How can you use imagemin with WebJars from Clojure? - clojure

As far as I can tell WebJars are designed to serve up static assets from a JVM based back end. There is a WebJar library for imagemin, but imagemin is a build time or run time concern. The browser has no idea what to do with gifsicle.exe or the like.
So how can imagemin be used from a JVM based language, specificially Clojure in my case?

Related

Advice for Web-based Remote Build System

I'm interested in setting up a remote build system at work, initially for internal use, potentially for some customers going forward. We need to compile library code on several different machines (PC, Mac) and with multiple compilers, and it can be a real pain trying to get access to a full set. This is not our main build system, which is Jenkins-based and uses an approach that is not easily modified for the purpose envisaged here.
The idea would be that you could post your source to a website with some basic build parameters, it would compile the code and you could then download the generated code. Ideally users could pick which version of the underlying software they compiled their libraries against. I envisage it being supported by a virtual machine.
Reason I'm posting is that I don't really want to roll-my-own as much as possible - longer term it has maintenance implications - and would prefer something as pre-existing as possible. Obviously one would expect some adaptation in terms of scripting.
Any suggestions? It would have to be supported on Mac and PC at absolute minimum.
This sounds like something you could do by creating a parameterized Jenkins job (the build params given as input to your web frontent could be passed on to the job, perhaps via the Jenkins API). Personally, I would see if you could skip the step of creating a new webfrontend, and have users pass their build params directly to Jenkins.
To support downloading the resulting compiled code, you could have the Jenkins job archive the build as an artifact. Users could then download the files from the result page for that individual build.
As for how to make a Jenkins job accept source code to compile as input, perhaps you could use branches in your CM system? Your users could push their code to a branch, and then pass the branch as a build param. Otherwise, you might be able to use the file parameter feature of Jenkins.

Reliable way to wrap Node.js+Socket.io into OSX executable? (or C/C++/Objective-C libraries to use as alternatives)

I'm working on a project that needs a simple, lightweight event server (i.e. a server that passes events between different client applications implemented in Javascript). At first Node.js and Socket.io seemed like the perfect solution but the amount of dependencies and config involved took some of the shine off (see below for details on the project and why configuration is an issue). Is there some tested and reliable way to package all those dependencies into a single executable that can be run with no additional configuration? If not are there any good C/C++ Websockets libraries that could be combined with something like Mongoose to create a standalone executable?
Project Details
Basic use case:
A moderator turns on the server on their OSX machine.
A group of 10-20 users point their mobile devices to a site hosted on the moderator's machine
Communication ensues for the duration of the session (about an hour)
Basic requirements:
Simple setup: The moderator will not be a developer and may have little to no technical expertise. Anything that requires the terminal or fiddling with configuration files or package managers is a non-starter.
Unreliable Configuration: The moderator's machine will be used in a lot of different contexts and by a lot of different users. Therefore the system shouldn't rely on very specific or pristine settings (i.e. would like to avoid something with lots of dependencies that requires special environment variables to be set)
Performance and security are not a concern: The server will run locally with small number of trusted users for a short time so security and high performance aren't important.
Interesting question.
I know there are some C and/or C++ WebSocket libraries under development in the WebSocket community (mentioned on the IETF discussion list) if you want to go in that direction.
It might interest you to know that some parts of Node.js are actually written in javascript and compiled during the build process as built-in modules, but I don't know of any way to accomplish that for your own code short of hacking up the build.
Since this is OSX you could package Node alongside your own code and any modules, built against a static v8 library, in your .app. This would be a fairly tight coupling though not quite what you are asking for.
It's also possible to build your extension (or part of it) as a C++ module loaded by Node and v8.

