spec VS smi-spec

I had a really (what I thought at the time) cool idea for a new Kubernetes storage driver, so I implemented the basic version in an evening. That's the first "rave-worthy" event - the architecture of these drivers is fairly complex and there are many ways to do it (see https://github.com/container-storage-interface/spec/blob/master/spec.md) so getting something working as I imagined it, knowing nothing beforehand, was the first moment of joy. The next day (after sharing in a few slacks) I got a DM from a tech lead at and he was really excited about the idea! That second affirmation that someone was excited about the project and wanted to brainstorm with me was my second moment of joy. And then for the third, last night and (some of today, still going to do more after dinner soon!) I've been doing detail work, and learning a ton, debugging, learning, making it slowly better... that flow state (often with music) is probably the closest thing to the idea of a rave. Anyway, that's my story! I love learning Kubernetes stuff, I'm so grateful I've been able to in my current role.

But if all of these are not an issue, then Containers and an orchestration system like Kubernetes can always take care of workload portability especially with OCI now in place for containers and CSI, CNI, CRI, SMI for storage, networking, runtime and service mesh respectively creating a healthy standards based ecosystem for all thereby enabling workload portability without lock-in since for a workload to be truly portable, all the underlying resources should be portable without any/very limited changes.

CSI (Container Storage Interface) is a standard which helps establish interoperability between multiple storage providers avoiding the need to have in-tree plugins within the core. So, any storage provider who supports CSI can work with Kubernetes without any issues. You can find a complete list of providers supporting CSI here

The Service Mesh Interface (SMI) specification was created to solve this portability issue.

> I suspect if a Service Mesh is ultimately shown to have broad value, one will make it's way into the K8S core

I'm not so sure. I suspect it'll follow the same roadmap as Gateway API, which it already kind of is with the Service Mesh Interface (https://smi-spec.io/)

It is very common that a service mesh deploys a control plane and a data plane. The control plane does what you might expect; it controls the service mesh and gives you the ability to interact with it. Many service meshes implement the Service Mesh Interface (SMI) which is an API specification to standardize the way cluster operators interact with and implement features.

Before we start, let's review the SMI Access Control Specification. There are two forms of traffic policies in osm-edge: Permissive Mode and Traffic Policy Mode. The former allows services in the mesh to access each other, while the latter requires the provision of the appropriate traffic policy to be accessible.

osm-edge is a simple, complete, and standalone service mesh and ships out-of-the-box with all the necessary components to deploy a complete service mesh. As a lightweight and SMI-compatible Service Mesh, osm-edge is designed to be intuitive and scalable.

I started on Monday, attending ServiceMeshCon2019. My guesstimate is that about 1000 people attended it. I believe Service Mesh is playing such a crucial role in scaling cloud native technologies that large scale cloud-native deployments may not be possible without service mesh. Just like you cannot really succeed in deploying a microservices based application without a microservices orchestration engine, like Kubernetes, you cannot scale the size and capacity of a microservices-based application without service mesh. That’s what makes it so compelling to see all the service mesh creators — Istio, Linkerd, Consul, Kuma — and listen to them. There was also a lot of discussion of SMI (Service Mesh Interface) — a common interface among all services mesh. The panel at the end of the day included all the major service mesh players, and some very thought provoking questions were asked and answered by the panel.

Do you need a Service Mesh?

In the episode with Annie, she gave a great overview of the CNCF and a handful of projects that she's excited about. Those include Helm, Linkerd, Kudo, Keda and Artifact Hub. I gave a bonus example of the Service Mesh Interface project.

SMI official website: https://smi-spec.io