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| Rise above the Cloud hype |
Are you tired of requesting a new development machine for your
application? Are you sick of having to setup a new test environment
for your application? Do you just want to focus on developing your
application in peace without 'dorking with the stack' all of the
time? We hear you. We have been there too. Have no fear, OpenShift is
here!
In this article will walk you through the simple steps it takes to setup
not one, not two, not three, but up to five new machines in the Cloud
with OpenShift. You will have your applications deployed for
development, testing or to present them to the world at large in
minutes. No more messing around.
We start with an overview of what OpenShift is, where it comes from and
how you can get the client tooling setup on your workstation. You
will then be taken on a tour of the client tooling as it applies to
the entry level of OpenShift, called Express. In minutes you will be
off and back to focusing on your application development, deploying
to test it in OpenShift Express. When finished you will just discard
your test machine and move on. When you have mastered this, it will
be time to ramp up into the next level with OpenShift Flex. This
opens up your options a bit so you can do more with complex
applications and deployments that might need a bit more fire power.
After this you will be fully capable of ascending into the OpenShift
Cloud when you chose, where you need it and at a moments notice. This
is how development is supposed to be, development without stack
distractions.
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| Dorking with the stack? |
Introduction
There is a great amount of hype in the IT world right now about Cloud.
There is no shortage of acronyms for the various areas that have
been carved out, like IaaS, PaaS and SaaS. OpenShift is a Platform as
a Service (PaaS) from Red Hat which provides you with a platform to
run your applications. For you as a developer, you want to look at
the environment where you put your applications as just a service
that is being provided. You don't want to bother with how that
service is constructed of a set of components, how they are
configured or where they are running.
You just want to make use of this service that they offer to deploy,
develop, test and run your application. At this basic level,
OpenShift provides a platform for your Java applications.
First let's take a quick look at where OpenShift comes from. It started at
a company called Makara that was based in Redwood City, Calif.,
providing solutions to enable organizations to deploy, manage,
monitor and scale their applications on both private or public
clouds. Red Hat acquired Makara in November of 2010, and in the
following year they have merged Red Hat technologies into a new
project called OpenShift[1]. They launched a first project that
initially provides two levels of service[2], a shared hosting
solution called Express and a dedicated hosting solution known as
Flex. What makes this merging of technologies interesting for a Java
developer is that Red Hat has included the next generation
application platform based on JBoss AS 7 in OpenShift[3]. This brings
a lightning fast application platform for all your development needs.
OpenShift Express
The OpenShift website states, “Express is a free, cloud-based
application platform for Java, Perl, PHP, Python, and Ruby
applications. It's super-simple—your development environment is
also your deployment environment:
git push,
"and you're in the cloud.” This peaks the interest so lets give it a
try and see if we can raise our web application into the clouds. For
this we have our jBPM Migration web application[4] which we will use
as a running example for the rest of this exercise.
Getting started in Express is well documented on the website as a quick
start[5], which you can get to once you have signed up for a Red Hat
Cloud (rhcloud) account. This quick start provides us with the four
steps you need to get our application online and starts with the
installation of the necessary client tools. This is outlined for Red
Hat Enterprise Linux (RHEL), Fedora Linux, generic Linux
distributions, Mac OS X and Windows. For RHEL and Fedora it is a
simple package installation, for the rest it is a Ruby based gem
installation which we will leave for the reader to apply to her
system.
Once the client tooling is installed, there are several commands based on
the form rhc-<command>. There is an online interface available
but most developers prefer the control offered by the command line
client tools so we will be making use of these. Here is an overview
of what is available with a brief description of each:
- rhc-create-domain
– used to bind a registered rhcloud user to a domain in rhcloud.
You can have maximum of one domain per registered rhcloud user.
- rhc-create-app
- used to create an application for a given rhcloud user, a given development environment
(Java, Ruby, Python, Perl, PHP) and for a given rhcloud domain. You
can create up to five applications for a given domain. This will
generate the full URI for your rhcloud instance, setup your rhcloud
instance based on the environment you chose and by default will
create a local git project for your chosen development environment.
- rhc-snapshot
– used to create a local backup of a given rhcloud instance.
- rhc-ctl-app
– used to control a given rhcloud application. Here you can add a
database, check the status of the instance, start, stop, etc.
- rhc-tail-files
– used to connect to a rhcloud applications log files and dump them
into your command shell.
- rhc-user-info
– used to look at a given rhcloud user, the defined domains and
created applications.
- rhc-chk
– used to run a simple configuration check on your setup.
