More and more developers are enjoying the convenience of hosting their applications on OpenShift Online--Red Hat's PaaS Platform as a Service.
Although OpenShift is simple to use, there are lots of other awesome functions and features OpenShift provides that you may not be aware of.
That's what I'm going to talk about here. We will find the answers to questions like:
- I'm a new developer, can I manage my database on OpenShift without knowing SQL?
- I just wanna remove one single record from my database, can I manage it without complicated commands or an pre-installed client tool?
- Is it easy to migrate my existing database to OpenShift?
- Can I backup my database on OpenShift like for a local one?
- Is there any way to use my database on cloud locally maybe for development or debugging purpose?
- I have some favorite GUI database client tools, can I use them to manage the database on OpenShift?
Please feel free to ask any other questions you might have. We are here for you :). You can reach us in comments here in the post, in the forums, or on IRC on Freenode in #openshift.
Before we start
We need a few things prepared for the journey:
Get a free OpenShift account
Install the OpenShift Client Tools
OpenShift supplies several different types of client tools for developers.
Because CLI is way more cooler and because it is the most complete in terms of all the functionality provided.
Let's start from 0
Set up your OpenShift account
At this point we're assuming you have an account on OpenShift.
If you haven't created any app with your account before, then you may need to choose a namespace and upload your public ssh key first.
It's easier with CLI, you can finished all these setup works simply by one RHC command:
Told ya it was easy!
Create an application
OK, now for the real work!
First, let's get familiar with the concepts of applications, cartridges and gears:
Cartridges are the containers that house the framework or components that can be used to create an application. One or more cartridges run on each gear or the same cartridge can run on many gears for clustering or scaling. We currently have cartridges that are enabled for PHP, JBoss, Python, Ruby, Perl & Node.JS. We also offer embedded cartridges in support of MySQL, MongoDB, phpmyadmin.
Applications are made up of at least one framework that is contained in a cartridge and runs on one or more gears. Additional cartridges can be added to the application on the same or different gears.
You can find the full list of them via OpenShift Web Console(https://openshift.redhat.com/app/console/application_types) or RHC command:
$ rhc cartridge list jbossas-7 JBoss Application Server 7.1 web jbosseap-6.0 JBoss Enterprise Application Platform 6.0 web jenkins-1.4 Jenkins Server 1.4 web nodejs-0.6 Node.js 0.6 web perl-5.10 Perl 5.10 web php-5.3 PHP 5.3 web python-2.6 Python 2.6 web python-2.7 Python 2.7 Community Cartridge web python-3.3 Python 3.3 Community Cartridge web ruby-1.8 Ruby 1.8 web ruby-1.9 Ruby 1.9 web jbossews-1.0 Tomcat 6 (JBoss EWS 1.0) web jbossews-2.0 Tomcat 7 (JBoss EWS 2.0) web zend-5.6 Zend Server 5.6 web diy-0.1 Do-It-Yourself web 10gen-mms-agent-0.1 10gen Mongo Monitoring Service Agent 0.1 addon cron-1.4 Cron 1.4 addon jenkins-client-1.4 Jenkins Client 1.4 addon mongodb-2.2 MongoDB NoSQL Database 2.2 addon mysql-5.1 MySQL Database 5.1 addon metrics-0.1 OpenShift Metrics 0.1 addon haproxy-1.4 OpenShift Web Balancer addon phpmyadmin-3.4 phpMyAdmin 3.4 addon postgresql-8.4 PostgreSQL Database 8.4 addon rockmongo-1.1 RockMongo 1.1 addon switchyard-0.6 SwitchYard 0.6 addon Note: Web cartridges can only be added to new applications.
Now, let's create a PHP application named myapp. Feel free to pick your favorite programming language and app name.
$ rhc app create myapp php-5.3 Application Options ------------------- Namespace: linqing Cartridges: php-5.3 Gear Size: default Scaling: no Creating application 'myapp' ... done Waiting for your DNS name to be available ... done Downloading the application Git repository ... Cloning into 'myapp'... Warning: Permanently added 'myapp-linqing.rhcloud.com,188.8.131.52' (RSA) to the list of known hosts. Your application code is now in 'myapp' myapp @ http://myapp-linqing.rhcloud.com/ (uuid: 511d5125e0b8cdf98d00xxxx) -------------------------------------------------------------------------- Created: 9:03 PM Gears: 1 (defaults to small) Git URL: ssh://firstname.lastname@example.org/~/git/myapp.git/ SSH: email@example.com php-5.3 (PHP 5.3) ----------------- Gears: 1 small RESULT: Application myapp was created.
Good! Our application is ready now. Let's move to the database part.
Embed databases into your app
To embed a database cartridge (take mysql as an example), run:
$ rhc cartridge add mysql-5.1 -a myapp Adding 'mysql-5.1' to application 'myapp' Success mysql-5.1 ========= Properties ========== Username = admin Password = smWh27V9eYaq Database Name = myapp Connection URL = mysql://127.3.110.129:3306/
Now you got mysql database embedded into your app. And it's running already.
