Archivable, replicable releases when building with Maven: is there a right way? - maven-2

We have a largish standalone (i.e. not Java EE) commercial Java project (10,000+ classes, four or five SVN repositories, ten or twenty third-party libraries) that's in the process of switching over to Maven. Unfortunately only one engineer (in a team of a dozen or so distributed across three countries) has any prior Maven experience, so we're kind of figuring it out as we go.
In the old Ant way of doing things, we'd:
check out source code from three or four repositories
compile it all into a single monolithic JAR
release that (as part of a ZIP file with library JARs, an installer, various config files, etc.)
check the JAR into SVN so we had a record of what the customers had actually got.
Now, we've got a Maven repository full of artifacts, and a build process that depends on Maven having access to that repository. So if we need to replicate what we actually shipped to a customer, we need to do a build against a Maven repository that has all the proper versions of everything. This is doable, I guess, if in (some version of) the (SVN-controlled) POM files we set all the dependencies to released versions?
But it gives our release engineer the creepy-crawlies, because there doesn't seem to be any way:
to make sure that somebody doesn't clobber the copy of foo-api-1.2.3.jar on the WebDAV server by mistake (the WebDAV server has access control, but that wouldn't stop a buggy build script)
to detect it if they did
to recover afterwards
His idea is, for release builds, to use a local file system as the repository rather than the WebDAV server, and put that local repository under SVN control.
Our one Maven-experienced engineer doesn't like that -- I guess because he doesn't like putting binaries under version control? -- and suggests that maybe the professional version of the Nexus server can solve the clobbering or clobber-tracking/recovery problem.
Personally, I'm not happy (sorry, Sonatype readers) with shelling out money for a non-free build system when we haven't even seen any benefit from the free version yet, and there's no guarantee it will actually solve the problem.
So our choices seem to be:
WebDAV server
Pros: only one server, also accessible by devs, ...?
Cons: easy clobbering, no clobber-tracking/recovery
Local file system
Pros: can be placed under revision control
Cons: only works with the distribution script
Frankly, both of these seem like hacks to me, and I have to wonder if there isn't a better way to do this.
So: Is there a right thing to do here?

I'm not sure to get everything but I would:
Use the maven-release-plugin (which automates the release process i.e. execute all the steps documented in release:prepare).
Use WebDAV with anonymous read-only and authenticated write policy (so only release engineer can actually deploy released artifacts to the corporate repo).
There is a no need to put generated artifacts under version control (if you have the poms under version control). I don't see the benefits of using the local file system instead of WebDAV (this is not providing more security, you can secure WebDAV as well). I don't see what the commercial version of Nexus would solve here.

Nexus has a setting which prevents you from clobbering an already released artefact in a release repository.
For a team of about a dozen, the free version of Nexus should be enough.

Related

Versioning APIs during internal development

In our team we have a number of APIs specified using the Open API Specification (formerly Swagger). We use Maven and OpenAPI Generator to generate code, build and publish the artifact to our local nexus. We build our code on TeamCity. The artifact is given the version that is specified in the pom.xml file of Maven.
During development we only use snapshot versions, that is versions which can be overwritten and will be cleaned up. This is opposite to release versions, that cannot be overwritten and needs administrative privileges to clean up. The reason for this is, that a developer usually changes a little bit at the time, which is much more convenient with snapshot versions. This also makes cleaning up outdated unreleased artifacts much easier.
Our problem is, that from time to time a developer makes API changes but forgets to set a new version. This works fine locally, but when the code is build on TeamCity the changed API overwrites the artifact of an older version. A developer not working on this branch will then experience a compile error, because the code does not match the API artifact being used.
What does others do? Is there a best practice? Preferably with standard tools. We have tried many things and nothing works well. At the same time this issue is so basic that someone must have a good solution - or at least experience enough to point to the least bad solution.

