In my project I use Maven to package a web application to a WAR which is later deployed to Jetty using a custom Maven plugin on CentOS. The custom plugin is used by every project that deployes to a production environment. There is now a requirement that all static content (like web site text, properties) is packed outside of the WAR so that it can be changed in production without requiring a new release cycle. I am unsure how to achieve this externalization.
The Jetty server has the directory structure described in Jetty quick start guide. Currently, the web application already offers some .properties files which can be altered externally, and these reside in the resources/ directory. These files are moved here by the custom Maven plugin. The WAR resides in the webapp/ folder. One option for my problem is to use <packagingExcludes> of maven-war-plugin to not include e.g. *.xhtml and *.properties in the WAR. Later, I can use the custom Maven plugin to move excluded files to resources/ directory. But, I have a feeling this is not the correct way to externalize static content... Shouldn't xhtml files live in webapp/ folder while the only the properties file live in resources/ folder?
I have also researched the option of deploying the WAR as exploded, but I am unsure of the implications of such. Clearly, the changes in the exploded WAR files will be overwritten in the next deploy, but the idea is to do static changes both in development and production. Also, I am not sure how to achieve WAR "explosion", is it something that Jetty does for your WAR if configured in jetty.xml or do I have to extract the WAR before deploying?
Lastly, how do people serve static content in Jetty which can be altered in production? Do both the WAR and static files live side by side
The Jetty resources folder should not be used for application files. A J2EE web application (war) should be self-contained -- and in Jetty, reside only on the /webapps folder -- and its only binding to the container (Jetty servlet engine) is via the web.xml deployment descriptor.
Since property files may be read from the classpath and the Jetty resources folder is part of the system classpath, a property file there could be read by the web application class loader. Note that there are other ways to read property files as well and the Jetty resources folder should not be used for application properties. Also, the application may not be portable as other application servers have different forms of webapp classloader isolation.
If the below architecture approach does not work for you, then your only approach would be to expand (explode the war) in the /webapps folder and hope for the best when files are edited.
Tackling this from a different angle,
- if your web application depends on .properties and .xhtml files in order to function properly, then these files are probably not 'content'. The fact that there is a business process that requires them to to be updated ad hoc does not make them content.
- 'content' is something like text, images, and videos that is added, edited and removed by an administrative user. The application does not depend on it for correct execution, it merely reads and passes it on the browser.
Suggestions:
I would suggest that you deploy your application every time there is a change to the .xhtml or .properties files change. If the editors of these files are power business users, you might think of a git push-pull tool for them and a continuous build hook, so that when they make changes and push them to the git repository, the application gets tagged with a newer version and gets built and deployed. If there is a problem (tag not closed in xhtml), then it would be easy to roll back to the last tag.
Alternately, if the changes are minor (such as text descriptions), then modify the application to read them from an arbitrary external file (outside the webapp) -- a location that is provided to the webapp on startup. You can then package a 'default' version of the file in the webapp, but the code would attempt to look in the specified external location first.
I discovered that you can add HTML tags to properties and later use <h:outputFormat> to fetch these properties with parameters. Also, you can do pretty neat stuff with property files as described in MessageFormat API.
My solution was to keep the .xhtml files inside the WAR, but use simple HTML snippets properties from the default resource bundle which is based on a .properties file. These properties were included in the .xhtml using <h:outputFormat>and <h:outputText>. This allows the user to add simple styling like bold and underline to the snippets.
The properties file are copied to the Jetty resource folder using the custom Maven plugin, so I have kept the .properties files in the WAR. For some reason the Jetty resource folder has precedence over the packed .properties files, so this works out fine. Also, as Akber pointed out, I will have the default versions of the properties available if for some reason the WAR was moved to some other application server where the resource folder is not available.
Of course, with this approach the code can break if malformed HTML is placed inside the snippet properties, as pointed out by Akber, but it works for our application as it is very small. I may never have done this if this was a much larger application, but then I might have gone for a database based solution for adding static text (like Joomla/Drupal/Wordpress).
Related
I am trying to do a log4j migration for a legacy application. I made the changes to the configuration files and tested it locally with Tomcat, where the logs were displayed correctly. However when I deploy on WAS, the logging stops.
I checked a lot of pages about the necessary dependencies and the possible problems, but now I feel I'm stuck. Here is what I already tried:
Added the log4j jars manually to the lib/ext directory in WAS (together with commons-logging, I read an article where it helped, although all these jar-s were already present in the ear)
Double checked, that the configuration file is on the classpath and that it's syntax is correct
Added logj42-web dependency
Added the necessary filters in web.xml (Spring version is 3.8, so also the config listener with the config name context-param)
Checked classloader in WAS - it's parent first
Am I missing something?
Any ideas are appreciated. Thank you in advance!
WAS includes its own commons-logging API (that does not utilize Log4j), so bringing your own logger requires a bit of extra class-loader-related config. Typically, that would go something like this:
Put your commons-logging and log4j jars, along with your logging properties files, in some directory (not WAS_HOME/lib/ext) readable by the user running the server.
Create a shared library on the server, with that directory as its class path, and select the "use an isolated class loader" option. Associate that shared library with your application or web module.
Ideally, that should be it. Isolated shared libraries search themselves before delegating to the server's loaders, so your application will "see" the commons-logging/log4j classes in the shared library instead of in the server, and likewise, it should pick up the configuration files from that directory instead of the ones found in the server.