Wait, you can even embed multiple databases into the same app!
$ rhc cartridge add mongodb-2.2 -a myapp Adding 'mongodb-2.2' to application 'myapp' Success mongodb-2.2 =========== Properties ========== Username = admin Password = wQM4SrQxrNxe Database Name = myapp Connection URL = mongodb://127.3.110.129:27017/ $ rhc cartridge add postgresql -a myapp Adding 'postgresql-8.4' to application 'myapp' Success postgresql-8.4 ============== Properties ========== Username = admin Password = HECLd-AbhlWb Database Name = myapp Connection URL = postgresql://127.3.110.129:5432/
That's so cool!!! One command gets you a fully configured and ready to use database, no tricks!
Now you have the database connection parameters for your app. Use them in your codes and get your app running!
Database connection parameters
I think this is the most significant part for developers:
Your database connection parameters are stored on your Application's gear as environment variables. You can find out what they are by entering the following command after connecting to your gear with ssh:
env | grep OPENSHIFT
You will notice the following entries for the databases we embedded:
#for MySQL OPENSHIFT_MYSQL_DB_PORT=3306 OPENSHIFT_MYSQL_DB_HOST=127.3.110.129 OPENSHIFT_MYSQL_DB_PASSWORD=smWh27V9eYaq OPENSHIFT_MYSQL_DB_USERNAME=admin OPENSHIFT_MYSQL_DB_URL=mysql://admin:smWh27V9eYaq@127.3.110.129:3306/ # for PostgreSQL OPENSHIFT_POSTGRESQL_DB_PASSWORD=HECLd-AbhlWb OPENSHIFT_POSTGRESQL_DB_HOST=127.3.110.129 OPENSHIFT_POSTGRESQL_DB_USERNAME=admin OPENSHIFT_POSTGRESQL_DB_URL=postgresql://admin:HECLd-AbhlWb@127.3.110.129:5432/ OPENSHIFT_POSTGRESQL_DB_PORT=5432 #for MongoDB OPENSHIFT_MONGODB_DB_USERNAME=admin OPENSHIFT_MONGODB_DB_PASSWORD=wQM4SrQxrNxe OPENSHIFT_MONGODB_DB_HOST=127.3.110.129 OPENSHIFT_MONGODB_DB_URL=mongodb://admin:wQM4SrQxrNxe@127.3.110.129:27017/ OPENSHIFT_MONGODB_DB_PORT=27017
Environment variables are the best way to configure your application's connection to a database. This is because we may migrate or update your Application/DB from time to time, resulting in potential IP address changes.
Manage your databases
Embedded databases are not bound to the external IP address of your Application's gear. Hence, only your application on that gear can access the database.
If you want to manage your databases manually OpenShift also provides tools to do that.
Embeded Open Source Tools
OpenShift offers some great open source tools for developers to manage their databases on the cloud easily.
phpMyAdmin is a free and open source tool written in PHP intended to handle the administration of MySQL using a Web browser. Features provided include:
- Web interface
- MySQL database management
- Import data from CSV and SQL
- Export data to various formats: CSV, SQL, XML, PDF (via the TCPDF library), ISO/IEC 26300 - OpenDocument Text and Spreadsheet, Word, Excel, LaTeX and others
- Administering multiple servers
- Creating PDF graphics of the database layout
- Creating complex queries using Query-by-example (QBE)
- Searching globally in a database or a subset of it
- Transforming stored data into any format using a set of predefined functions, like displaying BLOB-data as image or download-link
- Active query monitor (Processes)
Embed the phpMyAdmin cartridge to your app:
$ rhc cartridge add phpmyadmin-3.4 -a myapp Adding 'phpmyadmin-3.4' to application 'myapp' Success phpmyadmin-3.4 ============== Properties ========== Username = admin Password = smWh27V9eYaq Connection URL = https://myapp-linqing.rhcloud.com/phpmyadmin/
RockMongo is a MongoDB management tool, written in PHP 5. It's main features include:
- easy to install, and open source
- multiple hosts, and multiple administrators for one host
- password protection
- query dbs
- advanced collection query tool
- read, insert, update, duplicate and remove single row
- query, create and drop indexes
- clear collection
- remove and change (only work in higher php_mongo version) criteria matched rows
- view collection statistics
Embed RockMongo to your app by running:
$ rhc cartridge add rockmongo-1.1 -a myapp Adding 'rockmongo-1.1' to application 'myapp' Success rockmongo-1.1 ============= Properties ========== Username = admin Password = wQM4SrQxrNxe Connection URL = https://myapp-linqing.rhcloud.com/rockmongo/
Please note that both phpMyAdmin and RockMongo are publicly accessible from Internet.
It's quite convenient, but please keep your database credentials safe.
You can embed database or any other cartridges during the creation of your app. For example:
$ rhc app create myapp php-5.3 mysql-5.1 phpmyadmin-3.4
Long story short
Well, OpenShift has a lot more advantages on manipulating databases. But I think I've made my point, and this blog is long enough :)
Thanks for reading! Enjoy OpenShift and see you soon~