Trying to quickly resurrect an old Maven built project

First day on a project and first day with Maven and I've already wasted a lot of time trying to get it to build.
It appears the issue is that this old project has config, POMs, etc, that have many broken URLs embedded in them. i.e. Maven generated stack traces are presenting lots of URLs that are broken when trying to download project dependencies.
I have been given only the project source which includes Maven config files. I have not been supplied with existing Maven repositories, project dependent libraries or any build environment, etc.
I have been hacking away at these files but I don't get very far with each build attempt.
Am I doing something fundamentally wrong or is this Maven config really stuck in 2008?
Update:
My POM really was stuck in 2008, i.e. by virtue of versioning, it is a snapshot in time while the rest of the Java world moves on.
Some of the dependencies were no longer in any repositories, most of which were defunct projects and so I've ceased to use them. I had to rewrite the entire POM. I had to spend a lot of time tweaking versions to ensure compatibility between dependencies and between plugins. After much battling; some plugins just wouldn't coexist, clobbering each other.
All in all, it was many, many hours effort...too many for this project with only one developer, and I believe I only now know enough to be dangerous.
The good ol' IDE build system would have been a better choice in this instance.
ftr's advice (in the comments section) is right: Maven can't download certain dependencies, but that doesn't necessarily mean that those dependencies don't exist anymore. It could just be that the extra-repos section of the Maven configuration is now missing certain repositories, and/or there's some other connection issue (like bad proxy config - which may lead to you being able to access certain repos but not others).
I've been in a similar situation, and found out that while initially Maven reported errors when trying to download about 80% of the dependencies, after various tweaks on Maven's config I ended up making it download all of the dependencies (well except one which was really just a custom jar somebody did and which was fetched directly from the local file system, but that's besides the point).
Here's what I'd do:
Of all the dependencies that Maven says it can't download, try to spot 2 or 3 which are "well know" (like maybe if it says it can't download Servlet or some Spring library, write down the exact URL's he's trying to contact for those).
Manually check if those URL are indeed accessible (via browser). If so, make sure that the dependencies exist for the version Maven is looking for. Maybe they have been updated since the project was created, and the old version is no longer kept. In this case, 90% of the time the solution is to simply update Maven's pom to point to the new version.
If manually checking the dependency's URL shows you that in fact the dependency exists, for the version Maven is looking for, make sure there's no proxy or some other form of internet connection "extra config" which is done for your browser, but not for Maven. If that's the case, just update Maven's config with all those extra params (proxy, proxy authentication, etc).
If the dependency URL doesn't exist at all, try googling to see if that dependency doesn't now exist on some other repo. For example many of the JBoss dependencies (like Hibernate, etc) have changed repo location somewhere around 2007-2009. If that's the case just add the new repo to Maven's repo list (and remove the old one if it no longer exists).
Finally, the good old shameful way to fix this is to go to a colleague which has (or had) something to do with your project at some point, and copy his local Maven repo to your machine :)

Should we store JRE in CVS/SVN?

