One of the common requirements for Java based applications on OpenShift is to have these workloads connect back out to an enterprise database that resides outside of the OpenShift infrastructure. While OpenShift natively supports a variety of relational databases (including Postgres and MySQL) as Docker based deployments within the platform, connecting to an existing enterprise database infrastructure is preferred in many large organizations for a variety of reasons including:
- Inherent confidence in traditional databases due to in house experience around developing and managing these databases
- Ability to leverage existing backup/recovery procedures around these databases
- Technical limitations with these databases in being able to be deployed in a containerized model
One of the strengths of the OpenShift platform is its ability to accommodate these “traditional” workloads so that middleware operations can take advantage of the benefits/efficiencies gained from Dockeri’zed applications while giving development teams a platform to start designing/architecting applications that would fit into more of a Microservice based pattern that would leverage a datastore such as MongoDB or MySQL that OpenShift supports.
In addition to that, another common workflow in many organizations from a deployment point of view is to externalize the database connection information so that the application can be migrated from environment to environment (example Dev to QA to Prod) with the appropriate database connection information for the various environments. In addition, these teams typically work with the application binary (.war, .ear, .jar) deployment as the artifact thats promoted between environments as opposed to Docker based images.
In this article, I will walk through an example implementation for achieving this. A sensitive aspect of this migration process are the credentials to the database, where storing credentials in clear text is frowned upon. I will cover a variety of strategies in dealing with this in a follow on article. For this example, I will be using the following project which contains the source code that I will be covering in this article.
Lets get started!
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