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Kubernetes and cloud providers

In the microservices era, dominated by cloud providers the standard requirement that I receive on every strategic project is
The solution needs to independent from the hosting provider and needs to support on-premises solutions.
The standard context for this requirement is to support cloud providers - Microsoft Azure and AWS. Additional to this, with minimum effort (less than 5% of development cost), the solution shall be run on-premises.

The requirements are tricky even if at first glance you would say that Kubernetes is the solution. Two concerns need to be tackled. The first one is related to what kind of platform shall be used to host the Kubernetes solution. The second one related to how the solution shall use many native cloud services.

Kubernetes it is a powerful container-orchestration solution that allows us to scale our microservice solution. The downside of Kubernetes is that you need to install and configure many services besides Kubernetes itself if you want to have a working solution. From reverse proxy to package deployment solution, you will need to manage it by yourself.
AWS (EKS) and Microsoft Azure (Azure Kubernetes Service) are offering robust environments where you can run your Managed Kubernetes Environment. With low cost, you can spin-up your cluster and run solution inside such an environment. Even if it is super easy to spin-up your cluster, you need to know what you are doing there. Many times, you need to do the same things over and over again.
A solution that is starting to become more and more interesting for companies is OpenShift solution from Red Hat. The solution is constructed on top of Docker and managed using Kubernetes. It is not free but is providing a better experience by having more features included out of the box. Beside image management and deployment configuration, the so-called ‘Routes’ (reverse proxy) are integrated inside OpenShift much better than Ingress Resources and Ingress Controllers that need to be managed by yourself. OpenShift is supported on both AWS and Microsoft Azure ecosystem, and I notified that big organization prefers to pay for OpenShift costs to get them out of the box configuration that is already offered by default.
Things can become more interesting if you put on-premises on top of this. Managing the Kubernetes cluster by yourself, it is not an easy task and having the support of OpenShift can make the team life much more comfortable.

The second problem is the most sensible one because finding the right balance between native cloud services and build-by-yourself is hard. On one side you can optimize development and configuration cost by using native cloud services. This will force you in time to take technical decisions based on specific features available and sometimes forget about topics likes security or redundancy because you already have them by default.
When you build-by-yourself the solution, the dependency to a cloud provider is minimal, but the system looks more like on-premises system. The development and configuration effort are high, and you might ask yourself why I’m using a cloud provider.
A common approach for this situation is to build an API that isolated the cloud infrastructure from your application. In this way, you can control the area of your solution that has a direct dependency on the cloud provider. At least you know the code areas that need to be changed.
Another approach is to start to build components oriented to your functionality and design. The integration with cloud services shall be in only one location, but besides this, the API that is exposed by cloud integration components should take into account the features available cross-cloud provides. In this way, you can ensure that you have a solution that is compatible with other cloud providers too. For example, using Active Directory (AD) to control access to file storage can be a good solution when you are using Microsoft Azure, but you might have a problem if you would look for a similar solution on AWS.

Remember that no solution fits all and all the time is about tradeoffs. When you decide the approach that you want to use, take into account timeline and when you will need to integrate/use the second cloud provided.


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