I want to bundle JRE 6.0 together with my java application. All my source code reside in CVS. My client will check-out the code and build it themselves. Should I store JRE in CVS?
I normally advocate putting most everything in source control, but this seems a little excessive. Why ?
the JRE is readily available from http://java.sun.com
it doesn't change that often. I'd expect you to specify a minimum version for your code to run against (e.g. 1.5, 1.6 etc.)
I would not put a JDK or JRE into a source code repository:
It is bad practice to put externally versioned things into your version control because it usually leads to over-constraining, obscuring and/or hard-wiring your app's external dependencies. (Maven or Ivy are good solutions for dealing with external dependencies, though not in this case,)
Putting binaries into version control is a bad idea for some version control systems.
But I think your real problem (actually, your user's organization's problem) is the IT folks who refuse to contemplate upgrading the JRE:
They need to be made aware of the
fact that they can install multiple
JRE versions on the one machine, and
configure apps to launch with the JRE
version they require. (It is trivial
on Linux ...)
They need to be made aware of the fact
that their policy is an impediment to
progress.
They need to be made aware of the fact
that their policy is a potential security
issue. If they force users to deploy their
own copies of JDKs / JREs in random places,
it will be difficult to ensure that JRE security
patches get applied. (Besides, 1.4.2 is due
to be end-of-life'd soonish, and security
patches for it will cease.)
EDIT: and there is also the legal question of whether "redistributing" a JRE out of your source code repository is a violation of Sun's click-through JRE/JDK download license. (I don't know ...)
As best practice, you shouldn't keep any binary files in the source control system. For Java developers there is maven that does it's work better in versioning jar files. The reason is that we want to keep our source repository as small as possible so it is faster for those that checks out our code for the first time.
But if you still want to keep binary files in the source control, it would be best to avoid using CVS, because CVS is bad in versioning binary files. You can search with google, why it is bad. If you use SVN, then it still okay because SVN handles binary files much better than CVS.
I see nothing wrong with storing the JRE in CVS.
However, it's not so important whether you do or not as long as your script can pull it as part of the build. For example, if you want to host a downloadable jre.zip on an HTTP server, or point to it in a Maven repo, that's just as good.
Well won't your client all ready have the JRE if you expect him to compile the code before running it? The JDK contains the JRE.
Depends a lot on what you use to handle dependencies. If you use Maven, then create a maven package with the stuff you need, and host it on a local repository.
If you just have CVS (like we do) then it is fine to create big binary packages (since you will need them) which you can then put in CVS. Just be aware that they should be static for best CVS performance.
ALso note that the jsmooth package can create an EXE file of your jar with an JRE embedded in it. This might solve your deployment problem.
For remote compilation, Eclipse can work with a plain JRE. You just need to tell Eclipse where JRE you already have prepared above is located on the disk. There is also a folder inside the Eclipse distribution where the launcher looks automatically.
I'm wondering about the client building the application themselves. It will require some kind of Java compiler, most probably javac wich is part of the JDK. So your client will not only need a JRE, but a JDK as well (unless they will be using Jikes or another alternative compiler).
javac is capable of generating bytecode for previous versions of Java, so using a newer compiler should not pose any problems.
Personally, I would not include large binaries like a JRE as part of my own repository. The JRE can be considered very stable and just listing the minimum version required should be enough. Installing a JRE is also something quite different than installing a single Java application. The two activities should not be mixed.

How do you distribute the IDE and it's configuration within your Team?

I'm wondering how Software Development Team distribute their Standard IDE(s)?
E.g. developing with Eclipse, custom Code formatter, svn Resository, Copyright Header..
At the moment my Team has a standard zip File which is then distributed withhin the developers.
Problem:
If one file, a Plugin or the IDE itself changes, e.g. new Coding Guidlines, Upgrade Eclipse 3.5.1 the whole distribution has to be done again. Every developer needs to unzip the bundel again. Imagine your working with different Workspaces (Jetty, different Tomcamt Versions, WTP) due to Project History That doesn't scale
I know that there are some related Articels
A new version of Eclipse just came out. Is there anything I can do to avoid having to manually hunt down my plugins again?
Manage Your Eclipse Install With A Local Git Repository
And some comercial Programs.
Eclipse also has a new Update-Installer Approach
But I don't see the Killer App. How do your team solve this? Is there a best practice?
I guess best would be a Program letting you choose your current Project and then downloads the configured IDE from the Server and leting you know if Project Config Files are Updated
For eclipse look at Buckminster it targets exactly your target I suppose, didn't use it personally through.
At my previous company they wrote a custom update agent that pulled from a centrally configured server which was updated by the team leaders. It worked well, until people wanted to install their own plugins.
Basically, a developer wanted a plugin, fought in futility to get it included in the default (managed) repo, installed it himself, then updates broke on his machine when the team lead had a sudden stroke of common sense and included it.
They never did come up with a 'good' way to manage it. But, at least they didn't put us all on terminal servers with thin clients.

