Is there a way to deploy apps without deploying it as a war file? At the moment I am repackaging and redeploying the war after every change. Is there a way to host it like IIS so changes can be done to an individual file without having to repackage and redeploy. Im using glassfish at the moment
Glassfish permits deploying applications and modules in an exploded directory format. It also supports automatic deployment and dynamic reloading.
You can hot deploy few things. By hot deploy I mean replacing the file not full app. Like hot deploying a jsp file, some static content there might be some more things. But then there are other things which may not work properly if you try to just replace a file.
Having said that it's not a recommended practice in most production environments. Most people would like to deploy a full war file.
But if you are simply looking for productivity in development environment you can use tools like JRebel. It works great. You don't have to keep deploying the war file again and again.
With Tomcat, you can configure the container to serve a webapp that is located in another directory (such as your build target directory) using a config file found under tomcat/conf/Catalina/localhost
But, you generally need to restart Tomcat if you make changes other than static content or JSP changes.
This sort of approach should be restricted to development environments only.
I agree with Laird Nelson that GlassFish can do that the reason is that Glassfish use Apache Felix which is an OSGI implementation (OSGi Framework and Service platform). Here you can find projects using felix. If you are using a simple Servlet Container like Tomcat there a lot of solutions.
Related
I'm working on a set of independent applications that share some common endpoints. The way I have it setup is to have each application be an independent war, and to have an embedded jetty server which provides those common endpoints. The embedded jetty server sets up the endpoints and loads the wars upon start. Each of our customers will have different applications installed, but will always have the common part, hence the need to have independently installable application wars.
This basic architecture is working ok, but in the development cycle I need to build each of the applications war to then run the whole thing with the embedded jetty server. I would like for the whole thing just to auto deploy when changes are made to any of the application files.
Any thoughts on how to do this?
Use a DeploymentManager with a WebAppProvider to find the webapps and deploy them (it will auto-redeploy on change).
Then setup your deployment to use exploded webapp directories, not war files.
You can even opt to setup deployment XML's in a single place, pointing to the contents of each webapp project's target/${project.build.finalName} directory (if using maven).
This works for many things, but not ALL things.
If you change classes or libs then there's a category of issues around memory leaks, and pinned classloaders, that can result in your reloaded webapp not behaving as you expect.
See
https://www.eclipse.org/jetty/documentation/current/preventing-memory-leaks.html
I'm trying to understand the model that Apache Tomcat adheres to, and the documentation apparently doesn't make sense to me.
As I understand it, Tomcat is a server for hosting a wide variety of services - so it's pretty generic. I've got this application that I'm trying to understand how to host, and its main method of deployment appears to be as a Tomcat-hosted web service - the application is called Camunda (its on github). After going through the docs for Camunda, my Tomcat directory becomes absolutely filled with Camunda-related jars, and config files, etc. The docs say to just plop everything right into the Tomcat lib folder, conf folders, etc.
Most of my experience with other "platform" / "service" style host applications has been that the application itself, in this case Tomcat, stays pretty untouched in its own directory. Through config files, etc, it knows how to host whatever it needs to host.
In the case of Tomcat, it seems that it's customary to basically "pollute" the Tomcat dir with a bunch of libs for the hosted content?
This is why I made the title "is Tomcat meant to be one install per application", because for all intents and purposes once you host something in Tomcat the directory becomes so coupled with that something that the Tomcat directory IS that something.
Is this normal? Just looking for some clarification in perhaps other terms that the docs put it, because the docs don't seem to be very clear to me.
Here is a link to the install process that I am following and referring to: https://docs.camunda.org/manual/latest/installation/full/tomcat/manual/
It's been a while since I've used Tomcat, but not only is it not one-install-per-application, it's not even one-install-per-virtual-host.
Tomcat is (amongst other things) a servlet container. The directory layout and such for servlets was standardized in the Java Servlet Specification v2.2. You can download the latest servlet spec here.
The docs say to just plop everything right into the Tomcat lib folder, conf folders, etc.
Hopefully they're talking about the ones in a .war file or similar, or shared libs in the shared locations. You can put shared libraries in a location where they can be reused across applications (or even virtual hosts), which was probably useful back when disk space was more expensive, but these days I assume most people put the libs for an app in the /WEB-INF/lib directory in the application's .war file.
This page talks about the "directory" layout of a .war file (which is basically a .jar with a particular structure).
It's true that typically .war files are expanded into subdirectories of the Tomcat installation directory, but as indicated in the answer that Dan_Maff linked to in a comment, you can modify the server.xml file to have it look elsewhere instead.
