JITSI on ARM64 (Amazon Graviton2 / aarch64)

jitsi-aws-graviton2-aarch64-instructions.txt

JITSI et al. uses Java but there's no escaping a CPU-arch specific library for *coding video.  You get the x86 one by default,
so it needs to be recompiled.  

Seen lots of instructions out there that look complicated and are longer, change a bunch of extra settings, etc.  
For AWS ARM64, much of that cruft is not needed.  This is pretty simple.

As of 7/2/21, these are the *default* instructions for installing JITSI (Ubuntu LTS 20.04):
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sudo -s # be root

sed -i -e 's/#DefaultLimitNOFILE.*$/DefaultLimitNOFILE=65000/' -e 's/#DefaultLimitNPROC.*$/DefaultLimitNPROC=65000/' -e 's/#DefaultTasksMax.*$/DefaultTasksMax=65000/' /etc/systemd/system.conf
systemctl daemon-reload

curl https://download.jitsi.org/jitsi-key.gpg.key | sudo sh -c 'gpg --dearmor > /usr/share/keyrings/jitsi-keyring.gpg'
echo 'deb [signed-by=/usr/share/keyrings/jitsi-keyring.gpg] https://download.jitsi.org stable/' | sudo tee /etc/apt/sources.list.d/jitsi-stable.list > /dev/null
apt update

apt install -y jitsi-meet
   - choose your fully-qualified hostname
   - choose self-signed
   
/usr/share/jitsi-meet/scripts/install-letsencrypt-cert.sh
   - put in your email address
   - make sure the fully-qualified hostname exists in DNS, Lets Encrypt plans to connect back to it to verify
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Now you have a running JITSI, but the native library it's using for *coding is x86, so we just need to recompile 
for aarch64:
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sudo -s # be root

systemctl stop prosody jitsi-videobridge2 jicofo

apt install -y automake autoconf build-essential libtool git maven m4 

apt install -y openjdk-8-jdk-headless 
update-alternatives --config java # pick openjdk-8 - the one just installed

cd /tmp
git clone https://github.com/sctplab/usrsctp
git clone https://github.com/jitsi/jitsi-sctp
mv ./usrsctp ./jitsi-sctp/usrsctp/
cd ./jitsi-sctp

mvn package -DbuildSctp -DbuildNativeWrapper -DdeployNewJnilib -DskipTests
cp jniwrapper/native/target/libjnisctp-linux-aarch64.so ./jniwrapper/native/src/main/resources/lib/linux/libjnisctp.so
mvn package
rm /usr/share/jitsi-videobridge/lib/jniwrapper-native-1.0-*
cp ./jniwrapper/native/target/jniwrapper-native-1.0-SNAPSHOT.jar /usr/share/jitsi-videobridge/lib/jniwrapper-native-1.0-SNAPSHOT.jar
chown jvb:jitsi /usr/share/jitsi-videobridge/lib/jniwrapper-native-1.0-SNAPSHOT.jar

systemctl start prosody jitsi-videobridge2 jicofo
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And that's it!  Pretty simple.

If you were doing this for some other ARM64 architecture (not Amazon's), you'd just swap the `libjnisctp-linux-aarch64.so` 
above with `libjnisctp-linux-arm64.so` or whatever the `arch` command would resolve to, and it should work. 

For other ARM64 platforms that have system resource constraints (like Raspberry Pi), yeah you'll have to adjust parameters
so Java is not so greedy with RAM/etc.  You can google those instructions pretty easily.