buildbot vs hudson/jenkins for C++ continuous integration

I'm currently using jenkins/hudson for continuous integration a large mostly C++ project. We have separate projects for trunk and every branch. Also, there are some related projects for the Java code, but the setup for those are fairly basic right now (we may do more later though). The C++ projects do the following:
Builds everything with options for whether to reconfigure, do a clean build, or use a fresh checkout
Optionally builds and runs all tests
Optionally runs all tests using Valgrind's memcheck
Runs cppcheck
Generates doxygen documentation
Publishes reports: unit tests, valgrind, cppcheck, compiler warnings, SLOC, open tasks, and code coverage (using gcov, gcovr, and the cobertura plugin)
Deploys code nightly or on demand to a test environment and a package repository
Everything is configurable for automatic builds and optional for on demand builds. Underneath, there's a bash script that controls much of this, which farther depends on our build system, which uses automake and autoconf along with custom bash scripts.
We started using Hudson (at the time) because that's what the Java guys were using and we just wanted nightly builds. Since then, we've added a lot more and continue to add more. In some ways Hudson is great, but certainly isn't ideal.
I've looked at other solutions and the only one that looks like it could be a replacement is buildbot. Would buildbot be better for this situation? Is the investment worth it since we're already using Hudson? Why?
EDIT: Someone asked why I haven't found Hudson/Jenkins to be ideal. The short answer is that everything can be improved. I'm simply wondering if Jenkins is the best current solution for my use case or whether there is something better (buildbot?) that would be easier to maintain in the long run even as new requirements come up.
Both are open source projects, but you do not need to change buildbot code to "extend" it, it is actually quite easy to import your own packages in its configuration in which you can sub-class most of the features with your own additions. Examples: your own compilation or test code, some parsing of outputs/errors to be given to the next steps, your own formating of alert emails etc. there are lots of possibilities.
Generally I would say that buildbot is the most "general purpose" automatic builds tools. Jenkins however might be the best related to running tests, especially for parsing and presenting results in nice ways (results, details, charts.. some clicks away), things that buildbot does not do "out-of-the-box". I'm actually thinking of using both to have sexier test result pages.. :-)
Also as a rule of thumb it should not be difficult to create a new tool's config: if the specification of what to do (configs, builds, tests) is too hard to switch from one tool to another, it is a (bad) sign that not enough configuration scripts are moved to the sources. Buildbot (or Jenkins) should only call simple commands. If it is simple to run tests, then developers will do it as well and this will improve the success rate, whereas if only the continuous integration system runs the tests, you will be running after it to fix the new code failures, and will loose its non-regression value, just my 0.02€ :-)
Hope it'll help.
The 'result integration' is also in jenkins/hudson, and you can relatively easily capture build products without having to 'copy them elsewhere'.
For our instance, the coverage reports and unit test metrics and javadoc for the java code is all integrated. For our C++ code, the plugins are a little lacking, but you can still get most of it.
we ran buildbot since pre 0.7, and are now running 0.8 and are only now seeing any real reason to switch, as buildbot 0.8 forgot about windows slaves for an extended period of time and the support was pretty poor.
There are many other solutions out there, besides Jenkins/Hudson/BuildBot:
TeamCity by Jetbrains
Bamboo by Atlassian
Go by Thoughtworks
Cruise Control
OpenMake Meister
The specifics about what you are doing are not so important, in fact, as long as the agents (aka nodes) that you are doing them on support those tasks.
The beauty of a CI server is noticing when the build changes to trigger a new build (and test), publish the artifacts, and publish test results.
When you compare CI tools like those we mentioned, consider features like the usability of its interface, how easy is branching (and features it might offer like automatic merging), notifications (like XMPP/jabber), or an information-radiator (like hooking up a monitor to always show status). Product support is another thing to consider - Jenkins' support is only as good as who is responding to community questions at the time you have questions.
My personal favorite is Bamboo, but it comes with a license fee.
I'm a long-time Jenkins user in the middle of evaluating Buildbot and would like to offer a few items for folks considering using Buildbot for multi-module solutions:
*) Buildbot doesn't have any out-of-the-box concept of file artifacts related to each build. It's not in the UI and it's not in any of the builtin "steps" modules as far as I can see:
http://docs.buildbot.net/current/manual/configuration/buildsteps.html
...and I see no third party plugin:
https://github.com/buildbot/buildbot/wiki/PluginList#steps
Buildbot does collect all the console output from a given build, but critically, you can't collect files related to it.
*) Given that artifacts are not supported, it's not easy to create "collector" projects that bring multiple modules into say, a single installer. Jenkins has a great feature that lets you parameterize a build with builds from other modules (the parameter type is a run).
*) Establishing dependencies between modules is trickier in Buildbot. Say you have a library that three binaries depend on, and you want those binaries to rebuild each time the library changes. Jenkins has triggers built into the UI. If you want to do triggers in Buildbot you have to script them using schedulers.Dependent, and it causes a lot of item congestion in the Schedulers UI.
*) When you're working in Buildbot, it seems that pretty much all of the configuration is done in master.cfg in code. This is awesome and frustrating.
*) Buildbot forces you to create a worker in addition to a master server. This is annoying for beginners and systems for which a single build server is sufficient.
My impression after two days of Buildbot evaluation is that we'll stick with Jenkins, primarily due to it having artifacts. Buildbot is a tool we'd only use if we had more extensive customization needs, and the time to do it.
On the subject of buildbot and artifacts -- I don't have enough user score to make a comment -- you can get artifacts from buildbot 2.x series pretty easy with built-in file/directory upload actions. However you rarely want to just move files. Typically you make a triggered buildstep that does deployment directly off the worker for best results. eg push to cloud storage, containers, thirdparty (steam uploads), etc.
This way you can get metrics on the uploads and conditionally control them better (or even mix and match artifacts across worker machines).