You can install a webapp called Manager that helps with installing, activating, deactivating, and managing web apps via .war files. (There's also a Host Manager for managing virtual hosts.)
All that said, you certainly could do one application per Tomcat install if you wanted. You'd need a reverse proxy in front of it (Apache, Nginx, etc.) so the same port (e.g., 80) could be used for the external URL of the various applications, and you'd need to assign each Tomcat install its own internal port for the reverse proxy to talk to.
I'm distributing a simple Java webapp as open source. The webapp needs to be configured before it can be run – a configuration file needs to be created, and the location of that configuration file needs to be made known to the webapp as a parameter in web.xml.
Now my question is how to best package and distribute the webapp in order to make it easy to install, and how to describe that installation process in the documentation. The options I can think of are:
Distribute the webapp as a WAR archive. Recommend that users deploy the WAR into their Tomcat/Jetty/whatever, then drop their configuration file into /webapps/myapp/WEB-INF, and modify /webapps/myapp/WEB-INF/web.xml accordingly
Distribute the webapp as source. Recommend that users should drop their configuration file into the /src/main/webapp/WEB-INF folder, then modify their /src/main/webapp/WEB-INF/web.xml accordingly, then build a WAR using Ant or Maven, and deploy that into their servlet container.
There are probably other options that I can't think of.
What setup is likely to be most convenient to users that need to install, configure and deploy the webapp?
Edit: I should add that the configuration file isn't just a few lines – it's a large file that contains a database schema and other stuff and is potentially generated using an external editor; so just providing good defaults isn't an option.
Externalize this configuration and maybe provide some default values. If you make a new version of your app, everybody will have to remember to back-up that configuration file, then redeploy and then copy back that file--> this is a nightmare.
There are many ways to put that configuration somewhere else. You can use Java Preferences for example.
I would say the WAR, although not requiring the configuration would likely be more convenient :)
What is it, loosely, that must be configured such that there isn't a sensible default value for everyone? URL string?
Providing an answer of my own, after more reading on the issue: JNDI seems to be the “official”, although somewhat heavyweight, way of solving this. With JNDI, a configuration option (like the location of the full config file I need) can be declared in the web.xml, and its actual value can be set in a per-webapp context.xml that lives in the /webapps directory of Tomcat (or the /contexts directory of Jetty). This setup has a bunch of advantages:
The big configuration file can live outside of the servlet container and webapp
The webapp can be updated without danger of losing the configuration
The distributed war doesn't need to be modified or rebuilt
Downside: It's sort of complicated, requires messing around with XML, and configuring JNDI on Tomcat works differently from Jetty (requiring twice as much documentation).
Maybe use a system property for the config file location. Can easily be passed on the command line as -Dorg.example.config.file=/foo/bar, in startup scripts or in Java code. I think I've seen some tools, e.g. logging frameworks, use system properties for similar things in webapps.
We package our application as a .war file, we advertise support for JBoss AS5 and instruct our clients to copy the .war into their JBoss 'deploy' directory, and start up their application server in order to deploy the .war.
We are introducing support for JBoss AS7, so our deployment instructions for AS7 will have to change to something like
-copy the application.war to $JBOSS_HOME/standalone/deployments
-touch $JBOSS_HOME/standalone/deployments/application.war.dodeploy
-start JBoss AS7
This deployent method seems awkward to me, and possibly fragile, as failure to successfully create the *.dodeploy file would cause the deploy to fail. Also JBoss startup problems may cause the deploy to fail, causing the *.dodeploy file to be renamed *.failed - so it would have to be renamed back to *.dodeploy before attempting to redeploy. We are thinking the process seems a little awkward for some of our clients, who may not be familiar with JBoss AS7.
Is there any way to automate this deployment process so that it is smoother for deployers who may not be comfortable with how things work with JBoss AS7? How are other people handling this type of situation? thanks for any suggestions.
There is a web interface that's fairly easy to use. You can access it after JBoss AS7 has been started by going to http://localhost:8080. There is a link on that page that takes you to the administration console.
You could also write scripts for deployments using the CLI interface. There is some information here https://docs.jboss.org/author/display/AS7/Management+Clients about how to use it.
Lastly you can always write your own Java client to deploy applications. I wrote a blog post a while back on how to write a custom deployment CLI interface.