Should we use Nexus or Artifactory for a Maven Repo? [closed]

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We are using Maven for a large build process (> 100 modules). We have been storing our external dependencies in source control, and using that to update a local repo.
However, we are ready to graduate to a local repo that can cache central so that we don't have to proactively download all 3rd parties (but we can still have a local repo to pull from). In addition we want to publish our internal build artifacts from a nightly build so that developers don't have to build the world.
We are considering Nexus and Artifactory. What are the reasons for preferring one over the other? Are there others we should be considering?
I'm sure that if you only talk about storing binaries from "mvn deploy" both will do fine.
We use Artifactory very extensively with all upgrades along the way. Lots of projects, numerous snapshots deployed and external repos proxied. Not a single problem. I find it hard to explain how other people experience issues with its DB, indexing or anything else. Nothing like that ever happened to us. Also, Artifactory allows to store data on a disk and only use a DB for storing metadata, it is quite flexible (see more here).
What makes those applications very different is their approach towards integration with other build tools and technologies. Nexus and Sonatype are pretty much locked on Maven and m2eclipse. They ignore anything else and only recently started to work on their own proprietary Hudson integration (see their Maven 3 webinar).
EDIT: This is not true anymore as of 2017 Nexus gives a much larger support for other build tools End of Edit
Artifactory provides an awesome Hudson, TeamCity and Bamboo integration, and Gradle / Ivy support. So while Nexus gives you nothing once you step out of Sonatype "comfort zone" (Maven, m2eclipse), Artifactory embraces and collaborates with all major build tools.
In fact, being able to deploy build artifacts from Hudson, when job has finished, and not by "mvn deploy" is a huge difference: Artifactory Hudson plugin makes an atomic-like deploy of all artifacts at once, only when a build job finished successfully. "mvn deploy" runs after each module and can deploy a partial set of artifacts if a build job fails in the middle. Deploying from Maven on module completion and not from a build server on job completion is really a bad thing to do.
As you see, Artifactory thinks "outside the box" while Nexus thinks "inside the box" and only cares about Maven and Maven artifacts.
Something else that makes Artifactory more accessible is their cloud-based Artifactory Online solution. For about $80 a month you have your own Artifactory instance, no need to dedicate any server for it.
Artifactory has a simple and straightforward REST API, don't know how it works for Nexus.
Edit Nexus has also a REST API that you can use easily as well.
To summarize, for basic storage of Maven artifacts I think both are fine. But while Nexus stops there being strictly a "Maven repository manager", Artifactory goes on and on, being a general "Binaries storage" for binaries of any kind, from any build tool and CI server.
I don't know about Artifactory but here are my reasons for using Nexus:
Dead simple install (and since 1.2, dead simple upgrade, too)
Very good web UI
Easy to maintain, almost no administrative overhead
Provides you with RSS feeds of recently installed, broken artifacts and errors
It can group several repositories so you can mirror several sources but need only one or two entries in your settings.xml
Deploying from Maven works out of the box (no need for WebDAV hacks, etc).
it's free
You can redirect access paths (i.e. some broken pom.xml requires "a.b.c" from "xxx"). Instead of patching the POM, you can fix the bug in Nexus and redirect the request to the place where the artifact really is.
Artifactory supports both file-system and database storage backends. Storage is checksum based and identical binaries are stored only once, no matter how many times they appear in the repo, which makes Artifactory more efficient storage-wise. Move and copy are also very cheap because of this architecture (in Nexus there's no REST for move/copy - you have to move stuff on the file system, then run corrective actions on the repo to let it know content has changed).
Another important differentiator is Artifactory has unique integration with Hudson and TeamCity for capturing information about deployed artifacts, resolved dependencies and environment data associated with build runs, which provides full build traceability.
Artifactory stores the artifacts in a database, which means that if something goes wrong, all your artifacts are gone. Nexus uses a flat file for your precious artifacts so you don't have to worry about them all getting lost.