Best Practices for Code/Web Application Deployment?

I would love to hear ideas on how to best move code from development server to production server.
A list of gotcha's, don't do this list would be helpful.
Any tools to help automate the steps of.
Make backups of existing code, given these list of files
Record the Deployment of these files from dev to production
Allow easier rollback if deployment or app fails in any way...
I have never worked at a company that had a deployment process, other than a very manual, ftp files from dev to production.
What have you done in your companies, departments, etc?
Thank you...
Yes, I am a coldfusion programmer, but files are files, and this should be language agnostic question.
OK, I'll bite. There's the technology aspect of this problem, which other answers have already covered. But the real issue is a process problem. Where the real focus should be ensuring a meaningful software development life cycle (SDLC) - planning, development, validation, and deployment. I'll cover each in turn. What you want is a repeatable activity at each phase.
Planning
Articulating and recording what's to be delivered. Often tickets or user stories are enough. Sometimes you do more, like a written requirements document, that a customer signs off on, that's translated into various artifacts such as written use cases - ultimately what you want though is something recorded in an electronic system where you can associate changes to code with it. Which leads me to...
Development
Remember that electronic system? Good. Now when you make changes to code (you're committing to source control right?) you associate those change with something in this electronic system - typically tickets. I like Trac, but have also heard good things about Atlassian's suite. This gives you traceability. So you can assert what's been done and how. Then you can use this system and source control to create a build - all the bits needed for whatever's changed - and tag that build in source control - that's your list of what's changed. Even better, have a build contain everything, so that it's standalone entity that can easily be deployed on it's own. The build is then delivered for...
Validation
Perhaps the most important step that many shops ignore - at their own peril. Defects found in production are exponentially more expensive to fix then when they're discovered earlier in the process. And validation is often the only step where this occurs in many shops - so make sure yours does it.
This should not be done by the programmer! That's like the fox watching the hen house. And whoever is doing is should be following some sort of plan. We use Test Link. This means each build is validated the same way, so you can identify regression bugs. And, this build should be deployed in the same way as you would into production.
If all goes well (we usually need a minimum of 3 builds) the build is validated. And this goes to...
Deployment
This should be a non-event, because you're taking a validated build following the same steps as you did in testing. Could be first it hits a staging server, where there's an automated copying process, but the point being is that is shouldn't be an issue at this point, because you validated with the same process.
Conclusion
In terms of knowing what's where, what you really want is a logical way to group changes together. This is where the idea of a build comes in. It's really the unit that should segue between steps in the SDLC. If you already have that, then the ability to understand the state of a given system becomes trivial.
Check out Ant or Maven - these are build and deployment tools used in the Java world which can help you copy / ftp files, backup and even check out code from SVN.
You can automate your deployment steps using these tools, for example Ant will allow you declare a set of tasks as part of your deployment. So you could, for example:
Check out a revision using SVNAnt or similar to a directory
Copy (and perhaps zip first) these files to a backup directory
FTP all the files to your web server(s)
Create a report to email to the team illustrating the deployment
Really you can do almost anything you wish to put time into using Ant. Maven is a little more strucutred (and newer) and you can see a discussion of the differences here.
Hope that helps!
In a nutshell...
You should start with some source control solution - probably Subversion or Git. Once that's in place you can create a script that generates a clean build of your source code and deploys it to your production server(s).
You could do this with a simple batch script or use something like Ant for more control. Here is a simple example of a batch file using Subversion:
svn copy svn://path/to/your/project/trunk -r HEAD svn://path/to/your/project/tags/%version%
svn checkout svn://path/to/your/project/trunk -r HEAD //path/to/target/directory
Ant makes it easy to do things like automatically run unit tests and sync directories. For example:
<sync todir="//path/to/target/directory" includeEmptyDirs="true" overwrite="true">
<fileset dir="${basedir}">
<exclude name="**/*.svn"/>
<exclude name="**/test/"/>
</fileset>
</sync>
This is really just a starting point. A next step might be a continuous integration solution like Hudson. I would also recommend reading "Pragmatic Project Automation: How to Build, Deploy, and Monitor Java Applications".
One ColdFusion specific gotcha is to make sure you clear the Application scope when required (to update any singleton components). A common approach here is to use a URL parameter that causes onRequestStart() to call onApplicationStart(). You may also have to clear the trusted cache.
We use a system called AnthillPro: http://www.anthillpro.com
It's commercial software, but it allows us to completely automate our deployment process across multiple servers and operating systems (We currently use it for both ColdFusion and Java, but it can be used for most languages. It has a ton of 3rd party integrations:
http://www.anthillpro.com/html/products/anthillpro/tool-integrations.html

