Difference between revisions of "Kubernetes"

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(Add your own Service)
 
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* Currently running on [[Bellatrix]]
 
* Currently running on [[Bellatrix]]
 
* Backup: https://git.fixme.ch/Comite/fixme-kube-backup (restricted for secret access)
 
* Backup: https://git.fixme.ch/Comite/fixme-kube-backup (restricted for secret access)
 +
 +
=== Services ===
 +
 +
* Some services that are deployed on our instance
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** [[Chat]]
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** [[Etherpad]]
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** [[Power|Power monitoring]]
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** Fablab wiki
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** [[LED_Lighting|Led API endpoint]]
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** [[Trigger]]
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** [[MQTT|MQTT gateway]]
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** gitlab: ongoing
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 +
=== Add your own Service ===
 +
 +
A service is composed of:
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* A deployment
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* A service
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* An ingress controller
 +
 +
at minimum
 +
 +
==== SSL ====
 +
 +
* We use cert-manager to manage LetsEncrypt certs, you only need to add this annotation to your Ingress Controller for it to manage your cert,
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<pre>
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ubuntu@k8s:~$ k edit -n mattermost ingress/mattermost-ingress
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[...]
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metadata:
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  annotations:
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    cert-manager.io/cluster-issuer: letsencrypt
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[...]
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</pre>
 +
 +
=== Debug ===
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==== Access impossible ====
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 +
Sometimes the eth interface is in the sauce (to investigate), you have to reconfigure it.
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 +
<pre>
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ubuntu@k8s:~$ sudo ip addr add 62.220.135.219/32 dev ens6
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</pre>
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 +
It should look like this
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<pre>
 +
ubuntu@k8s:~$ ip -4 a show ens6
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2: ens6: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc fq_codel state UP group default qlen 1000
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    inet 62.220.135.205/26 brd 62.220.135.255 scope global ens6
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      valid_lft forever preferred_lft forever
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    inet 62.220.135.219/32 scope global ens6
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      valid_lft forever preferred_lft forever
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</pre>
 +
 +
==== Certificate expiration ====
 +
 +
Sometimes K8S is in the sauce, something like this might help regenerate the certs
 +
 +
<pre>
 +
# Service state
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systemctl stop kubelet.service
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systemctl restart docker.service
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# Backup
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rsync -av /etc/kubernetes/ /root/kubernetes-$(date +%s)/
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rsync -av /var/lib/etcd/ /root/etcd-$(date +%s)/
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 +
cd /etc/kubernetes
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rm {admin.conf,controller-manager.conf,kubelet.conf,scheduler.conf}
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 +
cd /etc/kubernetes/pki
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rm {apiserver.crt,apiserver-etcd-client.key,apiserver-kubelet-client.crt,front-proxy-ca.crt,front-proxy-client.crt,front-proxy-client.key,front-proxy-ca.key,apiserver-kubelet-client.key,apiserver.key,apiserver-etcd-client.crt}
 +
 +
# Regen certificates
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cd
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kubeadm init phase certs all --apiserver-advertise-address 62.220.135.205 --ignore-preflight-errors=all
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kubeadm init phase kubeconfig all
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cp -i /etc/kubernetes/admin.conf $HOME/.kube/config
 +
 +
# Check states
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kubeadm join 62.220.135.205:6443 --token XXX --discovery-token-ca-cert-hash YYY --ignore-preflight-errors=all
 +
kubectl get nodes
 +
kubectl get all
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</pre>

Latest revision as of 00:07, 9 August 2021

Kubernetes @ FIXME

Information

Services

Add your own Service

A service is composed of:

  • A deployment
  • A service
  • An ingress controller

at minimum

SSL

  • We use cert-manager to manage LetsEncrypt certs, you only need to add this annotation to your Ingress Controller for it to manage your cert,
ubuntu@k8s:~$ k edit -n mattermost ingress/mattermost-ingress
[...]
metadata:
  annotations:
    cert-manager.io/cluster-issuer: letsencrypt
[...]

Debug

Access impossible

Sometimes the eth interface is in the sauce (to investigate), you have to reconfigure it.

ubuntu@k8s:~$ sudo ip addr add 62.220.135.219/32 dev ens6

It should look like this

ubuntu@k8s:~$ ip -4 a show ens6 
2: ens6: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc fq_codel state UP group default qlen 1000
    inet 62.220.135.205/26 brd 62.220.135.255 scope global ens6
       valid_lft forever preferred_lft forever
    inet 62.220.135.219/32 scope global ens6
       valid_lft forever preferred_lft forever

Certificate expiration

Sometimes K8S is in the sauce, something like this might help regenerate the certs

# Service state
systemctl stop kubelet.service
systemctl restart docker.service

# Backup
rsync -av /etc/kubernetes/ /root/kubernetes-$(date +%s)/
rsync -av /var/lib/etcd/ /root/etcd-$(date +%s)/

cd /etc/kubernetes
rm {admin.conf,controller-manager.conf,kubelet.conf,scheduler.conf}

cd /etc/kubernetes/pki
rm {apiserver.crt,apiserver-etcd-client.key,apiserver-kubelet-client.crt,front-proxy-ca.crt,front-proxy-client.crt,front-proxy-client.key,front-proxy-ca.key,apiserver-kubelet-client.key,apiserver.key,apiserver-etcd-client.crt}

# Regen certificates
cd
kubeadm init phase certs all --apiserver-advertise-address 62.220.135.205 --ignore-preflight-errors=all
kubeadm init phase kubeconfig all
cp -i /etc/kubernetes/admin.conf $HOME/.kube/config

# Check states
kubeadm join 62.220.135.205:6443 --token XXX --discovery-token-ca-cert-hash YYY --ignore-preflight-errors=all
kubectl get nodes
kubectl get all