[EXAMPLE] Thespian director - dockerized cluster working example

[htarnacki]

hi,
during my personal work i prepared some example project that uses Thespian and has following features:

• cluster of 2 nodes: leader and worker
• nodes are separated docker containers
• actor implementation code is loaded into leader node and propagated to worker node through Thespian director
• actors on worker node are created from actors on leader node
• built in mechanism for an actor creation on selected worker nodes identified by their individual node id

requirements:

• docker (to run example)
• java with JAVA_HOME variable set (to build project. I use gradle as a build tool and it requires java to run)
• python 3.8
• pipenv

description of steps which happen after running an example:

• leader node is started
• worker node is started
• on leader node Thespian director starts 2 actors: ConventionListener and LeaderActor. After starting it sends to them "start messages"
• Leader actor starts "wake up" process. It will wake up every 60s to just log: "I am alive" message
• ConventionListener actor starts listening on ActorSystemConventionUpdate events
• When worker node starts then ActorSystemConventionUpdate event is emitted and then ConventionListener actor records node id of a started worker node and sends this information to Leader actor (in a WorkerNodeAdded message)
• Leader actor after receiving WorkerNodeAdded message records node id of started worker node and creates specifically on this node an instance of a WorkerActor. After that it sends a message to this WorkerActor asking it to say hello
• WorkerActor on worker node after receiving SayHello message just logs hello message

usage:

# unpack archive file
cd ./thespian/example
vim ./docker/worker-node/THESPIAN_DIRECTOR_DIR/convleader.cfg
# change string "x.x.x.x" to your real external ip adress (not local host!. Do not remove port from string!)
./gradlew install
./gradlew build
./start

# observe logs:
# ./docker/leader-node/logs/leader.log
# ./docker/worker-node/logs/worker.log

./stop

@kquick feel free to use it as an example in Thespian project if you find it usefull

thespian-example.zip