Clojure REPL philosophy and utility applications

Sorry for the long post, but this forum always asks for use cases :-).
I am frequently called upon to write utility applications (GUI and command line) for my organization. I most commonly write these in Java and more recently Scala.
The "philosophy" in Clojure (and other Lisps) seems to center around the REPL, and I have to agree that it makes a nice development environment, but I obviously cannot produce utilities that require that the users "Install Clojure and Clojure-contrib, then unzip the utility into a directory on your hard drive, start Clojure from the command line using the following classpath, ...". The users do not care that the utility is written in Clojure. They just want to point and click or, at most, type "java -jar Utility.jar -?" on the command line.
My question centers around compilation and separating the application into many namespaces/files.
I know that the main method must be in a Clojure file that includes the (gen-class...) command (or the :gen-class clause on the ns command). Do I do the same for the additional Clojure files, or should they be left as a source code that is packed in the JAR and loaded by the main file? How about testing the additional files from the REPL during development?
I have been using leiningen, cake, and maven to build self-contained JARs (containing unpacked clojure.jar, clojure-contrib.jar, and commons-cli.jar files), but so far I have been writing my code in the same file as the main method.
It's up to you whether you AOT-compile your .clj into .class or let Clojure do it dynamically at runtime. In general, I find it's easier during development to avoid AOT and just use AOT as a performance booster for cases where the cost of compiling your .clj on the fly doesn't make sense (limited environments like Google App Engine or utilities where startup time is critical). For server processes that will run for a long time, there is not much advantage in AOT-compiling.
There are a number of complexities around using AOT classes at dev times that are specific to different dev environments.
One down-side of AOT is that your compiled classes might be incompatible with a future version of Clojure and that is more likely than your clj files being incompatible. That may become more important over time.
When it comes to the separation, I'd keep them in separate namespaces/files:
One for the :gen-class namespace, containing -main and all the other Java-like things.
The other namespace for all the functions.
Ideally, your main should contain just the call to a function from the other namespace, or perhaps some logics for evaluating or repacking of the args.
Your question seems quite similar to the separation between logics code and ui code. You could see the namespace with :gen-class as just an interface provided by your program to Java code, nothing more.
When it comes to the utilities (like command-line, or Swing apps, etc.), there's a trouble with Java in general because of the JVM start time.
Now, you could solve this by making a server app run the REPL in the background all the time, and say, somehow receive an s-expr to be evaluated, and return the result. This could be done as a simple web application which receives an s-expr as URL parameter, and returns the result. Now, with this you could make all utilities in plain old Java, or even bash using wget, since all you'd have to do is access an URL (assuming that server with repl is running in background).
There's a good chance that something like this already exists, so if anyone knows - comments are more than welcome.
Oh, and another thing, the port where repl webapp is exposed would probably have to be closed to the outside world, to prevent Clojure-injections :D