Discover K8E: minimalist kubernetes distribution

TL;DR

This article introduces and experiences minimalism Kubernetes Distribution version , Also by the way, analyze and learn the compiling process .

background

k8e The original meaning is kuber easy, It's a Kubernetes Minimalist distribution of , The intention is to deploy the cloud natively Kubernetes More relaxed .k8e Based on another distribution k3s , Cropped （ Removed Edge/IoT Related functions 、traefix etc. ）、 Expand （ Join in ingress、sidecar Realization 、cilium etc. ） And come .

k8e It has the following characteristics ：

• Single binary file , Integrated k8s The various components of 、containerd、runc、kubectl、nerdctl etc.
• Use cilium As cni The implementation of the , convenient eBPF Fast landing of
• Support based on pipy Of ingress、sidecar proxy, Realize one-stop management of application traffic
• Only one... Is maintained k8s edition , At present, it is 1.21
• According to the experience of private cloud, increase 、 Optimize the code

Thanks to these characteristics ,k8e Very suitable CI、 Development and enterprise deployment , The stand-alone cluster is suitable for the technical verification environment .

Install the test

It can be downloaded from GitHub Download the corresponding version of Binary , You can also compile it manually （ The compilation process is briefly analyzed later ）.

sudo k8e check-configsudo k8e server &# Kubeconfig is written to /etc/k8e/k8e.yamlexport KUBECONFIG=/etc/k8e/k8e.yaml# On a different node run the below. NODE_TOKEN comes from# /var/lib/k8e/server/node-token on your serversudo k8e agent --server https://myserver:6443 --token ${NODE_TOKEN}# query all node from k8s clustersudo k8e kubectl get nodes

Because there is no default cni Realization , here pod All in Pending state . Manual installation required cilium：

adopt k8e check-config Can find builddata Catalog ：/var/lib/k8e/data/5a7ced03412504a18bf3f49cbee5dafca7187d86ef8fdaa789448d53d7fbb823

/var/lib/k8e/data/5a7ced03412504a18bf3f49cbee5dafca7187d86ef8fdaa789448d53d7fbb823/bin/cilium install

cilium After successful installation Pod Running successfully , You can see cilium state ：

/var/lib/k8e/data/5a7ced03412504a18bf3f49cbee5dafca7187d86ef8fdaa789448d53d7fbb823/bin/cilium status    /¯¯\ /¯¯\__/¯¯\    Cilium:         OK \__/¯¯\__/    Operator:       OK /¯¯\__/¯¯\    Hubble:         disabled \__/¯¯\__/    ClusterMesh:    disabled    \__/DaemonSet         cilium             Desired: 1, Ready: 1/1, Available: 1/1Deployment        cilium-operator    Desired: 1, Ready: 1/1, Available: 1/1Containers:       cilium             Running: 1                  cilium-operator    Running: 1Cluster Pods:     3/3 managed by CiliumImage versions    cilium             quay.io/cilium/cilium:v1.10.5: 1                  cilium-operator    quay.io/cilium/operator-generic:v1.10.5: 1

Or perform cilium connectivity test Check the network .

The above is the deployment as a development verification environment , To deploy standards Kubernetes, You can refer to Official documents .

Compilation process analysis

k8e The compilation and deployment of can be completed with two simple commands ：

make generatemake

perform make generate Download several built-in tools ：runc、nerdctl、cilium, Save in bin Directory .

.DEFAULT_GOAL yes ci, perform make Will perform target ci .

Dapper

stay makefile The first line is TARGETS := $(shell ls hack | grep -v \\.sh | grep -v package-airgap| grep -v clean) Defined variables TARGETS, then $(TARGETS): .dapper For a few target Specify preconditions . Among them ci, So in execution ci I'll do it before target .dapper.

target .dapper For downloading rancher dapper.dapper yes Docker Build wrapper for , It will be executed in the root directory of the source code Dockerfile.dapper Build a mirror image , And use it as a code building environment .

stay Dockerfile.dapper in , Will be ready to build the environment , And several settings that need attention ：

• WORKDIR：/go/src/github.com/xiaods/k8e/, That is, the working directory of the container .dapper At startup, the source code content will be copied to the container
• ENTRYPOINT：["./hack/entry.sh"], Container enabled entrypoint.
• CMD：["ci"], Default for container runtime CMD
• ENV
  • DAPPER_SOURCE：/go/src/github.com/xiaods/k8e/
  • DAPPER_OUTPUT：./bin ./dist ./build/out, After building , Will execute docker cp ${DAPPER_SOURCE}/${DAPPER_OUTPUT} . Copy the contents of the container to the outside of the container .
  • ...

dapper When the download is complete, execute ci The order of ：./.dapper ci, according to Dockerfile.dapper Configuration of , It will be executed after startup ./hack/entry.sh ci.

CI

CI Process and k3s The process is much simpler than that of . stay ./hack/ci in , Will execute in turn ：

• ./hack/validate： Code formatting 、 check
• ./hack/build： The code to compile
• ./hack/package： Download the previous 、 Compilation of bin/ The binaries in the directory are packaged into the same binary file （ Use go-bindata）.
• ./hack/binary_size_check.sh： Binary file size check , Is it more than 81 M（k3s Yes. 64M, Because of the addition of cilium etc. cli, The volume will increase ）.

The article is issued in official account The cloud points north