Create your domain
To get started with our demo application we need to do a few simple
thing to get an Express instance setup for hosting our Java
application, beginning with a domain.
# We need to create the domain for Express to start setting up
# We need to create the domain for Express to start setting up
# our URL with the client tooling using
# rhc-create-domain -n domainname -l rhlogin
#
$ rhc-create-domain --help
Usage: /usr/bin/rhc-create-domain
Bind a registered rhcloud user to a domain in rhcloud.
NOTE: to change ssh key, please alter your ~/.ssh/libra_id_rsa and
~/.ssh/libra_id_rsa.pub key, then re-run with --alter
-n|--namespace namespace Namespace for your application(s) (alphanumeric - max 16 chars) (required)
-l|--rhlogin rhlogin Red Hat login (RHN or OpenShift login with OpenShift Express access) (required)
-p|--password password RHLogin password (optional, will prompt)
-a|--alter Alter namespace (will change urls) and/or ssh key
-d|--debug Print Debug info
-h|--help Show Usage info
# So we setup one for our Java application. Note that we already have
# setup my ssh keys for OpenShift, if you have not yet done that,
# then it will walk you through it.
#
$ rhc-create-domain -n inthe -l [rhcloud-user] -p [mypassword]
OpenShift Express key found at /home/[homedir]/.ssh/libra_id_rsa. Reusing...
Contacting https://openshift.redhat.com
Creation successful
You may now create an application. Please make note of your local config file
in /home/[homedir]/.openshift/express.conf which has been created and populated for you.
Create your application
Next we want to create our application, which means we want to tell the
OpenShift Express which stack we need. This is done with the
rhc-create-app client tool.
# Let's take a look at the options available before we setup a Java
# instance for our application.
#
$ rhc-create-app --help
Contacting https://openshift.redhat.com to obtain list of cartridges...
(please excuse the delay)
Usage: /usr/bin/rhc-create-app
Create an OpenShift Express app.
-a|--app application Application name (alphanumeric - max 16 chars) (required)
-t|--type type Type of app to create (perl-5.10, jbossas-7.0, wsgi-3.2, rack-1.1, php-5.3) (required)
-l|--rhlogin rhlogin Red Hat login (RHN or OpenShift login with OpenShift Express access) (Default: xxxxxxxxx)
-p|--password password RHLogin password (optional, will prompt)
-r|--repo path Git Repo path (defaults to ./$app_name)
-n|--nogit Only create remote space, don't pull it locally
-d|--debug Print Debug info
-h|--help Show Usage info
# It seems we can choose between several but we want the jboss-as7.0
# stack (called a cartridge). Provide a user, password and location
# for the git repo to be created called 'jbpmmigration', see the
# documentation for the defaults. Let's watch the magic happen!
#
$ rhc-create-app -a jbpmmigration -t jbossas-7.0 -l [rhcloud-user] -p [mypassword] -r /home/[homedir]/git-projects/jbpmmigration
Found a bug? Post to the forum and we'll get right on it.
IRC: #openshift on freenode
Forums: https://www.redhat.com/openshift/forums
Attempting to create remote application space: jbpmmigration
Contacting https://openshift.redhat.com
API version: 1.1.1
Broker version: 1.1.1
RESULT:
Successfully created application: jbpmmigration
Checking ~/.ssh/config
Contacting https://openshift.redhat.com
Found rhcloud.com in ~/.ssh/config... No need to adjust
Now your new domain name is being propagated worldwide (this might take a minute)...
Pulling new repo down
Warning: Permanently added 'jbpmmigration-inthe.rhcloud.com,50.17.167.44' (RSA) to the list of known hosts.
Confirming application jbpmmigration is available
Attempt # 1
Success! Your application is now published here:
http://jbpmmigration-inthe.rhcloud.com/
The remote repository is located here:
ssh://1806d6b78bb844d49378874f222f4403@jbpmmigration-inthe.rhcloud.com/~/git/jbpmmigration.git/
To make changes to your application, commit to jbpmmigration/. Then run 'git push' to update your OpenShift Express space .
If we take a look at my given path to the repo we find a
git-projects/jbpmmigration git repository. Note that if you decide to
alter your domain name you will have to adjust the git repository
config file to reflect where the remote repository is, see above the
line with 'ssh:.....'. Also the page is already live at
http://jbpmmigration-ishereon.rhcloud.com/.
It is just a splash screen to get you started, so now we move on to
deploying our existing jBPM Migration project.
First lets look at the provided README in our git project which gives some
insight to the repository layout.
