Deploying Heterogeneous Artifacts to the Cloud with OSGi - Neil Bartlett
- 1. Copyright © 2005 - 2013 Paremus Ltd. May not be reproduced by any means without express permission. All rights reserved. Paremus Packager March 2013 Deploying Heterogeneous Artifacts to the Cloud with OSGi Neil Bartlett - Paremus neil.bartlett@paremus.com Friday, 29 March 13
- 2. Motivation Good OSGi Bundles are Self-Describing Dependency Management, Resolving, Provisioning... Consistent Interface: Bundle Install/Uninstall/Update/Start/ Stop, Config Admin, Metatype, Log Service... If I Have a Bundle, I Always Know How to Deploy It! Friday, 29 March 13
- 3. Unfortunately... Not All Software is Built in OSGi (yet). Lots of useful things are not even Java! How do we ensure this software is installed where it needs to go? Current state-of-the-art: assume it’s already there! Friday, 29 March 13
- 4. Proposal Wrap Native Artifacts in OSGi Bundles Tie the Lifecycle. Bundle Start => Launch, etc. Link to Standard OSGi Services: Configuration Admin, Metatype, Log Service... Friday, 29 March 13
- 5. Separation of Concerns 1. What and How Should we Run? 2. When, How Many, and How Configured? 3. Actually Run and Monitor It. Friday, 29 March 13
- 6. Separation of Concerns 1. What and How Should we Run? => Package Type 2. When, How Many, and How Configured? => Process Guard 3. Actually Run and Monitor It => Watchdog Friday, 29 March 13
- 7. The PackageType Usually Contains the Native Parts, or Knows Where to Get Them Installs the Native Program Returns Scripts to the Packager for: start, stop, ping... Is Platform Specific Friday, 29 March 13
- 8. The PackageType One Bundle for Each Type/Platform Combo Use Generic Caps/Reqs, e.g.: Provide-Capability: packager.type; packager.type=mongodb; version:Version=2.2.0 Require-Capability: osgi.native; filter:=”(& (osgi.native.osname=Linux) (osgi.native.processor=x86-64) )” Friday, 29 March 13
- 9. Example PackageType @Component(properties = "package.type=mongodb") public class MongoPackagerUNIX implements PackageType { @Override public PackageDescriptor create(Map<String,Object> properties, File data) throws Exception { MongoProperties config = Converter.cnv(MongoProperties.class, properties); PackageDescriptor pd = new PackageDescriptor(); // Expand mongod executable File mongod = new File(data, "mongod"); if (!mongod.isFile()) { IO.copy(getClass().getResource("/data/mongod"), mongod); run("chmod a+x " + mongod.getAbsolutePath()); } // Construct the start command StringBuilder sb = new StringBuilder().append(mongod.getAbsolutePath()); if (config.port() != 0) sb.append(" --port ").append(config.port()); pd.startScript = sb.toString(); // ... return pd; } Friday, 29 March 13
- 10. The ProcessGuard Gathers Process Config Properties Signals When to Start/Stop Receives State Change Events (started, crashed...) Advertises the Running Package (Optional) Friday, 29 March 13
- 12. The ProcessGuard 1. Published Service Means “Start the Process” 2. Packager Calls getProperties() to get Config 3. Passes Config to PackageType, gets Script 4. Unpublished Service Means “Stop the Process” Friday, 29 March 13
- 13. ProcessGuard Dependencies Use Declarative Services to Easily Create Dependencies for the Package E.g. Required Configuration Can Also Use Service References... Friday, 29 March 13
- 14. Example ProcessGuard @Reference(target = "(uri=http://*/rest)", type='*') void setRestService(Endpoint ep, Map<String, String> props) throws Exception { this.restSvcUri = new URI(props.get("uri")); } Friday, 29 March 13
- 15. Publishing an Endpoint Guard can Optionally Publish an Endpoint Service Just a Marker Interface with a URI Property, e.g.: mongodb:// 10.0.0.1:27017/ Use OSGi Remote Services (RSA) Discovery to Publish Across the Network Friday, 29 March 13
- 17. Consuming Endpoints Guards can be Endpoint Consumers as Well Example, Nginx Friday, 29 March 13
- 18. Nginx Load Balancer Web Server Web Server Web Server Web Server request forward Friday, 29 March 13
- 20. Nginx Guard Tracks Endpoints with a DS Multiple/Dynamic Reference PackageType Rewrites Nginx Config and Sends a UNIX Signal Friday, 29 March 13
- 21. Watchdog Java Program that Sits Between OSGi and Native Package Execs Native as a Child Process Death of Watchdog => Death of Native Package Heartbeat UDP Between OSGi and Watchdog Friday, 29 March 13
- 22. Native ProcessOSGi Application Watchdog heartbeat exec Friday, 29 March 13
- 23. Watchdog Must Be as Simple As Possible! Mustn’t Crash Might Need Elevated Privileges (e.g. setuid) Friday, 29 March 13
- 25. Tooling Bndtools Highly Recommended Project Templates Coming Soon... It’s Just Plain Declarative Services! Friday, 29 March 13
- 26. Conclusion Friday, 29 March 13
- 27. Availability API is Open Source (EPL): github.com/bndtools/bndtools-rt/ Paremus implementation releasing later this week, stay tuned: http://blogs.paremus.com Register interest: info@paremus.com Examples: MongoDb, Mosquitto, Nginx, Derby, Custom Play App In progress: RabbitMQ, Riak Friday, 29 March 13