bitcoin-tutorials/k8s

Kubernetes - Helm tips

• Install microk8s and helm on Debian 11 - RaspiBlitz
• Using the Galoy Helm charts
  • Inspect chart without installing
  • Install
• Bitcoind in kubernetes helm
  • install
  • logs
  • copy chain
  • get bitcoind password
• Secrets
• Debug
  • Troubleshooting
  • Check pods
  • Status
• Dashboard
• OS level tweaks
  • Increase open file limits
  • Free space without restart
  • Directories taking space
  • Change microk8s default-storage path in config

Install microk8s and helm on Debian 11 - RaspiBlitz

install.microk8s.sh

Using the Galoy Helm charts

Inspect chart without installing

helm pull galoy-repo/galoy
helm show chart galoy-0.2.52.tgz
helm show values galoy-0.2.52.tgz

Install

helm repo add galoy-repo https://github.com/GaloyMoney/charts
helm repo update
# microk8s.kubectl create namespace galoy
# helm install galoy -n galoy --set global.persistence.storageClass=microk8s-hostpath galoy-repo/galoy
# helm uninstall galoy -n galoy
helm install galoy --set global.persistence.storageClass=microk8s-hostpath galoy-repo/galoy --debug --timeout 10m

helm install galoy \
 --set needFirebaseServiceAccount=false \
 --set global.persistence.storageClass=microk8s-hostpath \
 galoy-repo/galoy --debug --timeout 10m

# needFirebaseServiceAccount: true
needFirebaseServiceAccount=false

helm install bitcoind galoy-repo/bitcoind
helm install lnd galoy-repo/lnd

helm install bitcoin galoy-repo/bitcoin

# monitor
microk8s kubectl get pod -n galoy -w

microk8s kubectl get service -n galoy

Bitcoind in kubernetes helm

install

helm install bitcoind galoy-repo/bitcoind
# monitor
kubectl describe pod bitcoind

logs

sudo tail -f /var/snap/microk8s/common/default-storage/default-bitcoind-pvc-*/debug.log

copy chain

# check storage
ls -la /var/snap/microk8s/common/default-storage
# stop with helm
helm uninstall bitcoind

# copy from clone / host (must not have bitcoind running)
# cd to the source bitcoin directory
cd /mnt/hdd/*/bitcoin

# copy ./chainstate ./blocks ./indexes recursively and verbose
sudo rsync -rv ./chainstate ./blocks ./indexes \
/var/snap/microk8s/common/default-storage/container-registry-registry-claim-pvc-*/

# restart with helm
helm install bitcoind galoy-repo/bitcoind

get bitcoind password

microk8s kubectl get secret bitcoind-rpcpassword -o jsonpath='{.data.password}'

Secrets

• https://kubernetes.io/docs/tasks/configmap-secret/managing-secret-using-kubectl/

microk8s kubectl edit secrets

Debug

• https://devopscube.com/troubleshoot-kubernetes-pods/

Troubleshooting

microk8s.inspect

Check pods

# all pods
microk8s.kubectl get pod --all-namespaces

# watch
microk8s.kubectl get pod -Aw

Status

microk8s.kubectl describe no

Dashboard

microk8s dashboard-proxy

# to just get the token:
token=$(microk8s kubectl -n kube-system get secret | grep default-token | cut -d " " -f1)
microk8s kubectl -n kube-system describe secret $token

OS level tweaks

Increase open file limits

The error:

Failed to allocate directory watch: Too many open files

Check:

sysctl fs.inotify

Fix:

sudo sysctl fs.inotify.max_user_instances=512

Free space without restart

sudo docker system prune -a

https://serverfault.com/questions/501963/how-do-i-recover-free-space-on-deleted-files-without-restarting-the-referencing

# check free space
df -h
# Find all opened file descriptors, grep deleted, StdError to /dev/null
sudo find /proc/*/fd -ls 2> /dev/null | grep '(deleted)'
# Find and truncate all deleted files, -p prompt before execute truncate
sudo find /proc/*/fd -ls 2> /dev/null | awk '/deleted/ {print $11}' | xargs -p -n 1 sudo truncate -s 0
df -h

Directories taking space

/var/snap/microk8s/common/default-storage
https://github.com/canonical/microk8s/issues/463#issuecomment-491285745
sudo lsof +D /var/snap | awk '!/COMMAND/{print $1 | "sort -u"}'

Change microk8s default-storage path in config

microk8s.kubectl -n kube-system edit deploy hostpath-provisioner

Change in:

      volumes:
      - hostPath:
          path: /mnt/ext/microk8s/common/default-storage
          type: ""
        name: pv-volume