B A C D B A The existential question Why OSGi? Hello World - - PowerPoint PPT Presentation

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B A C D B A The existential question Why OSGi? Hello World - - PowerPoint PPT Presentation

Jul 15, 2023 151 likes •880 views

OSGi enRoute An Development Chain for OSGi B A C D B A The existential question Why OSGi? Hello World is not a benchmark Dev Chain Language Small versus Large dynamic Java & languages OSGi cost of change

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OSGi enRoute

An Development Chain for OSGi

αβ

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A B A B C D

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The existential question

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Why OSGi?

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“Hello World”

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… is not a benchmark

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Language Dev Chain

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Small versus Large

cost of change functionality

dynamic languages Java & OSGi

Startup cost of Java (statically typed languages) is higher However, long term cost is much lower

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target.foo(15,”abc”); target.foo(15,”abc”);

Javascript Java

You HOPE target implements foo … You KNOW target implements foo … and expects an integer and a string Your IDE knows exactly who is using this

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OSGi extends type safety to modules that evolve

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What is OSGi enRoute?

cost of change functionality

dynamic languages Java & OSGi

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How?

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OSGi enRoute

  • µService Oriented Programming
  • To reduce system complexity
  • Dependency Management
  • To reduce errors in development & operations
  • Tooling
  • To reduce time to market
  • Documentation & Training
  • To reduce confusion with developers
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Development Process

Components Run Descriptor Distro enRoute Profile

  • ther

API’s Deployable Unit test compile resolve build release define baseline external dependencies QA & Production staging

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bnd, the little engine that built …

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bndlib bndtools (eclipse) maven gradle, ant bnd command line

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bundle bundle

workspace

project cnf project

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profiles

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Profiles

  • A profile is specific catalog of specifications that vendors

can provide in a distribution.

  • An OSGi Profile consists of
  • µServices — Specifications of either OSGi Alliance or

external µservices.

  • Extenders — An extender provides support functionality

to OSGi bundles.

  • Capabilities — A capability describes a feature/function/

resource of the underlying system in abstract format.

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Profiles

  • Each OSGi enRoute Profile is represented by a

clean signed JAR library that can be used to build bundles against.

  • This is a specification only library,
  • It can not introduce unwanted dependencies, or
  • Let developers accidentally use proprietary

features of a vendor

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Planned Profiles

  • java 1.8 — All profiles are based on Java 1.8
  • base — A minimum profile, mostly as common base and for
  • demonstrations. It provides support for the best practices in our

industry.

  • base.debug — Supports developing and debugging
  • web — Web application development optimized for single page

web apps.

  • web.debug — Supports developing and debugging web apps.
  • persistence — Provides support for JPA on OSGi
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Base Profile

  • OSGi Core Framework — R6
  • OSGi Compendium — ConfigurationAdmin, Coordinator, EventAdmin,

LogService, MetaTypeService,UserAdmin

  • Logging — Extensive Java Logging and SLF4J (dynamic!) logging
  • support. Both service based an statics.
  • OSGi enRoute Support
  • Requirements and Capabilities — Completely developed with the

R&C model in mind

  • Specifications in code — Extensive support to use Java classes and

interfaces to also specifies non-Java aspects. E.g. license headers, forms, versioning, etc. Mostly through annotations.

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Base Profile

  • OSGi enRoute services
  • Authenticator and Authority — For extensible security
  • ConfigurationDone — To signal end of initialization at startup
  • DTOs — Extensive support for Data Transfer Objects (JSON, conversion,

diffing, named access)

  • Launched — Provides access to startup parameters
  • LoggerAdmin — Administrative front end to logging. Can handle OSGi,

SLF4J, and Java Logging

  • java.util.Timer — Scheduled tasks
  • java.util.concurrent.Executor — Background tasks
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package com.api

publish bind subscribe dependency

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Components

Component (object)

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Creates a component Can (de)activate, gets configuration data Service dependency

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Bundles

Bundle

component component component component

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Bundles

Bundle

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Private packages Exported packages Calculated imports bnd descriptor

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Continuous build JARs Content, e.g. Component XML

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external dependencies

(or where the heck is maven central????)

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Repository (includes maven central)

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Search repos Opens browser window

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OSGi Framework

Bundle

Assemble

Bundle Bundle Bundle Bundle Bundle

OSGi Framework

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distros

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Distros

  • A distro provides the runtime environment for one
  • r more profiles
  • The OSGi enRoute project will deliver a reference

distribution for all profiles based on open source and OSGi provided bundles

  • Members and other companies can provide other,

competing, interoperable, distributions (And are actively encouraged to do so).

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how do we prevent vendor lock-in?

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foo =14 base =“bar” id =21 namespace

Capability Model

(foo>=14) Requirement Capability

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  • sgi.wiring.package

Capability Model

(& (osgi.wiring.package=com.acme) (version>=1.2) )

Import Export

  • sgi.wiring.package=com.acme

version=1.2

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Resolve requirements bndrun descriptor Requirements Debug

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Running Resolved bundles

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staging

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Staging

OSGi Framework

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Export

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release

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Semantic Versioning

  • major – Breaking change for consumers
  • minor – Breaking change for providers
  • micro – Invisible change
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baselining

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Released bundles

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NoSuchMethodException

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Incompatible API change version wrong

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command line

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continuous integration

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summary

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Continuous Integration? IDE? command line? Repository?

Method Class Package Bundle Workspace

return parameters method method class class package package bundle bundle

bnd(tools) gradle, bnd jpm4j (maven central) travis

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// TODO

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TODO

  • bnd(tools) documentation
  • Base Tutorial
  • Additional profiles
  • Additional deployment standards
  • Create a community!
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