[
https://issues.apache.org/jira/browse/CAMEL-10222?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=15477055#comment-15477055
]
ASF GitHub Bot commented on CAMEL-10222:
----------------------------------------
GitHub user nicolaferraro opened a pull request:
https://github.com/apache/camel/pull/1164
CAMEL-10222: New spring-boot BOM
I tried to run the integration tests (including the unit test part of each
module) using the starters only, but I found out that a mixture of spring-boot
dependencies and camel dependencies produce wrong classpaths, i.e. classpaths
that include different versions of jetty-core and jetty-util-xxx (9.3 and 9.2).
the same happens with submodules of activemq, hibernate, jackson and others.
Using Jetty 9.3 (the version supported by spring-boot) instead of the 9.2
has some advantages in that users can possibly use other sb-compatible
libraries in their applications.
The camel-jetty9 component had two issues with Jetty 9.3 (broken HTTPS
support and a changed method signature). I solved both.
Being able to always use Netty 4.15 (same for sb and camel) would be also
great. Unfortunately some modules (the one dependent on asynchttpclient) still
need to work with Netty 4.0.x.
Netty will not be part of the BOM.
This means that, in order to use a component, people just need to add the
starter to the application's pom, but if they include more starters, in some
(hopefully rare) circumstances, the application will not work (just because two
different versions of the same class cannot be present in a standard java
classpath).
I evaluated different options before creating the final BOM:
1)
A BOM with lower precedence over the spring-boot BOM (this bom would simply
be included by the users AFTER the spring-boot BOM declaration in their
applications)
Drawbacks:
- Some modules require specific versions of some libraries. Eg. Spring-boot
uses the cassandra v2 driver, while our component requires version 3. Cannot
override it with a BOM with lower precedence.
- In general, there's no way to force a specific camel version for a
particular library if spring-boot provides its own in the BOM (another example
is activeMQ)
2)
A BOM with higher precedence over the spring-boot one
Drawbacks:
- Problems with gson and other libraries. Some of our modules use different
versions of gson, so it should simply be excluded from the BOM and included in
each starter
- If spring-boot adds eg. google guava in the future we will have more
issues
3)
A brand new BOM, that includes all SAFE dependencies of the spring-boot BOM
and then all safe dependencies of Camel parent.
Drawbacks:
- The user must use the org.apache.camel:camel-spring-boot-dependencies
instead of the org.springframework.boot:spring-boot-dependencies
- Switching to a different version of spring-boot may be difficult (but
many components would not work out of the box)
Advantages:
- Possibility to change any user dependency in the future (to fix issues)
- Possibility to choose camel versions over spring-boot versions and
vice-versa
- Auto-generated from a reduced set of rules
I implemented the 3rd choice.
I also provided a separate camel-starter-parent to be able to change the
libraries included in the starters without affecting the user BOM.
To create the full BOM I created a generator: a simple maven plugin that
produces a flattened pom.xml file from information contained in a generator
project, using inclusion/exclusion rules.
I had to put a small set (~20) of version numbers in a separate
(camel-spring-boot-dm/pom.xml) file. The versions belonging to camel-parent
should be aligned when the corresponding entry is changed.
I changed the integration tests to use the new structure:
- No module is failing when included in a spring-boot application (at
least... before the rebase :D)
- Some modules (<20 / 220) are failing when running the unit tests from the
integration framework. Many problems are simply related to the testing tool
(it's difficult to make it stable). I'll investigate and correct real issues,
if any.
I fixed many problems either by changing the starter's pom or changing the
BOM, so now we have a more powerful tool for choosing the right libraries to
include in the user apps.
Also, non-spring-boot users (eg. Karaf) are not impacted by the changes.
