Packaging Eclipse Plugins
Glossary
- Bundle: An "OSGi bundle".
- Plugin: A functional unit of Eclipse functionality. Post-Eclipse 3.0, the term "plugin" can almost always be interchanged with the term "bundle". Colloquially, among non-Eclipse developers, the term is used to refer to a set of functional Eclipse plugins ex. "CDT".
- Feature: A collection of plugins.
- Fragment: A bundle with native elements ex.
org.eclipse.core.filesystem.linux.${arch}
Introduction
Eclipse is a modular platform that can be used for building everything from server-side applications to full-blown graphical applications like the Eclipse IDE and Lotus Notes. Each of the modular blobs is referred to as a plugin or a bundle. In a nutshell, the system itself is a small runtime (Equinox) based on the OSGi specifications [see http://www.eclipse.org/equinox/ for more information] which loads and runs a given list of bundles. Most people think of Eclipse as a programming integrated development environment (IDE). This document details best practices for packaging Eclipse IDE plugins. Examples include adding Subversion functionality (eclipse-subclipse) and tools for tracking your tasks (eclipse-mylyn).
Naming
Eclipse plugin packages MUST be named eclipse-<projectname>. For example, a package of the anyedit plugin for Eclipse would by named eclipse-anyedit.
Binary RPM naming
If a project provides multiple features, package each of the features as a separate binary plugin, matching the naming and grouping of plugins directly.
Group Tag
There is no single Group tag for Eclipse plugins. Choose a Group that best fits the plugin and satisfies rpmlint. Some of the existing Groups include:
Development/Tools Development/Languages System Environment/Libraries
Source
Obtaining source for Eclipse plugins is sometimes difficult. Most projects do not release source tarballs so it is often necessary to create an archive from a source revision control system. Ensure that instructions for reproducing the source archive are included in comments in the specfile. These instructions can take the form of either explicit instructions as in eclipse-cdt or be put into a separate shell script as in eclipse-rpm-editor .
Remember that Eclipse plugin packages, like all Fedora software packages, must be built from source, and cannot contain any "pre-built" binary components.
Building
Eclipse plugins SHOULD be built with the Eclipse Plugin Development Environment (PDE; PDE Build specifically) because these builds are generally easier to maintain. ant builds are acceptable, but are generally more difficult to maintain. Following what upstream does is the best practice.
eclipse-pdebuild
There is a script that makes invoking PDE Build easy: eclipse-pdebuild:
usage: eclipse-pdebuild [<options>]
Use PDE Build to build Eclipse features
Optional arguments:
-h Show this help message
-f Feature ID to build
-d Plugin dependencies in addition to Eclipse SDK
(space-separated, names on which to glob features and plugins)
-a Additional build arguments (ex. -DjavacSource=1.5)
-j VM arguments (ex. -DJ2SE-1.5=%{_jvmdir}/java/jre/lib/rt.jar)
-v Be verbose
-D Debug platform itself (passes -consolelog -debug to Eclipse)
-o Orbit dependencies
File Locations
All platform-independent plugins/features should go into %{_datadir}/eclipse/dropins/<one word name of this feature or plugin>. JARs should therefore go into %{_datadir}/eclipse/dropins/<name>/plugins and features should go into %{_datadir}/eclipse/dropins/<name>/features. Architecture-specific plugins/features should go into %{_libdir}/eclipse/dropins/<one word name of this feature or plugin>. JARs should therefore go into %{_eclipse_base}/dropins/<name>/plugins and features should go into %{_eclipse_base}/dropins/<name>/features. Example:
%install
installDir=%{buildroot}%{_datadir}/eclipse/dropins/quickrex
install -d -m 755 $installDir
unzip -q -d $installDir \
build/rpmBuild/de.babe.eclipse.plugins.QuickREx.zip
Arch vs. noarch
While many Eclipse plugins will be architecture-independent, there will be some that contain native parts. Plugins without native fragments should be noarch and go into %{_datadir}/eclipse/dropins and plugins with native fragments should be arch-dependent and go into %{_eclipse_base}/dropins.
Things to avoid
Pre-built binaries
If Eclipse plugins depend upon third party libraries (and licensing permits it), developers often include these libraries directly in their source control system. In this case, the libraries must exist as other packages in Fedora and their contents (such as their JARs) be symlinked from within the source and build trees of the Eclipse plugin being packaged. While it may make source archives smaller in size if they are cleansed of these pre-built files, it is not necessary to do so unless the libraries themselves are not redistributable. Binary RPMs MUST NOT include pre-built files.
A simple check which may be run at the end of %prep (courtesy David Walluck (I think that's who gave it to Ben Konrath)):
JARS="" for j in $(find -name \*.jar); do if [ ! -L $j ] ; then JARS="$JARS $j" fi done if [ ! -z "$JARS" ] ; then echo "These JARs should be deleted and symlinked to system JARs: $JARS" exit 1 fi
Differing from upstream
Plugins that are jarred should remain jarred and those that are expanded should be expanded in their RPM. There are two cases (that we can think of as of this writing) that warrant diverging from upstream:
- Symlinking to a binary JAR from another package
- Expanding a JAR to allow for symlinking to a binary JAR from another package
See below for a tip on how to deal with the expanded JAR case.
Specfile Template
Name: eclipse-plugin
Version: 1.0
Release: 1%{?dist}
Summary: Plugin provides such and such functionality for the Eclipse IDE.
