+:::
+
+All users and groups in authentik's database are searchable. Currently, there is limited support for filters (you can only search for objectClass), but this will be expanded in further releases.
+
+Binding against the LDAP Server uses a flow in the background. This allows you to use the same policies and flows as you do for web-based logins. For more info, see [Bind modes](#bind-modes).
+
+You can configure under which base DN the information should be available. For this documentation we'll use the default of `DC=ldap,DC=goauthentik,DC=io`.
+
+Users are available under `ou=users,<base DN>` and groups under `ou=groups,<base DN>`. To aid compatibility, each user belongs to its own "virtual" group, as is standard on most Unix-like systems. This group does not exist in the authentik database, and is generated on the fly. These virtual groups are under the `ou=virtual-groups,<base DN>` DN.
+
+The following fields are currently sent for users:
+
+-   `cn`: User's username
+-   `uid`: Unique user identifier
+-   `uidNumber`: A unique numeric identifier for the user
+-   `name`: User's name
+-   `displayName`: User's name
+-   `mail`: User's email address
+-   `objectClass`: A list of these strings:
+    -   "user"
+    -   "organizationalPerson"
+    -   "goauthentik.io/ldap/user"
+-   `memberOf`: A list of all DNs that the user is a member of
+-   `goauthentik.io/ldap/active`: "true" if the account is active, otherwise "false"
+-   `goauthentik.io/ldap/superuser`: "true" if the account is part of a group with superuser permissions, otherwise "false"
+
+The following fields are current set for groups:
+
+-   `cn`: The group's name
+-   `uid`: Unique group identifier
+-   `gidNumber`: A unique numeric identifier for the group
+-   `member`: A list of all DNs of the groups members
+-   `objectClass`: A list of these strings:
+    -   "group"
+    -   "goauthentik.io/ldap/group"
+
+A virtual group is also created for each user, they have the same fields as groups but have an additional objectClass: `goauthentik.io/ldap/virtual-group`.
+The virtual groups gidNumber is equal to the uidNumber of the user.
+
+**Additionally**, for both users and (non-virtual) groups, any attributes you set are also present as LDAP Attributes.
+
+:::info
+Starting with 2021.9.1, custom attributes will override the inbuilt attributes.
+:::
+
+## SSL
+
+You can also configure SSL for your LDAP Providers by selecting a certificate and a server name in the provider settings.
+
+This enables you to bind on port 636 using LDAPS, StartTLS is not supported.
+
+## Integrations
+
+See the integration guide for [sssd](../../../integrations/services/sssd/) for
+an example guide.
+
+## Bind Modes
+
+All bind modes rely on flows.
+
+The following stages are supported:
+
+-   [Identification](../../flow/stages/identification/)
+-   [Password](../../flow/stages/password/)
+-   [Authenticator validation](../../flow/stages/authenticator_validate/)
+
+    Note: Authenticator validation currently only supports DUO devices
+
+#### Direct bind
+
+In this mode, the outpost will always execute the configured flow when a new bind request arrives.
+
+#### Cached bind
+
+This mode uses the same logic as direct bind, however the result is cached for the entered credentials, and saved in memory for the standard session duration. Sessions are saved independently, meaning that revoking sessions does _not_ remove them from the outpost, and neither will changing a users credentials.
+
+## Search Modes
+
+#### Direct search
+
+Every LDAP search request will trigger one or more requests to the authentik core API. This will always return the latest data, however also has a performance hit due all the layers the backend requests have to go through, etc.
+
+#### Cached search
+
+In this mode, the outpost will periodically fetch all users and groups from the backend, hold them in memory, and respond to search queries directly. This means greatly improved performance but potentially returning old/invalid data.