If you're aware of the marker files then you might have made a conscious choice to disable the automatic deployment mode for the deployment folder, which ships enabled by default. Autodeploy is great for everything but exploded files, and removes the need to manually manage the marker files. With autodeploy enabled, you can use the "touch" command on the application itself, which will update the timstamp and trigger the application for deployment (or redeployment). So you can still script if need be, but focus on the file rather than the marker files.
Just for reference, there are five ways to deploy files, of which three will be common to the typical administration setup. These are the graphical Management Console, the Management Command Line Interface (CLI) and the deployment folder you mention. The other two are via an IDE (such as JBoss Developer Studio or Eclipse with JBoss Tools), and even via Maven.
For people that may not be comfortable with the scripting as you say, then you can't go past the Manage Deployments section in the Console GUI. The Console deployment does not move/copy the application to the deployment folder, so using both the Console and the Deployment folder can make for some effort in file management.
For bash-savvy users, the CLI is great, and is often recommended by the AS7 team as a preferred method of deploying and managing applications. The user guide section on the CLI is located here: https://docs.jboss.org/author/display/AS7/Admin+Guide#AdminGuide-RunningtheCLI.
An example of all deployment methods can be found on this YouTube video by one of the developers: "5 ways to deploy your application to JBoss AS 7". Hope that helps.
You only need .dodeploy for exploded deployments. If your deployment is a zipped war,ear,etc. then it will be picked up automatically.
Change your deployment mode from manual to auto which does this deployment automatically.
Steps :
1) Open your jboss configuration file : standalone.xml.
2) Look for deployment-scanner and add auto-deploy-zipped="true"
<deployment-scanner scan-interval="5000" relative-to="jboss.server.base.dir"
path="deployments" auto-deploy-zipped="true" auto-deploy-exploded="false"/>
3) Restart your Jboss.
Now it will automatically pick your zipped version of ear/war/jar/sar files for deployment.
You can still use your old scripts without using any markers.
This can be changed in the standalone.xml by changing the "auto-deploy" attributes on the deployment-scanner element in the standalone.xml configuration file.
More details can be found in the deployments folder README.
I have several webapps deployed to production. I have used Tomcat as my servlet engine for ~10 years now. I'm considering moving to embedding Jetty model from the deploy-a-war-into-Tomcat model.
These webapps are deployed over several servers and some of the are horizontally scaled (using nginx IP hash based partitioning).
I see some advantages:
I can configure my servlet engine for a particular webapp (instead of having a generic configuration for Tomcat which is running several different webapps)
It's easier to horizontally scale my webapp by running multiple Jetty instances (configured to listen on different ports) on the same host. I could also do this with Tomcat (and I have run multiple tomcat instance on the same host in the past), but I've moved to using Debian packages (.deb archives) for deployment and it's not as easy to run multiple Tomcats using this method.
My deployment package (.deb) is more "complete" at build time i.e. I don't have to be sure the Tomcat instance is configured correctly.
And disadvantages:
More instances of a servlet engine running on a server means more resources being used
I've never used Jetty. I don't think I have any Tomcat-specific stuff going on in my webapps, but I'm not sure.
My main concern is the amount of resources that Jetty will use. If I had one Tomcat instance running 4 webapps, what will the difference in resources (memory/processor) be with four Jetty instances running?
This question is probably too open-ended, but I'm curious to know if I'm overlooking something or if anybody has any experience moving from Tomcat to (embedded) Jetty.
The web container I've found easiest to embed in a jar file (and it is still a valid WAR too) is Winstone (http://winstone.sourceforge.net/).
Jenkins - http://jenkins-ci.org/ - use this container so it has been pretty stress-tested. Note that it is Servlet 2.4 only.
Well I think there is no direct answer;
I might not fully understand the ".deb" part as I'm not a debian freak :)
I prefer having an instance of tomcat with a number of configurations aka CATALINA_HOME folders where you may specify apps and ports running, so you can always have all your configs separately and change the tomcat instance if needed.
Also, see related post:
Jetty: To embed or not to embed?
I also was used to Tomcat, so in my new project I tried using Jetty to learn about it.
In an enterprise environment (where you have production / testing / development servers) I would stick to Tomcat, mainly because it helps you in getting to separate code from configuration files (now I am working in setting the conf files in a separate jar, because that way when I move changes from testing to production they do not have to manually update the jars that I'll pass to sysadmin).
Other issue is that it looks like that Jetty has changed ownership not so long ago, and looking for info often got me to the old version.
Apart from that, using Jetty is not that different from Tomcat; had to run a little through docs for finding where everything is, but structure is (as last what I have seen, I have not tried anything too complicated) more or less like Tomcat.