You can merge this pull request into a Git repository by running:
$ git pull https://github.com/nicolaferraro/camel CAMEL-10222-P2
Alternatively you can review and apply these changes as the patch at:
https://github.com/apache/camel/pull/1164.patch
To close this pull request, make a commit to your master/trunk branch
with (at least) the following in the commit message:
This closes #1164
----
commit 9914a683e0cd894b10c02250e33364681fc41753
Author: Nicola Ferraro <[email protected]>
Date: 2016-09-01T10:41:55Z
CAMEL-10222: Fixed some poms up to HBase
commit f5060038ae0167da3e87599c9fc6b01e1449cb7e
Author: Nicola Ferraro <[email protected]>
Date: 2016-09-02T10:09:48Z
CAMEL-10222: Good configuration up to Jetty9
commit 1c153e005db8c06a49880da3f29eec192abaed93
Author: Nicola Ferraro <[email protected]>
Date: 2016-09-02T11:43:38Z
CAMEL-10222: Fixed resolution of wrong versions
commit fc3236c677476411abdc874c53b8442768d294ed
Author: Nicola Ferraro <[email protected]>
Date: 2016-09-06T10:09:54Z
CAMEL-10222: Added more stuff to the BOM
commit 575f8b4227d204e85a24623de4438742efc66314
Author: Nicola Ferraro <[email protected]>
Date: 2016-09-06T10:17:41Z
CAMEL-10222: Stable version
commit cc8ca7a676313788a17e367f60500bab097c338f
Author: Nicola Ferraro <[email protected]>
Date: 2016-09-06T15:36:11Z
CAMEL-10222: First generated BOM
commit e8adc961cae68679f11455022a2082269a9aa2ca
Author: Nicola Ferraro <[email protected]>
Date: 2016-09-07T09:46:56Z
CAMEL-10222: First real BOM
commit 991e8b679a45b360773e5dc0bd70bb4546abd6f1
Author: Nicola Ferraro <[email protected]>
Date: 2016-09-07T09:52:35Z
CAMEL-10222: Simpler BOM
commit 10502bfdc4e61d2b59e472b546c7b470fa1cf65c
Author: Nicola Ferraro <[email protected]>
Date: 2016-09-07T12:21:00Z
CAMEL-10222: Pre-test release
commit f6c574f3f0604006720320c25d9945dd4f2a65a1
Author: Nicola Ferraro <[email protected]>
Date: 2016-09-07T14:37:23Z
CAMEL-10222: First working version (no unit tests)
commit d54938c491c342b5d6e6565f43600e00ad8f140e
Author: Nicola Ferraro <[email protected]>
Date: 2016-09-08T09:52:32Z
CAMEL-10222: Fixing compatibility with Jetty 9.3 (provided with spring-boot)
commit a60bc3931c2ba2da5f771262b254e14b5f744067
Author: Nicola Ferraro <[email protected]>
Date: 2016-09-08T15:23:21Z
CAMEL-10222: Fixed several modules and starters
commit 2234e70f423cd4ddac9e54edb784a2fc923020d8
Author: Nicola Ferraro <[email protected]>
Date: 2016-09-09T09:07:14Z
CAMEL-10222: Rewriting the examples to use the new spring-boot BOM
commit 2dc87ca8f8a7f5e30772ae5c0b19b7765439a151
Author: Nicola Ferraro <[email protected]>
Date: 2016-09-09T09:30:55Z
CAMEL-10222: Rewriting the archetype to use the new BOM
commit e9f5a67fc3b06b88311e4103eb81a27243112ff7
Author: Nicola Ferraro <[email protected]>
Date: 2016-09-09T09:42:31Z
CAMEL-10222: Adding starters to the assembly
commit 4eda8803f524e2a52f323ef4f9fcef15f1b55cca
Author: Nicola Ferraro <[email protected]>
Date: 2016-09-09T09:53:01Z
CAMEL-10222: Simplified pom configuration
commit 421c82209938b4431e978720b5a76aca5268cd42
Author: Nicola Ferraro <[email protected]>
Date: 2016-09-09T11:29:48Z
CAMEL-10222: Fixing scala and servlet starters
commit 0ee01c19ac386a29a93973f088e8848b9a4aedd3
Author: Nicola Ferraro <[email protected]>
Date: 2016-09-01T10:41:55Z
CAMEL-10222: Fixed some poms up to HBase
commit 31b3eaaa7d8cfc87cebb640e2fde4a2abd806f6c
Author: Nicola Ferraro <[email protected]>
Date: 2016-09-02T10:09:48Z
CAMEL-10222: Good configuration up to Jetty9
commit bb07a8698547c3bcdc6dec98885243f74d1810ad
Author: Nicola Ferraro <[email protected]>
Date: 2016-09-02T11:43:38Z
CAMEL-10222: Fixed resolution of wrong versions
commit 28cde2f90449055a498311351dc5168548131449
Author: Nicola Ferraro <[email protected]>
Date: 2016-09-06T10:09:54Z
CAMEL-10222: Added more stuff to the BOM
commit a31baf8bb02b645316ee3929b2978f5c731d703a
Author: Nicola Ferraro <[email protected]>
Date: 2016-09-06T10:17:41Z
CAMEL-10222: Stable version
commit 8a0262f5edf7d3158c297e54defa766d6abf86aa
