Add posture checks doc (#144)

src/components/NavigationDocs.jsx

@@ -62,6 +62,7 @@ export const docsNavigation = [
             { title: 'CLI', href: '/how-to/cli' },
             { title: 'Delete your NetBird account', href: '/how-to/delete-account' },
             { title: 'IdP sync', href: '/how-to/idp-sync' },
+            { title: 'Manage access with posture checks', href: '/how-to/manage-posture-checks' },
             { title: 'Report bugs and issues', href: '/how-to/report-bug-issues' },
             { title: 'Troubleshooting client issues', href: '/how-to/troubleshooting-client' },
         ],

src/pages/how-to/manage-posture-checks.mdx

@@ -0,0 +1,120 @@
+# Manage access with posture checks
+
+NetBird enables administrators to manage network access by creating access policies that dictate
+which peer groups can interact with other peers in your network.
+Posture checks extend these policies, augmenting their capabilities by allowing administrators to
+enforce access restrictions based on specified criteria. By integrating posture checks seamlessly
+into policy-based ACLs, NetBird evaluates various attributes to determine the eligibility of peers to
+connect to the network.
+
+## Concepts
+
+### NetBird client version check
+
+The NetBird client version check verifies the version of NetBird installed on the device attempting to connect to the
+network. This check ensures that only devices running a specified version of NetBird can gain access,
+thus preventing outdated or incompatible clients from compromising network security.
+
+### Operating system version check
+
+The operating system version check evaluates the operating system (OS) version running on the connecting device.
+This check allows for enforcing minimum OS requirements, ensuring that only devices with up-to-date and
+secure operating systems can access network resources.
+
+<Note>
+    This check requires NetBird version [0.26.0](https://github.com/netbirdio/netbird/releases) or newer.
+</Note>
+
+The check evaluates the actual `OS version` for Android, macOS, and iOS, while for Linux and Windows, it assesses
+the `kernel version`.
+
+Below are some examples of OS versions for each operating system:
+
+* Android 14 Upside Down Cake: `14`, `14.3`
+* macIS 13	Ventura: `13`, `13.6.4`
+* macOS 14 Sonoma: `14`, `14.3.1`
+* iOS 16 / iPadOS 16: `16`, `16.7.5`
+* Linux kernel: `6`, `6.7.5`
+* Windows 10, version 22H2: `10.0.19045`
+* Windows 11, version 23H2: `10.0.22631`
+* Windows Server 2022, Version 21H2: `10.0.20348`
+
+### Geolocation check
+
+The geolocation check examines the connecting device's geographical location based on its IP address.
+This check allows administrators to enforce access restrictions based on geographic regions,
+offering country-wide and city-level granularity.
+
+## Managing Posture Checks
+
+Posture Checks are dynamic, and you can create a policy with multiple posture checks. A single posture
+check can also be reused across different policies. When managing posture checks, you can update them as
+per your requirements.
+
+However, deleting a posture check is only possible if it's not currently used in any policy. If a posture
+check is in use, you need to unassigned it from the respective policy before you can delete it.
+This precaution ensures the continuity and integrity of your security setup.
+
+Here are some steps to help you create and manage your posture checks effectively:
+
+In the example below, we are creating a posture check that will only allow clients running NetBird version 0.25.0 or
+higher to connect and access network resources.
+
+### Creating posture checks
+Access the `Access Control` tab, the `Posture Checks` section and click `Create Posture Check`.
+
+<p>
+    <img src="/docs-static/img/how-to-guides/add-posture-check.png" alt="high-level-dia" className="imagewrapper"/>
+</p>
+
+That will open a posture checks configuration screen where you can configure the checks.
+
+<p>
+    <img src="/docs-static/img/how-to-guides/posture-check-create-list.png" alt="high-level-dia" className="imagewrapper"/>
+</p>
+
+Select the `NetBird Client Version` check option and set it with the following information:
+- Version: `0.25.0`
+
+<p>
+    <img src="/docs-static/img/how-to-guides/netbird-version-check.png" alt="high-level-dia" className="imagewrapper"/>
+</p>
+
+Click `Save`, and the `NetBird Client Version` check will be enabled.
+<p>
+    <img src="/docs-static/img/how-to-guides/posture-check-netbird-version-enabled.png" alt="high-level-dia" className="imagewrapper"/>
+</p>
+
+Click `Continue`, fill out the form with the following information, and click `Create Posture Check` to save:
+- Name of the posture check: `Netbird Version`
+- Description: `Allow Netbird client with version 0.25.0 or greater`
+
+<p>
+    <img src="/docs-static/img/how-to-guides/posture-check-post-config.png" alt="high-level-dia" className="imagewrapper"/>
+</p>
+
+### Adding posture checks to policy
+
+Navigate to the `Access Control` tab and select the `Policies` section.
+
+<p>
+    <img src="/docs-static/img/how-to-guides/policies-list.png" alt="high-level-dia" className="imagewrapper"/>
+</p>
+
+Choose the policy to which you want to assign the posture check. This will open the policy update screen. Then,
+select the `Posture Checks` tab.
+<p>
+    <img src="/docs-static/img/how-to-guides/policy-new-posture-check.png" alt="high-level-dia" className="imagewrapper"/>
+</p>
+
+Click `Browse Checks` and select the posture check we created earlier, `Netbird Version`. Then, click `Add Posture Checks`.
+
+<p>
+    <img src="/docs-static/img/how-to-guides/policy-posture-checks-select.png" alt="high-level-dia" className="imagewrapper"/>
+</p>
+
+The `Netbird Version` check will be assigned to the policy. Click `Save Changes` to save the policy updates.
+<p>
+    <img src="/docs-static/img/how-to-guides/policy-posture-checks-assigned.png" alt="high-level-dia" className="imagewrapper"/>
+</p>
+