Docs: Add sync server list (#856)

docs/deployment/configuration.md

@@ -38,7 +38,7 @@ also known as mobileconfig files, which are in an Apple-specific XML format.
 | BannedBlockMessage                | String     | This is the message shown to the user when a binary is blocked because of a rule if that rule doesn't provide a custom message. If this is not configured a reasonable  default is provided. |
 | ModeNotificationMonitor           | String     | The notification text to display when the client goes into Monitor mode. Defaults to "Switching into Monitor mode". |
 | ModeNotificationLockdown          | String     | The notification text to display when the client goes into Lockdown mode. Defaults to "Switching into Lockdown mode". |
-| SyncBaseURL                       | String     | The base URL of the sync server.         |
+| <a name="sync-base-url"></a>SyncBaseURL                       | String     | The base URL of the sync server.         |
 | SyncProxyConfiguration            | Dictionary | The proxy configuration to use when syncing. See the [Apple Documentation](https://developer.apple.com/documentation/cfnetwork/global_proxy_settings_constants) for details on the keys that can be used in this dictionary. |
 | SyncEnableCleanSyncEventUpload    | Bool       | If true, events will be uploaded to the sync server even if a clean sync is requested. Defaults to false. |
 | ClientAuthCertificateFile         | String     | If set, this contains the location of a PKCS#12 certificate to be used for sync authentication. |

docs/deployment/getting-started.md

@@ -10,8 +10,7 @@ This page shows you the process to get started with your deployment of Santa.
 
 **Note:** You can combine each of the profiles listed in the following steps into a single profile containing the different payloads: configuration, TCC, system extension, and notifications.
 
-1. (Optional) Set up a [sync server](../introduction/syncing-overview.md). Without a sync server, [`santactl`](../binaries/santactl.md) can configure rules locally.
-<!--TODO Add in list of sync servers to another page in docs from ReadMe & expand here with a link to new page/section  -->
+1. (Optional) Set up a [sync server](../introduction/syncing-overview.md). For a list of open-source sync servers, see [Sync Servers](sync-servers.md). Without a sync server, [`santactl`](../binaries/santactl.md) can configure rules locally.
 
 1. Create and install your Santa configuration profile to customize your deployment of Santa. See [Configuration](configuration.md) for a reference list of the available options and an [example profile](https://github.com/google/santa/blob/main/docs/deployment/com.google.santa.example.mobileconfig).
 

docs/deployment/sync-servers.md

@@ -0,0 +1,20 @@
+---
+title: Sync Servers
+parent: Deployment
+nav_order: 3
+---
+
+# Sync Servers
+
+Santa's [SyncBaseURL](configuration.md#sync-base-url) configuration flag allows you to synchronize with a management server, which uploads events that have occurred on the machine and downloads new rules. 
+
+There are several open-source servers you can sync with:
+
+* [Moroz](https://github.com/groob/moroz): A simple golang server that serves hard-coded rules from configuration files.
+* [Rudolph](https://github.com/airbnb/rudolph): An AWS-based serverless sync service primarily built on API GW, DynamoDB, and Lambda components to reduce operational burden. Rudolph is designed to be fast, easy-to-use, and cost-efficient.
+* [Zentral](https://github.com/zentralopensource/zentral/wiki): A centralized service that pulls data from multiple sources and deploys configurations to multiple services.
+* [Zercurity](https://github.com/zercurity/zercurity): A dockerized service for managing and monitoring applications across a large fleet using Santa + Osquery.
+
+Alternatively, `santactl` can configure rules locally without a sync server.
+
+See the [Syncing Overview](../introduction/syncing-overview.md) page for an explanation of how syncing works in Santa.

docs/deployment/troubleshooting.md

@@ -1,7 +1,7 @@
 ---
 title: Troubleshooting
 parent: Deployment
-nav_order: 3
+nav_order: 4
 ---
 
 # Troubleshooting

docs/index.md

@@ -32,6 +32,7 @@ The following pages give an overview of how Santa accomplishes authorization at
 
 * [Getting Started](deployment/getting-started.md): A quick guide to setting up your deployment.
 * [Configuration](deployment/configuration.md): The local and sync server configuration options, along with example needed mobileconfig files.
+* [Sync Servers](deployment/sync-servers.md): A list of open-source sync servers.
 * [Troubleshooting](deployment/troubleshooting.md): How to troubleshoot issues with your Santa deployment.
 
 ### Concepts