Added docs for apply-config.sh

Author: ffdixon

_posts/2015-04-05-faq.md

@@ -412,13 +412,9 @@ In short, if the user is having any problems (such as audio is garbled or they a
 
 ## How many simultaneous users can BigBlueButton support
 
-As a rule of thumb, without knowing anything about your server, we recommend running your BigBlueButton with sessions of one hundred (100) users or less.  
+As a rule of thumb, if your BigBlueButton server meets the [minimum requirements](http://docs.bigbluebutton.org/2.2/install.html#minimum-server-requirements), the server should be able to support 150 simultaneous users, such as 3 simultaneous sessions of 50 users, 6 x 25, etc.
 
-For example, if after testing your server under load, you find it can support 250 simultaneous users, then we recommend running up to two sessions of 100 users, 3 x 75, 5 x 50, etc.
-
-See [minimum server requirements](/install/install.html).
-
-Of course, there is a big difference between running BigBlueButton on a single core Celeron CPU vs. a quad core X3450 processor.  The latter will be able to hold more simultaneous users than the former.
+We recommend no single sessions exceed one hundred (100) users.  
 
 Members of our community periodically host stress tests for BigBlueButton, which gives others a data point on what a particular server was able to handle.   Take any stress test with a grain of salt.  There are many variables at play:
 
@@ -428,7 +424,9 @@ Members of our community periodically host stress tests for BigBlueButton, which
 * Configuration of BigBlueButton
 * Version of BigBlueButton
 
-In BigBlueButton, it also depends on what users do in a session.  If you have a session with 20 users and all share their webcam (yes, this is possible) will generate 400 streams (10 incoming streams to the server and 390 outgoing streams).  If you have a session with 20 users and all share their microphones, there will be a two-way audio stream for each user to the BigBlueButton server; whereas if 19 of the users join the Listen Only stream, then there is only two two-way audio streams to the BigBlueButton server (one for the presenter and the other for the listen only stream).
+The scalability of a BigBlueButton session also depends on what media users are sharing in a session.  If you have a session with 20 users and all sharing their webcam, this scenario will generate 400 streams (10 incoming streams to the server and 390 outgoing streams).  Alternatively, if in the same session there is only one person (the instructor) sharing their webcam, there will be 20 streams (1 incoming and 19 outgoing).
+
+If you have a session with 20 users and all share their microphones, there will be 20 two-way audio stream being mixed by in real-time by FreeSWITCH. Alternatively, if only one user (the instructor) shares their microphone and 19 join Listen Only, then there is only one stream mixed by FreeSWITCH (less CPU), and 19 one way streams shared to the user.
 
 If you are unsure of how many users your server will support, we **strongly** recommend you first stress test your own server with a group of users to get real-world data.
 

_posts/2019-02-14-customize.md

@@ -372,6 +372,134 @@ This change will cause BigBlueButton to generate an additional `.mp4` file for t
 
 This change will increase the processing time and storage size of recordings with video files as it will now generate two videos: `.webm` and `.mp4` for the webcam and screen share videos.
 
