SAP on Google Cloud : When SAP Developers join the cloud (pt. 1)
During the first SAP Online Track, Fatima Silveira and I had the privilege of sharing our newest experiments with extensions to SAP on containers, SAP HANA, HDI containers and CI/CD pipelines.
This blog post provides some preliminary context and is the first of a series showing what and how we did it, with notes on how to implement this in a real-life scenario.
When SAP joins the cloud
This adventure started when a team of seasoned cloud-native developers heard the SAP workload was joining the cloud. This team already had a set of established practices for cloud-native development. They knew SAP is queen in business processes and wanted to invite her to the party.
They knew they could bring a lot of innovation to the business, they just needed to get past the acronyms in the SAP world first.
The first acronym — HDI
Together with SAP’s take on Cloud Foundry, in the SAP HANA world, came HANA Deployment Infrastructure containers. Despite being presented together, HDI containers do not need the XS Advanced or SAP Cloud Platform layer to exist in a HANA database. Thomas Jung made this very easy to understand with a practical approach in this blog post.
HDI containers have been a source of heated disputes at SAP family dinners. Without understanding the benefits they bring, it’s hard to make the case to migrate an existing codebase written in a traditional schema in a sidecar HANA. You have your calculation views feeding your reporting tool and it works like a charm, then why bother?
Here is one reason why: HDI containers allow for branching and isolation. We’ll see this in practice in our pipeline.
The second acronym — CI/CD
This one was not coined by SAP but defining this acronym can quickly turn into a debate. As a refresher:
- Continuous integration: There is a shared repo (e.g., GitHub) to which developers merge their code. This merging process triggers automated code checks and tests to make sure nothing is broken by the new changes. If the tests pass, the whole thing is bundled to be deployed.
- Continuous delivery: Act of manually triggering the deployment of artifacts. For example, the changes have been approved and can be pushed into production. This a standardized workflow not too different from what most of the traditional SAP ABAP devs do to move a transport request into a productive Netweaver installation. The ability to rollback a change is also relevant.
- Continuous deployment: Same as delivery, but the deployment into production is automated.
The main point here is that we want to make small, incremental changes to add functionality to our code and release it as often as possible. We will use a series of tools to check our code, test it and release it.
If you’d like to understand more, here are some introductory resources to bookmark:
- Continuous Integration and Continuous Delivery by Martin Fowler
- Google’s CI/CD Developer Hub
- Nice intro video with code examples and tools
- Another video about CI/CD Across Multiple Environments
What about DevOps?
Well, DevOps goes beyond CI/CD and includes concepts like Infrastructure as Code which deserve their own full chapter. The one principle I’d take from DevOps culture is automation and focusing on a faster feedback loop.
Cloud Run and Knative— not an acronym, still important
I have loved Cloud Run since it was first announced because it allows you to deploy managed containers that autoscale and serve HTTPS endpoints without knowing much about containers at all.
The magic behind this is Knative, an open source project started by Google and contributed to by SAP, IBM, Pivotal and others. Knative is about simplifying serving and eventing in an application deployed in Kubernetes.
Why is it magic? It converts Kubernetes containers into serverless applications.
To understand what Knative does, think of what you would need to manually deal with if Knative wasn’t serving the application above:
- Start with defining services and deployments for Kubernetes
- Routing and balancing of incoming traffic to new revisions of an application
- Automatically increasing or decreasing the number of replicas based on incoming requests (i.e., auto-scaling, even to zero)
- Keeping a stable endpoint the other apps or users can connect to (even after you deploy a new version of the container)
Now that we have established some context, let’s roll up our sleeves and dive into details.
Part 2 in this post for details on how the SAP HANA HDI containers work in a CI/CD pipeline.
