osgi semantic versioning with baselining in enroute - p kriens
DESCRIPTION
OSGi Community Event 2014 Abstract: Most people consider versions tedious and boring. And they are right! However, that does not make them less important. Unless you always compile all your code together and never have to go back in time, versions are the threads that keep the systems together in a stable way. That is, if people did not make those stupid mistakes with versions ... Meet semantic versioning and baselining. Semantic versions provide a framework to automate version handling. This framework is used in bnd(tools) to automate most version handling. This presentation will show what OSGi semantic versions are and its extension to also semantically version contracts. It will demonstrate the bnd(tools) support which is part of enRoute to detect semantic version violations in real time as well as in the continuous build. Speaker Bio: Peter Kriens is an independent consultant since 1990.He currently works for the OSGi Alliance and jpm4j. During the eighties he developed advanced distributed systems for newspapers based on microcomputers based on, at the time very novel, object oriented technologies. For this experience in Objects he was hired by a number of international companies, including Adobe, Intel, Ericsson, IBM, and many others. During his work at Ericsson Research in 1998 he got involved with the OSGi specification; Later he became the primary editor for these specifications. In 2005 he was awarded the OSGi Fellows title. After taking a sabbatical in 2012 to develop jpm4j he returned to the OSGi Alliance to help increasing adoption. He is Dutch but decided to live in France.TRANSCRIPT
Baselining with OSGi enRoute
Peter Kriens
Baselining with enRoute• Why baselining?
• Semantic versions
• Consumers & Providers
• Reports
• IDE Support
• Demo
Why Baselining?
3.80
DISCLAIMER!No children were harmed
for the next image …
Need more reasons?
NoClassDefFoundError
NoSuchFieldError
NoSuchFieldException
NoSuchMethodErrorNoSuchMethodException
UnsatisfiedLinkErrorUnsupportedClassVersionError
TypeNotPresentException
LinkageError
IllegalAccessError
ClassNotFoundException
AbstractMethodError
InstantiationError
Semantic Versioning
1.2.3.qual
MAJOR
MINOR
MICRO
who cares?
MAJOR
MINOR
MICRO
2.0.0 breaks everybody
1.3.0 backward compatible
1.2.4 no semantic change
Change to:1.2.3
Compatibility as in binary compatibility
Binary Compatibility• Reimplementing existing methods, constructors, and initializers to improve performance.
• Changing methods or constructors to return values on inputs for which they previously either threw exceptions that normally should not occur or failed by going into an infinite loop or causing a deadlock.
• Adding new fields, methods, or constructors to an existing class or interface.
• Deleting private fields, methods, or constructors of a class.
• When an entire package is updated, deleting default (package-only) access fields, methods, or constructors of classes and interfaces in the package.
• Reordering the fields, methods, or constructors in an existing type declaration.
• Moving a method upward in the class hierarchy.
• Reordering the list of direct superinterfaces of a class or interface.
• Inserting new class or interface types in the type hierarchy.
One example …
public interface Foo { void foo(); }
class FooImpl implements Foo { void foo(); }
class SomeCode { void bar(Foo f) { f.foo(); } }
public interface Foo { void foo(); void bar(); }
class FooImpl implements Foo { void foo(); }
class SomeCode { void bar(Foo f) { f.foo(); } }
⊗
interface Foo { void bar(); }
class FooImpl implements Foo { void foo(); }
class SomeCode { void bar(Foo f) { f.foo(); } }
⊗
⊗
All interfaces are created equal but some interfaces are
more equal than others …
org.osgi.service.eventadmin
Event!Admin!
Implement.
Event Admin
Event Handler
Event!Admin!
Observer
ProviderConsumer Contract
contract providerconsumer
• Consumers – Changes to the contract are usually backward compatible. Only MAJOR changes require a new implementation.
• Providers – Almost any change to the contract requires a new implementation. MAJOR and MINOR changes require a new implementation.
contract providerconsumer
1.2.3 [1.2,1.3)[1.2,2)
contract
1.3.0
contract
2.0.0
org.osgi.service.eventadmin
Event!Admin!
Implement.!
Event Admin
Event Handler
Event!Admin!
Observer!
ProviderConsumer Contract
org.osgi.service.eventadmin
Event!Admin!
Implement.
org.osgi.service.eventadmin
Event!Admin!
Implement.
@ConsumerType public interface EventHandler { void handleEvent(Event event); }
@ProviderType public interface EventAdmin { void sendEvent(Event event); void postEvent(Event event); }
org.osgi.service.eventadmin
Event!Admin!
Implement.
— Java Language Specification
“We encourage development systems to provide facilities that alert developers to the
impact of changes on pre-existing binaries that cannot be recompiled.”
So we did …
bndlib
bndtools antmaven
older newer
[{…},{…},{…},…]
jpm gradle
bndtools
web
* com.liferay.portal.kernel.dao.search MINOR 6.2.0 6.2.0 6.3.0 VERSION INCREASE REQUIRED < class com.liferay.portal.kernel.dao.search.DisplayTerms + method isSearch() + return boolean !!com.liferay.portal.kernel.dao.search MINOR 6.3.0 6.2.0 6.3.0 - < class com.liferay.portal.kernel.dao.search.DisplayTerms + method isSearch() + return boolean - version 6.2.0 + version 6.3.0
ant
[INFO] PACKAGE_NAME DELTA CUR_VER BASE_VER REC_VER WARNINGS [INFO] = ================================================== ========== ========== ========== ========== ========== [INFO] * com.example.stuff changed 5.7.1 5.7.1 5.7.2 Version increase required [INFO] ~ class com.example.stuff.SomeImporter [INFO] ~ annotated org.apache.felix.scr.annotations.Properties [INFO] + property value=[org.apache.felix.scr.annotations.Property:TYPE:CLASS:] [INFO] - property value=[org.apache.felix.scr.annotations.Property:TYPE:CLASS:]
maven
Drums …
Conclusion
Pretty Cool, eh!
Q&A