The Module Launcher provides a single entry point that bootstraps module JARs located in a home directory. A single Docker image that contains such a directory of module JARs can then be used to launch any of those JARs based on an environment variable. When running standalone, a system property may be used instead of an environment variable, so that multiple instances of the Module Launcher may run on a single machine. The following examples demonstrate running the modules for the ticktock stream (time | log).
1: clone and build this project:
git clone https://github.com/markfisher/module-launcher.git
cd module-launcher
./gradlew build
cd ..
2: clone and build the spring-cloud-streams project:
git clone https://github.com/spring-cloud/spring-cloud-streams.git
cd spring-cloud-streams
mvn -s .settings.xml package
cd ..
3: copy the spring-cloud-streams source and sink sample JARs to /opt/spring/modules:
mkdir -p /opt/spring/modules
cp spring-cloud-streams/spring-cloud-streams-samples/source/target/spring-cloud-streams-sample-source-1.0.0.BUILD-SNAPSHOT-exec.jar /opt/spring/modules/time.jar
cp spring-cloud-streams/spring-cloud-streams-samples/sink/target/spring-cloud-streams-sample-sink-1.0.0.BUILD-SNAPSHOT-exec.jar /opt/spring/modules/log.jar
4: start redis locally via redis-server (optionally start redis-cli and use the MONITOR command to watch activity)
java -Dmodules=time -Dserver.port=8081 -jar module-launcher/build/libs/module-launcher-0.0.1-SNAPSHOT.jar
java -Dmodules=log -Dserver.port=8082 -jar module-launcher/build/libs/module-launcher-0.0.1-SNAPSHOT.jar
The time messages will be emitted every 5 seconds. The console for the log module will display each:
2015-06-05 12:39:58.896 INFO 51078 --- [hannel-adapter1] config.ModuleDefinition : Received: 2015-06-05 12:39:58
2015-06-05 12:40:02.699 INFO 51078 --- [hannel-adapter1] config.ModuleDefinition : Received: 2015-06-05 16:39:52
2015-06-05 12:40:03.897 INFO 51078 --- [hannel-adapter1] config.ModuleDefinition : Received: 2015-06-05 12:40:03
1: build the module-launcher Docker image, including a copy of the module directory:
cd module-launcher
mkdir artifacts
cp -r /opt/spring/modules artifacts/
./dockerize.sh
2: run each module as a docker process by passing environment variables for the module name as well as the host machine's IP address for the redis connection to be established within the container:
docker run -p 8080:8080 -e MODULES=time -e SPRING_REDIS_HOST=<host.ip> 192.168.59.103:5000/module-launcher
docker run -p 8081:8081 -e MODULES=log -e SPRING_REDIS_HOST=<host.ip> 192.168.59.103:5000/module-launcher
1: Launch lattice with vagrant as described here.
2: Run a private Docker registry, and configure Lattice to use that as described here.
1: Push the Docker image to the private registry (if necessary, run $(boot2docker shellinit) first):
$ docker push 192.168.59.103:5000/module-launcher
2: Create a Redis instance on Lattice (running as root):
$ ltc create redis redis -r
3: Run the modules as long-running processes (LRPs) on Lattice:
$ ltc create time 192.168.59.103:5000/module-launcher -e MODULES=time -e SPRING_PROFILES_ACTIVE=cloud
$ ltc create log 192.168.59.103:5000/module-launcher -e MODULES=log -e SPRING_PROFILES_ACTIVE=cloud