Exploring OpenShift – Red Hat's next-generation PaaS tool

Gearbox

Commons and Marketplace

Red Hat is known for building ecosystems – complete communities surrounding its products. For OpenShift and its cloud landscape, Red Hat set up OpenShift Commons [9] (Figure 4) and the OpenShift Marketplace [10] (Figure 5). The commons is defined as "a place for companies using OpenShift to accelerate its success and adoption," and the Marketplace lets users, companies, and partners add their products to the OpenShift world, making them downloadable and deployable for everybody.

Figure 4: Red Hat created the OpenShift Commons as a place for customers, partners, and users to collaborate and share information..

Figure 5: In the OpenShift Marketplace, you'll find an increasing number of containers.

First Test

For a first test of the OpenShift environment, the free online version is absolutely sufficient. The online service still uses OpenShift v2, so the examples in the OpenShift Online User guide [11] still apply. You'll need knowledge of SSH, the basics of Git (which is how all configuration will be stored), and, of course, your favorite web application. As a first step, you'll need a Red Hat account – sign up on the OpenShift website, wait for the email, and log in to OpenShift Online (Figure 6).

Figure 6: Namespace, public key, authorizations: In the OpenShift Online settings dialog, you'll have to define your workspace environment.

Once you have created a namespace and added your public key, hit Save , and wait for the confirmation. Next, you should install the RHC tools – the client tools for the OpenShift cloud. You can install the RHC tools either via Ruby gems (yum install rubygems and gem install rhc) or directly by typing yum install rubygem-rhc. Either way, after your Fedora, CentOS, or RHEL system has finished, you must configure it with rhc setup. Listing 1 shows the questions and example answers.

Listing 1

Configuring OpenShift

01 [mfeilner@desktop ~]$ rhc setup
02 OpenShift Client Tools (RHC) Setup Wizard
03
04 This wizard will help you upload your SSH keys, set your application \
   namespace, and check that other programs like Git are properly installed.
05
06 If you have your own OpenShift server, you can specify it now. \
   Just hit enter to use the server for OpenShift Online: openshift.redhat.com.
07 Enter the server hostname: |openshift.redhat.com|
08
09 You can add more servers later using 'rhc server'.
10
11 Login to openshift.redhat.com: mfeilner@linux-magazin.de
12 Password: **********
13
14 OpenShift can create and store a token on disk which allows to you to \
   access the server without using your password. The key is stored in your \
   home directory and should be kept secret.  You can delete the key at
15 any time by running 'rhc logout'.
16 Generate a token now? (yes|no) yes
17 Generating an authorization token for this client ... lasts about 1 month
18
19 Saving configuration to /home/mfeilner/.openshift/express.conf ... done
20
21 Checking for git ... found git version 2.1.0
22
23 Checking common problems .. done
24
25 Checking for a domain ... feilner
26
27 Checking for applications ... none
28
29 Run 'rhc create-app' to create your first application.
30
31   Do-It-Yourself 0.1                      rhc create-app <app name> diy-0.1
32   JBoss Application Server 7              rhc create-app <app name> jbossas-7
33   JBoss Data Virtualization 6             rhc create-app <app name> \
                                               jboss-dv-6.1.0
34   JBoss Data Virtualization 6             rhc create-app <app name> \
                                               jboss-dv-6.0.0
35   JBoss Enterprise Application Platform 6 rhc create-app <app name> \
                                               jbosseap-6
36   JBoss Unified Push Server 1.0.0.Beta1   rhc create-app <app name> \
                                               jboss-unified-push-1
37   Jenkins Server                          rhc create-app <app name> jenkins-1
38   Node.js 0.10                            rhc create-app <app name> \
                                                nodejs-0.10
39   PHP 5.3                                 rhc create-app <app name> php-5.3
40   PHP 5.4                                 rhc create-app <app name> php-5.4
41   PHP 5.4 with Zend Server 6.1            rhc create-app <app name> zend-6.1
42   Perl 5.10                               rhc create-app <app name> perl-5.10
43   Python 2.6                              rhc create-app <app name> \
                                                python-2.6
44   Python 2.7                              rhc create-app <app name> \
                                                python-2.7
45   Python 3.3                              rhc create-app <app name> \
                                                python-3.3
46   Ruby 1.8                                rhc create-app <app name> ruby-1.8
47   Ruby 1.9                                rhc create-app <app name> ruby-1.9
48   Ruby 2.0                                rhc create-app <app name> ruby-2.0
49   Tomcat 6 (JBoss EWS 1.0)                rhc create-app <app name> \
                                                jbossews-1.0
50   Tomcat 7 (JBoss EWS 2.0)                rhc create-app <app name> \
                                                jbossews-2.0
51   Vert.x 2.1                              rhc create-app <app name> \
                                                jboss-vertx-2.1
52   WildFly Application Server 8.2.0.Final  rhc create-app <app name> \
                                                jboss-wildfly-8
53
54   You are using 0 of 3 total gears
55   The following gear sizes are available to you: small
56
57 Your client tools are now configured.

As a last service, the Setup tool shows available applications and the number of free gears. In the free version, only small gears are available. The command rhc cartridge list shows a complete list of all available cartridges (Listing 2).