Group: Development/Tools
License: EPL
URL: http://www.eclipse.org/plugin
Source0: org.eclipse.plugin-TAG-fetched-src.tar.bz2
Arch: noarch
BuildRequires: java-devel >= 1.5.0
BuildRequires: eclipse-pde
Requires: eclipse-platform
BuildRequires: eclipse-platform
%description
Plugin provides such and such functionality for the Eclipse IDE.
Specific functionality b is provided in %{name}-b.
%package b
Summary: b functionality for plugin
Requires: %{name} = %{version}-%{release}
Group: Development/Tools
%description b
%{name}-b enhances plugin with b-specific functionality.
%prep
%setup -q org.eclipse.plugin
%build
eclipse-pdebuild -f org.eclipse.plugin_feature
eclipse-pdebuild -f org.eclipse.plugin.b_feature
%install
install -d -m 755 $RPM_BUILD_ROOT%{_datadir}/eclipse/dropins/plugin-a
unzip -q -d $RPM_BUILD_ROOT%{_datadir}/eclipse/dropins/plugin-a \
build/rpmBuild/org.eclipse.plugin_feature.zip
unzip -q -d $RPM_BUILD_ROOT%{_datadir}/eclipse/dropins/plugin-b \
build/rpmBuild/org.eclipse.plugin.b_feature.zip
%files
%{_datadir}/eclipse/dropins/plugin-a
%files b
%{_datadir}/eclipse/dropins/plugin-b
%changelog
* Fri Oct 17 2008 Andrew Overholt <overholt redhat com> 1.0-2
- Update for Eclipse 3.4.x
* Fri Feb 29 2008 Andrew Overholt <overholt@redhat.com> 1.0-1
- Initial Fedora package
Tips and Notes
Common Defines
Requires
Until rpmstubby (see below) is released and/or more widespread, Requires on bits provided by the Eclipse SDK (RCP, SWT, Platform, JDT, PDE, CVS, etc.) should only be on the binary package providing the required functionality (ex. eclipse-cvs-client or eclipse-rcp). For IDE features, the most common requirement will be eclipse-platform.
Features vs. Plugins
Eclipse features are groups of plugins. They are preferred, but not required since they provide nice demarcation lines for binary RPMs. We generally try to make binary RPMs mirror upstream features. Eclipse features also work nicely with rpmstubby (see below), but not all plugins have features.
JAR Expansion
In rare cases it may be necessary to symlink to something inside a JAR. This situation is often referred to as "nested JARs". If the plugin code itself is not enclosed in a nested JAR, expansion will result in a directory structure containing class files. This is best illustrated with an example:
$ unzip -l org.eclipse.mylyn.web.core_2.2.0.I20071220-1700.jar | grep jar$ 46725 12-20-07 20:08 lib-httpclient/commons-codec-1.3.jar 279781 12-20-07 20:08 lib-httpclient/commons-httpclient-3.0.1.jar 38015 12-20-07 20:08 lib-httpclient/commons-logging-1.0.4.jar 26202 12-20-07 20:08 lib-httpclient/commons-logging-api-1.0.4.jar 153253 12-20-07 20:08 lib-rome/jdom-1.0.jar 197290 12-20-07 20:08 lib-rome/rome-0.8.jar 26624 12-20-07 20:08 lib-xmlrpc/ws-commons-util-1.0.1-sources.jar 34840 12-20-07 20:08 lib-xmlrpc/ws-commons-util-1.0.1.jar 35142 12-20-07 20:08 lib-xmlrpc/xmlrpc-client-3.0-sources.jar 43312 12-20-07 20:08 lib-xmlrpc/xmlrpc-client-3.0.jar 91225 12-20-07 20:08 lib-xmlrpc/xmlrpc-common-3.0-sources.jar 98051 12-20-07 20:08 lib-xmlrpc/xmlrpc-common-3.0.jar
Note that we have embedded JARs which we would like to turn into symlinks to existing JARs (from other packages). If we simply unzip the plugin JAR and symlink, one would think we would be okay:
$ unzip -qq org.eclipse.mylyn.web.core_2.2.0.I20071220-1700.jar $ rm !$ $ ls about.html lib-httpclient lib-rome lib-xmlrpc META-INF org $ <do symlinking here>
However, we end up with the plugin classes themselves being expanded in the org directory. Bug #273881 causes build failures when building debuginfo packages in this case. The acceptable workaround is to modify the build.properties file in the plugin to JAR the plugin code separately (ex. mylyn-webcore.jar) and include it within this expanded plugin directory. An example of this work-around can be seen in eclipse-mylyn (specifically the patches related to org.eclipse.mylyn.webcore).
rpmstubby
rpmstubby is a small project that is part of the linuxdistros project at eclipse.org. Its aim is to make packaging Eclipse plugins as RPMs extremely simple. Specfiles for packages like eclipse-mylyn were originally stubbed out using it. Available as eclipse-rpmstubby package.
_libdir and _eclipse_base macros
Some Eclipse packages, while generally being noarch, require architecure specific Eclipse plugins to be compiled and run. Unfortunately, the %{_libdir} macro is not always correctly resolved during noarch builds (it may point to /usr/lib64 on 32 bit architecture and vice-versa), so it should not be used in eclipse packages. A new macro, that is correctly resolved to /usr/lib/eclipse on 32 bit systems, and to /usr/lib64/eclipse on 64 bit systems, is %{_eclipse_base}, and should be used in all places where a noarch eclipse bundle depends on arch specific bundle.