Author: Nicola Ferraro <[email protected]>
Date: 2016-09-06T15:36:11Z
CAMEL-10222: First generated BOM
commit eda18b03173877854f5625f7933590c2f5e5e231
Author: Nicola Ferraro <[email protected]>
Date: 2016-09-07T09:46:56Z
CAMEL-10222: First real BOM
commit f9ea57a5cd09cefab98236a5709f1aa4791fe51c
Author: Nicola Ferraro <[email protected]>
Date: 2016-09-07T09:52:35Z
CAMEL-10222: Simpler BOM
commit 8011560ec3de40b96923dbc2d9a3f3fa8afe5ec5
Author: Nicola Ferraro <[email protected]>
Date: 2016-09-07T12:21:00Z
CAMEL-10222: Pre-test release
commit b6599d0744b542a1dd2f43937fde3e848dc2471b
Author: Nicola Ferraro <[email protected]>
Date: 2016-09-07T14:37:23Z
CAMEL-10222: First working version (no unit tests)
commit f8a5e7111f8a2aecd54f2418c13248413e81696e
Author: Nicola Ferraro <[email protected]>
Date: 2016-09-08T09:52:32Z
CAMEL-10222: Fixing compatibility with Jetty 9.3 (provided with spring-boot)
commit 2855f2f03be451b76c7733213d59d29185c8d2ba
Author: Nicola Ferraro <[email protected]>
Date: 2016-09-08T15:23:21Z
CAMEL-10222: Fixed several modules and starters
commit a9b6ef2526c7c0a7f39cbb6b9f620a44bd9ba6a5
Author: Nicola Ferraro <[email protected]>
Date: 2016-09-09T09:07:14Z
CAMEL-10222: Rewriting the examples to use the new spring-boot BOM
----
> camel-spring-boot - New starters and BOMs
> -----------------------------------------
>
> Key: CAMEL-10222
> URL: https://issues.apache.org/jira/browse/CAMEL-10222
> Project: Camel
> Issue Type: New Feature
> Components: camel-spring-boot
> Reporter: Nicola Ferraro
> Assignee: Nicola Ferraro
> Fix For: 2.18.0
>
>
> It would be great if all camel components could be mixed-in in a spring-boot
> application without having to worry about dependencies.
> This would allow users to choose the camel components in a tool like forge on
> fabric8 or spring initializr to produce a base artifact. Writing camel routes
> will be the only task left to the user.
> Unfortunately, integration tests have shown that there are many (small,
> trivial) issues that need to be fixed before people can use a component with
> spring-boot (list follows).
> A possible solution that will provide a better experience with spring-boot
> would be:
> - Providing a new spring-boot bom
> - Providing a spring-boot-starter project for each camel component
> A user application pom will look like the following:
> {code:xml}
> <project xmlns="http://maven.apache.org/POM/4.0.0";
> xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance";
> xsi:schemaLocation="http://maven.apache.org/POM/4.0.0
> http://maven.apache.org/xsd/maven-4.0.0.xsd";>
> <modelVersion>4.0.0</modelVersion>
> <groupId>com.company</groupId>
> <artifactId>myapp</artifactId>
> <version>1.0</version>
> <dependencyManagement>
> <dependencies>
> <dependency>
> <groupId>org.springframework.boot</groupId>
> <artifactId>spring-boot-dependencies</artifactId>
> <version>xxx</version>
> <type>pom</type>
> <scope>import</scope>
> </dependency>
> <dependency>
> <groupId>org.apache.camel</groupId>
> <artifactId>camel-spring-boot-dependencies</artifactId>
> <version>xxx</version>
> <type>pom</type>
> <scope>import</scope>
> </dependency>
> </dependencies>
> </dependencyManagement>
> <dependencies>
> <dependency>
> <groupId>org.apache.camel</groupId>
> <artifactId>camel-starter-docker</artifactId>
> <!-- camel-spring-boot-starter-docker is a better (but longer)
> option, according to the s.b. documentation -->
> </dependency>
> <!-- Others -->
> <dependency>
> <groupId>org.apache.camel</groupId>
> <artifactId>camel-starter-http</artifactId>
> </dependency>
> </dependencies>
> </project>
> {code}
> As suggested by [~chirino], the creation of such starters (and of the bom)
> could be automated. Rules for creating such artifacts will be (at least) the
> following:
> *0) Basic*
> The spring-boot-bom will be derived from _camel-parent_, with some exceptions
> to solve particular issues. Most of the starters will just include a
> dependency on the artifact they refer to.