If you need the "Pro" features of either (e.g. Staging repos, artifact promotion, NuGet), , then you need to consider the different pricing models, which are displayed on their websites.
http://www.jfrog.com/home/v_pricing
http://www.sonatype.com/nexus/purchase
In summary:
Artifactory Pro
you pay per server
you can pay more for increased service hours
Nexus Pro
you pay per seat, i.e. how many developers downloading artifacts
support service is Mon-Fri 0800-2000 ET only, no matter what you pay
No matter how many users you have, Nexus Pro offers a support service that's broadly equivalent to Artifactory's $7,450/year "Silver Value Pack".
$7,450/year will buy you approximately 67 Nexus Pro seats (1-50 # $108, the rest # $120).
On price and support alone then, Nexus Pro makes sense until you get to 67 users, at which point Artifactory becomes the cheaper option.
If you're doing all the support in-house; however, that magic point is about 23 users (Artifactory's most basic support offering is $2,750/year).
I made some research recenly about Artifactory 2 and Nexus 1.3. I'll list here the main differences I found:
Artifactory stores metadata and optionally files in DB, Nexus writes directly to file system. There are pros. and cons. for each approach. DB supports transactions, while in FS stored files can be accessed directly.
Artifactory has higher system requirements especially for disk space.
The most complete comparison: http://binary-repositories-comparison.github.io/
You should use Artifactory
Its latest version was a real jump
You can backup incrementally your repositories , which means you can have all your artifacts saved and maintain
Its has a easy to use web ui
and is really easy to set up
i enjoyed it a lot
check out its new version 2.0
From a learners point of view I note some specific differences between the two.
Sonatype .war deployment is not supported on Jboss application server at the time, although it does run under Tomcat.
Sonatype does not offer me an Amazon Machine Image (AMI), at present, that I could quickly stand up and test.
An Artifactory AMI is provided by Bitnami and takes a only a few minutes to stand up and a few more minutes to configure, maybe several tens of minutes dependant upon what you're trying to achieve.
Artifactory offer a SaaS version of Artifactory in the cloud so you can focus on getting things done rather than infrastructure.
I've no experience with Nexus but I've found Artifactory very intuitive and easy to configure, at least initially.
Added - I do note that the Artifactory User Guide, which may be OK for a seasoned pro, is a bit light on for some in depth explanations. For instance, starting out, one unzips and then addes a Repository, say RedHat's Jboss EAP Enterprise Repo. All goes fine but then when I tried to view the artifacts that were imported Artifactory reports zero artifacts? No errors or warnings so I'm now looking for an explanation. Is this normal or not normal? A simple explanation in the doco can quickly point one in the right direction. Being a good contributor I'm adding these comments to the project for the benefit of other starters.
All politics/religion aside, licensing makes a difference for some organizations.
Nexus is GPL now AGPLv3 and now Eclipse Public License (EPL).
Artifactory is Apache licensed LGPLv3 licensed as of version 2.1 of the product.
You may also want to consider Archiva, just for comparison's sake. It's Apache 2.0 licensed.
I see that Nexus usage is growing, while Artifcatory usage is generaly staying flat.
Picture is taken from here http://blog.sonatype.com/2014/11/42000-nexus-repository-managers-and-growing/
There is also matrix-comparison http://docs.codehaus.org/display/MAVENUSER/Maven+Repository+Manager+Feature+Matrix
Both Artifactory and Nexus have more or less similar feature set but Artifactory's LDAP support makes it more attractive over Nexus. Though Nexus also have LDAP support but in paid version :-(
Hmmm...my experience with artifactory is awful...but I'm a relative newbie so take it with a grain of salt. My overall complaint is that jar files recently uploaded to Artifactory do not seem to get indexed right away - as in for hours - and there does not seem to be a good way to force it. I've tried various things that appeared as if they should have worked, but didn't. I have been working with m2eclipse, adding dependencies to a project that i'm converting from ant. When I try to add a jar that I have just added to artifactory, I expect it to show up as a choice in the selector but it does not.
a coworker told me that they had installed nexus and so far they like it...but I can't vouch for it yet. I'm about to install that on a Linux box as soon as IT can find me one.