Add OPNsense example config. (#558)

* Add OPNsense example config.
---------

Co-authored-by: Tyler Pace <tpace@newrelic.com>

example_configs/opnsense.md

@@ -0,0 +1,113 @@
+# Configuration for OPNsense
+
+## Create a LDAP Server
+
+- Login to OPNsense
+- Navigate to: `System > Access > Servers`
+- Create a new server by clicking on the `+` icon
+
+## Server Config
+
+- Descriptive Name: `A Descriptive Name`
+- Type: `LDAP`
+- Hostname or IP address: `Hostname or IP for your LLDAP host`
+- Port value: `Your LLDAP port`
+  - Default: `3890`
+- Transport: `TCP - Standard`
+- Protocol version: `3`
+
+Make sure the host running LLDAP is accessible to OPNsense and that you mapped the LLDAP port to the LLDAP host.
+
+## LDAP Config
+
+### Bind credentials
+
+#### User DN
+
+```
+uid=admin,ou=people,dc=example,dc=com
+```
+
+It is recommended that you create a separate user account (e.g, `bind_user`) instead of `admin` for sharing Bind credentials with other services. The `bind_user` should be a member of the `lldap_strict_readonly` group to limit access to your LDAP configuration in LLDAP.
+
+#### Password
+
+```
+xxx
+```
+
+Enter the password that you set for the user specified in the User DN field.
+
+### Search Scope
+
+```
+One Level
+```
+
+### Base DN
+
+```
+dc=example,dc=com
+```
+
+This is the same LDAP Base DN that you set via the *LLDAP_LDAP_BASE_DN* environment variable or in `lldap_config.toml`.
+
+### Authentication containers
+
+```
+ou=people,dc=example,dc=com
+```
+
+Note: The `Select` box may not work for selecting containers. You can just enter the `Authentication containers` directly into the text field.
+
+### Extended Query
+
+```
+&(objectClass=person)(memberof=cn=lldap_admin,ou=groups,dc=example,dc=com)
+```
+
+It is recommended that you create a unique LDAP group (e.g., `lldap_opnsense`) in LLDAP and use that group in this query instead of `lldap_admin`. This will limit OPNsense access to  users in the `lldap_opnsense` group and make it easier to synchronize LLDAP groups with OPNsense groups for managing OPNsense access.
+
+### Initial Template
+
+```
+OpenLDAP
+```
+
+### User naming attribute
+
+```
+uid
+```
+
+## Optional Configuration
+
+The above configuration will connect OPNsense to LLDAP. This optional configuration will synchronize groups between LLDAP and OPNsense and automate user creation when an authorized LLDAP user logs into OPNsense.
+
+### Remaining Server Configuration
+
+Enable the following options on the OPNsense configuration page for your LLDAP server (the same page where you entered the prior configuration):
+
+- Read Properties: `Checked`
+- Synchronize groups: `Checked`
+- Automatic user creation: `Checked`
+
+### Create OPNsense Group
+
+Go to `System > Access > Groups` and create a new group with the **same** name as the LLDAP group used to authenticate users for OPNsense.
+
+By default, you would name your OPNsense group `lldap_admin` unless you followed the recommended advice in this guide and created a separate `lldap_opnsense` group for managing OPNsense users.
+
+If you want your LLDAP users to have full administrator access in OPNsense, then you need to edit the `Assigned Privileges` for the group and add the `GUI - All pages` system privilege.
+
+### Enable LLDAP as an Authentication Option
+
+Go to `System > Settings > Administration` page and scroll down to the `Authentication` section. Add your LLDAP server configuration to the `Server` field.
+
+## Testing LLDAP
+
+OPNsense includes a built-in feature for testing user authentication at `System > Access > Tester`. Select your LLDAP server configuration in the `Authentication Server` to test logins for your LLDAP users.
+
+## More Information
+
+Please read the [OPNsense docs](https://docs.opnsense.org/manual/how-tos/user-ldap.html) for more information on LDAP configuration and managing access to OPNsense.