Can I run my Tomcat app on Bluemix?

Question

We have a simple app that runs on tomcat7 and has been working for about a year. We're planning to kick the tires on Bluemix and we would like to know if there's any information that can assist us in this effort. I saw a post that discussed migrating apps from WebSphere Application Server v7 to the Liberty profile but I didn't see any reference to Tomcat. Any documentation or samples you could provide would be appreciated.

Answer 1

As others have explained, Bluemix includes the java_buildpack buildpack, which includes Tomcat. To use it to create a runtime in Bluemix using this buildpack, run this command:

cf push <appname> -b java_buildpack -p <apparchive>

You might wonder: What is this buildpack and what is it doing?

You can see the list of buildpacks avaiable in Bluemix. Run this command:

cf buildpacks

The output (as of today) is:

Getting buildpacks...

buildpack                              position   enabled   locked   filename
liberty-for-java                       1          true      false    buildpack_liberty-for-java_v1.18-20150519-1642-yp.zip
sdk-for-nodejs                         2          true      false    buildpack_sdk-for-nodejs_v1.18-20150519-1759-yp.zip
noop-buildpack                         3          true      false    noop-buildpack-20140311-1519.zip
java_buildpack                         4          true      false    java-buildpack-v2.7.1.zip
ruby_buildpack                         5          true      false    ruby_buildpack-cached-v1.3.0.zip
nodejs_buildpack                       6          true      false    nodejs_buildpack-cached-v1.2.0.zip
go_buildpack                           7          true      false    go_buildpack-cached-v1.2.0.zip
python_buildpack                       8          true      false    python_buildpack-cached-v1.2.0.zip
php_buildpack                          9          true      false    php_buildpack-offline-v3.1.0.zip
aspnet5-experimental                   10         true      false    buildpack_aspnet5-experimental_v0.1.5-20150508-1205.zip
liberty-for-java_v1-17-20150501-1729   11         true      false    buildpack_liberty-for-java_v1.17-20150501-1729-yp.zip
sdk-for-nodejs_v1-17-1-20150519-0951   12         true      false    buildpack_sdk-for-nodejs_v1.17.1-20150519-0951-yp.zip

As you can see, the java_buildpack buildpack is implemented by java-buildpack-v2.7.1.zip. That is documented in Java Buildpack v2.7.1. As the docs show, the buildpack includes Tomcat v8.0.20.

You can also see that the liberty-for-java buildpack, which creates the Liberty for Java runtime in Bluemix, is implemented by buildpack_liberty-for-java_v1.18-20150519-1642-yp.zip, which is v1.18 of the buildpack. If you need the previous release, you can use the liberty-for-java_v1-17-20150501-1729 buildpack, which is v1.17 of the buildpack. Options for pushing Liberty applications explains how to use the buildpack.

You can also see the buildpacks for Node.js (nodejs_buildpack), PHP (php_buildpack), and so on. There's even a buildpack for ASP.NET 5 (aspnet5-experimental).

Answer 2

I would recommend the below command:

cf push <appname> -b java_buildpack

This will use the built-in Java buildpack in Bluemix. The benefit of this approach is that you always get the version of the java buildpack that matches the current CloudFoundry level in Bluemix. If you use the external git master, it may or may not work.

Answer 3

Yes, you can run your application on Bluemix, however, due to config information spread out in a few different xml files (server, content & web come to mind) on Tomcat, I suggest you take a staggered approach to moving your app. You first need to get your app working on the WebSphere Application Server V8.5.5 Liberty Profile, then you can push a server package to Bluemix.

Essentially, you want to do the following:

1) Migrate your Tomcat application and server config to the Liberty profile using the WebSphere Application Server Migration Toolkit - Competitive Migration. The article below provides details on the usage of this tool:

http://www.ibm.com/developerworks/websphere/downloads/migtoolkit/compmig.html

2) Test your app on the Liberty Profile

3) Push the Liberty Server package to bluemix. I've found the article below useful for pushing server packages:

https://developer.ibm.com/bluemix/2015/01/06/modify-liberty-server-xml-configurations-ibm-bluemix/#

Answer 4

Yup. You can use the community Java buildpack to use Tomcat as your Java runtime.

cf push -b https://github.com/cloudfoundry/java-buildpack.git

Edit:

cf push <appname> -b java_buildpack

Doc for Tomcat buildpack: https://github.com/cloudfoundry/java-buildpack

The pre-installed buildpack name or external url after -b option is the open source java Tomcat buildpack. When pushing a Java application, if you don't specify a buildpack name or url, the default Java buildpack will be chosen. In Bluemix, the default buildpack is the WebSphere Liberty buildpack.

Doc for Liberty buildpack: https://www.ng.bluemix.net/docs/#starters/liberty/index.html#optionsforpushinglibertyapplications