Listing 2

Listing Available Cartridges

01 [mfeilner@desktop ~]$ rhc cartridge list
02 jbossas-7                JBoss Application Server 7              web
03 jboss-dv-6.0.0 (!)       JBoss Data Virtualization 6             web
04 jboss-dv-6.1.0 (!)       JBoss Data Virtualization 6             web
05 jbosseap-6 (*)           JBoss Enterprise Application Platform 6 web
06 jboss-unified-push-1 (!) JBoss Unified Push Server 1.0.0.Beta1   web
07 jenkins-1                Jenkins Server                          web
08 nodejs-0.10              Node.js 0.10                            web
09 perl-5.10                Perl 5.10                               web
10 php-5.3                  PHP 5.3                                 web
11 php-5.4                  PHP 5.4                                 web
12 zend-6.1                 PHP 5.4 with Zend Server 6.1            web
13 python-2.6               Python 2.6                              web
14 python-2.7               Python 2.7                              web
15 python-3.3               Python 3.3                              web
16 ruby-1.8                 Ruby 1.8                                web
17 ruby-1.9                 Ruby 1.9                                web
18 ruby-2.0                 Ruby 2.0                                web
19 jbossews-1.0             Tomcat 6 (JBoss EWS 1.0)                web
20 jbossews-2.0             Tomcat 7 (JBoss EWS 2.0)                web
21 jboss-vertx-2.1 (!)      Vert.x 2.1                              web
22 jboss-wildfly-8 (!)      WildFly Application Server 8.2.0.Final  web
23 diy-0.1                  Do-It-Yourself 0.1                      web
24 10gen-mms-agent-0.1      10gen Mongo Monitoring Service Agent    addon
25 cron-1.4                 Cron 1.4                                addon
26 jenkins-client-1         Jenkins Client                          addon
27 mongodb-2.4              MongoDB 2.4                             addon
28 mysql-5.1                MySQL 5.1                               addon
29 mysql-5.5                MySQL 5.5                               addon
30 phpmyadmin-4             phpMyAdmin 4.0                          addon
31 postgresql-8.4           PostgreSQL 8.4                          addon
32 postgresql-9.2           PostgreSQL 9.2                          addon
33 rockmongo-1.1            RockMongo 1.1                           addon
34 switchyard-0             SwitchYard 0.8.0                        addon
35 haproxy-1.4              Web Load Balancer                       addon
36
37 Note: Web cartridges can only be added to new applications.
38
39 (*) denotes a cartridge with additional usage costs.
40
41 (!) denotes a cartridge that will not receive automatic security updates.
42 [mfeilner@desktop~]$

Creating an Application

The next step is to create your first application. Click on the link labeled Create your first application now in OpenShift Online's web interface, or type rc app create, followed by the name of the app and the type of the cartridge (Listing 3).

Listing 3

Creating an Application

01 mfeilner@desktop ~] rhc app create MyFirstApp python-2.7
02 Application Options
03 -------------------
04 Domain:     feilner
05 Cartridges: python-2.7
06 Gear Size:  default
07 Scaling:    no
08
09 Creating application 'MyFirstApp' ... done
10
11
12 Waiting for your DNS name to be available ... done
13
14 Clones for 'myfirstapp'...
15 The authenticity of host 'myfirstapp-feilner.rhcloud.com \
   (54.89.183.121)' can't be established.
16 RSA key fingerprint is cf:ee:77:cb:0e:fc:02:d7:72:7e:ae:80:c0:90:88:a7.
17 Are you sure you want to continue connecting (yes/no)? yes
18 Warning: Permanently added 'myfirstapp-feilner.rhcloud.com,\
   54.89.183.121' (RSA) to the list of known hosts.
19 Connection closed by 54.89.183.121
20 fatal: Could not read from remote repository.
21
22 Please make sure you have the correct access rights
23 and the repository exists.
24 Unable to clone your repository.
25
26 (...)
27
28 Your application 'myfirstapp' is now available.
29
30   URL:        http://myfirstapp-feilner.rhcloud.com/
31   SSH to:     55060dfae0b8cd7df90000b6@myfirstapp-feilner.rhcloud.com
32   Git remote: ssh://55060dfae0b8cd7df90000b6@myfirstapp-feilner.rhcloud.com\
                     /~/git/myfirstapp.git/
33
34 Run 'rhc show-app MyFirstApp' for more details about your app.
35 mfeilner@desktop ~] rhc show-app MyFirstApp
36 myfirstapp @ http://myfirstapp-feilner.rhcloud.com/ \
   (uuid: 55060dfae0b8cd7df90000b6)
37 ----------------------------------------------------------------------
38   Domain:     feilner
39   Created:    Mar 15 11:55 PM
40   Gears:      1 (defaults to small)
41   Git URL:    ssh://55060dfae0b8cd7df90000b6@myfirstapp-feilner.rhcloud.com\
                     /~/git/myfirstapp.git/
42   SSH:        55060dfae0b8cd7df90000b6@myfirstapp-feilner.rhcloud.com
43   Deployment: auto (on git push)
44
45   python-2.7 (Python 2.7)
46   -----------------------
47     Gears: 1 small

You can always get more information about your gear(s) with the rhc show-app tool. However, rhc app create encountered a problem: You have not yet specified a configuration for this application . Because this configuration would be stored in a Git repository that does not yet exist, the Red Hat tools failed to locate it.

You can delete apps with rhc del app (Listing 4); the OpenShift configuration and tokens will reside in ~/.openshift/. Nevertheless, if you start rhc setup now, it will tell you, You are using 1 of 3 total gears – your first container is running! If you don't believe it, visit the URL offered (Figure 7).

Listing 4

Deleting an App

01 rhc app delete myfirstapp
02 This is a non-reversible action! Your application code and \
   data will be permanently deleted if you continue!
03
04 Are you sure you want to delete the application 'myfirstapp'? (yes|no): yes
05
06 Deleting application 'myfirstapp' ... deleted

Figure 7: You have successfully started your first Python-based container in Red Hat's OpenShift cloud.

The next step is to set up your own Git repository with all the features you want your app to have (see the OpenShift Users Guide [11] for more on setting up a Git repository for OpenShift).

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