The Altinn 3 Raspberry Pi 3 challenge

[altinnadmin]

I've had a Raspberry Pi 3 laying around for a couple of years, but I've never found the time to use it for something cool.

We're talking only 1 GiB of RAM and a 1.4 GHz 64-bit quad-core ARM Cortex-A53 processor, with 512 KiB shared L2 cache. Tiny specs indeed...

So, then the natural question is: Can it run Altinn 3?? 😁

Is it possible to run the entire Altinn 3 infrastructure (Altinn Studio, Altinn Platform and a couple of apps) on this tiny device? To put this into context, I want to run Altinn 3 on something that has just a fraction of the memory in your phone and costs only $35.

Let's find out!

The software

So what software are we using in Altinn 3 that I need to get up and running on my Pi?

• Kubernetes is used to host all our Alpine Linux containers. K3S looks promising. We're within the minimum specs, it supports Alpine Linux, and it's optimized for ARM. "K3s works great from something as small as a Raspberry Pi to an AWS a1.4xlarge 32GiB server."
• Alpine Linux is used as OS in our containers. It runs on ARM and uses its small size as a selling point. "Alpine Linux is built around musl libc and busybox. This makes it smaller and more resource efficient than traditional GNU/Linux distributions."
• Gitea is used in Altinn Studio Repos to store users and the app repositories. We're within the system requirements. "A Raspberry Pi 3 is powerful enough to run Gitea for small workloads."
• NGINX is used in Altinn Studio for routing requests between Designer and Repos. Should be no problem according to the Why Use NGINX. "NGINX used one worker, 15% CPU and 1MB of memory to serve 11,500 requests per second."
• .NET 5 is used by Altinn Studio Designer and almost all the containers in Platform. Microsoft has focused alot on performance and memory usage. Hopefully that's enough.
• PDFBox and Java is used in the PDF-microservice in Platform. I do hope PDFBox is not a memory hog.
• PostgreSQL is used by Gitea in Studio and Events in Platform. This might cause problems, since it seems like 2 GB is the minimum requirement, twice the memory of the Pi. Luckily Gitea also supports SQLite, but Events might need support for an alternative more lightweight backend.
• Cosmos DB and Blob Storage is used by Storage in Platform. Azure-only, and is not even possible to emulate on Linux. Seems like we need Altinn/altinn-storage#127... Or can we use the file-based implementations used in LocalTest?
• Key Vault is used for storing and retrieving secrets. Azure-only. I assume absctractions and alternative fallbacks has already been implemented since things works locally, but if not that needs to be done.

Hmmm, this might actually work! It seems possible with some effort. Wow!

Altinn 2

For fun, could this be remotely possible with the software used in Altinn 2? Short answer: no.

• Almost everything in Altinn 2 runs on Windows, and Windows Server requires x64 and does not run on ARM processors.
  • None of the stuff running on top of Windows in Altinn 2 supports ARM anyways :)
• And the minimum system requirements for just two pieces of software is 20 times of what the Pi has available:
  • SharePoint: 16 GB, BizTalk: 4 GB...
  • ...and then we have Windows (0.5-2 GB), SQL Server (1 GB), .NET Framework (512 MB), etc, etc...

Out of scope

• Build/deploy pipelines - used for building and deploying apps automatically
• Container Registry - used for storing the built app images

Tasks

• [ ] Infrastructure using K3S up and running
• [ ] Altinn Studio up and running
  • [ ] Repos (Gitea)
  • [ ] Designer
  • [ ] NGINX
• [ ] Platform up and running
  • [ ] Authorization
  • [ ] Authentication
  • [ ] Events
  • [ ] PDF
  • [ ] Profile
  • [ ] Register
  • [ ] Storage Altinn/altinn-storage#127
• [ ] An app or two up and running

[astromoskar]

@altinnadmin

Cosmos DB and Blob Storage is used by Storage in Platform. Azure-only, and is not even possible to emulate on Linux. Seems like we need Altinn/altinn-storage#127... Or can we use the file-based implementations used in LocalTest?

Might be possible to use the "real deal" instead of emulating on Linux? https://docs.microsoft.com/en-us/azure/cosmos-db/optimize-dev-test#azure-cosmos-db-free-tier

[altinnadmin]

Might be possible to use the "real deal" instead of emulating on Linux? https://docs.microsoft.com/en-us/azure/cosmos-db/optimize-dev-test#azure-cosmos-db-free-tier

Heh, wouldn't that be cheating? The challenge (and fun) is getting everything running on a Pi :)