Proxy Layers

The OSI model attempts to build a model for network communications, where increasingly high level layers are built upon lower layers. This is only slightly useful in practice, as the real world is not so simple. In service mesh, generally discussion is reduced to L4 and L7, or TCP and HTTP. This oversimplifies the problem, leading to some confusion. Thinking in terms of termination Simply saying "HTTP" is not really clear about what is going on. Instead, I think its more useful to think about what layer we terminate. ...

October 12, 2023 · 4 min

Service Mesh Proxy Classes

When looking at service mesh (or even general networking) architectures, the basic idea is to send network traffic through some component, which handles various functionality. This could be authentication, authorization, encryption, observability, reliability, networking, etc. There are a few different classes of components that can do this, though: Different types of proxy deployments Native application enhancement. The application itself is compiled in with functionality. This could be something like gRPC (or, even more "meshy", gRPC with xDS), Finagle, Hystrix, etc. Even simply instrumenting your application with metrics and traces could be classified here. "Sidecar", or running a proxy-per-application, is probably the most common service mesh deployment pattern today, used by Istio, Linkerd, and more. Per-node proxy; like sidecar, but instead of per-application the proxy is per-node. Each node contains multiple unique workloads, so the proxy is multi-tenant. Remote proxy. A completely standalone proxy deployment we send some traffic through. This could be correlated to one or many service(s), one or many workload(s), etc -- the correlation between proxies and other infrastructure components is flexible here. Within each of these, there is 2 actors: a client and a server. This gives us 8 points to insert functionality. Presumably, all 8 will not be used at once -- but its possible. If we are willing to blur the lines a bit, even a traditional sidecar based service mesh utilizes 6 of these! The most rich "service mesh" functionality may exist in the sidecar, but the application itself has some functionality (even if its not terribly rich), and the node does as well (again, this may not be terribly rich -- kube-proxy, for example, has very minimal functionality). And the same is mirror on the client and server side. ...

October 11, 2023 · 8 min

User space isn't slow

In-kernel networking solutions, such as WireGuard, are not always faster than user space.

September 10, 2023 · 3 min

An optimal CI/CD system

Exploring an (unfortunately, hypothetical) CI/CD system for end to end tests on Kubernetes.

September 6, 2023 · 6 min

Istio Ambient is not a "Node Proxy"

The common messaging around Istio Ambient Mesh is that is a "node proxy." For example, from The New Stack ... architecture that moves the proxy functionality from the pod-level to the node-level. While this is technically accurate, it is misleading and really missing the point and benefits of Ambient. A brief history of service mesh architectures This skips quite a bit of information, but is close enough. One of the earlier service meshes on the market was Linkerd 1 - not to be confused with Linkerd 2, which most people just call "Linkerd" today. Linkerd 1 was a per-node proxy that did all the service mesh functionality we know and love, at the node level. ...

August 22, 2023 · 3 min

Waypoint Proxies The Hard Way

How to achieve an architecture similar to "Waypoint Proxies" without ambient mesh, or even Istio.

August 22, 2023 · 11 min

Building a lot of docker images

Fully utilizing buildkit's potentional

August 4, 2023 · 5 min

GOMAXPROCS and GOMEMLIMIT in Kubernetes

How and why to easily these fields

July 31, 2023 · 2 min

Saying No In Open Source

As an open source maintainer, I am reviewing roughly 25 ideas per day - whether they are feature requests, design proposals, or pull requests. Inevitably, this leads to saying "No" quite a bit as well. Usually, this is in a softer for like "No, not right now", "No, not in its current form", or "No, unless someone else approves", but the outcome is the same: the change is not accepted, and the emotional impact on the reviewer and contributor is similar. ...

July 27, 2023 · 5 min

Useful tools for Kubernetes

Most people using Kubernetes extensive have already defined alias k=kubectl and are using tools like kubectx. As someone really lazy though, I have found/developed a few less common tools to help work with Kubernetes efficiently. kubectl apply from clipboard This relies on zsh, and uses the zle to define a custom command. function zle_apply { LBUFFER=" cat <<EOF | kubectl apply -f - $(xclip -se c -o) EOF" CURSOR=31 } zle -N zle_apply; bindkey "^k" zle_apply This defines a function and binds it to Ctrl+k. ...

July 12, 2023 · 3 min