Kubernetes

install nginx ingress controller

https://docs.k3s.io/cluster-access

helm upgrade --install ingress-nginx ingress-nginx \
  --repo https://kubernetes.github.io/ingress-nginx \
  --namespace ingress-nginx --create-namespace

access k3s cluster via helm

export KUBECONFIG=/etc/rancher/k3s/k3s.yaml
kubectl get pods --all-namespaces
helm ls --all-namespaces

install k3s

with rights to access it as user

curl -sfL https://get.k3s.io | INSTALL_K3S_EXEC='--write-kubeconfig-mode=644' sh -
curl -sfL https://get.k3s.io | K3S_KUBECONFIG_MODE="644" INSTALL_K3S_EXEC="server" sh -s - --flannel-backend none

change interface

https://jaehong21.com/posts/k3s/02-access-outside/

sudo vi /etc/systemd/system/k3s.service

ExecStart=/usr/local/bin/k3s \
    server \
        '--flannel-backend' \
        'none' \
        '--write-kubeconfig-mode=644' \
        '–advertise-address=192.168.0.137' \
        '-tls-san=192.168.0.137' \

remove k3s

/usr/local/bin/k3s-uninstall.sh

show everything in a namespace

kubectl --namespace=gitlab-runner show all

get shell

kubectl exec --stdin --tty shell-demo -- /bin/bash

events

kubectl get events --namespace=gitlab-runner

get all events

kubectl get events --all-namespaces  --sort-by='.metadata.creationTimestamp'

create namespace

kubectl create ns gitlab-runner

gitlab-runner

• https://github.com/ulm0/gitlab

For swep20:

cd ~/kubernetes/gitlab-runner/
helm install --namespace gitlab-runner gitlab-runner-swep20-2 -f values_swep20.yaml gitlab/gitlab-runner
helm uninstall gitlab-runner --namespace=gitlab-runner

edit configmap via editor

kubectl edit cm -n kube-system coredns

Recreate/Restart after edit:

kubectl delete pod coredns

fix gitlab-runner for docker in docker

• https://gitlab.com/gitlab-org/gitlab-runner/-/issues/2578

Edit config map and add following before runner start command:

    # Add docker volumes
    cat >> /home/gitlab-runner/.gitlab-runner/config.toml << EOF
        [[runners.kubernetes.volumes.host_path]]
              name = "alias-docker-in-docker"
              mount_path = "/var/run/docker.sock"
              read_only = true
              host_path = "/var/run/docker.sock"
    EOF

add helm charts

helm repo add stable https://charts.helm.sh/stable 
helm repo add gitlab https://charts.gitlab.io/
helm repo update

cluster info

kubectl cluster-info