Repo layout
===========
deployments/ - location for built wars (Details below)
src/ - maven src structure
pom.xml - maven build file
.openshift/ - location for openshift specific files
.openshift/config/ - location for configuration files such as standalone.xml (used to modify jboss config such as datasources)
../data - For persistent data (also in env var OPENSHIFT_DATA_DIR)
.openshift/action_hooks/build - Script that gets run every push, just prior to starting your app
For this article we only will examine the deployments and src directories. You can just drop
in your WAR files, remove the pom.xml file in the root of the project
and they will be automatically deployed. If you want to deploy
exploded WAR files then you just add a file called '.dodeploy' as
outlined in the README file. For real project development we want to
push our code through the normal src directory structure and this is
also possible by working with the provided pom.xml file. The README
file provided gives all the details needed to get your started.
Our demo application, jbpmmigration also comes with a README file that
provides the instructions to add the project contents to our new git
repository, so we will run these commands to pull the files into our
local project.
# placing our application into our express git repo.
#
$ cd jbpmmigration
$ git remote add upstream -m master git://github.com/eschabell/openshift-jbpmmigration.git
$ git pull -s recursive -X theirs upstream master
# now we need to push the content.
#
$ git push origin
[jbpmmigration maven build log output removed]
...
remote: [INFO] ------------------------------------------------------------------------
remote: [INFO] BUILD SUCCESS
remote: [INFO] ------------------------------------------------------------------------
remote: [INFO] Total time: 3.114s
remote: [INFO] Finished at: Mon Nov 14 10:26:57 EST 2011
remote: [INFO] Final Memory: 5M/141M
remote: [INFO] ------------------------------------------------------------------------
remote: ~/git/jbpmmigration.git
remote: Running .openshift/action_hooks/build
remote: Running .openshift/action_hooks/deploy
remote: Starting application...
remote: Done
remote: Running .openshift/action_hooks/post_deploy
To ssh://1806d6b78bb844d49378874f222f4403@jbpmmigration-inthe.rhcloud.com/~/git/jbpmmigration.git/
410a1c9..7ea0003 master -> master
As you can see we have now pushed our content to the rhcloud instance we
created, it deployed the content and started our instance. Now we
should be able to find our application online at
http://jbpmmigration-ishereon.rhcloud.com/jbpmmigration_upload-0.4/.
The final step would then be that you are finished working on this
application and want to free it up for a new application. You can
then make a backup with the
rhc-snapshot client tool and then remove your instance with
rhc-ctl-app client tool.
# Ready to get rid of our application now.
#
$ rhc-ctl-app -a jbpmmigration -l eschabell -c destroy
Password: ********
Contacting https://openshift.redhat.com
!!!! WARNING !!!! WARNING !!!! WARNING !!!!
You are about to destroy the jbpmmigration application.
This is NOT reversible, all remote data for this application will be removed.
Do you want to destroy this application (y/n): y
Contacting https://openshift.redhat.com
API version: 1.1.1
Broker version: 1.1.1
RESULT:
Successfully destroyed application: jbpmmigration
As you can see, it is really easy to get started with the five free
instances you have to play with for your application development. You
might notice that there are limitation, with no ability to use
specific integrated monitoring tooling, auto-scaling features are
missing and control of the configuration is limited. For those
needing more access and features, take a look at the next step up
with OpenShift Flex[6].
This completes our tour of the OpenShift Express project where we provided
you with a glimpse of the possibilities that await you and your
applications. It was a breeze to create your domain, define your
applications needs and import your project into the provided git
project. After pushing your changes to the new Express instance you
are off and testing your application development in the cloud. This
is real. This is easy. Now get out there and raise your code above
the cloud hype.
References
- OpenShift,https://openshift.redhat.com.
- Project overview OpenShift, https://openshift.redhat.com/app/platform.
- JBoss AS7 in the Cloud, http://www.jboss.org/openshift.
- jBPM Migration project web application,
https://github.com/eschabell/jbpmmigration_upload.
- OpenShift Express Quick Start,
https://openshift.redhat.com/app/express#quickstart.
- OpenShift Flex Quick Start, https://openshift.redhat.com/app/flex#quickstart.
Final note: I was asked at the end of 2011 to put together and introduction article to OpenShift, the Red Hat Platform as a Service (PaaS) open source project. It was to be published in a Dutch language magazine at the beginning of 2012. I wanted to post the English language version here for the rest of the non-Dutch speaking population.
As previously posted, I was in Lisbon last week to meet with the Portugal Java User Group (PTJUG) and present on the jBPM5 project followed by OpenShift.
