04-etcdhelper

Enhanced version of etcdhelper

This is a modified version of etcdhelper from OpenShift (modifications are made by Flant). Two new functions are introduced: changeServiceCIDR and changePodCIDR.

This repo is intended to be used as a playground for a corresponding article:

• «How to modify etcd data of your Kubernetes directly (without K8s API)».
• Russian version: «Наш опыт работы с данными в etcd Kubernetes-кластера напрямую (без K8s API)».

Using etcdhelper

Build

The fastest way is to use official golang image:

docker run --rm -v $(pwd):/app -w /app -e CGO_ENABLED=0 -e GOOS=linux golang:1.18-alpine go build etcdhelper.go

etcdhelper binary will be created in the current directory. Use GOOS=darwin to build MacOS executable.

Using

Change service CIDR

./etcdhelper -cacert /etc/kubernetes/pki/etcd/ca.crt -cert /etc/kubernetes/pki/etcd/server.crt -key /etc/kubernetes/pki/etcd/server.key -endpoint https://127.0.0.1:2379 change-service-cidr 172.30.0.0/16

Change pod CIDR

./etcdhelper -cacert /etc/kubernetes/pki/etcd/ca.crt -cert /etc/kubernetes/pki/etcd/server.crt -key /etc/kubernetes/pki/etcd/server.key -endpoint https://127.0.0.1:2379 change-pod-cidr 10.55.0.0/16

Change Ceph PV monitors list

This feature was added later (#15), thus it was not mentioned in the original article.

./etcdhelper -cacert /etc/kubernetes/pki/etcd/ca.crt -cert /etc/kubernetes/pki/etcd/server.crt -key /etc/kubernetes/pki/etcd/server.key -endpoint https://127.0.0.1:2379 change-monitors-list pvc-d748b019-52be-4c0c-a928-44503ccd94ac 10.0.1.1:6789,10.0.1.2:6789,10.0.1.3:6789

Status

This enhanced version of etcdhelper is PoC (proof of concept). Use it on your own risk.