> *1) Logging*
> Logging issues have been found during integration tests, but they will be
> solved on the main artifacts (see CAMEL-10217). The starter generator will
> just check that logging implementation are missing from the artifact to
> prevent conflicts with slf4j-logback (used by spring-boot-starter).
> *2) Transitive overrides*
> Using the current implementation (with _camel-parent_ in the BOM), whenever a
> component requires a library that is different from the one declared in
> _camel-parent_, some hacks should be done, because the definition in the BOM
> takes precedence.
> Eg. An user wants to use camel-jclouds, but instead of the pretty:
> {code:xml}
> <dependency>
> <groupId>org.apache.camel</groupId>
> <artifactId>camel-jclouds</artifactId>
> </dependency>
> {code}
> He will end up with the following declaration in his application pom:
> {code:xml}
> <dependency>
> <groupId>org.apache.camel</groupId>
> <artifactId>camel-jclouds</artifactId>
> <exclusions>
> <exclusion>
> <groupId>org.slf4j</groupId>
> <artifactId>slf4j-log4j12</artifactId>
> </exclusion>
> </exclusions>
> </dependency>
> <dependency>
> <groupId>com.google.guava</groupId>
> <artifactId>guava</artifactId>
> <version>16.0.1</version> <!-- To override, again, the BOM version -->
> </dependency>
> <dependency>
> <groupId>com.google.inject</groupId>
> <artifactId>guice</artifactId>
> <version>3.0</version> <!-- To override, again, the BOM version -->
> </dependency>
> {code}
> As a solution to this problem, if there are at least two components requiring
> eg. a different version of guava, guava will not be included in the
> spring-boot bom, instead the specific version will be enforced on each
> starter (for all components using guava).
> Of course, this will not prevent issues when two components requiring
> different versions of guava will be used in the same user application. I
> think this issue cannot be avoided in applications with a standard
> classloader.
> *3) API implementations*
> In many cases, spring-boot detects the presence of a particular api in the
> classpath and expects an implementation is present. This happens for example
> with the bean validation api:
> {noformat}
> ***************************
> APPLICATION FAILED TO START
> ***************************
> Description:
> The Bean Validation API is on the classpath but no implementation could be
> found
> Action:
> Add an implementation, such as Hibernate Validator, to the classpath
> {noformat}
> The starters will include eg. the Hibernate Validator each time it is
> required to start the application.
> *4) Optional dependencies as variants*
> Starters are often used to provide a full stack for some higher level
> libraries/api.
> Eg. The JTA api can be provided in spring with three starters (as of 1.4.0):
> - spring-boot-starter-jta-atomikos
> - spring-boot-starter-jta-bitronix
> - spring-boot-starter-jta-narayana
> Each starter will include everything that is necessary in terms of libraries
> and auto-configuration for the particular implementation.
> Having such an automated tool for generating poms, we could create starters
> like:
> - camel-starter-rest-netty
> - camel-starter-rest-jetty
> - camel-starter-rest-undertow
> Each one having everything needed to run routes described using rest dsl
> (auto-configuration included. It will probably be developed on the main
> component).
> Similarly we can have:
> - camel-starter-jms
> - camel-starter-jms-jta
> The latter providing a preferred implementation and autoconfiguration (such
> as Narayana).
> *5) Tests*
> Each configuration will be checked by the already existing spring-boot
> integration tests. Support will be added for executing specific tests related
> to the a particular starter configuration, if needed.
> In case of dependencies enforced by both camel-parent and spring-boot (with
> different versions), the _camel-spring-boot_ BOM will use the spring-boot
> version. Problems will be highlighted by integration tests.
> I started this Jira mainly to check if this feature can improve the user
> experience and if the points I highlighted are sound, before starting the
> implementation.
> Probably there are also other issues/use-cases that I didn't cover in my list.
--
This message was sent by Atlassian JIRA
(v6.3.4#6332)