You can also accomplish this same basic thing by leaving all the logging stuff in your WAR or EAR and setting its class loader to parent-last (which causes the class loader to search locally before delegating to the server-level loaders), but that is a bit riskier configuration - if your application includes APIs that are also provided by the server, parent-last class loading increases the possibility of ClassCastExceptions or LinkageErrors.
I'm working on a project that uses two maven projects (named core and webapp); core is built with JAR packaging and used for two different purposes: as a stand-alone app (essentially an executable JAR), and also embedded into webapp.
For its purpose as a stand-alone app, core needs to have its own logback configuration (a logback.xml file) that needs to be included on the classpath. Normal Maven convention would have me put it in src/main/resources/logback.xml. That works fine, but causes a problem when the core JAR is included in webapp. webapp needs to have its own logback configuration, but the container (tc Server or Jetty) is picking up the one from core.jar first.
I realize that logback can be told about a custom config location via a system property (-D on the command line) but that's not viable in a app container like Tomcat or Jetty.
I've read some other people asking about this situation, but none of the solutions I've seen sits well with me. One solution involved setting up a context listener that runs early in the webapp initialization and explicitly configures logback based on a <context-param>. That's a bit brutish in my opinion, and probably a hard sell to my fellow dev team when log4j "just works" in this situation.
I'm far from a Maven expert, so I'm hoping there is some elegant way to get Maven to help me here. Or perhaps some logback extension or add-on that makes it more web-app friendly. Or even a clever idea that I haven't thought of.
There are a number of possible solutions, but the easiest is to put the file in its own module and mark the dependency as provided. The, conspire to have it on the classpath when running the standalone version of the app.
The solution that we ended up using was to leave only the common "non-app" pieces (code and configuration) in core and then extract the other "app" pieces into a new module (batch-app).
The logging configuration only lives in the 2 app projects (webapp and batch-app) that depend on core. core has a logback-test.xml configuration in it, but that's excluded from the JAR that maven builds (since it's in the src/test/resources folder).
We've multiple wars being deployed on one server.
The CSS, JS, images, ... are mostly common for all war files.
What is the best way to serve these resources?
Options I've found so far:
Use Maven Overlay plugin (This causes us to loose flexibility of hot-swapping resources in our IDE)
Create a common jar to package in your war (needs Servlet 3.0 api if I'm correct)
Create a war file that contains only resources and that can be deployed on the server as well
If you have may users, then a content delivery network would be an appropriate way to deliver the static files.
What is the best practice to make changes in beans.xml file in production environment?
Lets imagine Hello World application with one Interface and 2 Implementations. After creating jar and running JVM how can we change implementation in beans.xml without opening jar and reassembling it afterwards?
Is it any trick that permits having beans.xml outside the jar, but without knowing the full file-system path?
On top of suggestion made by OrangeDog, I would suggest considering leaving the beans.xml inside your deployed application AND using the PropertyOverrideConfigurer mechanism.
Configure an override configurer to point to some fixed path outside of the application, something like /opt/configuration/something/override.properties would be ideal. If you can't use an absolute path, you can always try to play with file:../../.. style of paths. Then you can list only the changed values within the override.properties file.
Don't have the XML in a JAR. Your application should be deployed in at least a WAR, which the app server will probably "explode". The folder WEB-INF/classes will be added to the classpath. You can make changes to the exploded XML here and the app server should detect this and reload the app.
Edit:
If you are using plain Java SE, you can use a system property to pass the location of the XML file. System.getProperty("property") in code and -Dproperty=value on the command line.
I have problem with deploying JSR168 portlet using xmlaccess. I have no problem with deploy and join to conrete page but I would like to add shared library reference automatically. Is it possible?? I added shared library named 'libshared' using IBM WS console. Can I add this reference in input xml using by xmlaccess?
I don't think you can do this in xmlaccess. But you may try putting a reference to the library under the Manifest.MF file of the META-INF directory of your portlet's war file.
Or could just put the shared jar file under your /shared/ext directory. Or you could put it inside your wps.ear file. Mind you, either of these two solutions would share your library with the entire portal installation, rather than just select portlets.
You can deploy the application using wsadmin or similar and use that to update the classpath (i.e. for the shared library), you can then use xmlaccess to deploy the portlets and reference the previously deployed application - although I think this may only work in WebSphere Portal 6.1.
Give me a shout if you need further details.
I encountered this as well, a while ago... and researched it to the max, including spending some time chatting with IBM's support in various levels.
The XMLAccess protocol doesn't provide for such "system-level" configuration alongside Portlet application deployment; it can only be used to install, customize and uninstall Portlet applications and related artifacts.
If your deployment strategy involves deploying WAR files directly through XMLAccess, then you will have to manually add the shared-library to the application through the WAS admin console; this will have to be done manually because, when deploying WAR files through XMLAccess, an EAR with some random name is being created by WebSphere Portal to "host" your WAR file; hence you can't script the attachment of a shared library.
(alternatively, you may wish to add the shared library to the server's (WebSphere_Portal) classpath)
If your deployment strategy, instead, involves deploying Portlet applications packaged as EARs, then you're in a better position; you could automate the shared-library attachment as part of your EAR deployment process, then use XMLAccess to inform WebSphere Portal about the location, in the EAR, of your Portlet applications (which is what Michael mentioned above; it works in WebSphere Portal 6.0 as well).
Good luck.