+## Automatically apply configuration changes on restart
+
+When you upgrade to the latest build of BigBlueButton using either the [manual steps](/2.2/install.html#upgrading-from-bigbluebutton-22) or [bbb-install.sh](https://github.com/bigbluebutton/bbb-install) script, if you have made manual changes to BigBlueButton's configuration, the packaging scripts may overwrite your changes.
+
+Instead of an error-prone step to manually re-applying any changes after each upgrade, a better approach would be to have your custom configuration changes in a script that gets automatically when BigBlueButton gets restarted.
+
+Whenever you manually update BigBlueButton, the [instructions](/2.2/install.html#upgrading-from-bigbluebutton-22) state to run `sudo bbb-conf --setip <hostname>` to re-apply the `<hostname>` to BigBlueButton's configuration files ([bbb-install.sh](https://github.com/bigbluebutton/bbb-install) does this for you automatically).  
+
+There is now logic in `bbb-conf` to look for a BASH script at `/etc/bigbluebutton/bbb-conf/apply-config.sh` when doing either `--restart` or `--setip <hostname>` and, if found, execute this script before starting up BigBlueButton.
+
+You can then put your configuration changes in `apply-config.sh` to ensure they are automatically applied.  Here's a sample `apply-config.sh` script
+
+~~~sh
+!/bin/bash
+
+# Pull in the helper functions for configuring BigBlueButton
+source /etc/bigbluebutton/bbb-conf/apply-lib.sh
+
+enableUFWRules
+~~~
+
+Notice it includes `apply-lib.sh` which is another BASH script that contains some helper functions (see [apply-lib.sh](https://github.com/bigbluebutton/bigbluebutton/blob/master/bigbluebutton-config/bin/apply-lib.sh) source).  It then calls `enableUFWRules` to apply the settings in [restrict access to specific ports](#restrict-access-to-specific-ports).  
+The contents of `apply-config.sh` are not owned by any package, so it will never be overwritten.  
+
+When you create `apply-config.sh`, make it executable (`chmod +x /etc/bigbluebutton/bbb-conf/apply-config.sh`).  Using the above script as an example, whenever you do `bbb-conf` with `--restart` or `--setip`, you'll see the following output
+
+~~~
+Restarting BigBlueButton 2.2.0-xx-x ...
+Stopping BigBlueButton
+
+Applying updates in /etc/bigbluebutton/bbb-conf/apply-config.sh: 
+  - Enable Firewall and opening 22/tcp, 80/tcp, 443/tcp and 16384:32768/udp
+Rules updated
+Rules updated (v6)
+Rules updated
+Rules updated (v6)
+Rules updated
+Rules updated (v6)
+Rules updated
+Rules updated (v6)
+Firewall is active and enabled on system startup
+
+Starting BigBlueButton
+~~~
+
+The next sections give some examples of customizations you could add to `apply-config.sh`.
+
+
+### Reduce bandwidth for webcams
+
+If you expect users to share many webcams, to [reduce bandwidth for webcams](#reduce-bandwidth-from-webcams), add the following to `apply-config.sh`.
+
+~~~bash
+echo "  - Setting camera defaults"
+yq w -i $HTML5_CONFIG public.kurento.cameraProfiles.[0].bitrate 50
+yq w -i $HTML5_CONFIG public.kurento.cameraProfiles.[1].bitrate 100
+yq w -i $HTML5_CONFIG public.kurento.cameraProfiles.[2].bitrate 200
+yq w -i $HTML5_CONFIG public.kurento.cameraProfiles.[3].bitrate 300
+
+yq w -i $HTML5_CONFIG public.kurento.cameraProfiles.[0].default true
+yq w -i $HTML5_CONFIG public.kurento.cameraProfiles.[1].default false
+yq w -i $HTML5_CONFIG public.kurento.cameraProfiles.[2].default false
+yq w -i $HTML5_CONFIG public.kurento.cameraProfiles.[3].default false
+
+~~~
+
+### Apply lock settings to restrict webcams
+
+To enable lock settings for `Share webcam` by default (viewers are unable to share their webcam), add the following to `apply-config.sh`.
+
+~~~bash
+echo "  - Prevent viewers from sharing webcams"
+sed -i 's/lockSettingsDisableCam=.*/lockSettingsDisableCam=true/g' /usr/share/bbb-web/WEB-INF/classes/bigbluebutton.properties
+~~~
+
+After restart, if you open the lock settings you'll see `Share webcam` lock enabled.
+
+<p align="center">
+  <img src="/images/html5-lock-webcam.png"/>
+</p><br>
+
+### Apply custom settings for TURN server
+
+If always want a specific TURN server configuration, the following to `apply-config.sh` and modify `aaa.bbb.ccc.ddd` and `secret` with your values.
+
+~~~bash
+echo "  - Update TURN server configuration turn-stun-servers.xml"
+  cat <<HERE > /usr/share/bbb-web/WEB-INF/classes/spring/turn-stun-servers.xml
+<?xml version="1.0" encoding="UTF-8"?>
+<beans xmlns="http://www.springframework.org/schema/beans"
+        xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
+        xsi:schemaLocation="http://www.springframework.org/schema/beans
+        http://www.springframework.org/schema/beans/spring-beans-2.5.xsd">
+    <bean id="stun0" class="org.bigbluebutton.web.services.turn.StunServer">
+        <constructor-arg index="0" value="stun:aaa.bbb.ccc.ddd"/>
+    </bean>
+    <bean id="turn0" class="org.bigbluebutton.web.services.turn.TurnServer">
+        <constructor-arg index="0" value="secret"/>
+        <constructor-arg index="1" value="turns:aaa.bbb.ccc.ddd:443?transport=tcp"/>
+        <constructor-arg index="2" value="86400"/>
+    </bean>
+    <bean id="stunTurnService"
+            class="org.bigbluebutton.web.services.turn.StunTurnService">
+        <property name="stunServers">
+            <set>
+                <ref bean="stun0"/>
+            </set>
+        </property>
+        <property name="turnServers">
+            <set>
+                <ref bean="turn0"/>
+            </set>
+        </property>
+    </bean>
+</beans>
+~~~
+
+### Always record every meeting
+
+To [always record every meeting](#always-record-every-meeting), add the following to `apply-config.sh`. 
+
+~~~bash
+echo "  - Prevent viewers from sharing webcams"
+sed -i 's/autoStartRecording=.*/autoStartRecording=true/g' /usr/share/bbb-web/WEB-INF/classes/bigbluebutton.properties
+sed -i 's/allowStartStopRecording=.*/allowStartStopRecording=false/g' /usr/share/bbb-web/WEB-INF/classes/bigbluebutton.properties
+~~~
+
+
 # Other configuration options
 
 ## Increase the file size for an uploaded presentation